security/selinux/hooks.c

   1 /*
   2  *  NSA Security-Enhanced Linux (SELinux) security module
   3  *
   4  *  This file contains the SELinux hook function implementations.
   5  *
   6  *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
   7  *            Chris Vance, <cvance@nai.com>
   8  *            Wayne Salamon, <wsalamon@nai.com>
   9  *            James Morris <jmorris@redhat.com>
  10  *
  11  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
  12  *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
  13  *                                         Eric Paris <eparis@redhat.com>
  14  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  15  *                          <dgoeddel@trustedcs.com>
  16  *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
  17  *      Paul Moore <paul@paul-moore.com>
  18  *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
  19  *                     Yuichi Nakamura <ynakam@hitachisoft.jp>
  20  *
  21  *      This program is free software; you can redistribute it and/or modify
  22  *      it under the terms of the GNU General Public License version 2,
  23  *      as published by the Free Software Foundation.
  24  */
  25
  26 #include <linux/init.h>
  27 #include <linux/kd.h>
  28 #include <linux/kernel.h>
  29 #include <linux/tracehook.h>
  30 #include <linux/errno.h>
  31 #include <linux/ext2_fs.h>
  32 #include <linux/sched.h>
  33 #include <linux/security.h>
  34 #include <linux/xattr.h>
  35 #include <linux/capability.h>
  36 #include <linux/unistd.h>
  37 #include <linux/mm.h>
  38 #include <linux/mman.h>
  39 #include <linux/slab.h>
  40 #include <linux/pagemap.h>
  41 #include <linux/proc_fs.h>
  42 #include <linux/swap.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/syscalls.h>
  45 #include <linux/dcache.h>
  46 #include <linux/file.h>
  47 #include <linux/fdtable.h>
  48 #include <linux/namei.h>
  49 #include <linux/mount.h>
  50 #include <linux/netfilter_ipv4.h>
  51 #include <linux/netfilter_ipv6.h>
  52 #include <linux/tty.h>
  53 #include <net/icmp.h>
  54 #include <net/ip.h>             /* for local_port_range[] */
  55 #include <net/tcp.h>            /* struct or_callable used in sock_rcv_skb */
  56 #include <net/inet_connection_sock.h>
  57 #include <net/net_namespace.h>
  58 #include <net/netlabel.h>
  59 #include <linux/uaccess.h>
  60 #include <asm/ioctls.h>
  61 #include <linux/atomic.h>
  62 #include <linux/bitops.h>
  63 #include <linux/interrupt.h>
  64 #include <linux/netdevice.h>    /* for network interface checks */
  65 #include <linux/netlink.h>
  66 #include <linux/tcp.h>
  67 #include <linux/udp.h>
  68 #include <linux/dccp.h>
  69 #include <linux/quota.h>
  70 #include <linux/un.h>           /* for Unix socket types */
  71 #include <net/af_unix.h>        /* for Unix socket types */
  72 #include <linux/parser.h>
  73 #include <linux/nfs_mount.h>
  74 #include <net/ipv6.h>
  75 #include <linux/hugetlb.h>
  76 #include <linux/personality.h>
  77 #include <linux/audit.h>
  78 #include <linux/string.h>
  79 #include <linux/selinux.h>
  80 #include <linux/mutex.h>
  81 #include <linux/posix-timers.h>
  82 #include <linux/syslog.h>
  83 #include <linux/user_namespace.h>
  84 #include <linux/export.h>
  85
  86 #include "avc.h"
  87 #include "objsec.h"
  88 #include "netif.h"
  89 #include "netnode.h"
  90 #include "netport.h"
  91 #include "xfrm.h"
  92 #include "netlabel.h"
  93 #include "audit.h"
  94 #include "avc_ss.h"
  95
  96 #define NUM_SEL_MNT_OPTS 5
  97
  98 extern struct security_operations *security_ops;
  99
 100 /* SECMARK reference count */
 101 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
 102
 103 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 104 int selinux_enforcing;
 105
 106 static int __init enforcing_setup(char *str)
 107 {
 108         unsigned long enforcing;
 109         if (!strict_strtoul(str, 0, &enforcing))
 110                 selinux_enforcing = enforcing ? 1 : 0;
 111         return 1;
 112 }
 113 __setup("enforcing=", enforcing_setup);
 114 #endif
 115
 116 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
 117 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
 118
 119 static int __init selinux_enabled_setup(char *str)
 120 {
 121         unsigned long enabled;
 122         if (!strict_strtoul(str, 0, &enabled))
 123                 selinux_enabled = enabled ? 1 : 0;
 124         return 1;
 125 }
 126 __setup("selinux=", selinux_enabled_setup);
 127 #else
 128 int selinux_enabled = 1;
 129 #endif
 130
 131 static struct kmem_cache *sel_inode_cache;
 132
 133 /**
 134  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
 135  *
 136  * Description:
 137  * This function checks the SECMARK reference counter to see if any SECMARK
 138  * targets are currently configured, if the reference counter is greater than
 139  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
 140  * enabled, false (0) if SECMARK is disabled.
 141  *
 142  */
 143 static int selinux_secmark_enabled(void)
 144 {
 145         return (atomic_read(&selinux_secmark_refcount) > 0);
 146 }
 147
 148 /*
 149  * initialise the security for the init task
 150  */
 151 static void cred_init_security(void)
 152 {
 153         struct cred *cred = (struct cred *) current->real_cred;
 154         struct task_security_struct *tsec;
 155
 156         tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
 157         if (!tsec)
 158                 panic("SELinux:  Failed to initialize initial task.\n");
 159
 160         tsec->osid = tsec->sid = SECINITSID_KERNEL;
 161         cred->security = tsec;
 162 }
 163
 164 /*
 165  * get the security ID of a set of credentials
 166  */
 167 static inline u32 cred_sid(const struct cred *cred)
 168 {
 169         const struct task_security_struct *tsec;
 170
 171         tsec = cred->security;
 172         return tsec->sid;
 173 }
 174
 175 /*
 176  * get the objective security ID of a task
 177  */
 178 static inline u32 task_sid(const struct task_struct *task)
 179 {
 180         u32 sid;
 181
 182         rcu_read_lock();
 183         sid = cred_sid(__task_cred(task));
 184         rcu_read_unlock();
 185         return sid;
 186 }
 187
 188 /*
 189  * get the subjective security ID of the current task
 190  */
 191 static inline u32 current_sid(void)
 192 {
 193         const struct task_security_struct *tsec = current_security();
 194
 195         return tsec->sid;
 196 }
 197
 198 /* Allocate and free functions for each kind of security blob. */
 199
 200 static int inode_alloc_security(struct inode *inode)
 201 {
 202         struct inode_security_struct *isec;
 203         u32 sid = current_sid();
 204
 205         isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
 206         if (!isec)
 207                 return -ENOMEM;
 208
 209         mutex_init(&isec->lock);
 210         INIT_LIST_HEAD(&isec->list);
 211         isec->inode = inode;
 212         isec->sid = SECINITSID_UNLABELED;
 213         isec->sclass = SECCLASS_FILE;
 214         isec->task_sid = sid;
 215         inode->i_security = isec;
 216
 217         return 0;
 218 }
 219
 220 static void inode_free_security(struct inode *inode)
 221 {
 222         struct inode_security_struct *isec = inode->i_security;
 223         struct superblock_security_struct *sbsec = inode->i_sb->s_security;
 224
 225         spin_lock(&sbsec->isec_lock);
 226         if (!list_empty(&isec->list))
 227                 list_del_init(&isec->list);
 228         spin_unlock(&sbsec->isec_lock);
 229
 230         inode->i_security = NULL;
 231         kmem_cache_free(sel_inode_cache, isec);
 232 }
 233
 234 static int file_alloc_security(struct file *file)
 235 {
 236         struct file_security_struct *fsec;
 237         u32 sid = current_sid();
 238
 239         fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
 240         if (!fsec)
 241                 return -ENOMEM;
 242
 243         fsec->sid = sid;
 244         fsec->fown_sid = sid;
 245         file->f_security = fsec;
 246
 247         return 0;
 248 }
 249
 250 static void file_free_security(struct file *file)
 251 {
 252         struct file_security_struct *fsec = file->f_security;
 253         file->f_security = NULL;
 254         kfree(fsec);
 255 }
 256
 257 static int superblock_alloc_security(struct super_block *sb)
 258 {
 259         struct superblock_security_struct *sbsec;
 260
 261         sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
 262         if (!sbsec)
 263                 return -ENOMEM;
 264
 265         mutex_init(&sbsec->lock);
 266         INIT_LIST_HEAD(&sbsec->isec_head);
 267         spin_lock_init(&sbsec->isec_lock);
 268         sbsec->sb = sb;
 269         sbsec->sid = SECINITSID_UNLABELED;
 270         sbsec->def_sid = SECINITSID_FILE;
 271         sbsec->mntpoint_sid = SECINITSID_UNLABELED;
 272         sb->s_security = sbsec;
 273
 274         return 0;
 275 }
 276
 277 static void superblock_free_security(struct super_block *sb)
 278 {
 279         struct superblock_security_struct *sbsec = sb->s_security;
 280         sb->s_security = NULL;
 281         kfree(sbsec);
 282 }
 283
 284 /* The file system's label must be initialized prior to use. */
 285
 286 static const char *labeling_behaviors[6] = {
 287         "uses xattr",
 288         "uses transition SIDs",
 289         "uses task SIDs",
 290         "uses genfs_contexts",
 291         "not configured for labeling",
 292         "uses mountpoint labeling",
 293 };
 294
 295 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
 296
 297 static inline int inode_doinit(struct inode *inode)
 298 {
 299         return inode_doinit_with_dentry(inode, NULL);
 300 }
 301
 302 enum {
 303         Opt_error = -1,
 304         Opt_context = 1,
 305         Opt_fscontext = 2,
 306         Opt_defcontext = 3,
 307         Opt_rootcontext = 4,
 308         Opt_labelsupport = 5,
 309 };
 310
 311 static const match_table_t tokens = {
 312         {Opt_context, CONTEXT_STR "%s"},
 313         {Opt_fscontext, FSCONTEXT_STR "%s"},
 314         {Opt_defcontext, DEFCONTEXT_STR "%s"},
 315         {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
 316         {Opt_labelsupport, LABELSUPP_STR},
 317         {Opt_error, NULL},
 318 };
 319
 320 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
 321
 322 static int may_context_mount_sb_relabel(u32 sid,
 323                         struct superblock_security_struct *sbsec,
 324                         const struct cred *cred)
 325 {
 326         const struct task_security_struct *tsec = cred->security;
 327         int rc;
 328
 329         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
 330                           FILESYSTEM__RELABELFROM, NULL);
 331         if (rc)
 332                 return rc;
 333
 334         rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
 335                           FILESYSTEM__RELABELTO, NULL);
 336         return rc;
 337 }
 338
 339 static int may_context_mount_inode_relabel(u32 sid,
 340                         struct superblock_security_struct *sbsec,
 341                         const struct cred *cred)
 342 {
 343         const struct task_security_struct *tsec = cred->security;
 344         int rc;
 345         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
 346                           FILESYSTEM__RELABELFROM, NULL);
 347         if (rc)
 348                 return rc;
 349
 350         rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
 351                           FILESYSTEM__ASSOCIATE, NULL);
 352         return rc;
 353 }
 354
 355 static int sb_finish_set_opts(struct super_block *sb)
 356 {
 357         struct superblock_security_struct *sbsec = sb->s_security;
 358         struct dentry *root = sb->s_root;
 359         struct inode *root_inode = root->d_inode;
 360         int rc = 0;
 361
 362         if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
 363                 /* Make sure that the xattr handler exists and that no
 364                    error other than -ENODATA is returned by getxattr on
 365                    the root directory.  -ENODATA is ok, as this may be
 366                    the first boot of the SELinux kernel before we have
 367                    assigned xattr values to the filesystem. */
 368                 if (!root_inode->i_op->getxattr) {
 369                         printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
 370                                "xattr support\n", sb->s_id, sb->s_type->name);
 371                         rc = -EOPNOTSUPP;
 372                         goto out;
 373                 }
 374                 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
 375                 if (rc < 0 && rc != -ENODATA) {
 376                         if (rc == -EOPNOTSUPP)
 377                                 printk(KERN_WARNING "SELinux: (dev %s, type "
 378                                        "%s) has no security xattr handler\n",
 379                                        sb->s_id, sb->s_type->name);
 380                         else
 381                                 printk(KERN_WARNING "SELinux: (dev %s, type "
 382                                        "%s) getxattr errno %d\n", sb->s_id,
 383                                        sb->s_type->name, -rc);
 384                         goto out;
 385                 }
 386         }
 387
 388         sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
 389
 390         if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
 391                 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
 392                        sb->s_id, sb->s_type->name);
 393         else
 394                 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
 395                        sb->s_id, sb->s_type->name,
 396                        labeling_behaviors[sbsec->behavior-1]);
 397
 398         if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
 399             sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
 400             sbsec->behavior == SECURITY_FS_USE_NONE ||
 401             sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
 402                 sbsec->flags &= ~SE_SBLABELSUPP;
 403
 404         /* Special handling for sysfs. Is genfs but also has setxattr handler*/
 405         if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
 406                 sbsec->flags |= SE_SBLABELSUPP;
 407
 408         /* Initialize the root inode. */
 409         rc = inode_doinit_with_dentry(root_inode, root);
 410
 411         /* Initialize any other inodes associated with the superblock, e.g.
 412            inodes created prior to initial policy load or inodes created
 413            during get_sb by a pseudo filesystem that directly
 414            populates itself. */
 415         spin_lock(&sbsec->isec_lock);
 416 next_inode:
 417         if (!list_empty(&sbsec->isec_head)) {
 418                 struct inode_security_struct *isec =
 419                                 list_entry(sbsec->isec_head.next,
 420                                            struct inode_security_struct, list);
 421                 struct inode *inode = isec->inode;
 422                 spin_unlock(&sbsec->isec_lock);
 423                 inode = igrab(inode);
 424                 if (inode) {
 425                         if (!IS_PRIVATE(inode))
 426                                 inode_doinit(inode);
 427                         iput(inode);
 428                 }
 429                 spin_lock(&sbsec->isec_lock);
 430                 list_del_init(&isec->list);
 431                 goto next_inode;
 432         }
 433         spin_unlock(&sbsec->isec_lock);
 434 out:
 435         return rc;
 436 }
 437
 438 /*
 439  * This function should allow an FS to ask what it's mount security
 440  * options were so it can use those later for submounts, displaying
 441  * mount options, or whatever.
 442  */
 443 static int selinux_get_mnt_opts(const struct super_block *sb,
 444                                 struct security_mnt_opts *opts)
 445 {
 446         int rc = 0, i;
 447         struct superblock_security_struct *sbsec = sb->s_security;
 448         char *context = NULL;
 449         u32 len;
 450         char tmp;
 451
 452         security_init_mnt_opts(opts);
 453
 454         if (!(sbsec->flags & SE_SBINITIALIZED))
 455                 return -EINVAL;
 456
 457         if (!ss_initialized)
 458                 return -EINVAL;
 459
 460         tmp = sbsec->flags & SE_MNTMASK;
 461         /* count the number of mount options for this sb */
 462         for (i = 0; i < 8; i++) {
 463                 if (tmp & 0x01)
 464                         opts->num_mnt_opts++;
 465                 tmp >>= 1;
 466         }
 467         /* Check if the Label support flag is set */
 468         if (sbsec->flags & SE_SBLABELSUPP)
 469                 opts->num_mnt_opts++;
 470
 471         opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
 472         if (!opts->mnt_opts) {
 473                 rc = -ENOMEM;
 474                 goto out_free;
 475         }
 476
 477         opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
 478         if (!opts->mnt_opts_flags) {
 479                 rc = -ENOMEM;
 480                 goto out_free;
 481         }
 482
 483         i = 0;
 484         if (sbsec->flags & FSCONTEXT_MNT) {
 485                 rc = security_sid_to_context(sbsec->sid, &context, &len);
 486                 if (rc)
 487                         goto out_free;
 488                 opts->mnt_opts[i] = context;
 489                 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
 490         }
 491         if (sbsec->flags & CONTEXT_MNT) {
 492                 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
 493                 if (rc)
 494                         goto out_free;
 495                 opts->mnt_opts[i] = context;
 496                 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
 497         }
 498         if (sbsec->flags & DEFCONTEXT_MNT) {
 499                 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
 500                 if (rc)
 501                         goto out_free;
 502                 opts->mnt_opts[i] = context;
 503                 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
 504         }
 505         if (sbsec->flags & ROOTCONTEXT_MNT) {
 506                 struct inode *root = sbsec->sb->s_root->d_inode;
 507                 struct inode_security_struct *isec = root->i_security;
 508
 509                 rc = security_sid_to_context(isec->sid, &context, &len);
 510                 if (rc)
 511                         goto out_free;
 512                 opts->mnt_opts[i] = context;
 513                 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
 514         }
 515         if (sbsec->flags & SE_SBLABELSUPP) {
 516                 opts->mnt_opts[i] = NULL;
 517                 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
 518         }
 519
 520         BUG_ON(i != opts->num_mnt_opts);
 521
 522         return 0;
 523
 524 out_free:
 525         security_free_mnt_opts(opts);
 526         return rc;
 527 }
 528
 529 static int bad_option(struct superblock_security_struct *sbsec, char flag,
 530                       u32 old_sid, u32 new_sid)
 531 {
 532         char mnt_flags = sbsec->flags & SE_MNTMASK;
 533
 534         /* check if the old mount command had the same options */
 535         if (sbsec->flags & SE_SBINITIALIZED)
 536                 if (!(sbsec->flags & flag) ||
 537                     (old_sid != new_sid))
 538                         return 1;
 539
 540         /* check if we were passed the same options twice,
 541          * aka someone passed context=a,context=b
 542          */
 543         if (!(sbsec->flags & SE_SBINITIALIZED))
 544                 if (mnt_flags & flag)
 545                         return 1;
 546         return 0;
 547 }
 548
 549 /*
 550  * Allow filesystems with binary mount data to explicitly set mount point
 551  * labeling information.
 552  */
 553 static int selinux_set_mnt_opts(struct super_block *sb,
 554                                 struct security_mnt_opts *opts)
 555 {
 556         const struct cred *cred = current_cred();
 557         int rc = 0, i;
 558         struct superblock_security_struct *sbsec = sb->s_security;
 559         const char *name = sb->s_type->name;
 560         struct inode *inode = sbsec->sb->s_root->d_inode;
 561         struct inode_security_struct *root_isec = inode->i_security;
 562         u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
 563         u32 defcontext_sid = 0;
 564         char **mount_options = opts->mnt_opts;
 565         int *flags = opts->mnt_opts_flags;
 566         int num_opts = opts->num_mnt_opts;
 567
 568         mutex_lock(&sbsec->lock);
 569
 570         if (!ss_initialized) {
 571                 if (!num_opts) {
 572                         /* Defer initialization until selinux_complete_init,
 573                            after the initial policy is loaded and the security
 574                            server is ready to handle calls. */
 575                         goto out;
 576                 }
 577                 rc = -EINVAL;
 578                 printk(KERN_WARNING "SELinux: Unable to set superblock options "
 579                         "before the security server is initialized\n");
 580                 goto out;
 581         }
 582
 583         /*
 584          * Binary mount data FS will come through this function twice.  Once
 585          * from an explicit call and once from the generic calls from the vfs.
 586          * Since the generic VFS calls will not contain any security mount data
 587          * we need to skip the double mount verification.
 588          *
 589          * This does open a hole in which we will not notice if the first
 590          * mount using this sb set explict options and a second mount using
 591          * this sb does not set any security options.  (The first options
 592          * will be used for both mounts)
 593          */
 594         if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
 595             && (num_opts == 0))
 596                 goto out;
 597
 598         /*
 599          * parse the mount options, check if they are valid sids.
 600          * also check if someone is trying to mount the same sb more
 601          * than once with different security options.
 602          */
 603         for (i = 0; i < num_opts; i++) {
 604                 u32 sid;
 605
 606                 if (flags[i] == SE_SBLABELSUPP)
 607                         continue;
 608                 rc = security_context_to_sid(mount_options[i],
 609                                              strlen(mount_options[i]), &sid);
 610                 if (rc) {
 611                         printk(KERN_WARNING "SELinux: security_context_to_sid"
 612                                "(%s) failed for (dev %s, type %s) errno=%d\n",
 613                                mount_options[i], sb->s_id, name, rc);
 614                         goto out;
 615                 }
 616                 switch (flags[i]) {
 617                 case FSCONTEXT_MNT:
 618                         fscontext_sid = sid;
 619
 620                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
 621                                         fscontext_sid))
 622                                 goto out_double_mount;
 623
 624                         sbsec->flags |= FSCONTEXT_MNT;
 625                         break;
 626                 case CONTEXT_MNT:
 627                         context_sid = sid;
 628
 629                         if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
 630                                         context_sid))
 631                                 goto out_double_mount;
 632
 633                         sbsec->flags |= CONTEXT_MNT;
 634                         break;
 635                 case ROOTCONTEXT_MNT:
 636                         rootcontext_sid = sid;
 637
 638                         if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
 639                                         rootcontext_sid))
 640                                 goto out_double_mount;
 641
 642                         sbsec->flags |= ROOTCONTEXT_MNT;
 643
 644                         break;
 645                 case DEFCONTEXT_MNT:
 646                         defcontext_sid = sid;
 647
 648                         if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
 649                                         defcontext_sid))
 650                                 goto out_double_mount;
 651
 652                         sbsec->flags |= DEFCONTEXT_MNT;
 653
 654                         break;
 655                 default:
 656                         rc = -EINVAL;
 657                         goto out;
 658                 }
 659         }
 660
 661         if (sbsec->flags & SE_SBINITIALIZED) {
 662                 /* previously mounted with options, but not on this attempt? */
 663                 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
 664                         goto out_double_mount;
 665                 rc = 0;
 666                 goto out;
 667         }
 668
 669         if (strcmp(sb->s_type->name, "proc") == 0)
 670                 sbsec->flags |= SE_SBPROC;
 671
 672         /* Determine the labeling behavior to use for this filesystem type. */
 673         rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
 674         if (rc) {
 675                 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
 676                        __func__, sb->s_type->name, rc);
 677                 goto out;
 678         }
 679
 680         /* sets the context of the superblock for the fs being mounted. */
 681         if (fscontext_sid) {
 682                 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
 683                 if (rc)
 684                         goto out;
 685
 686                 sbsec->sid = fscontext_sid;
 687         }
 688
 689         /*
 690          * Switch to using mount point labeling behavior.
 691          * sets the label used on all file below the mountpoint, and will set
 692          * the superblock context if not already set.
 693          */
 694         if (context_sid) {
 695                 if (!fscontext_sid) {
 696                         rc = may_context_mount_sb_relabel(context_sid, sbsec,
 697                                                           cred);
 698                         if (rc)
 699                                 goto out;
 700                         sbsec->sid = context_sid;
 701                 } else {
 702                         rc = may_context_mount_inode_relabel(context_sid, sbsec,
 703                                                              cred);
 704                         if (rc)
 705                                 goto out;
 706                 }
 707                 if (!rootcontext_sid)
 708                         rootcontext_sid = context_sid;
 709
 710                 sbsec->mntpoint_sid = context_sid;
 711                 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
 712         }
 713
 714         if (rootcontext_sid) {
 715                 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
 716                                                      cred);
 717                 if (rc)
 718                         goto out;
 719
 720                 root_isec->sid = rootcontext_sid;
 721                 root_isec->initialized = 1;
 722         }
 723
 724         if (defcontext_sid) {
 725                 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
 726                         rc = -EINVAL;
 727                         printk(KERN_WARNING "SELinux: defcontext option is "
 728                                "invalid for this filesystem type\n");
 729                         goto out;
 730                 }
 731
 732                 if (defcontext_sid != sbsec->def_sid) {
 733                         rc = may_context_mount_inode_relabel(defcontext_sid,
 734                                                              sbsec, cred);
 735                         if (rc)
 736                                 goto out;
 737                 }
 738
 739                 sbsec->def_sid = defcontext_sid;
 740         }
 741
 742         rc = sb_finish_set_opts(sb);
 743 out:
 744         mutex_unlock(&sbsec->lock);
 745         return rc;
 746 out_double_mount:
 747         rc = -EINVAL;
 748         printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
 749                "security settings for (dev %s, type %s)\n", sb->s_id, name);
 750         goto out;
 751 }
 752
 753 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
 754                                         struct super_block *newsb)
 755 {
 756         const struct superblock_security_struct *oldsbsec = oldsb->s_security;
 757         struct superblock_security_struct *newsbsec = newsb->s_security;
 758
 759         int set_fscontext =     (oldsbsec->flags & FSCONTEXT_MNT);
 760         int set_context =       (oldsbsec->flags & CONTEXT_MNT);
 761         int set_rootcontext =   (oldsbsec->flags & ROOTCONTEXT_MNT);
 762
 763         /*
 764          * if the parent was able to be mounted it clearly had no special lsm
 765          * mount options.  thus we can safely deal with this superblock later
 766          */
 767         if (!ss_initialized)
 768                 return;
 769
 770         /* how can we clone if the old one wasn't set up?? */
 771         BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
 772
 773         /* if fs is reusing a sb, just let its options stand... */
 774         if (newsbsec->flags & SE_SBINITIALIZED)
 775                 return;
 776
 777         mutex_lock(&newsbsec->lock);
 778
 779         newsbsec->flags = oldsbsec->flags;
 780
 781         newsbsec->sid = oldsbsec->sid;
 782         newsbsec->def_sid = oldsbsec->def_sid;
 783         newsbsec->behavior = oldsbsec->behavior;
 784
 785         if (set_context) {
 786                 u32 sid = oldsbsec->mntpoint_sid;
 787
 788                 if (!set_fscontext)
 789                         newsbsec->sid = sid;
 790                 if (!set_rootcontext) {
 791                         struct inode *newinode = newsb->s_root->d_inode;
 792                         struct inode_security_struct *newisec = newinode->i_security;
 793                         newisec->sid = sid;
 794                 }
 795                 newsbsec->mntpoint_sid = sid;
 796         }
 797         if (set_rootcontext) {
 798                 const struct inode *oldinode = oldsb->s_root->d_inode;
 799                 const struct inode_security_struct *oldisec = oldinode->i_security;
 800                 struct inode *newinode = newsb->s_root->d_inode;
 801                 struct inode_security_struct *newisec = newinode->i_security;
 802
 803                 newisec->sid = oldisec->sid;
 804         }
 805
 806         sb_finish_set_opts(newsb);
 807         mutex_unlock(&newsbsec->lock);
 808 }
 809
 810 static int selinux_parse_opts_str(char *options,
 811                                   struct security_mnt_opts *opts)
 812 {
 813         char *p;
 814         char *context = NULL, *defcontext = NULL;
 815         char *fscontext = NULL, *rootcontext = NULL;
 816         int rc, num_mnt_opts = 0;
 817
 818         opts->num_mnt_opts = 0;
 819
 820         /* Standard string-based options. */
 821         while ((p = strsep(&options, "|")) != NULL) {
 822                 int token;
 823                 substring_t args[MAX_OPT_ARGS];
 824
 825                 if (!*p)
 826                         continue;
 827
 828                 token = match_token(p, tokens, args);
 829
 830                 switch (token) {
 831                 case Opt_context:
 832                         if (context || defcontext) {
 833                                 rc = -EINVAL;
 834                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 835                                 goto out_err;
 836                         }
 837                         context = match_strdup(&args[0]);
 838                         if (!context) {
 839                                 rc = -ENOMEM;
 840                                 goto out_err;
 841                         }
 842                         break;
 843
 844                 case Opt_fscontext:
 845                         if (fscontext) {
 846                                 rc = -EINVAL;
 847                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 848                                 goto out_err;
 849                         }
 850                         fscontext = match_strdup(&args[0]);
 851                         if (!fscontext) {
 852                                 rc = -ENOMEM;
 853                                 goto out_err;
 854                         }
 855                         break;
 856
 857                 case Opt_rootcontext:
 858                         if (rootcontext) {
 859                                 rc = -EINVAL;
 860                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 861                                 goto out_err;
 862                         }
 863                         rootcontext = match_strdup(&args[0]);
 864                         if (!rootcontext) {
 865                                 rc = -ENOMEM;
 866                                 goto out_err;
 867                         }
 868                         break;
 869
 870                 case Opt_defcontext:
 871                         if (context || defcontext) {
 872                                 rc = -EINVAL;
 873                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 874                                 goto out_err;
 875                         }
 876                         defcontext = match_strdup(&args[0]);
 877                         if (!defcontext) {
 878                                 rc = -ENOMEM;
 879                                 goto out_err;
 880                         }
 881                         break;
 882                 case Opt_labelsupport:
 883                         break;
 884                 default:
 885                         rc = -EINVAL;
 886                         printk(KERN_WARNING "SELinux:  unknown mount option\n");
 887                         goto out_err;
 888
 889                 }
 890         }
 891
 892         rc = -ENOMEM;
 893         opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
 894         if (!opts->mnt_opts)
 895                 goto out_err;
 896
 897         opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
 898         if (!opts->mnt_opts_flags) {
 899                 kfree(opts->mnt_opts);
 900                 goto out_err;
 901         }
 902
 903         if (fscontext) {
 904                 opts->mnt_opts[num_mnt_opts] = fscontext;
 905                 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
 906         }
 907         if (context) {
 908                 opts->mnt_opts[num_mnt_opts] = context;
 909                 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
 910         }
 911         if (rootcontext) {
 912                 opts->mnt_opts[num_mnt_opts] = rootcontext;
 913                 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
 914         }
 915         if (defcontext) {
 916                 opts->mnt_opts[num_mnt_opts] = defcontext;
 917                 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
 918         }
 919
 920         opts->num_mnt_opts = num_mnt_opts;
 921         return 0;
 922
 923 out_err:
 924         kfree(context);
 925         kfree(defcontext);
 926         kfree(fscontext);
 927         kfree(rootcontext);
 928         return rc;
 929 }
 930 /*
 931  * string mount options parsing and call set the sbsec
 932  */
 933 static int superblock_doinit(struct super_block *sb, void *data)
 934 {
 935         int rc = 0;
 936         char *options = data;
 937         struct security_mnt_opts opts;
 938
 939         security_init_mnt_opts(&opts);
 940
 941         if (!data)
 942                 goto out;
 943
 944         BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
 945
 946         rc = selinux_parse_opts_str(options, &opts);
 947         if (rc)
 948                 goto out_err;
 949
 950 out:
 951         rc = selinux_set_mnt_opts(sb, &opts);
 952
 953 out_err:
 954         security_free_mnt_opts(&opts);
 955         return rc;
 956 }
 957
 958 static void selinux_write_opts(struct seq_file *m,
 959                                struct security_mnt_opts *opts)
 960 {
 961         int i;
 962         char *prefix;
 963
 964         for (i = 0; i < opts->num_mnt_opts; i++) {
 965                 char *has_comma;
 966
 967                 if (opts->mnt_opts[i])
 968                         has_comma = strchr(opts->mnt_opts[i], ',');
 969                 else
 970                         has_comma = NULL;
 971
 972                 switch (opts->mnt_opts_flags[i]) {
 973                 case CONTEXT_MNT:
 974                         prefix = CONTEXT_STR;
 975                         break;
 976                 case FSCONTEXT_MNT:
 977                         prefix = FSCONTEXT_STR;
 978                         break;
 979                 case ROOTCONTEXT_MNT:
 980                         prefix = ROOTCONTEXT_STR;
 981                         break;
 982                 case DEFCONTEXT_MNT:
 983                         prefix = DEFCONTEXT_STR;
 984                         break;
 985                 case SE_SBLABELSUPP:
 986                         seq_putc(m, ',');
 987                         seq_puts(m, LABELSUPP_STR);
 988                         continue;
 989                 default:
 990                         BUG();
 991                         return;
 992                 };
 993                 /* we need a comma before each option */
 994                 seq_putc(m, ',');
 995                 seq_puts(m, prefix);
 996                 if (has_comma)
 997                         seq_putc(m, '\"');
 998                 seq_puts(m, opts->mnt_opts[i]);
 999                 if (has_comma)
1000                         seq_putc(m, '\"');
1001         }
1002 }
1003
1004 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1005 {
1006         struct security_mnt_opts opts;
1007         int rc;
1008
1009         rc = selinux_get_mnt_opts(sb, &opts);
1010         if (rc) {
1011                 /* before policy load we may get EINVAL, don't show anything */
1012                 if (rc == -EINVAL)
1013                         rc = 0;
1014                 return rc;
1015         }
1016
1017         selinux_write_opts(m, &opts);
1018
1019         security_free_mnt_opts(&opts);
1020
1021         return rc;
1022 }
1023
1024 static inline u16 inode_mode_to_security_class(umode_t mode)
1025 {
1026         switch (mode & S_IFMT) {
1027         case S_IFSOCK:
1028                 return SECCLASS_SOCK_FILE;
1029         case S_IFLNK:
1030                 return SECCLASS_LNK_FILE;
1031         case S_IFREG:
1032                 return SECCLASS_FILE;
1033         case S_IFBLK:
1034                 return SECCLASS_BLK_FILE;
1035         case S_IFDIR:
1036                 return SECCLASS_DIR;
1037         case S_IFCHR:
1038                 return SECCLASS_CHR_FILE;
1039         case S_IFIFO:
1040                 return SECCLASS_FIFO_FILE;
1041
1042         }
1043
1044         return SECCLASS_FILE;
1045 }
1046
1047 static inline int default_protocol_stream(int protocol)
1048 {
1049         return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1050 }
1051
1052 static inline int default_protocol_dgram(int protocol)
1053 {
1054         return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1055 }
1056
1057 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1058 {
1059         switch (family) {
1060         case PF_UNIX:
1061                 switch (type) {
1062                 case SOCK_STREAM:
1063                 case SOCK_SEQPACKET:
1064                         return SECCLASS_UNIX_STREAM_SOCKET;
1065                 case SOCK_DGRAM:
1066                         return SECCLASS_UNIX_DGRAM_SOCKET;
1067                 }
1068                 break;
1069         case PF_INET:
1070         case PF_INET6:
1071                 switch (type) {
1072                 case SOCK_STREAM:
1073                         if (default_protocol_stream(protocol))
1074                                 return SECCLASS_TCP_SOCKET;
1075                         else
1076                                 return SECCLASS_RAWIP_SOCKET;
1077                 case SOCK_DGRAM:
1078                         if (default_protocol_dgram(protocol))
1079                                 return SECCLASS_UDP_SOCKET;
1080                         else
1081                                 return SECCLASS_RAWIP_SOCKET;
1082                 case SOCK_DCCP:
1083                         return SECCLASS_DCCP_SOCKET;
1084                 default:
1085                         return SECCLASS_RAWIP_SOCKET;
1086                 }
1087                 break;
1088         case PF_NETLINK:
1089                 switch (protocol) {
1090                 case NETLINK_ROUTE:
1091                         return SECCLASS_NETLINK_ROUTE_SOCKET;
1092                 case NETLINK_FIREWALL:
1093                         return SECCLASS_NETLINK_FIREWALL_SOCKET;
1094                 case NETLINK_INET_DIAG:
1095                         return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1096                 case NETLINK_NFLOG:
1097                         return SECCLASS_NETLINK_NFLOG_SOCKET;
1098                 case NETLINK_XFRM:
1099                         return SECCLASS_NETLINK_XFRM_SOCKET;
1100                 case NETLINK_SELINUX:
1101                         return SECCLASS_NETLINK_SELINUX_SOCKET;
1102                 case NETLINK_AUDIT:
1103                         return SECCLASS_NETLINK_AUDIT_SOCKET;
1104                 case NETLINK_IP6_FW:
1105                         return SECCLASS_NETLINK_IP6FW_SOCKET;
1106                 case NETLINK_DNRTMSG:
1107                         return SECCLASS_NETLINK_DNRT_SOCKET;
1108                 case NETLINK_KOBJECT_UEVENT:
1109                         return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1110                 default:
1111                         return SECCLASS_NETLINK_SOCKET;
1112                 }
1113         case PF_PACKET:
1114                 return SECCLASS_PACKET_SOCKET;
1115         case PF_KEY:
1116                 return SECCLASS_KEY_SOCKET;
1117         case PF_APPLETALK:
1118                 return SECCLASS_APPLETALK_SOCKET;
1119         }
1120
1121         return SECCLASS_SOCKET;
1122 }
1123
1124 #ifdef CONFIG_PROC_FS
1125 static int selinux_proc_get_sid(struct dentry *dentry,
1126                                 u16 tclass,
1127                                 u32 *sid)
1128 {
1129         int rc;
1130         char *buffer, *path;
1131
1132         buffer = (char *)__get_free_page(GFP_KERNEL);
1133         if (!buffer)
1134                 return -ENOMEM;
1135
1136         path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1137         if (IS_ERR(path))
1138                 rc = PTR_ERR(path);
1139         else {
1140                 /* each process gets a /proc/PID/ entry. Strip off the
1141                  * PID part to get a valid selinux labeling.
1142                  * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1143                 while (path[1] >= '0' && path[1] <= '9') {
1144                         path[1] = '/';
1145                         path++;
1146                 }
1147                 rc = security_genfs_sid("proc", path, tclass, sid);
1148         }
1149         free_page((unsigned long)buffer);
1150         return rc;
1151 }
1152 #else
1153 static int selinux_proc_get_sid(struct dentry *dentry,
1154                                 u16 tclass,
1155                                 u32 *sid)
1156 {
1157         return -EINVAL;
1158 }
1159 #endif
1160
1161 /* The inode's security attributes must be initialized before first use. */
1162 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1163 {
1164         struct superblock_security_struct *sbsec = NULL;
1165         struct inode_security_struct *isec = inode->i_security;
1166         u32 sid;
1167         struct dentry *dentry;
1168 #define INITCONTEXTLEN 255
1169         char *context = NULL;
1170         unsigned len = 0;
1171         int rc = 0;
1172
1173         if (isec->initialized)
1174                 goto out;
1175
1176         mutex_lock(&isec->lock);
1177         if (isec->initialized)
1178                 goto out_unlock;
1179
1180         sbsec = inode->i_sb->s_security;
1181         if (!(sbsec->flags & SE_SBINITIALIZED)) {
1182                 /* Defer initialization until selinux_complete_init,
1183                    after the initial policy is loaded and the security
1184                    server is ready to handle calls. */
1185                 spin_lock(&sbsec->isec_lock);
1186                 if (list_empty(&isec->list))
1187                         list_add(&isec->list, &sbsec->isec_head);
1188                 spin_unlock(&sbsec->isec_lock);
1189                 goto out_unlock;
1190         }
1191
1192         switch (sbsec->behavior) {
1193         case SECURITY_FS_USE_XATTR:
1194                 if (!inode->i_op->getxattr) {
1195                         isec->sid = sbsec->def_sid;
1196                         break;
1197                 }
1198
1199                 /* Need a dentry, since the xattr API requires one.
1200                    Life would be simpler if we could just pass the inode. */
1201                 if (opt_dentry) {
1202                         /* Called from d_instantiate or d_splice_alias. */
1203                         dentry = dget(opt_dentry);
1204                 } else {
1205                         /* Called from selinux_complete_init, try to find a dentry. */
1206                         dentry = d_find_alias(inode);
1207                 }
1208                 if (!dentry) {
1209                         /*
1210                          * this is can be hit on boot when a file is accessed
1211                          * before the policy is loaded.  When we load policy we
1212                          * may find inodes that have no dentry on the
1213                          * sbsec->isec_head list.  No reason to complain as these
1214                          * will get fixed up the next time we go through
1215                          * inode_doinit with a dentry, before these inodes could
1216                          * be used again by userspace.
1217                          */
1218                         goto out_unlock;
1219                 }
1220
1221                 len = INITCONTEXTLEN;
1222                 context = kmalloc(len+1, GFP_NOFS);
1223                 if (!context) {
1224                         rc = -ENOMEM;
1225                         dput(dentry);
1226                         goto out_unlock;
1227                 }
1228                 context[len] = '\0';
1229                 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1230                                            context, len);
1231                 if (rc == -ERANGE) {
1232                         kfree(context);
1233
1234                         /* Need a larger buffer.  Query for the right size. */
1235                         rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1236                                                    NULL, 0);
1237                         if (rc < 0) {
1238                                 dput(dentry);
1239                                 goto out_unlock;
1240                         }
1241                         len = rc;
1242                         context = kmalloc(len+1, GFP_NOFS);
1243                         if (!context) {
1244                                 rc = -ENOMEM;
1245                                 dput(dentry);
1246                                 goto out_unlock;
1247                         }
1248                         context[len] = '\0';
1249                         rc = inode->i_op->getxattr(dentry,
1250                                                    XATTR_NAME_SELINUX,
1251                                                    context, len);
1252                 }
1253                 dput(dentry);
1254                 if (rc < 0) {
1255                         if (rc != -ENODATA) {
1256                                 printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1257                                        "%d for dev=%s ino=%ld\n", __func__,
1258                                        -rc, inode->i_sb->s_id, inode->i_ino);
1259                                 kfree(context);
1260                                 goto out_unlock;
1261                         }
1262                         /* Map ENODATA to the default file SID */
1263                         sid = sbsec->def_sid;
1264                         rc = 0;
1265                 } else {
1266                         rc = security_context_to_sid_default(context, rc, &sid,
1267                                                              sbsec->def_sid,
1268                                                              GFP_NOFS);
1269                         if (rc) {
1270                                 char *dev = inode->i_sb->s_id;
1271                                 unsigned long ino = inode->i_ino;
1272
1273                                 if (rc == -EINVAL) {
1274                                         if (printk_ratelimit())
1275                                                 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1276                                                         "context=%s.  This indicates you may need to relabel the inode or the "
1277                                                         "filesystem in question.\n", ino, dev, context);
1278                                 } else {
1279                                         printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
1280                                                "returned %d for dev=%s ino=%ld\n",
1281                                                __func__, context, -rc, dev, ino);
1282                                 }
1283                                 kfree(context);
1284                                 /* Leave with the unlabeled SID */
1285                                 rc = 0;
1286                                 break;
1287                         }
1288                 }
1289                 kfree(context);
1290                 isec->sid = sid;
1291                 break;
1292         case SECURITY_FS_USE_TASK:
1293                 isec->sid = isec->task_sid;
1294                 break;
1295         case SECURITY_FS_USE_TRANS:
1296                 /* Default to the fs SID. */
1297                 isec->sid = sbsec->sid;
1298
1299                 /* Try to obtain a transition SID. */
1300                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1301                 rc = security_transition_sid(isec->task_sid, sbsec->sid,
1302                                              isec->sclass, NULL, &sid);
1303                 if (rc)
1304                         goto out_unlock;
1305                 isec->sid = sid;
1306                 break;
1307         case SECURITY_FS_USE_MNTPOINT:
1308                 isec->sid = sbsec->mntpoint_sid;
1309                 break;
1310         default:
1311                 /* Default to the fs superblock SID. */
1312                 isec->sid = sbsec->sid;
1313
1314                 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1315                         if (opt_dentry) {
1316                                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1317                                 rc = selinux_proc_get_sid(opt_dentry,
1318                                                           isec->sclass,
1319                                                           &sid);
1320                                 if (rc)
1321                                         goto out_unlock;
1322                                 isec->sid = sid;
1323                         }
1324                 }
1325                 break;
1326         }
1327
1328         isec->initialized = 1;
1329
1330 out_unlock:
1331         mutex_unlock(&isec->lock);
1332 out:
1333         if (isec->sclass == SECCLASS_FILE)
1334                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1335         return rc;
1336 }
1337
1338 /* Convert a Linux signal to an access vector. */
1339 static inline u32 signal_to_av(int sig)
1340 {
1341         u32 perm = 0;
1342
1343         switch (sig) {
1344         case SIGCHLD:
1345                 /* Commonly granted from child to parent. */
1346                 perm = PROCESS__SIGCHLD;
1347                 break;
1348         case SIGKILL:
1349                 /* Cannot be caught or ignored */
1350                 perm = PROCESS__SIGKILL;
1351                 break;
1352         case SIGSTOP:
1353                 /* Cannot be caught or ignored */
1354                 perm = PROCESS__SIGSTOP;
1355                 break;
1356         default:
1357                 /* All other signals. */
1358                 perm = PROCESS__SIGNAL;
1359                 break;
1360         }
1361
1362         return perm;
1363 }
1364
1365 /*
1366  * Check permission between a pair of credentials
1367  * fork check, ptrace check, etc.
1368  */
1369 static int cred_has_perm(const struct cred *actor,
1370                          const struct cred *target,
1371                          u32 perms)
1372 {
1373         u32 asid = cred_sid(actor), tsid = cred_sid(target);
1374
1375         return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1376 }
1377
1378 /*
1379  * Check permission between a pair of tasks, e.g. signal checks,
1380  * fork check, ptrace check, etc.
1381  * tsk1 is the actor and tsk2 is the target
1382  * - this uses the default subjective creds of tsk1
1383  */
1384 static int task_has_perm(const struct task_struct *tsk1,
1385                          const struct task_struct *tsk2,
1386                          u32 perms)
1387 {
1388         const struct task_security_struct *__tsec1, *__tsec2;
1389         u32 sid1, sid2;
1390
1391         rcu_read_lock();
1392         __tsec1 = __task_cred(tsk1)->security;  sid1 = __tsec1->sid;
1393         __tsec2 = __task_cred(tsk2)->security;  sid2 = __tsec2->sid;
1394         rcu_read_unlock();
1395         return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1396 }
1397
1398 /*
1399  * Check permission between current and another task, e.g. signal checks,
1400  * fork check, ptrace check, etc.
1401  * current is the actor and tsk2 is the target
1402  * - this uses current's subjective creds
1403  */
1404 static int current_has_perm(const struct task_struct *tsk,
1405                             u32 perms)
1406 {
1407         u32 sid, tsid;
1408
1409         sid = current_sid();
1410         tsid = task_sid(tsk);
1411         return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1412 }
1413
1414 #if CAP_LAST_CAP > 63
1415 #error Fix SELinux to handle capabilities > 63.
1416 #endif
1417
1418 /* Check whether a task is allowed to use a capability. */
1419 static int task_has_capability(struct task_struct *tsk,
1420                                const struct cred *cred,
1421                                int cap, int audit)
1422 {
1423         struct common_audit_data ad;
1424         struct av_decision avd;
1425         u16 sclass;
1426         u32 sid = cred_sid(cred);
1427         u32 av = CAP_TO_MASK(cap);
1428         int rc;
1429
1430         COMMON_AUDIT_DATA_INIT(&ad, CAP);
1431         ad.tsk = tsk;
1432         ad.u.cap = cap;
1433
1434         switch (CAP_TO_INDEX(cap)) {
1435         case 0:
1436                 sclass = SECCLASS_CAPABILITY;
1437                 break;
1438         case 1:
1439                 sclass = SECCLASS_CAPABILITY2;
1440                 break;
1441         default:
1442                 printk(KERN_ERR
1443                        "SELinux:  out of range capability %d\n", cap);
1444                 BUG();
1445                 return -EINVAL;
1446         }
1447
1448         rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1449         if (audit == SECURITY_CAP_AUDIT) {
1450                 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1451                 if (rc2)
1452                         return rc2;
1453         }
1454         return rc;
1455 }
1456
1457 /* Check whether a task is allowed to use a system operation. */
1458 static int task_has_system(struct task_struct *tsk,
1459                            u32 perms)
1460 {
1461         u32 sid = task_sid(tsk);
1462
1463         return avc_has_perm(sid, SECINITSID_KERNEL,
1464                             SECCLASS_SYSTEM, perms, NULL);
1465 }
1466
1467 /* Check whether a task has a particular permission to an inode.
1468    The 'adp' parameter is optional and allows other audit
1469    data to be passed (e.g. the dentry). */
1470 static int inode_has_perm(const struct cred *cred,
1471                           struct inode *inode,
1472                           u32 perms,
1473                           struct common_audit_data *adp,
1474                           unsigned flags)
1475 {
1476         struct inode_security_struct *isec;
1477         u32 sid;
1478
1479         validate_creds(cred);
1480
1481         if (unlikely(IS_PRIVATE(inode)))
1482                 return 0;
1483
1484         sid = cred_sid(cred);
1485         isec = inode->i_security;
1486
1487         return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
1488 }
1489
1490 static int inode_has_perm_noadp(const struct cred *cred,
1491                                 struct inode *inode,
1492                                 u32 perms,
1493                                 unsigned flags)
1494 {
1495         struct common_audit_data ad;
1496
1497         COMMON_AUDIT_DATA_INIT(&ad, INODE);
1498         ad.u.inode = inode;
1499         return inode_has_perm(cred, inode, perms, &ad, flags);
1500 }
1501
1502 /* Same as inode_has_perm, but pass explicit audit data containing
1503    the dentry to help the auditing code to more easily generate the
1504    pathname if needed. */
1505 static inline int dentry_has_perm(const struct cred *cred,
1506                                   struct dentry *dentry,
1507                                   u32 av)
1508 {
1509         struct inode *inode = dentry->d_inode;
1510         struct common_audit_data ad;
1511
1512         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1513         ad.u.dentry = dentry;
1514         return inode_has_perm(cred, inode, av, &ad, 0);
1515 }
1516
1517 /* Same as inode_has_perm, but pass explicit audit data containing
1518    the path to help the auditing code to more easily generate the
1519    pathname if needed. */
1520 static inline int path_has_perm(const struct cred *cred,
1521                                 struct path *path,
1522                                 u32 av)
1523 {
1524         struct inode *inode = path->dentry->d_inode;
1525         struct common_audit_data ad;
1526
1527         COMMON_AUDIT_DATA_INIT(&ad, PATH);
1528         ad.u.path = *path;
1529         return inode_has_perm(cred, inode, av, &ad, 0);
1530 }
1531
1532 /* Check whether a task can use an open file descriptor to
1533    access an inode in a given way.  Check access to the
1534    descriptor itself, and then use dentry_has_perm to
1535    check a particular permission to the file.
1536    Access to the descriptor is implicitly granted if it
1537    has the same SID as the process.  If av is zero, then
1538    access to the file is not checked, e.g. for cases
1539    where only the descriptor is affected like seek. */
1540 static int file_has_perm(const struct cred *cred,
1541                          struct file *file,
1542                          u32 av)
1543 {
1544         struct file_security_struct *fsec = file->f_security;
1545         struct inode *inode = file->f_path.dentry->d_inode;
1546         struct common_audit_data ad;
1547         u32 sid = cred_sid(cred);
1548         int rc;
1549
1550         COMMON_AUDIT_DATA_INIT(&ad, PATH);
1551         ad.u.path = file->f_path;
1552
1553         if (sid != fsec->sid) {
1554                 rc = avc_has_perm(sid, fsec->sid,
1555                                   SECCLASS_FD,
1556                                   FD__USE,
1557                                   &ad);
1558                 if (rc)
1559                         goto out;
1560         }
1561
1562         /* av is zero if only checking access to the descriptor. */
1563         rc = 0;
1564         if (av)
1565                 rc = inode_has_perm(cred, inode, av, &ad, 0);
1566
1567 out:
1568         return rc;
1569 }
1570
1571 /* Check whether a task can create a file. */
1572 static int may_create(struct inode *dir,
1573                       struct dentry *dentry,
1574                       u16 tclass)
1575 {
1576         const struct task_security_struct *tsec = current_security();
1577         struct inode_security_struct *dsec;
1578         struct superblock_security_struct *sbsec;
1579         u32 sid, newsid;
1580         struct common_audit_data ad;
1581         int rc;
1582
1583         dsec = dir->i_security;
1584         sbsec = dir->i_sb->s_security;
1585
1586         sid = tsec->sid;
1587         newsid = tsec->create_sid;
1588
1589         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1590         ad.u.dentry = dentry;
1591
1592         rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1593                           DIR__ADD_NAME | DIR__SEARCH,
1594                           &ad);
1595         if (rc)
1596                 return rc;
1597
1598         if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
1599                 rc = security_transition_sid(sid, dsec->sid, tclass,
1600                                              &dentry->d_name, &newsid);
1601                 if (rc)
1602                         return rc;
1603         }
1604
1605         rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1606         if (rc)
1607                 return rc;
1608
1609         return avc_has_perm(newsid, sbsec->sid,
1610                             SECCLASS_FILESYSTEM,
1611                             FILESYSTEM__ASSOCIATE, &ad);
1612 }
1613
1614 /* Check whether a task can create a key. */
1615 static int may_create_key(u32 ksid,
1616                           struct task_struct *ctx)
1617 {
1618         u32 sid = task_sid(ctx);
1619
1620         return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1621 }
1622
1623 #define MAY_LINK        0
1624 #define MAY_UNLINK      1
1625 #define MAY_RMDIR       2
1626
1627 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1628 static int may_link(struct inode *dir,
1629                     struct dentry *dentry,
1630                     int kind)
1631
1632 {
1633         struct inode_security_struct *dsec, *isec;
1634         struct common_audit_data ad;
1635         u32 sid = current_sid();
1636         u32 av;
1637         int rc;
1638
1639         dsec = dir->i_security;
1640         isec = dentry->d_inode->i_security;
1641
1642         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1643         ad.u.dentry = dentry;
1644
1645         av = DIR__SEARCH;
1646         av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1647         rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1648         if (rc)
1649                 return rc;
1650
1651         switch (kind) {
1652         case MAY_LINK:
1653                 av = FILE__LINK;
1654                 break;
1655         case MAY_UNLINK:
1656                 av = FILE__UNLINK;
1657                 break;
1658         case MAY_RMDIR:
1659                 av = DIR__RMDIR;
1660                 break;
1661         default:
1662                 printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
1663                         __func__, kind);
1664                 return 0;
1665         }
1666
1667         rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1668         return rc;
1669 }
1670
1671 static inline int may_rename(struct inode *old_dir,
1672                              struct dentry *old_dentry,
1673                              struct inode *new_dir,
1674                              struct dentry *new_dentry)
1675 {
1676         struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1677         struct common_audit_data ad;
1678         u32 sid = current_sid();
1679         u32 av;
1680         int old_is_dir, new_is_dir;
1681         int rc;
1682
1683         old_dsec = old_dir->i_security;
1684         old_isec = old_dentry->d_inode->i_security;
1685         old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1686         new_dsec = new_dir->i_security;
1687
1688         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1689
1690         ad.u.dentry = old_dentry;
1691         rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1692                           DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1693         if (rc)
1694                 return rc;
1695         rc = avc_has_perm(sid, old_isec->sid,
1696                           old_isec->sclass, FILE__RENAME, &ad);
1697         if (rc)
1698                 return rc;
1699         if (old_is_dir && new_dir != old_dir) {
1700                 rc = avc_has_perm(sid, old_isec->sid,
1701                                   old_isec->sclass, DIR__REPARENT, &ad);
1702                 if (rc)
1703                         return rc;
1704         }
1705
1706         ad.u.dentry = new_dentry;
1707         av = DIR__ADD_NAME | DIR__SEARCH;
1708         if (new_dentry->d_inode)
1709                 av |= DIR__REMOVE_NAME;
1710         rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1711         if (rc)
1712                 return rc;
1713         if (new_dentry->d_inode) {
1714                 new_isec = new_dentry->d_inode->i_security;
1715                 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1716                 rc = avc_has_perm(sid, new_isec->sid,
1717                                   new_isec->sclass,
1718                                   (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1719                 if (rc)
1720                         return rc;
1721         }
1722
1723         return 0;
1724 }
1725
1726 /* Check whether a task can perform a filesystem operation. */
1727 static int superblock_has_perm(const struct cred *cred,
1728                                struct super_block *sb,
1729                                u32 perms,
1730                                struct common_audit_data *ad)
1731 {
1732         struct superblock_security_struct *sbsec;
1733         u32 sid = cred_sid(cred);
1734
1735         sbsec = sb->s_security;
1736         return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1737 }
1738
1739 /* Convert a Linux mode and permission mask to an access vector. */
1740 static inline u32 file_mask_to_av(int mode, int mask)
1741 {
1742         u32 av = 0;
1743
1744         if ((mode & S_IFMT) != S_IFDIR) {
1745                 if (mask & MAY_EXEC)
1746                         av |= FILE__EXECUTE;
1747                 if (mask & MAY_READ)
1748                         av |= FILE__READ;
1749
1750                 if (mask & MAY_APPEND)
1751                         av |= FILE__APPEND;
1752                 else if (mask & MAY_WRITE)
1753                         av |= FILE__WRITE;
1754
1755         } else {
1756                 if (mask & MAY_EXEC)
1757                         av |= DIR__SEARCH;
1758                 if (mask & MAY_WRITE)
1759                         av |= DIR__WRITE;
1760                 if (mask & MAY_READ)
1761                         av |= DIR__READ;
1762         }
1763
1764         return av;
1765 }
1766
1767 /* Convert a Linux file to an access vector. */
1768 static inline u32 file_to_av(struct file *file)
1769 {
1770         u32 av = 0;
1771
1772         if (file->f_mode & FMODE_READ)
1773                 av |= FILE__READ;
1774         if (file->f_mode & FMODE_WRITE) {
1775                 if (file->f_flags & O_APPEND)
1776                         av |= FILE__APPEND;
1777                 else
1778                         av |= FILE__WRITE;
1779         }
1780         if (!av) {
1781                 /*
1782                  * Special file opened with flags 3 for ioctl-only use.
1783                  */
1784                 av = FILE__IOCTL;
1785         }
1786
1787         return av;
1788 }
1789
1790 /*
1791  * Convert a file to an access vector and include the correct open
1792  * open permission.
1793  */
1794 static inline u32 open_file_to_av(struct file *file)
1795 {
1796         u32 av = file_to_av(file);
1797
1798         if (selinux_policycap_openperm)
1799                 av |= FILE__OPEN;
1800
1801         return av;
1802 }
1803
1804 /* Hook functions begin here. */
1805
1806 static int selinux_ptrace_access_check(struct task_struct *child,
1807                                      unsigned int mode)
1808 {
1809         int rc;
1810
1811         rc = cap_ptrace_access_check(child, mode);
1812         if (rc)
1813                 return rc;
1814
1815         if (mode == PTRACE_MODE_READ) {
1816                 u32 sid = current_sid();
1817                 u32 csid = task_sid(child);
1818                 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1819         }
1820
1821         return current_has_perm(child, PROCESS__PTRACE);
1822 }
1823
1824 static int selinux_ptrace_traceme(struct task_struct *parent)
1825 {
1826         int rc;
1827
1828         rc = cap_ptrace_traceme(parent);
1829         if (rc)
1830                 return rc;
1831
1832         return task_has_perm(parent, current, PROCESS__PTRACE);
1833 }
1834
1835 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1836                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
1837 {
1838         int error;
1839
1840         error = current_has_perm(target, PROCESS__GETCAP);
1841         if (error)
1842                 return error;
1843
1844         return cap_capget(target, effective, inheritable, permitted);
1845 }
1846
1847 static int selinux_capset(struct cred *new, const struct cred *old,
1848                           const kernel_cap_t *effective,
1849                           const kernel_cap_t *inheritable,
1850                           const kernel_cap_t *permitted)
1851 {
1852         int error;
1853
1854         error = cap_capset(new, old,
1855                                       effective, inheritable, permitted);
1856         if (error)
1857                 return error;
1858
1859         return cred_has_perm(old, new, PROCESS__SETCAP);
1860 }
1861
1862 /*
1863  * (This comment used to live with the selinux_task_setuid hook,
1864  * which was removed).
1865  *
1866  * Since setuid only affects the current process, and since the SELinux
1867  * controls are not based on the Linux identity attributes, SELinux does not
1868  * need to control this operation.  However, SELinux does control the use of
1869  * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1870  */
1871
1872 static int selinux_capable(struct task_struct *tsk, const struct cred *cred,
1873                            struct user_namespace *ns, int cap, int audit)
1874 {
1875         int rc;
1876
1877         rc = cap_capable(tsk, cred, ns, cap, audit);
1878         if (rc)
1879                 return rc;
1880
1881         return task_has_capability(tsk, cred, cap, audit);
1882 }
1883
1884 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1885 {
1886         const struct cred *cred = current_cred();
1887         int rc = 0;
1888
1889         if (!sb)
1890                 return 0;
1891
1892         switch (cmds) {
1893         case Q_SYNC:
1894         case Q_QUOTAON:
1895         case Q_QUOTAOFF:
1896         case Q_SETINFO:
1897         case Q_SETQUOTA:
1898                 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1899                 break;
1900         case Q_GETFMT:
1901         case Q_GETINFO:
1902         case Q_GETQUOTA:
1903                 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1904                 break;
1905         default:
1906                 rc = 0;  /* let the kernel handle invalid cmds */
1907                 break;
1908         }
1909         return rc;
1910 }
1911
1912 static int selinux_quota_on(struct dentry *dentry)
1913 {
1914         const struct cred *cred = current_cred();
1915
1916         return dentry_has_perm(cred, dentry, FILE__QUOTAON);
1917 }
1918
1919 static int selinux_syslog(int type)
1920 {
1921         int rc;
1922
1923         switch (type) {
1924         case SYSLOG_ACTION_READ_ALL:    /* Read last kernel messages */
1925         case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
1926                 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1927                 break;
1928         case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
1929         case SYSLOG_ACTION_CONSOLE_ON:  /* Enable logging to console */
1930         /* Set level of messages printed to console */
1931         case SYSLOG_ACTION_CONSOLE_LEVEL:
1932                 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1933                 break;
1934         case SYSLOG_ACTION_CLOSE:       /* Close log */
1935         case SYSLOG_ACTION_OPEN:        /* Open log */
1936         case SYSLOG_ACTION_READ:        /* Read from log */
1937         case SYSLOG_ACTION_READ_CLEAR:  /* Read/clear last kernel messages */
1938         case SYSLOG_ACTION_CLEAR:       /* Clear ring buffer */
1939         default:
1940                 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1941                 break;
1942         }
1943         return rc;
1944 }
1945
1946 /*
1947  * Check that a process has enough memory to allocate a new virtual
1948  * mapping. 0 means there is enough memory for the allocation to
1949  * succeed and -ENOMEM implies there is not.
1950  *
1951  * Do not audit the selinux permission check, as this is applied to all
1952  * processes that allocate mappings.
1953  */
1954 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
1955 {
1956         int rc, cap_sys_admin = 0;
1957
1958         rc = selinux_capable(current, current_cred(),
1959                              &init_user_ns, CAP_SYS_ADMIN,
1960                              SECURITY_CAP_NOAUDIT);
1961         if (rc == 0)
1962                 cap_sys_admin = 1;
1963
1964         return __vm_enough_memory(mm, pages, cap_sys_admin);
1965 }
1966
1967 /* binprm security operations */
1968
1969 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
1970 {
1971         const struct task_security_struct *old_tsec;
1972         struct task_security_struct *new_tsec;
1973         struct inode_security_struct *isec;
1974         struct common_audit_data ad;
1975         struct inode *inode = bprm->file->f_path.dentry->d_inode;
1976         int rc;
1977
1978         rc = cap_bprm_set_creds(bprm);
1979         if (rc)
1980                 return rc;
1981
1982         /* SELinux context only depends on initial program or script and not
1983          * the script interpreter */
1984         if (bprm->cred_prepared)
1985                 return 0;
1986
1987         old_tsec = current_security();
1988         new_tsec = bprm->cred->security;
1989         isec = inode->i_security;
1990
1991         /* Default to the current task SID. */
1992         new_tsec->sid = old_tsec->sid;
1993         new_tsec->osid = old_tsec->sid;
1994
1995         /* Reset fs, key, and sock SIDs on execve. */
1996         new_tsec->create_sid = 0;
1997         new_tsec->keycreate_sid = 0;
1998         new_tsec->sockcreate_sid = 0;
1999
2000         if (old_tsec->exec_sid) {
2001                 new_tsec->sid = old_tsec->exec_sid;
2002                 /* Reset exec SID on execve. */
2003                 new_tsec->exec_sid = 0;
2004         } else {
2005                 /* Check for a default transition on this program. */
2006                 rc = security_transition_sid(old_tsec->sid, isec->sid,
2007                                              SECCLASS_PROCESS, NULL,
2008                                              &new_tsec->sid);
2009                 if (rc)
2010                         return rc;
2011         }
2012
2013         COMMON_AUDIT_DATA_INIT(&ad, PATH);
2014         ad.u.path = bprm->file->f_path;
2015
2016         if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
2017                 new_tsec->sid = old_tsec->sid;
2018
2019         if (new_tsec->sid == old_tsec->sid) {
2020                 rc = avc_has_perm(old_tsec->sid, isec->sid,
2021                                   SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2022                 if (rc)
2023                         return rc;
2024         } else {
2025                 /* Check permissions for the transition. */
2026                 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2027                                   SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2028                 if (rc)
2029                         return rc;
2030
2031                 rc = avc_has_perm(new_tsec->sid, isec->sid,
2032                                   SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2033                 if (rc)
2034                         return rc;
2035
2036                 /* Check for shared state */
2037                 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2038                         rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2039                                           SECCLASS_PROCESS, PROCESS__SHARE,
2040                                           NULL);
2041                         if (rc)
2042                                 return -EPERM;
2043                 }
2044
2045                 /* Make sure that anyone attempting to ptrace over a task that
2046                  * changes its SID has the appropriate permit */
2047                 if (bprm->unsafe &
2048                     (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2049                         struct task_struct *tracer;
2050                         struct task_security_struct *sec;
2051                         u32 ptsid = 0;
2052
2053                         rcu_read_lock();
2054                         tracer = ptrace_parent(current);
2055                         if (likely(tracer != NULL)) {
2056                                 sec = __task_cred(tracer)->security;
2057                                 ptsid = sec->sid;
2058                         }
2059                         rcu_read_unlock();
2060
2061                         if (ptsid != 0) {
2062                                 rc = avc_has_perm(ptsid, new_tsec->sid,
2063                                                   SECCLASS_PROCESS,
2064                                                   PROCESS__PTRACE, NULL);
2065                                 if (rc)
2066                                         return -EPERM;
2067                         }
2068                 }
2069
2070                 /* Clear any possibly unsafe personality bits on exec: */
2071                 bprm->per_clear |= PER_CLEAR_ON_SETID;
2072         }
2073
2074         return 0;
2075 }
2076
2077 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2078 {
2079         const struct task_security_struct *tsec = current_security();
2080         u32 sid, osid;
2081         int atsecure = 0;
2082
2083         sid = tsec->sid;
2084         osid = tsec->osid;
2085
2086         if (osid != sid) {
2087                 /* Enable secure mode for SIDs transitions unless
2088                    the noatsecure permission is granted between
2089                    the two SIDs, i.e. ahp returns 0. */
2090                 atsecure = avc_has_perm(osid, sid,
2091                                         SECCLASS_PROCESS,
2092                                         PROCESS__NOATSECURE, NULL);
2093         }
2094
2095         return (atsecure || cap_bprm_secureexec(bprm));
2096 }
2097
2098 /* Derived from fs/exec.c:flush_old_files. */
2099 static inline void flush_unauthorized_files(const struct cred *cred,
2100                                             struct files_struct *files)
2101 {
2102         struct common_audit_data ad;
2103         struct file *file, *devnull = NULL;
2104         struct tty_struct *tty;
2105         struct fdtable *fdt;
2106         long j = -1;
2107         int drop_tty = 0;
2108
2109         tty = get_current_tty();
2110         if (tty) {
2111                 spin_lock(&tty_files_lock);
2112                 if (!list_empty(&tty->tty_files)) {
2113                         struct tty_file_private *file_priv;
2114                         struct inode *inode;
2115
2116                         /* Revalidate access to controlling tty.
2117                            Use inode_has_perm on the tty inode directly rather
2118                            than using file_has_perm, as this particular open
2119                            file may belong to another process and we are only
2120                            interested in the inode-based check here. */
2121                         file_priv = list_first_entry(&tty->tty_files,
2122                                                 struct tty_file_private, list);
2123                         file = file_priv->file;
2124                         inode = file->f_path.dentry->d_inode;
2125                         if (inode_has_perm_noadp(cred, inode,
2126                                            FILE__READ | FILE__WRITE, 0)) {
2127                                 drop_tty = 1;
2128                         }
2129                 }
2130                 spin_unlock(&tty_files_lock);
2131                 tty_kref_put(tty);
2132         }
2133         /* Reset controlling tty. */
2134         if (drop_tty)
2135                 no_tty();
2136
2137         /* Revalidate access to inherited open files. */
2138
2139         COMMON_AUDIT_DATA_INIT(&ad, INODE);
2140
2141         spin_lock(&files->file_lock);
2142         for (;;) {
2143                 unsigned long set, i;
2144                 int fd;
2145
2146                 j++;
2147                 i = j * __NFDBITS;
2148                 fdt = files_fdtable(files);
2149                 if (i >= fdt->max_fds)
2150                         break;
2151                 set = fdt->open_fds->fds_bits[j];
2152                 if (!set)
2153                         continue;
2154                 spin_unlock(&files->file_lock);
2155                 for ( ; set ; i++, set >>= 1) {
2156                         if (set & 1) {
2157                                 file = fget(i);
2158                                 if (!file)
2159                                         continue;
2160                                 if (file_has_perm(cred,
2161                                                   file,
2162                                                   file_to_av(file))) {
2163                                         sys_close(i);
2164                                         fd = get_unused_fd();
2165                                         if (fd != i) {
2166                                                 if (fd >= 0)
2167                                                         put_unused_fd(fd);
2168                                                 fput(file);
2169                                                 continue;
2170                                         }
2171                                         if (devnull) {
2172                                                 get_file(devnull);
2173                                         } else {
2174                                                 devnull = dentry_open(
2175                                                         dget(selinux_null),
2176                                                         mntget(selinuxfs_mount),
2177                                                         O_RDWR, cred);
2178                                                 if (IS_ERR(devnull)) {
2179                                                         devnull = NULL;
2180                                                         put_unused_fd(fd);
2181                                                         fput(file);
2182                                                         continue;
2183                                                 }
2184                                         }
2185                                         fd_install(fd, devnull);
2186                                 }
2187                                 fput(file);
2188                         }
2189                 }
2190                 spin_lock(&files->file_lock);
2191
2192         }
2193         spin_unlock(&files->file_lock);
2194 }
2195
2196 /*
2197  * Prepare a process for imminent new credential changes due to exec
2198  */
2199 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2200 {
2201         struct task_security_struct *new_tsec;
2202         struct rlimit *rlim, *initrlim;
2203         int rc, i;
2204
2205         new_tsec = bprm->cred->security;
2206         if (new_tsec->sid == new_tsec->osid)
2207                 return;
2208
2209         /* Close files for which the new task SID is not authorized. */
2210         flush_unauthorized_files(bprm->cred, current->files);
2211
2212         /* Always clear parent death signal on SID transitions. */
2213         current->pdeath_signal = 0;
2214
2215         /* Check whether the new SID can inherit resource limits from the old
2216          * SID.  If not, reset all soft limits to the lower of the current
2217          * task's hard limit and the init task's soft limit.
2218          *
2219          * Note that the setting of hard limits (even to lower them) can be
2220          * controlled by the setrlimit check.  The inclusion of the init task's
2221          * soft limit into the computation is to avoid resetting soft limits
2222          * higher than the default soft limit for cases where the default is
2223          * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2224          */
2225         rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2226                           PROCESS__RLIMITINH, NULL);
2227         if (rc) {
2228                 /* protect against do_prlimit() */
2229                 task_lock(current);
2230                 for (i = 0; i < RLIM_NLIMITS; i++) {
2231                         rlim = current->signal->rlim + i;
2232                         initrlim = init_task.signal->rlim + i;
2233                         rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2234                 }
2235                 task_unlock(current);
2236                 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2237         }
2238 }
2239
2240 /*
2241  * Clean up the process immediately after the installation of new credentials
2242  * due to exec
2243  */
2244 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2245 {
2246         const struct task_security_struct *tsec = current_security();
2247         struct itimerval itimer;
2248         u32 osid, sid;
2249         int rc, i;
2250
2251         osid = tsec->osid;
2252         sid = tsec->sid;
2253
2254         if (sid == osid)
2255                 return;
2256
2257         /* Check whether the new SID can inherit signal state from the old SID.
2258          * If not, clear itimers to avoid subsequent signal generation and
2259          * flush and unblock signals.
2260          *
2261          * This must occur _after_ the task SID has been updated so that any
2262          * kill done after the flush will be checked against the new SID.
2263          */
2264         rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2265         if (rc) {
2266                 memset(&itimer, 0, sizeof itimer);
2267                 for (i = 0; i < 3; i++)
2268                         do_setitimer(i, &itimer, NULL);
2269                 spin_lock_irq(&current->sighand->siglock);
2270                 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2271                         __flush_signals(current);
2272                         flush_signal_handlers(current, 1);
2273                         sigemptyset(&current->blocked);
2274                 }
2275                 spin_unlock_irq(&current->sighand->siglock);
2276         }
2277
2278         /* Wake up the parent if it is waiting so that it can recheck
2279          * wait permission to the new task SID. */
2280         read_lock(&tasklist_lock);
2281         __wake_up_parent(current, current->real_parent);
2282         read_unlock(&tasklist_lock);
2283 }
2284
2285 /* superblock security operations */
2286
2287 static int selinux_sb_alloc_security(struct super_block *sb)
2288 {
2289         return superblock_alloc_security(sb);
2290 }
2291
2292 static void selinux_sb_free_security(struct super_block *sb)
2293 {
2294         superblock_free_security(sb);
2295 }
2296
2297 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2298 {
2299         if (plen > olen)
2300                 return 0;
2301
2302         return !memcmp(prefix, option, plen);
2303 }
2304
2305 static inline int selinux_option(char *option, int len)
2306 {
2307         return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2308                 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2309                 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2310                 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2311                 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2312 }
2313
2314 static inline void take_option(char **to, char *from, int *first, int len)
2315 {
2316         if (!*first) {
2317                 **to = ',';
2318                 *to += 1;
2319         } else
2320                 *first = 0;
2321         memcpy(*to, from, len);
2322         *to += len;
2323 }
2324
2325 static inline void take_selinux_option(char **to, char *from, int *first,
2326                                        int len)
2327 {
2328         int current_size = 0;
2329
2330         if (!*first) {
2331                 **to = '|';
2332                 *to += 1;
2333         } else
2334                 *first = 0;
2335
2336         while (current_size < len) {
2337                 if (*from != '"') {
2338                         **to = *from;
2339                         *to += 1;
2340                 }
2341                 from += 1;
2342                 current_size += 1;
2343         }
2344 }
2345
2346 static int selinux_sb_copy_data(char *orig, char *copy)
2347 {
2348         int fnosec, fsec, rc = 0;
2349         char *in_save, *in_curr, *in_end;
2350         char *sec_curr, *nosec_save, *nosec;
2351         int open_quote = 0;
2352
2353         in_curr = orig;
2354         sec_curr = copy;
2355
2356         nosec = (char *)get_zeroed_page(GFP_KERNEL);
2357         if (!nosec) {
2358                 rc = -ENOMEM;
2359                 goto out;
2360         }
2361
2362         nosec_save = nosec;
2363         fnosec = fsec = 1;
2364         in_save = in_end = orig;
2365
2366         do {
2367                 if (*in_end == '"')
2368                         open_quote = !open_quote;
2369                 if ((*in_end == ',' && open_quote == 0) ||
2370                                 *in_end == '\0') {
2371                         int len = in_end - in_curr;
2372
2373                         if (selinux_option(in_curr, len))
2374                                 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2375                         else
2376                                 take_option(&nosec, in_curr, &fnosec, len);
2377
2378                         in_curr = in_end + 1;
2379                 }
2380         } while (*in_end++);
2381
2382         strcpy(in_save, nosec_save);
2383         free_page((unsigned long)nosec_save);
2384 out:
2385         return rc;
2386 }
2387
2388 static int selinux_sb_remount(struct super_block *sb, void *data)
2389 {
2390         int rc, i, *flags;
2391         struct security_mnt_opts opts;
2392         char *secdata, **mount_options;
2393         struct superblock_security_struct *sbsec = sb->s_security;
2394
2395         if (!(sbsec->flags & SE_SBINITIALIZED))
2396                 return 0;
2397
2398         if (!data)
2399                 return 0;
2400
2401         if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2402                 return 0;
2403
2404         security_init_mnt_opts(&opts);
2405         secdata = alloc_secdata();
2406         if (!secdata)
2407                 return -ENOMEM;
2408         rc = selinux_sb_copy_data(data, secdata);
2409         if (rc)
2410                 goto out_free_secdata;
2411
2412         rc = selinux_parse_opts_str(secdata, &opts);
2413         if (rc)
2414                 goto out_free_secdata;
2415
2416         mount_options = opts.mnt_opts;
2417         flags = opts.mnt_opts_flags;
2418
2419         for (i = 0; i < opts.num_mnt_opts; i++) {
2420                 u32 sid;
2421                 size_t len;
2422
2423                 if (flags[i] == SE_SBLABELSUPP)
2424                         continue;
2425                 len = strlen(mount_options[i]);
2426                 rc = security_context_to_sid(mount_options[i], len, &sid);
2427                 if (rc) {
2428                         printk(KERN_WARNING "SELinux: security_context_to_sid"
2429                                "(%s) failed for (dev %s, type %s) errno=%d\n",
2430                                mount_options[i], sb->s_id, sb->s_type->name, rc);
2431                         goto out_free_opts;
2432                 }
2433                 rc = -EINVAL;
2434                 switch (flags[i]) {
2435                 case FSCONTEXT_MNT:
2436                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2437                                 goto out_bad_option;
2438                         break;
2439                 case CONTEXT_MNT:
2440                         if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2441                                 goto out_bad_option;
2442                         break;
2443                 case ROOTCONTEXT_MNT: {
2444                         struct inode_security_struct *root_isec;
2445                         root_isec = sb->s_root->d_inode->i_security;
2446
2447                         if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2448                                 goto out_bad_option;
2449                         break;
2450                 }
2451                 case DEFCONTEXT_MNT:
2452                         if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2453                                 goto out_bad_option;
2454                         break;
2455                 default:
2456                         goto out_free_opts;
2457                 }
2458         }
2459
2460         rc = 0;
2461 out_free_opts:
2462         security_free_mnt_opts(&opts);
2463 out_free_secdata:
2464         free_secdata(secdata);
2465         return rc;
2466 out_bad_option:
2467         printk(KERN_WARNING "SELinux: unable to change security options "
2468                "during remount (dev %s, type=%s)\n", sb->s_id,
2469                sb->s_type->name);
2470         goto out_free_opts;
2471 }
2472
2473 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2474 {
2475         const struct cred *cred = current_cred();
2476         struct common_audit_data ad;
2477         int rc;
2478
2479         rc = superblock_doinit(sb, data);
2480         if (rc)
2481                 return rc;
2482
2483         /* Allow all mounts performed by the kernel */
2484         if (flags & MS_KERNMOUNT)
2485                 return 0;
2486
2487         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2488         ad.u.dentry = sb->s_root;
2489         return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2490 }
2491
2492 static int selinux_sb_statfs(struct dentry *dentry)
2493 {
2494         const struct cred *cred = current_cred();
2495         struct common_audit_data ad;
2496
2497         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2498         ad.u.dentry = dentry->d_sb->s_root;
2499         return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2500 }
2501
2502 static int selinux_mount(char *dev_name,
2503                          struct path *path,
2504                          char *type,
2505                          unsigned long flags,
2506                          void *data)
2507 {
2508         const struct cred *cred = current_cred();
2509
2510         if (flags & MS_REMOUNT)
2511                 return superblock_has_perm(cred, path->mnt->mnt_sb,
2512                                            FILESYSTEM__REMOUNT, NULL);
2513         else
2514                 return path_has_perm(cred, path, FILE__MOUNTON);
2515 }
2516
2517 static int selinux_umount(struct vfsmount *mnt, int flags)
2518 {
2519         const struct cred *cred = current_cred();
2520
2521         return superblock_has_perm(cred, mnt->mnt_sb,
2522                                    FILESYSTEM__UNMOUNT, NULL);
2523 }
2524
2525 /* inode security operations */
2526
2527 static int selinux_inode_alloc_security(struct inode *inode)
2528 {
2529         return inode_alloc_security(inode);
2530 }
2531
2532 static void selinux_inode_free_security(struct inode *inode)
2533 {
2534         inode_free_security(inode);
2535 }
2536
2537 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2538                                        const struct qstr *qstr, char **name,
2539                                        void **value, size_t *len)
2540 {
2541         const struct task_security_struct *tsec = current_security();
2542         struct inode_security_struct *dsec;
2543         struct superblock_security_struct *sbsec;
2544         u32 sid, newsid, clen;
2545         int rc;
2546         char *namep = NULL, *context;
2547
2548         dsec = dir->i_security;
2549         sbsec = dir->i_sb->s_security;
2550
2551         sid = tsec->sid;
2552         newsid = tsec->create_sid;
2553
2554         if ((sbsec->flags & SE_SBINITIALIZED) &&
2555             (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2556                 newsid = sbsec->mntpoint_sid;
2557         else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2558                 rc = security_transition_sid(sid, dsec->sid,
2559                                              inode_mode_to_security_class(inode->i_mode),
2560                                              qstr, &newsid);
2561                 if (rc) {
2562                         printk(KERN_WARNING "%s:  "
2563                                "security_transition_sid failed, rc=%d (dev=%s "
2564                                "ino=%ld)\n",
2565                                __func__,
2566                                -rc, inode->i_sb->s_id, inode->i_ino);
2567                         return rc;
2568                 }
2569         }
2570
2571         /* Possibly defer initialization to selinux_complete_init. */
2572         if (sbsec->flags & SE_SBINITIALIZED) {
2573                 struct inode_security_struct *isec = inode->i_security;
2574                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2575                 isec->sid = newsid;
2576                 isec->initialized = 1;
2577         }
2578
2579         if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2580                 return -EOPNOTSUPP;
2581
2582         if (name) {
2583                 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2584                 if (!namep)
2585                         return -ENOMEM;
2586                 *name = namep;
2587         }
2588
2589         if (value && len) {
2590                 rc = security_sid_to_context_force(newsid, &context, &clen);
2591                 if (rc) {
2592                         kfree(namep);
2593                         return rc;
2594                 }
2595                 *value = context;
2596                 *len = clen;
2597         }
2598
2599         return 0;
2600 }
2601
2602 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2603 {
2604         return may_create(dir, dentry, SECCLASS_FILE);
2605 }
2606
2607 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2608 {
2609         return may_link(dir, old_dentry, MAY_LINK);
2610 }
2611
2612 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2613 {
2614         return may_link(dir, dentry, MAY_UNLINK);
2615 }
2616
2617 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2618 {
2619         return may_create(dir, dentry, SECCLASS_LNK_FILE);
2620 }
2621
2622 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2623 {
2624         return may_create(dir, dentry, SECCLASS_DIR);
2625 }
2626
2627 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2628 {
2629         return may_link(dir, dentry, MAY_RMDIR);
2630 }
2631
2632 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2633 {
2634         return may_create(dir, dentry, inode_mode_to_security_class(mode));
2635 }
2636
2637 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2638                                 struct inode *new_inode, struct dentry *new_dentry)
2639 {
2640         return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2641 }
2642
2643 static int selinux_inode_readlink(struct dentry *dentry)
2644 {
2645         const struct cred *cred = current_cred();
2646
2647         return dentry_has_perm(cred, dentry, FILE__READ);
2648 }
2649
2650 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2651 {
2652         const struct cred *cred = current_cred();
2653
2654         return dentry_has_perm(cred, dentry, FILE__READ);
2655 }
2656
2657 static int selinux_inode_permission(struct inode *inode, int mask)
2658 {
2659         const struct cred *cred = current_cred();
2660         struct common_audit_data ad;
2661         u32 perms;
2662         bool from_access;
2663         unsigned flags = mask & MAY_NOT_BLOCK;
2664
2665         from_access = mask & MAY_ACCESS;
2666         mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2667
2668         /* No permission to check.  Existence test. */
2669         if (!mask)
2670                 return 0;
2671
2672         COMMON_AUDIT_DATA_INIT(&ad, INODE);
2673         ad.u.inode = inode;
2674
2675         if (from_access)
2676                 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS;
2677
2678         perms = file_mask_to_av(inode->i_mode, mask);
2679
2680         return inode_has_perm(cred, inode, perms, &ad, flags);
2681 }
2682
2683 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2684 {
2685         const struct cred *cred = current_cred();
2686         unsigned int ia_valid = iattr->ia_valid;
2687
2688         /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2689         if (ia_valid & ATTR_FORCE) {
2690                 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2691                               ATTR_FORCE);
2692                 if (!ia_valid)
2693                         return 0;
2694         }
2695
2696         if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2697                         ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2698                 return dentry_has_perm(cred, dentry, FILE__SETATTR);
2699
2700         return dentry_has_perm(cred, dentry, FILE__WRITE);
2701 }
2702
2703 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2704 {
2705         const struct cred *cred = current_cred();
2706         struct path path;
2707
2708         path.dentry = dentry;
2709         path.mnt = mnt;
2710
2711         return path_has_perm(cred, &path, FILE__GETATTR);
2712 }
2713
2714 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2715 {
2716         const struct cred *cred = current_cred();
2717
2718         if (!strncmp(name, XATTR_SECURITY_PREFIX,
2719                      sizeof XATTR_SECURITY_PREFIX - 1)) {
2720                 if (!strcmp(name, XATTR_NAME_CAPS)) {
2721                         if (!capable(CAP_SETFCAP))
2722                                 return -EPERM;
2723                 } else if (!capable(CAP_SYS_ADMIN)) {
2724                         /* A different attribute in the security namespace.
2725                            Restrict to administrator. */
2726                         return -EPERM;
2727                 }
2728         }
2729
2730         /* Not an attribute we recognize, so just check the
2731            ordinary setattr permission. */
2732         return dentry_has_perm(cred, dentry, FILE__SETATTR);
2733 }
2734
2735 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2736                                   const void *value, size_t size, int flags)
2737 {
2738         struct inode *inode = dentry->d_inode;
2739         struct inode_security_struct *isec = inode->i_security;
2740         struct superblock_security_struct *sbsec;
2741         struct common_audit_data ad;
2742         u32 newsid, sid = current_sid();
2743         int rc = 0;
2744
2745         if (strcmp(name, XATTR_NAME_SELINUX))
2746                 return selinux_inode_setotherxattr(dentry, name);
2747
2748         sbsec = inode->i_sb->s_security;
2749         if (!(sbsec->flags & SE_SBLABELSUPP))
2750                 return -EOPNOTSUPP;
2751
2752         if (!inode_owner_or_capable(inode))
2753                 return -EPERM;
2754
2755         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2756         ad.u.dentry = dentry;
2757
2758         rc = avc_has_perm(sid, isec->sid, isec->sclass,
2759                           FILE__RELABELFROM, &ad);
2760         if (rc)
2761                 return rc;
2762
2763         rc = security_context_to_sid(value, size, &newsid);
2764         if (rc == -EINVAL) {
2765                 if (!capable(CAP_MAC_ADMIN))
2766                         return rc;
2767                 rc = security_context_to_sid_force(value, size, &newsid);
2768         }
2769         if (rc)
2770                 return rc;
2771
2772         rc = avc_has_perm(sid, newsid, isec->sclass,
2773                           FILE__RELABELTO, &ad);
2774         if (rc)
2775                 return rc;
2776
2777         rc = security_validate_transition(isec->sid, newsid, sid,
2778                                           isec->sclass);
2779         if (rc)
2780                 return rc;
2781
2782         return avc_has_perm(newsid,
2783                             sbsec->sid,
2784                             SECCLASS_FILESYSTEM,
2785                             FILESYSTEM__ASSOCIATE,
2786                             &ad);
2787 }
2788
2789 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2790                                         const void *value, size_t size,
2791                                         int flags)
2792 {
2793         struct inode *inode = dentry->d_inode;
2794         struct inode_security_struct *isec = inode->i_security;
2795         u32 newsid;
2796         int rc;
2797
2798         if (strcmp(name, XATTR_NAME_SELINUX)) {
2799                 /* Not an attribute we recognize, so nothing to do. */
2800                 return;
2801         }
2802
2803         rc = security_context_to_sid_force(value, size, &newsid);
2804         if (rc) {
2805                 printk(KERN_ERR "SELinux:  unable to map context to SID"
2806                        "for (%s, %lu), rc=%d\n",
2807                        inode->i_sb->s_id, inode->i_ino, -rc);
2808                 return;
2809         }
2810
2811         isec->sid = newsid;
2812         return;
2813 }
2814
2815 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2816 {
2817         const struct cred *cred = current_cred();
2818
2819         return dentry_has_perm(cred, dentry, FILE__GETATTR);
2820 }
2821
2822 static int selinux_inode_listxattr(struct dentry *dentry)
2823 {
2824         const struct cred *cred = current_cred();
2825
2826         return dentry_has_perm(cred, dentry, FILE__GETATTR);
2827 }
2828
2829 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2830 {
2831         if (strcmp(name, XATTR_NAME_SELINUX))
2832                 return selinux_inode_setotherxattr(dentry, name);
2833
2834         /* No one is allowed to remove a SELinux security label.
2835            You can change the label, but all data must be labeled. */
2836         return -EACCES;
2837 }
2838
2839 /*
2840  * Copy the inode security context value to the user.
2841  *
2842  * Permission check is handled by selinux_inode_getxattr hook.
2843  */
2844 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2845 {
2846         u32 size;
2847         int error;
2848         char *context = NULL;
2849         struct inode_security_struct *isec = inode->i_security;
2850
2851         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2852                 return -EOPNOTSUPP;
2853
2854         /*
2855          * If the caller has CAP_MAC_ADMIN, then get the raw context
2856          * value even if it is not defined by current policy; otherwise,
2857          * use the in-core value under current policy.
2858          * Use the non-auditing forms of the permission checks since
2859          * getxattr may be called by unprivileged processes commonly
2860          * and lack of permission just means that we fall back to the
2861          * in-core context value, not a denial.
2862          */
2863         error = selinux_capable(current, current_cred(),
2864                                 &init_user_ns, CAP_MAC_ADMIN,
2865                                 SECURITY_CAP_NOAUDIT);
2866         if (!error)
2867                 error = security_sid_to_context_force(isec->sid, &context,
2868                                                       &size);
2869         else
2870                 error = security_sid_to_context(isec->sid, &context, &size);
2871         if (error)
2872                 return error;
2873         error = size;
2874         if (alloc) {
2875                 *buffer = context;
2876                 goto out_nofree;
2877         }
2878         kfree(context);
2879 out_nofree:
2880         return error;
2881 }
2882
2883 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2884                                      const void *value, size_t size, int flags)
2885 {
2886         struct inode_security_struct *isec = inode->i_security;
2887         u32 newsid;
2888         int rc;
2889
2890         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2891                 return -EOPNOTSUPP;
2892
2893         if (!value || !size)
2894                 return -EACCES;
2895
2896         rc = security_context_to_sid((void *)value, size, &newsid);
2897         if (rc)
2898                 return rc;
2899
2900         isec->sid = newsid;
2901         isec->initialized = 1;
2902         return 0;
2903 }
2904
2905 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2906 {
2907         const int len = sizeof(XATTR_NAME_SELINUX);
2908         if (buffer && len <= buffer_size)
2909                 memcpy(buffer, XATTR_NAME_SELINUX, len);
2910         return len;
2911 }
2912
2913 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2914 {
2915         struct inode_security_struct *isec = inode->i_security;
2916         *secid = isec->sid;
2917 }
2918
2919 /* file security operations */
2920
2921 static int selinux_revalidate_file_permission(struct file *file, int mask)
2922 {
2923         const struct cred *cred = current_cred();
2924         struct inode *inode = file->f_path.dentry->d_inode;
2925
2926         /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2927         if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2928                 mask |= MAY_APPEND;
2929
2930         return file_has_perm(cred, file,
2931                              file_mask_to_av(inode->i_mode, mask));
2932 }
2933
2934 static int selinux_file_permission(struct file *file, int mask)
2935 {
2936         struct inode *inode = file->f_path.dentry->d_inode;
2937         struct file_security_struct *fsec = file->f_security;
2938         struct inode_security_struct *isec = inode->i_security;
2939         u32 sid = current_sid();
2940
2941         if (!mask)
2942                 /* No permission to check.  Existence test. */
2943                 return 0;
2944
2945         if (sid == fsec->sid && fsec->isid == isec->sid &&
2946             fsec->pseqno == avc_policy_seqno())
2947                 /* No change since dentry_open check. */
2948                 return 0;
2949
2950         return selinux_revalidate_file_permission(file, mask);
2951 }
2952
2953 static int selinux_file_alloc_security(struct file *file)
2954 {
2955         return file_alloc_security(file);
2956 }
2957
2958 static void selinux_file_free_security(struct file *file)
2959 {
2960         file_free_security(file);
2961 }
2962
2963 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2964                               unsigned long arg)
2965 {
2966         const struct cred *cred = current_cred();
2967         int error = 0;
2968
2969         switch (cmd) {
2970         case FIONREAD:
2971         /* fall through */
2972         case FIBMAP:
2973         /* fall through */
2974         case FIGETBSZ:
2975         /* fall through */
2976         case EXT2_IOC_GETFLAGS:
2977         /* fall through */
2978         case EXT2_IOC_GETVERSION:
2979                 error = file_has_perm(cred, file, FILE__GETATTR);
2980                 break;
2981
2982         case EXT2_IOC_SETFLAGS:
2983         /* fall through */
2984         case EXT2_IOC_SETVERSION:
2985                 error = file_has_perm(cred, file, FILE__SETATTR);
2986                 break;
2987
2988         /* sys_ioctl() checks */
2989         case FIONBIO:
2990         /* fall through */
2991         case FIOASYNC:
2992                 error = file_has_perm(cred, file, 0);
2993                 break;
2994
2995         case KDSKBENT:
2996         case KDSKBSENT:
2997                 error = task_has_capability(current, cred, CAP_SYS_TTY_CONFIG,
2998                                         SECURITY_CAP_AUDIT);
2999                 break;
3000
3001         /* default case assumes that the command will go
3002          * to the file's ioctl() function.
3003          */
3004         default:
3005                 error = file_has_perm(cred, file, FILE__IOCTL);
3006         }
3007         return error;
3008 }
3009
3010 static int default_noexec;
3011
3012 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3013 {
3014         const struct cred *cred = current_cred();
3015         int rc = 0;
3016
3017         if (default_noexec &&
3018             (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
3019                 /*
3020                  * We are making executable an anonymous mapping or a
3021                  * private file mapping that will also be writable.
3022                  * This has an additional check.
3023                  */
3024                 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3025                 if (rc)
3026                         goto error;
3027         }
3028
3029         if (file) {
3030                 /* read access is always possible with a mapping */
3031                 u32 av = FILE__READ;
3032
3033                 /* write access only matters if the mapping is shared */
3034                 if (shared && (prot & PROT_WRITE))
3035                         av |= FILE__WRITE;
3036
3037                 if (prot & PROT_EXEC)
3038                         av |= FILE__EXECUTE;
3039
3040                 return file_has_perm(cred, file, av);
3041         }
3042
3043 error:
3044         return rc;
3045 }
3046
3047 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
3048                              unsigned long prot, unsigned long flags,
3049                              unsigned long addr, unsigned long addr_only)
3050 {
3051         int rc = 0;
3052         u32 sid = current_sid();
3053
3054         /*
3055          * notice that we are intentionally putting the SELinux check before
3056          * the secondary cap_file_mmap check.  This is such a likely attempt
3057          * at bad behaviour/exploit that we always want to get the AVC, even
3058          * if DAC would have also denied the operation.
3059          */
3060         if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3061                 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3062                                   MEMPROTECT__MMAP_ZERO, NULL);
3063                 if (rc)
3064                         return rc;
3065         }
3066
3067         /* do DAC check on address space usage */
3068         rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
3069         if (rc || addr_only)
3070                 return rc;
3071
3072         if (selinux_checkreqprot)
3073                 prot = reqprot;
3074
3075         return file_map_prot_check(file, prot,
3076                                    (flags & MAP_TYPE) == MAP_SHARED);
3077 }
3078
3079 static int selinux_file_mprotect(struct vm_area_struct *vma,
3080                                  unsigned long reqprot,
3081                                  unsigned long prot)
3082 {
3083         const struct cred *cred = current_cred();
3084
3085         if (selinux_checkreqprot)
3086                 prot = reqprot;
3087
3088         if (default_noexec &&
3089             (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3090                 int rc = 0;
3091                 if (vma->vm_start >= vma->vm_mm->start_brk &&
3092                     vma->vm_end <= vma->vm_mm->brk) {
3093                         rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3094                 } else if (!vma->vm_file &&
3095                            vma->vm_start <= vma->vm_mm->start_stack &&
3096                            vma->vm_end >= vma->vm_mm->start_stack) {
3097                         rc = current_has_perm(current, PROCESS__EXECSTACK);
3098                 } else if (vma->vm_file && vma->anon_vma) {
3099                         /*
3100                          * We are making executable a file mapping that has
3101                          * had some COW done. Since pages might have been
3102                          * written, check ability to execute the possibly
3103                          * modified content.  This typically should only
3104                          * occur for text relocations.
3105                          */
3106                         rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3107                 }
3108                 if (rc)
3109                         return rc;
3110         }
3111
3112         return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3113 }
3114
3115 static int selinux_file_lock(struct file *file, unsigned int cmd)
3116 {
3117         const struct cred *cred = current_cred();
3118
3119         return file_has_perm(cred, file, FILE__LOCK);
3120 }
3121
3122 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3123                               unsigned long arg)
3124 {
3125         const struct cred *cred = current_cred();
3126         int err = 0;
3127
3128         switch (cmd) {
3129         case F_SETFL:
3130                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3131                         err = -EINVAL;
3132                         break;
3133                 }
3134
3135                 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3136                         err = file_has_perm(cred, file, FILE__WRITE);
3137                         break;
3138                 }
3139                 /* fall through */
3140         case F_SETOWN:
3141         case F_SETSIG:
3142         case F_GETFL:
3143         case F_GETOWN:
3144         case F_GETSIG:
3145                 /* Just check FD__USE permission */
3146                 err = file_has_perm(cred, file, 0);
3147                 break;
3148         case F_GETLK:
3149         case F_SETLK:
3150         case F_SETLKW:
3151 #if BITS_PER_LONG == 32
3152         case F_GETLK64:
3153         case F_SETLK64:
3154         case F_SETLKW64:
3155 #endif
3156                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3157                         err = -EINVAL;
3158                         break;
3159                 }
3160                 err = file_has_perm(cred, file, FILE__LOCK);
3161                 break;
3162         }
3163
3164         return err;
3165 }
3166
3167 static int selinux_file_set_fowner(struct file *file)
3168 {
3169         struct file_security_struct *fsec;
3170
3171         fsec = file->f_security;
3172         fsec->fown_sid = current_sid();
3173
3174         return 0;
3175 }
3176
3177 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3178                                        struct fown_struct *fown, int signum)
3179 {
3180         struct file *file;
3181         u32 sid = task_sid(tsk);
3182         u32 perm;
3183         struct file_security_struct *fsec;
3184
3185         /* struct fown_struct is never outside the context of a struct file */
3186         file = container_of(fown, struct file, f_owner);
3187
3188         fsec = file->f_security;
3189
3190         if (!signum)
3191                 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3192         else
3193                 perm = signal_to_av(signum);
3194
3195         return avc_has_perm(fsec->fown_sid, sid,
3196                             SECCLASS_PROCESS, perm, NULL);
3197 }
3198
3199 static int selinux_file_receive(struct file *file)
3200 {
3201         const struct cred *cred = current_cred();
3202
3203         return file_has_perm(cred, file, file_to_av(file));
3204 }
3205
3206 static int selinux_dentry_open(struct file *file, const struct cred *cred)
3207 {
3208         struct file_security_struct *fsec;
3209         struct inode *inode;
3210         struct inode_security_struct *isec;
3211
3212         inode = file->f_path.dentry->d_inode;
3213         fsec = file->f_security;
3214         isec = inode->i_security;
3215         /*
3216          * Save inode label and policy sequence number
3217          * at open-time so that selinux_file_permission
3218          * can determine whether revalidation is necessary.
3219          * Task label is already saved in the file security
3220          * struct as its SID.
3221          */
3222         fsec->isid = isec->sid;
3223         fsec->pseqno = avc_policy_seqno();
3224         /*
3225          * Since the inode label or policy seqno may have changed
3226          * between the selinux_inode_permission check and the saving
3227          * of state above, recheck that access is still permitted.
3228          * Otherwise, access might never be revalidated against the
3229          * new inode label or new policy.
3230          * This check is not redundant - do not remove.
3231          */
3232         return inode_has_perm_noadp(cred, inode, open_file_to_av(file), 0);
3233 }
3234
3235 /* task security operations */
3236
3237 static int selinux_task_create(unsigned long clone_flags)
3238 {
3239         return current_has_perm(current, PROCESS__FORK);
3240 }
3241
3242 /*
3243  * allocate the SELinux part of blank credentials
3244  */
3245 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3246 {
3247         struct task_security_struct *tsec;
3248
3249         tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3250         if (!tsec)
3251                 return -ENOMEM;
3252
3253         cred->security = tsec;
3254         return 0;
3255 }
3256
3257 /*
3258  * detach and free the LSM part of a set of credentials
3259  */
3260 static void selinux_cred_free(struct cred *cred)
3261 {
3262         struct task_security_struct *tsec = cred->security;
3263
3264         /*
3265          * cred->security == NULL if security_cred_alloc_blank() or
3266          * security_prepare_creds() returned an error.
3267          */
3268         BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3269         cred->security = (void *) 0x7UL;
3270         kfree(tsec);
3271 }
3272
3273 /*
3274  * prepare a new set of credentials for modification
3275  */
3276 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3277                                 gfp_t gfp)
3278 {
3279         const struct task_security_struct *old_tsec;
3280         struct task_security_struct *tsec;
3281
3282         old_tsec = old->security;
3283
3284         tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3285         if (!tsec)
3286                 return -ENOMEM;
3287
3288         new->security = tsec;
3289         return 0;
3290 }
3291
3292 /*
3293  * transfer the SELinux data to a blank set of creds
3294  */
3295 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3296 {
3297         const struct task_security_struct *old_tsec = old->security;
3298         struct task_security_struct *tsec = new->security;
3299
3300         *tsec = *old_tsec;
3301 }
3302
3303 /*
3304  * set the security data for a kernel service
3305  * - all the creation contexts are set to unlabelled
3306  */
3307 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3308 {
3309         struct task_security_struct *tsec = new->security;
3310         u32 sid = current_sid();
3311         int ret;
3312
3313         ret = avc_has_perm(sid, secid,
3314                            SECCLASS_KERNEL_SERVICE,
3315                            KERNEL_SERVICE__USE_AS_OVERRIDE,
3316                            NULL);
3317         if (ret == 0) {
3318                 tsec->sid = secid;
3319                 tsec->create_sid = 0;
3320                 tsec->keycreate_sid = 0;
3321                 tsec->sockcreate_sid = 0;
3322         }
3323         return ret;
3324 }
3325
3326 /*
3327  * set the file creation context in a security record to the same as the
3328  * objective context of the specified inode
3329  */
3330 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3331 {
3332         struct inode_security_struct *isec = inode->i_security;
3333         struct task_security_struct *tsec = new->security;
3334         u32 sid = current_sid();
3335         int ret;
3336
3337         ret = avc_has_perm(sid, isec->sid,
3338                            SECCLASS_KERNEL_SERVICE,
3339                            KERNEL_SERVICE__CREATE_FILES_AS,
3340                            NULL);
3341
3342         if (ret == 0)
3343                 tsec->create_sid = isec->sid;
3344         return ret;
3345 }
3346
3347 static int selinux_kernel_module_request(char *kmod_name)
3348 {
3349         u32 sid;
3350         struct common_audit_data ad;
3351
3352         sid = task_sid(current);
3353
3354         COMMON_AUDIT_DATA_INIT(&ad, KMOD);
3355         ad.u.kmod_name = kmod_name;
3356
3357         return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3358                             SYSTEM__MODULE_REQUEST, &ad);
3359 }
3360
3361 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3362 {
3363         return current_has_perm(p, PROCESS__SETPGID);
3364 }
3365
3366 static int selinux_task_getpgid(struct task_struct *p)
3367 {
3368         return current_has_perm(p, PROCESS__GETPGID);
3369 }
3370
3371 static int selinux_task_getsid(struct task_struct *p)
3372 {
3373         return current_has_perm(p, PROCESS__GETSESSION);
3374 }
3375
3376 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3377 {
3378         *secid = task_sid(p);
3379 }
3380
3381 static int selinux_task_setnice(struct task_struct *p, int nice)
3382 {
3383         int rc;
3384
3385         rc = cap_task_setnice(p, nice);
3386         if (rc)
3387                 return rc;
3388
3389         return current_has_perm(p, PROCESS__SETSCHED);
3390 }
3391
3392 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3393 {
3394         int rc;
3395
3396         rc = cap_task_setioprio(p, ioprio);
3397         if (rc)
3398                 return rc;
3399
3400         return current_has_perm(p, PROCESS__SETSCHED);
3401 }
3402
3403 static int selinux_task_getioprio(struct task_struct *p)
3404 {
3405         return current_has_perm(p, PROCESS__GETSCHED);
3406 }
3407
3408 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3409                 struct rlimit *new_rlim)
3410 {
3411         struct rlimit *old_rlim = p->signal->rlim + resource;
3412
3413         /* Control the ability to change the hard limit (whether
3414            lowering or raising it), so that the hard limit can
3415            later be used as a safe reset point for the soft limit
3416            upon context transitions.  See selinux_bprm_committing_creds. */
3417         if (old_rlim->rlim_max != new_rlim->rlim_max)
3418                 return current_has_perm(p, PROCESS__SETRLIMIT);
3419
3420         return 0;
3421 }
3422
3423 static int selinux_task_setscheduler(struct task_struct *p)
3424 {
3425         int rc;
3426
3427         rc = cap_task_setscheduler(p);
3428         if (rc)
3429                 return rc;
3430
3431         return current_has_perm(p, PROCESS__SETSCHED);
3432 }
3433
3434 static int selinux_task_getscheduler(struct task_struct *p)
3435 {
3436         return current_has_perm(p, PROCESS__GETSCHED);
3437 }
3438
3439 static int selinux_task_movememory(struct task_struct *p)
3440 {
3441         return current_has_perm(p, PROCESS__SETSCHED);
3442 }
3443
3444 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3445                                 int sig, u32 secid)
3446 {
3447         u32 perm;
3448         int rc;
3449
3450         if (!sig)
3451                 perm = PROCESS__SIGNULL; /* null signal; existence test */
3452         else
3453                 perm = signal_to_av(sig);
3454         if (secid)
3455                 rc = avc_has_perm(secid, task_sid(p),
3456                                   SECCLASS_PROCESS, perm, NULL);
3457         else
3458                 rc = current_has_perm(p, perm);
3459         return rc;
3460 }
3461
3462 static int selinux_task_wait(struct task_struct *p)
3463 {
3464         return task_has_perm(p, current, PROCESS__SIGCHLD);
3465 }
3466
3467 static void selinux_task_to_inode(struct task_struct *p,
3468                                   struct inode *inode)
3469 {
3470         struct inode_security_struct *isec = inode->i_security;
3471         u32 sid = task_sid(p);
3472
3473         isec->sid = sid;
3474         isec->initialized = 1;
3475 }
3476
3477 /* Returns error only if unable to parse addresses */
3478 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3479                         struct common_audit_data *ad, u8 *proto)
3480 {
3481         int offset, ihlen, ret = -EINVAL;
3482         struct iphdr _iph, *ih;
3483
3484         offset = skb_network_offset(skb);
3485         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3486         if (ih == NULL)
3487                 goto out;
3488
3489         ihlen = ih->ihl * 4;
3490         if (ihlen < sizeof(_iph))
3491                 goto out;
3492
3493         ad->u.net.v4info.saddr = ih->saddr;
3494         ad->u.net.v4info.daddr = ih->daddr;
3495         ret = 0;
3496
3497         if (proto)
3498                 *proto = ih->protocol;
3499
3500         switch (ih->protocol) {
3501         case IPPROTO_TCP: {
3502                 struct tcphdr _tcph, *th;
3503
3504                 if (ntohs(ih->frag_off) & IP_OFFSET)
3505                         break;
3506
3507                 offset += ihlen;
3508                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3509                 if (th == NULL)
3510                         break;
3511
3512                 ad->u.net.sport = th->source;
3513                 ad->u.net.dport = th->dest;
3514                 break;
3515         }
3516
3517         case IPPROTO_UDP: {
3518                 struct udphdr _udph, *uh;
3519
3520                 if (ntohs(ih->frag_off) & IP_OFFSET)
3521                         break;
3522
3523                 offset += ihlen;
3524                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3525                 if (uh == NULL)
3526                         break;
3527
3528                 ad->u.net.sport = uh->source;
3529                 ad->u.net.dport = uh->dest;
3530                 break;
3531         }
3532
3533         case IPPROTO_DCCP: {
3534                 struct dccp_hdr _dccph, *dh;
3535
3536                 if (ntohs(ih->frag_off) & IP_OFFSET)
3537                         break;
3538
3539                 offset += ihlen;
3540                 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3541                 if (dh == NULL)
3542                         break;
3543
3544                 ad->u.net.sport = dh->dccph_sport;
3545                 ad->u.net.dport = dh->dccph_dport;
3546                 break;
3547         }
3548
3549         default:
3550                 break;
3551         }
3552 out:
3553         return ret;
3554 }
3555
3556 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3557
3558 /* Returns error only if unable to parse addresses */
3559 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3560                         struct common_audit_data *ad, u8 *proto)
3561 {
3562         u8 nexthdr;
3563         int ret = -EINVAL, offset;
3564         struct ipv6hdr _ipv6h, *ip6;
3565
3566         offset = skb_network_offset(skb);
3567         ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3568         if (ip6 == NULL)
3569                 goto out;
3570
3571         ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
3572         ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
3573         ret = 0;
3574
3575         nexthdr = ip6->nexthdr;
3576         offset += sizeof(_ipv6h);
3577         offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
3578         if (offset < 0)
3579                 goto out;
3580
3581         if (proto)
3582                 *proto = nexthdr;
3583
3584         switch (nexthdr) {
3585         case IPPROTO_TCP: {
3586                 struct tcphdr _tcph, *th;
3587
3588                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3589                 if (th == NULL)
3590                         break;
3591
3592                 ad->u.net.sport = th->source;
3593                 ad->u.net.dport = th->dest;
3594                 break;
3595         }
3596
3597         case IPPROTO_UDP: {
3598                 struct udphdr _udph, *uh;
3599
3600                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3601                 if (uh == NULL)
3602                         break;
3603
3604                 ad->u.net.sport = uh->source;
3605                 ad->u.net.dport = uh->dest;
3606                 break;
3607         }
3608
3609         case IPPROTO_DCCP: {
3610                 struct dccp_hdr _dccph, *dh;
3611
3612                 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3613                 if (dh == NULL)
3614                         break;
3615
3616                 ad->u.net.sport = dh->dccph_sport;
3617                 ad->u.net.dport = dh->dccph_dport;
3618                 break;
3619         }
3620
3621         /* includes fragments */
3622         default:
3623                 break;
3624         }
3625 out:
3626         return ret;
3627 }
3628
3629 #endif /* IPV6 */
3630
3631 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3632                              char **_addrp, int src, u8 *proto)
3633 {
3634         char *addrp;
3635         int ret;
3636
3637         switch (ad->u.net.family) {
3638         case PF_INET:
3639                 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3640                 if (ret)
3641                         goto parse_error;
3642                 addrp = (char *)(src ? &ad->u.net.v4info.saddr :
3643                                        &ad->u.net.v4info.daddr);
3644                 goto okay;
3645
3646 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3647         case PF_INET6:
3648                 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3649                 if (ret)
3650                         goto parse_error;
3651                 addrp = (char *)(src ? &ad->u.net.v6info.saddr :
3652                                        &ad->u.net.v6info.daddr);
3653                 goto okay;
3654 #endif  /* IPV6 */
3655         default:
3656                 addrp = NULL;
3657                 goto okay;
3658         }
3659
3660 parse_error:
3661         printk(KERN_WARNING
3662                "SELinux: failure in selinux_parse_skb(),"
3663                " unable to parse packet\n");
3664         return ret;
3665
3666 okay:
3667         if (_addrp)
3668                 *_addrp = addrp;
3669         return 0;
3670 }
3671
3672 /**
3673  * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3674  * @skb: the packet
3675  * @family: protocol family
3676  * @sid: the packet's peer label SID
3677  *
3678  * Description:
3679  * Check the various different forms of network peer labeling and determine
3680  * the peer label/SID for the packet; most of the magic actually occurs in
3681  * the security server function security_net_peersid_cmp().  The function
3682  * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3683  * or -EACCES if @sid is invalid due to inconsistencies with the different
3684  * peer labels.
3685  *
3686  */
3687 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3688 {
3689         int err;
3690         u32 xfrm_sid;
3691         u32 nlbl_sid;
3692         u32 nlbl_type;
3693
3694         selinux_skb_xfrm_sid(skb, &xfrm_sid);
3695         selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3696
3697         err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3698         if (unlikely(err)) {
3699                 printk(KERN_WARNING
3700                        "SELinux: failure in selinux_skb_peerlbl_sid(),"
3701                        " unable to determine packet's peer label\n");
3702                 return -EACCES;
3703         }
3704
3705         return 0;
3706 }
3707
3708 /**
3709  * selinux_conn_sid - Determine the child socket label for a connection
3710  * @sk_sid: the parent socket's SID
3711  * @skb_sid: the packet's SID
3712  * @conn_sid: the resulting connection SID
3713  *
3714  * If @skb_sid is valid then the user:role:type information from @sk_sid is
3715  * combined with the MLS information from @skb_sid in order to create
3716  * @conn_sid.  If @skb_sid is not valid then then @conn_sid is simply a copy
3717  * of @sk_sid.  Returns zero on success, negative values on failure.
3718  *
3719  */
3720 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
3721 {
3722         int err = 0;
3723
3724         if (skb_sid != SECSID_NULL)
3725                 err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid);
3726         else
3727                 *conn_sid = sk_sid;
3728
3729         return err;
3730 }
3731
3732 /* socket security operations */
3733
3734 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
3735                                  u16 secclass, u32 *socksid)
3736 {
3737         if (tsec->sockcreate_sid > SECSID_NULL) {
3738                 *socksid = tsec->sockcreate_sid;
3739                 return 0;
3740         }
3741
3742         return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
3743                                        socksid);
3744 }
3745
3746 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
3747 {
3748         struct sk_security_struct *sksec = sk->sk_security;
3749         struct common_audit_data ad;
3750         u32 tsid = task_sid(task);
3751
3752         if (sksec->sid == SECINITSID_KERNEL)
3753                 return 0;
3754
3755         COMMON_AUDIT_DATA_INIT(&ad, NET);
3756         ad.u.net.sk = sk;
3757
3758         return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
3759 }
3760
3761 static int selinux_socket_create(int family, int type,
3762                                  int protocol, int kern)
3763 {
3764         const struct task_security_struct *tsec = current_security();
3765         u32 newsid;
3766         u16 secclass;
3767         int rc;
3768
3769         if (kern)
3770                 return 0;
3771
3772         secclass = socket_type_to_security_class(family, type, protocol);
3773         rc = socket_sockcreate_sid(tsec, secclass, &newsid);
3774         if (rc)
3775                 return rc;
3776
3777         return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
3778 }
3779
3780 static int selinux_socket_post_create(struct socket *sock, int family,
3781                                       int type, int protocol, int kern)
3782 {
3783         const struct task_security_struct *tsec = current_security();
3784         struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3785         struct sk_security_struct *sksec;
3786         int err = 0;
3787
3788         isec->sclass = socket_type_to_security_class(family, type, protocol);
3789
3790         if (kern)
3791                 isec->sid = SECINITSID_KERNEL;
3792         else {
3793                 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
3794                 if (err)
3795                         return err;
3796         }
3797
3798         isec->initialized = 1;
3799
3800         if (sock->sk) {
3801                 sksec = sock->sk->sk_security;
3802                 sksec->sid = isec->sid;
3803                 sksec->sclass = isec->sclass;
3804                 err = selinux_netlbl_socket_post_create(sock->sk, family);
3805         }
3806
3807         return err;
3808 }
3809
3810 /* Range of port numbers used to automatically bind.
3811    Need to determine whether we should perform a name_bind
3812    permission check between the socket and the port number. */
3813
3814 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3815 {
3816         struct sock *sk = sock->sk;
3817         u16 family;
3818         int err;
3819
3820         err = sock_has_perm(current, sk, SOCKET__BIND);
3821         if (err)
3822                 goto out;
3823
3824         /*
3825          * If PF_INET or PF_INET6, check name_bind permission for the port.
3826          * Multiple address binding for SCTP is not supported yet: we just
3827          * check the first address now.
3828          */
3829         family = sk->sk_family;
3830         if (family == PF_INET || family == PF_INET6) {
3831                 char *addrp;
3832                 struct sk_security_struct *sksec = sk->sk_security;
3833                 struct common_audit_data ad;
3834                 struct sockaddr_in *addr4 = NULL;
3835                 struct sockaddr_in6 *addr6 = NULL;
3836                 unsigned short snum;
3837                 u32 sid, node_perm;
3838
3839                 if (family == PF_INET) {
3840                         addr4 = (struct sockaddr_in *)address;
3841                         snum = ntohs(addr4->sin_port);
3842                         addrp = (char *)&addr4->sin_addr.s_addr;
3843                 } else {
3844                         addr6 = (struct sockaddr_in6 *)address;
3845                         snum = ntohs(addr6->sin6_port);
3846                         addrp = (char *)&addr6->sin6_addr.s6_addr;
3847                 }
3848
3849                 if (snum) {
3850                         int low, high;
3851
3852                         inet_get_local_port_range(&low, &high);
3853
3854                         if (snum < max(PROT_SOCK, low) || snum > high) {
3855                                 err = sel_netport_sid(sk->sk_protocol,
3856                                                       snum, &sid);
3857                                 if (err)
3858                                         goto out;
3859                                 COMMON_AUDIT_DATA_INIT(&ad, NET);
3860                                 ad.u.net.sport = htons(snum);
3861                                 ad.u.net.family = family;
3862                                 err = avc_has_perm(sksec->sid, sid,
3863                                                    sksec->sclass,
3864                                                    SOCKET__NAME_BIND, &ad);
3865                                 if (err)
3866                                         goto out;
3867                         }
3868                 }
3869
3870                 switch (sksec->sclass) {
3871                 case SECCLASS_TCP_SOCKET:
3872                         node_perm = TCP_SOCKET__NODE_BIND;
3873                         break;
3874
3875                 case SECCLASS_UDP_SOCKET:
3876                         node_perm = UDP_SOCKET__NODE_BIND;
3877                         break;
3878
3879                 case SECCLASS_DCCP_SOCKET:
3880                         node_perm = DCCP_SOCKET__NODE_BIND;
3881                         break;
3882
3883                 default:
3884                         node_perm = RAWIP_SOCKET__NODE_BIND;
3885                         break;
3886                 }
3887
3888                 err = sel_netnode_sid(addrp, family, &sid);
3889                 if (err)
3890                         goto out;
3891
3892                 COMMON_AUDIT_DATA_INIT(&ad, NET);
3893                 ad.u.net.sport = htons(snum);
3894                 ad.u.net.family = family;
3895
3896                 if (family == PF_INET)
3897                         ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
3898                 else
3899                         ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr);
3900
3901                 err = avc_has_perm(sksec->sid, sid,
3902                                    sksec->sclass, node_perm, &ad);
3903                 if (err)
3904                         goto out;
3905         }
3906 out:
3907         return err;
3908 }
3909
3910 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3911 {
3912         struct sock *sk = sock->sk;
3913         struct sk_security_struct *sksec = sk->sk_security;
3914         int err;
3915
3916         err = sock_has_perm(current, sk, SOCKET__CONNECT);
3917         if (err)
3918                 return err;
3919
3920         /*
3921          * If a TCP or DCCP socket, check name_connect permission for the port.
3922          */
3923         if (sksec->sclass == SECCLASS_TCP_SOCKET ||
3924             sksec->sclass == SECCLASS_DCCP_SOCKET) {
3925                 struct common_audit_data ad;
3926                 struct sockaddr_in *addr4 = NULL;
3927                 struct sockaddr_in6 *addr6 = NULL;
3928                 unsigned short snum;
3929                 u32 sid, perm;
3930
3931                 if (sk->sk_family == PF_INET) {
3932                         addr4 = (struct sockaddr_in *)address;
3933                         if (addrlen < sizeof(struct sockaddr_in))
3934                                 return -EINVAL;
3935                         snum = ntohs(addr4->sin_port);
3936                 } else {
3937                         addr6 = (struct sockaddr_in6 *)address;
3938                         if (addrlen < SIN6_LEN_RFC2133)
3939                                 return -EINVAL;
3940                         snum = ntohs(addr6->sin6_port);
3941                 }
3942
3943                 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
3944                 if (err)
3945                         goto out;
3946
3947                 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
3948                        TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
3949
3950                 COMMON_AUDIT_DATA_INIT(&ad, NET);
3951                 ad.u.net.dport = htons(snum);
3952                 ad.u.net.family = sk->sk_family;
3953                 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
3954                 if (err)
3955                         goto out;
3956         }
3957
3958         err = selinux_netlbl_socket_connect(sk, address);
3959
3960 out:
3961         return err;
3962 }
3963
3964 static int selinux_socket_listen(struct socket *sock, int backlog)
3965 {
3966         return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
3967 }
3968
3969 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3970 {
3971         int err;
3972         struct inode_security_struct *isec;
3973         struct inode_security_struct *newisec;
3974
3975         err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
3976         if (err)
3977                 return err;
3978
3979         newisec = SOCK_INODE(newsock)->i_security;
3980
3981         isec = SOCK_INODE(sock)->i_security;
3982         newisec->sclass = isec->sclass;
3983         newisec->sid = isec->sid;
3984         newisec->initialized = 1;
3985
3986         return 0;
3987 }
3988
3989 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3990                                   int size)
3991 {
3992         return sock_has_perm(current, sock->sk, SOCKET__WRITE);
3993 }
3994
3995 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
3996                                   int size, int flags)
3997 {
3998         return sock_has_perm(current, sock->sk, SOCKET__READ);
3999 }
4000
4001 static int selinux_socket_getsockname(struct socket *sock)
4002 {
4003         return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4004 }
4005
4006 static int selinux_socket_getpeername(struct socket *sock)
4007 {
4008         return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4009 }
4010
4011 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4012 {
4013         int err;
4014
4015         err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4016         if (err)
4017                 return err;
4018
4019         return selinux_netlbl_socket_setsockopt(sock, level, optname);
4020 }
4021
4022 static int selinux_socket_getsockopt(struct socket *sock, int level,
4023                                      int optname)
4024 {
4025         return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
4026 }
4027
4028 static int selinux_socket_shutdown(struct socket *sock, int how)
4029 {
4030         return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
4031 }
4032
4033 static int selinux_socket_unix_stream_connect(struct sock *sock,
4034                                               struct sock *other,
4035                                               struct sock *newsk)
4036 {
4037         struct sk_security_struct *sksec_sock = sock->sk_security;
4038         struct sk_security_struct *sksec_other = other->sk_security;
4039         struct sk_security_struct *sksec_new = newsk->sk_security;
4040         struct common_audit_data ad;
4041         int err;
4042
4043         COMMON_AUDIT_DATA_INIT(&ad, NET);
4044         ad.u.net.sk = other;
4045
4046         err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
4047                            sksec_other->sclass,
4048                            UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4049         if (err)
4050                 return err;
4051
4052         /* server child socket */
4053         sksec_new->peer_sid = sksec_sock->sid;
4054         err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4055                                     &sksec_new->sid);
4056         if (err)
4057                 return err;
4058
4059         /* connecting socket */
4060         sksec_sock->peer_sid = sksec_new->sid;
4061
4062         return 0;
4063 }
4064
4065 static int selinux_socket_unix_may_send(struct socket *sock,
4066                                         struct socket *other)
4067 {
4068         struct sk_security_struct *ssec = sock->sk->sk_security;
4069         struct sk_security_struct *osec = other->sk->sk_security;
4070         struct common_audit_data ad;
4071
4072         COMMON_AUDIT_DATA_INIT(&ad, NET);
4073         ad.u.net.sk = other->sk;
4074
4075         return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4076                             &ad);
4077 }
4078
4079 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
4080                                     u32 peer_sid,
4081                                     struct common_audit_data *ad)
4082 {
4083         int err;
4084         u32 if_sid;
4085         u32 node_sid;
4086
4087         err = sel_netif_sid(ifindex, &if_sid);
4088         if (err)
4089                 return err;
4090         err = avc_has_perm(peer_sid, if_sid,
4091                            SECCLASS_NETIF, NETIF__INGRESS, ad);
4092         if (err)
4093                 return err;
4094
4095         err = sel_netnode_sid(addrp, family, &node_sid);
4096         if (err)
4097                 return err;
4098         return avc_has_perm(peer_sid, node_sid,
4099                             SECCLASS_NODE, NODE__RECVFROM, ad);
4100 }
4101
4102 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4103                                        u16 family)
4104 {
4105         int err = 0;
4106         struct sk_security_struct *sksec = sk->sk_security;
4107         u32 sk_sid = sksec->sid;
4108         struct common_audit_data ad;
4109         char *addrp;
4110
4111         COMMON_AUDIT_DATA_INIT(&ad, NET);
4112         ad.u.net.netif = skb->skb_iif;
4113         ad.u.net.family = family;
4114         err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4115         if (err)
4116                 return err;
4117
4118         if (selinux_secmark_enabled()) {
4119                 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4120                                    PACKET__RECV, &ad);
4121                 if (err)
4122                         return err;
4123         }
4124
4125         err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4126         if (err)
4127                 return err;
4128         err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4129
4130         return err;
4131 }
4132
4133 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4134 {
4135         int err;
4136         struct sk_security_struct *sksec = sk->sk_security;
4137         u16 family = sk->sk_family;
4138         u32 sk_sid = sksec->sid;
4139         struct common_audit_data ad;
4140         char *addrp;
4141         u8 secmark_active;
4142         u8 peerlbl_active;
4143
4144         if (family != PF_INET && family != PF_INET6)
4145                 return 0;
4146
4147         /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4148         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4149                 family = PF_INET;
4150
4151         /* If any sort of compatibility mode is enabled then handoff processing
4152          * to the selinux_sock_rcv_skb_compat() function to deal with the
4153          * special handling.  We do this in an attempt to keep this function
4154          * as fast and as clean as possible. */
4155         if (!selinux_policycap_netpeer)
4156                 return selinux_sock_rcv_skb_compat(sk, skb, family);
4157
4158         secmark_active = selinux_secmark_enabled();
4159         peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4160         if (!secmark_active && !peerlbl_active)
4161                 return 0;
4162
4163         COMMON_AUDIT_DATA_INIT(&ad, NET);
4164         ad.u.net.netif = skb->skb_iif;
4165         ad.u.net.family = family;
4166         err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4167         if (err)
4168                 return err;
4169
4170         if (peerlbl_active) {
4171                 u32 peer_sid;
4172
4173                 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4174                 if (err)
4175                         return err;
4176                 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4177                                                peer_sid, &ad);
4178                 if (err) {
4179                         selinux_netlbl_err(skb, err, 0);
4180                         return err;
4181                 }
4182                 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4183                                    PEER__RECV, &ad);
4184                 if (err) {
4185                         selinux_netlbl_err(skb, err, 0);
4186                         return err;
4187                 }
4188         }
4189
4190         if (secmark_active) {
4191                 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4192                                    PACKET__RECV, &ad);
4193                 if (err)
4194                         return err;
4195         }
4196
4197         return err;
4198 }
4199
4200 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4201                                             int __user *optlen, unsigned len)
4202 {
4203         int err = 0;
4204         char *scontext;
4205         u32 scontext_len;
4206         struct sk_security_struct *sksec = sock->sk->sk_security;
4207         u32 peer_sid = SECSID_NULL;
4208
4209         if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4210             sksec->sclass == SECCLASS_TCP_SOCKET)
4211                 peer_sid = sksec->peer_sid;
4212         if (peer_sid == SECSID_NULL)
4213                 return -ENOPROTOOPT;
4214
4215         err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4216         if (err)
4217                 return err;
4218
4219         if (scontext_len > len) {
4220                 err = -ERANGE;
4221                 goto out_len;
4222         }
4223
4224         if (copy_to_user(optval, scontext, scontext_len))
4225                 err = -EFAULT;
4226
4227 out_len:
4228         if (put_user(scontext_len, optlen))
4229                 err = -EFAULT;
4230         kfree(scontext);
4231         return err;
4232 }
4233
4234 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4235 {
4236         u32 peer_secid = SECSID_NULL;
4237         u16 family;
4238
4239         if (skb && skb->protocol == htons(ETH_P_IP))
4240                 family = PF_INET;
4241         else if (skb && skb->protocol == htons(ETH_P_IPV6))
4242                 family = PF_INET6;
4243         else if (sock)
4244                 family = sock->sk->sk_family;
4245         else
4246                 goto out;
4247
4248         if (sock && family == PF_UNIX)
4249                 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4250         else if (skb)
4251                 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4252
4253 out:
4254         *secid = peer_secid;
4255         if (peer_secid == SECSID_NULL)
4256                 return -EINVAL;
4257         return 0;
4258 }
4259
4260 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4261 {
4262         struct sk_security_struct *sksec;
4263
4264         sksec = kzalloc(sizeof(*sksec), priority);
4265         if (!sksec)
4266                 return -ENOMEM;
4267
4268         sksec->peer_sid = SECINITSID_UNLABELED;
4269         sksec->sid = SECINITSID_UNLABELED;
4270         selinux_netlbl_sk_security_reset(sksec);
4271         sk->sk_security = sksec;
4272
4273         return 0;
4274 }
4275
4276 static void selinux_sk_free_security(struct sock *sk)
4277 {
4278         struct sk_security_struct *sksec = sk->sk_security;
4279
4280         sk->sk_security = NULL;
4281         selinux_netlbl_sk_security_free(sksec);
4282         kfree(sksec);
4283 }
4284
4285 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4286 {
4287         struct sk_security_struct *sksec = sk->sk_security;
4288         struct sk_security_struct *newsksec = newsk->sk_security;
4289
4290         newsksec->sid = sksec->sid;
4291         newsksec->peer_sid = sksec->peer_sid;
4292         newsksec->sclass = sksec->sclass;
4293
4294         selinux_netlbl_sk_security_reset(newsksec);
4295 }
4296
4297 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4298 {
4299         if (!sk)
4300                 *secid = SECINITSID_ANY_SOCKET;
4301         else {
4302                 struct sk_security_struct *sksec = sk->sk_security;
4303
4304                 *secid = sksec->sid;
4305         }
4306 }
4307
4308 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4309 {
4310         struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4311         struct sk_security_struct *sksec = sk->sk_security;
4312
4313         if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4314             sk->sk_family == PF_UNIX)
4315                 isec->sid = sksec->sid;
4316         sksec->sclass = isec->sclass;
4317 }
4318
4319 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4320                                      struct request_sock *req)
4321 {
4322         struct sk_security_struct *sksec = sk->sk_security;
4323         int err;
4324         u16 family = sk->sk_family;
4325         u32 connsid;
4326         u32 peersid;
4327
4328         /* handle mapped IPv4 packets arriving via IPv6 sockets */
4329         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4330                 family = PF_INET;
4331
4332         err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4333         if (err)
4334                 return err;
4335         err = selinux_conn_sid(sksec->sid, peersid, &connsid);
4336         if (err)
4337                 return err;
4338         req->secid = connsid;
4339         req->peer_secid = peersid;
4340
4341         return selinux_netlbl_inet_conn_request(req, family);
4342 }
4343
4344 static void selinux_inet_csk_clone(struct sock *newsk,
4345                                    const struct request_sock *req)
4346 {
4347         struct sk_security_struct *newsksec = newsk->sk_security;
4348
4349         newsksec->sid = req->secid;
4350         newsksec->peer_sid = req->peer_secid;
4351         /* NOTE: Ideally, we should also get the isec->sid for the
4352            new socket in sync, but we don't have the isec available yet.
4353            So we will wait until sock_graft to do it, by which
4354            time it will have been created and available. */
4355
4356         /* We don't need to take any sort of lock here as we are the only
4357          * thread with access to newsksec */
4358         selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4359 }
4360
4361 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4362 {
4363         u16 family = sk->sk_family;
4364         struct sk_security_struct *sksec = sk->sk_security;
4365
4366         /* handle mapped IPv4 packets arriving via IPv6 sockets */
4367         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4368                 family = PF_INET;
4369
4370         selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4371 }
4372
4373 static int selinux_secmark_relabel_packet(u32 sid)
4374 {
4375         const struct task_security_struct *__tsec;
4376         u32 tsid;
4377
4378         __tsec = current_security();
4379         tsid = __tsec->sid;
4380
4381         return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4382 }
4383
4384 static void selinux_secmark_refcount_inc(void)
4385 {
4386         atomic_inc(&selinux_secmark_refcount);
4387 }
4388
4389 static void selinux_secmark_refcount_dec(void)
4390 {
4391         atomic_dec(&selinux_secmark_refcount);
4392 }
4393
4394 static void selinux_req_classify_flow(const struct request_sock *req,
4395                                       struct flowi *fl)
4396 {
4397         fl->flowi_secid = req->secid;
4398 }
4399
4400 static int selinux_tun_dev_create(void)
4401 {
4402         u32 sid = current_sid();
4403
4404         /* we aren't taking into account the "sockcreate" SID since the socket
4405          * that is being created here is not a socket in the traditional sense,
4406          * instead it is a private sock, accessible only to the kernel, and
4407          * representing a wide range of network traffic spanning multiple
4408          * connections unlike traditional sockets - check the TUN driver to
4409          * get a better understanding of why this socket is special */
4410
4411         return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4412                             NULL);
4413 }
4414
4415 static void selinux_tun_dev_post_create(struct sock *sk)
4416 {
4417         struct sk_security_struct *sksec = sk->sk_security;
4418
4419         /* we don't currently perform any NetLabel based labeling here and it
4420          * isn't clear that we would want to do so anyway; while we could apply
4421          * labeling without the support of the TUN user the resulting labeled
4422          * traffic from the other end of the connection would almost certainly
4423          * cause confusion to the TUN user that had no idea network labeling
4424          * protocols were being used */
4425
4426         /* see the comments in selinux_tun_dev_create() about why we don't use
4427          * the sockcreate SID here */
4428
4429         sksec->sid = current_sid();
4430         sksec->sclass = SECCLASS_TUN_SOCKET;
4431 }
4432
4433 static int selinux_tun_dev_attach(struct sock *sk)
4434 {
4435         struct sk_security_struct *sksec = sk->sk_security;
4436         u32 sid = current_sid();
4437         int err;
4438
4439         err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4440                            TUN_SOCKET__RELABELFROM, NULL);
4441         if (err)
4442                 return err;
4443         err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4444                            TUN_SOCKET__RELABELTO, NULL);
4445         if (err)
4446                 return err;
4447
4448         sksec->sid = sid;
4449
4450         return 0;
4451 }
4452
4453 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4454 {
4455         int err = 0;
4456         u32 perm;
4457         struct nlmsghdr *nlh;
4458         struct sk_security_struct *sksec = sk->sk_security;
4459
4460         if (skb->len < NLMSG_SPACE(0)) {
4461                 err = -EINVAL;
4462                 goto out;
4463         }
4464         nlh = nlmsg_hdr(skb);
4465
4466         err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4467         if (err) {
4468                 if (err == -EINVAL) {
4469                         audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4470                                   "SELinux:  unrecognized netlink message"
4471                                   " type=%hu for sclass=%hu\n",
4472                                   nlh->nlmsg_type, sksec->sclass);
4473                         if (!selinux_enforcing || security_get_allow_unknown())
4474                                 err = 0;
4475                 }
4476
4477                 /* Ignore */
4478                 if (err == -ENOENT)
4479                         err = 0;
4480                 goto out;
4481         }
4482
4483         err = sock_has_perm(current, sk, perm);
4484 out:
4485         return err;
4486 }
4487
4488 #ifdef CONFIG_NETFILTER
4489
4490 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4491                                        u16 family)
4492 {
4493         int err;
4494         char *addrp;
4495         u32 peer_sid;
4496         struct common_audit_data ad;
4497         u8 secmark_active;
4498         u8 netlbl_active;
4499         u8 peerlbl_active;
4500
4501         if (!selinux_policycap_netpeer)
4502                 return NF_ACCEPT;
4503
4504         secmark_active = selinux_secmark_enabled();
4505         netlbl_active = netlbl_enabled();
4506         peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4507         if (!secmark_active && !peerlbl_active)
4508                 return NF_ACCEPT;
4509
4510         if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4511                 return NF_DROP;
4512
4513         COMMON_AUDIT_DATA_INIT(&ad, NET);
4514         ad.u.net.netif = ifindex;
4515         ad.u.net.family = family;
4516         if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4517                 return NF_DROP;
4518
4519         if (peerlbl_active) {
4520                 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4521                                                peer_sid, &ad);
4522                 if (err) {
4523                         selinux_netlbl_err(skb, err, 1);
4524                         return NF_DROP;
4525                 }
4526         }
4527
4528         if (secmark_active)
4529                 if (avc_has_perm(peer_sid, skb->secmark,
4530                                  SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4531                         return NF_DROP;
4532
4533         if (netlbl_active)
4534                 /* we do this in the FORWARD path and not the POST_ROUTING
4535                  * path because we want to make sure we apply the necessary
4536                  * labeling before IPsec is applied so we can leverage AH
4537                  * protection */
4538                 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4539                         return NF_DROP;
4540
4541         return NF_ACCEPT;
4542 }
4543
4544 static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4545                                          struct sk_buff *skb,
4546                                          const struct net_device *in,
4547                                          const struct net_device *out,
4548                                          int (*okfn)(struct sk_buff *))
4549 {
4550         return selinux_ip_forward(skb, in->ifindex, PF_INET);
4551 }
4552
4553 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4554 static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4555                                          struct sk_buff *skb,
4556                                          const struct net_device *in,
4557                                          const struct net_device *out,
4558                                          int (*okfn)(struct sk_buff *))
4559 {
4560         return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4561 }
4562 #endif  /* IPV6 */
4563
4564 static unsigned int selinux_ip_output(struct sk_buff *skb,
4565                                       u16 family)
4566 {
4567         struct sock *sk;
4568         u32 sid;
4569
4570         if (!netlbl_enabled())
4571                 return NF_ACCEPT;
4572
4573         /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4574          * because we want to make sure we apply the necessary labeling
4575          * before IPsec is applied so we can leverage AH protection */
4576         sk = skb->sk;
4577         if (sk) {
4578                 struct sk_security_struct *sksec;
4579
4580                 if (sk->sk_state == TCP_LISTEN)
4581                         /* if the socket is the listening state then this
4582                          * packet is a SYN-ACK packet which means it needs to
4583                          * be labeled based on the connection/request_sock and
4584                          * not the parent socket.  unfortunately, we can't
4585                          * lookup the request_sock yet as it isn't queued on
4586                          * the parent socket until after the SYN-ACK is sent.
4587                          * the "solution" is to simply pass the packet as-is
4588                          * as any IP option based labeling should be copied
4589                          * from the initial connection request (in the IP
4590                          * layer).  it is far from ideal, but until we get a
4591                          * security label in the packet itself this is the
4592                          * best we can do. */
4593                         return NF_ACCEPT;
4594
4595                 /* standard practice, label using the parent socket */
4596                 sksec = sk->sk_security;
4597                 sid = sksec->sid;
4598         } else
4599                 sid = SECINITSID_KERNEL;
4600         if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4601                 return NF_DROP;
4602
4603         return NF_ACCEPT;
4604 }
4605
4606 static unsigned int selinux_ipv4_output(unsigned int hooknum,
4607                                         struct sk_buff *skb,
4608                                         const struct net_device *in,
4609                                         const struct net_device *out,
4610                                         int (*okfn)(struct sk_buff *))
4611 {
4612         return selinux_ip_output(skb, PF_INET);
4613 }
4614
4615 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4616                                                 int ifindex,
4617                                                 u16 family)
4618 {
4619         struct sock *sk = skb->sk;
4620         struct sk_security_struct *sksec;
4621         struct common_audit_data ad;
4622         char *addrp;
4623         u8 proto;
4624
4625         if (sk == NULL)
4626                 return NF_ACCEPT;
4627         sksec = sk->sk_security;
4628
4629         COMMON_AUDIT_DATA_INIT(&ad, NET);
4630         ad.u.net.netif = ifindex;
4631         ad.u.net.family = family;
4632         if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4633                 return NF_DROP;
4634
4635         if (selinux_secmark_enabled())
4636                 if (avc_has_perm(sksec->sid, skb->secmark,
4637                                  SECCLASS_PACKET, PACKET__SEND, &ad))
4638                         return NF_DROP_ERR(-ECONNREFUSED);
4639
4640         if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4641                 return NF_DROP_ERR(-ECONNREFUSED);
4642
4643         return NF_ACCEPT;
4644 }
4645
4646 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4647                                          u16 family)
4648 {
4649         u32 secmark_perm;
4650         u32 peer_sid;
4651         struct sock *sk;
4652         struct common_audit_data ad;
4653         char *addrp;
4654         u8 secmark_active;
4655         u8 peerlbl_active;
4656
4657         /* If any sort of compatibility mode is enabled then handoff processing
4658          * to the selinux_ip_postroute_compat() function to deal with the
4659          * special handling.  We do this in an attempt to keep this function
4660          * as fast and as clean as possible. */
4661         if (!selinux_policycap_netpeer)
4662                 return selinux_ip_postroute_compat(skb, ifindex, family);
4663 #ifdef CONFIG_XFRM
4664         /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4665          * packet transformation so allow the packet to pass without any checks
4666          * since we'll have another chance to perform access control checks
4667          * when the packet is on it's final way out.
4668          * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4669          *       is NULL, in this case go ahead and apply access control. */
4670         if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4671                 return NF_ACCEPT;
4672 #endif
4673         secmark_active = selinux_secmark_enabled();
4674         peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4675         if (!secmark_active && !peerlbl_active)
4676                 return NF_ACCEPT;
4677
4678         sk = skb->sk;
4679         if (sk == NULL) {
4680                 /* Without an associated socket the packet is either coming
4681                  * from the kernel or it is being forwarded; check the packet
4682                  * to determine which and if the packet is being forwarded
4683                  * query the packet directly to determine the security label. */
4684                 if (skb->skb_iif) {
4685                         secmark_perm = PACKET__FORWARD_OUT;
4686                         if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4687                                 return NF_DROP;
4688                 } else {
4689                         secmark_perm = PACKET__SEND;
4690                         peer_sid = SECINITSID_KERNEL;
4691                 }
4692         } else if (sk->sk_state == TCP_LISTEN) {
4693                 /* Locally generated packet but the associated socket is in the
4694                  * listening state which means this is a SYN-ACK packet.  In
4695                  * this particular case the correct security label is assigned
4696                  * to the connection/request_sock but unfortunately we can't
4697                  * query the request_sock as it isn't queued on the parent
4698                  * socket until after the SYN-ACK packet is sent; the only
4699                  * viable choice is to regenerate the label like we do in
4700                  * selinux_inet_conn_request().  See also selinux_ip_output()
4701                  * for similar problems. */
4702                 u32 skb_sid;
4703                 struct sk_security_struct *sksec = sk->sk_security;
4704                 if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
4705                         return NF_DROP;
4706                 if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
4707                         return NF_DROP;
4708                 secmark_perm = PACKET__SEND;
4709         } else {
4710                 /* Locally generated packet, fetch the security label from the
4711                  * associated socket. */
4712                 struct sk_security_struct *sksec = sk->sk_security;
4713                 peer_sid = sksec->sid;
4714                 secmark_perm = PACKET__SEND;
4715         }
4716
4717         COMMON_AUDIT_DATA_INIT(&ad, NET);
4718         ad.u.net.netif = ifindex;
4719         ad.u.net.family = family;
4720         if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4721                 return NF_DROP;
4722
4723         if (secmark_active)
4724                 if (avc_has_perm(peer_sid, skb->secmark,
4725                                  SECCLASS_PACKET, secmark_perm, &ad))
4726                         return NF_DROP_ERR(-ECONNREFUSED);
4727
4728         if (peerlbl_active) {
4729                 u32 if_sid;
4730                 u32 node_sid;
4731
4732                 if (sel_netif_sid(ifindex, &if_sid))
4733                         return NF_DROP;
4734                 if (avc_has_perm(peer_sid, if_sid,
4735                                  SECCLASS_NETIF, NETIF__EGRESS, &ad))
4736                         return NF_DROP_ERR(-ECONNREFUSED);
4737
4738                 if (sel_netnode_sid(addrp, family, &node_sid))
4739                         return NF_DROP;
4740                 if (avc_has_perm(peer_sid, node_sid,
4741                                  SECCLASS_NODE, NODE__SENDTO, &ad))
4742                         return NF_DROP_ERR(-ECONNREFUSED);
4743         }
4744
4745         return NF_ACCEPT;
4746 }
4747
4748 static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4749                                            struct sk_buff *skb,
4750                                            const struct net_device *in,
4751                                            const struct net_device *out,
4752                                            int (*okfn)(struct sk_buff *))
4753 {
4754         return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4755 }
4756
4757 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4758 static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4759                                            struct sk_buff *skb,
4760                                            const struct net_device *in,
4761                                            const struct net_device *out,
4762                                            int (*okfn)(struct sk_buff *))
4763 {
4764         return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4765 }
4766 #endif  /* IPV6 */
4767
4768 #endif  /* CONFIG_NETFILTER */
4769
4770 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4771 {
4772         int err;
4773
4774         err = cap_netlink_send(sk, skb);
4775         if (err)
4776                 return err;
4777
4778         return selinux_nlmsg_perm(sk, skb);
4779 }
4780
4781 static int selinux_netlink_recv(struct sk_buff *skb, int capability)
4782 {
4783         int err;
4784         struct common_audit_data ad;
4785         u32 sid;
4786
4787         err = cap_netlink_recv(skb, capability);
4788         if (err)
4789                 return err;
4790
4791         COMMON_AUDIT_DATA_INIT(&ad, CAP);
4792         ad.u.cap = capability;
4793
4794         security_task_getsecid(current, &sid);
4795         return avc_has_perm(sid, sid, SECCLASS_CAPABILITY,
4796                             CAP_TO_MASK(capability), &ad);
4797 }
4798
4799 static int ipc_alloc_security(struct task_struct *task,
4800                               struct kern_ipc_perm *perm,
4801                               u16 sclass)
4802 {
4803         struct ipc_security_struct *isec;
4804         u32 sid;
4805
4806         isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4807         if (!isec)
4808                 return -ENOMEM;
4809
4810         sid = task_sid(task);
4811         isec->sclass = sclass;
4812         isec->sid = sid;
4813         perm->security = isec;
4814
4815         return 0;
4816 }
4817
4818 static void ipc_free_security(struct kern_ipc_perm *perm)
4819 {
4820         struct ipc_security_struct *isec = perm->security;
4821         perm->security = NULL;
4822         kfree(isec);
4823 }
4824
4825 static int msg_msg_alloc_security(struct msg_msg *msg)
4826 {
4827         struct msg_security_struct *msec;
4828
4829         msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4830         if (!msec)
4831                 return -ENOMEM;
4832
4833         msec->sid = SECINITSID_UNLABELED;
4834         msg->security = msec;
4835
4836         return 0;
4837 }
4838
4839 static void msg_msg_free_security(struct msg_msg *msg)
4840 {
4841         struct msg_security_struct *msec = msg->security;
4842
4843         msg->security = NULL;
4844         kfree(msec);
4845 }
4846
4847 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4848                         u32 perms)
4849 {
4850         struct ipc_security_struct *isec;
4851         struct common_audit_data ad;
4852         u32 sid = current_sid();
4853
4854         isec = ipc_perms->security;
4855
4856         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4857         ad.u.ipc_id = ipc_perms->key;
4858
4859         return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4860 }
4861
4862 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4863 {
4864         return msg_msg_alloc_security(msg);
4865 }
4866
4867 static void selinux_msg_msg_free_security(struct msg_msg *msg)
4868 {
4869         msg_msg_free_security(msg);
4870 }
4871
4872 /* message queue security operations */
4873 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4874 {
4875         struct ipc_security_struct *isec;
4876         struct common_audit_data ad;
4877         u32 sid = current_sid();
4878         int rc;
4879
4880         rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4881         if (rc)
4882                 return rc;
4883
4884         isec = msq->q_perm.security;
4885
4886         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4887         ad.u.ipc_id = msq->q_perm.key;
4888
4889         rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4890                           MSGQ__CREATE, &ad);
4891         if (rc) {
4892                 ipc_free_security(&msq->q_perm);
4893                 return rc;
4894         }
4895         return 0;
4896 }
4897
4898 static void selinux_msg_queue_free_security(struct msg_queue *msq)
4899 {
4900         ipc_free_security(&msq->q_perm);
4901 }
4902
4903 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4904 {
4905         struct ipc_security_struct *isec;
4906         struct common_audit_data ad;
4907         u32 sid = current_sid();
4908
4909         isec = msq->q_perm.security;
4910
4911         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4912         ad.u.ipc_id = msq->q_perm.key;
4913
4914         return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4915                             MSGQ__ASSOCIATE, &ad);
4916 }
4917
4918 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4919 {
4920         int err;
4921         int perms;
4922
4923         switch (cmd) {
4924         case IPC_INFO:
4925         case MSG_INFO:
4926                 /* No specific object, just general system-wide information. */
4927                 return task_has_system(current, SYSTEM__IPC_INFO);
4928         case IPC_STAT:
4929         case MSG_STAT:
4930                 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4931                 break;
4932         case IPC_SET:
4933                 perms = MSGQ__SETATTR;
4934                 break;
4935         case IPC_RMID:
4936                 perms = MSGQ__DESTROY;
4937                 break;
4938         default:
4939                 return 0;
4940         }
4941
4942         err = ipc_has_perm(&msq->q_perm, perms);
4943         return err;
4944 }
4945
4946 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4947 {
4948         struct ipc_security_struct *isec;
4949         struct msg_security_struct *msec;
4950         struct common_audit_data ad;
4951         u32 sid = current_sid();
4952         int rc;
4953
4954         isec = msq->q_perm.security;
4955         msec = msg->security;
4956
4957         /*
4958          * First time through, need to assign label to the message
4959          */
4960         if (msec->sid == SECINITSID_UNLABELED) {
4961                 /*
4962                  * Compute new sid based on current process and
4963                  * message queue this message will be stored in
4964                  */
4965                 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
4966                                              NULL, &msec->sid);
4967                 if (rc)
4968                         return rc;
4969         }
4970
4971         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4972         ad.u.ipc_id = msq->q_perm.key;
4973
4974         /* Can this process write to the queue? */
4975         rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4976                           MSGQ__WRITE, &ad);
4977         if (!rc)
4978                 /* Can this process send the message */
4979                 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
4980                                   MSG__SEND, &ad);
4981         if (!rc)
4982                 /* Can the message be put in the queue? */
4983                 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
4984                                   MSGQ__ENQUEUE, &ad);
4985
4986         return rc;
4987 }
4988
4989 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
4990                                     struct task_struct *target,
4991                                     long type, int mode)
4992 {
4993         struct ipc_security_struct *isec;
4994         struct msg_security_struct *msec;
4995         struct common_audit_data ad;
4996         u32 sid = task_sid(target);
4997         int rc;
4998
4999         isec = msq->q_perm.security;
5000         msec = msg->security;
5001
5002         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5003         ad.u.ipc_id = msq->q_perm.key;
5004
5005         rc = avc_has_perm(sid, isec->sid,
5006                           SECCLASS_MSGQ, MSGQ__READ, &ad);
5007         if (!rc)
5008                 rc = avc_has_perm(sid, msec->sid,
5009                                   SECCLASS_MSG, MSG__RECEIVE, &ad);
5010         return rc;
5011 }
5012
5013 /* Shared Memory security operations */
5014 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
5015 {
5016         struct ipc_security_struct *isec;
5017         struct common_audit_data ad;
5018         u32 sid = current_sid();
5019         int rc;
5020
5021         rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
5022         if (rc)
5023                 return rc;
5024
5025         isec = shp->shm_perm.security;
5026
5027         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5028         ad.u.ipc_id = shp->shm_perm.key;
5029
5030         rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5031                           SHM__CREATE, &ad);
5032         if (rc) {
5033                 ipc_free_security(&shp->shm_perm);
5034                 return rc;
5035         }
5036         return 0;
5037 }
5038
5039 static void selinux_shm_free_security(struct shmid_kernel *shp)
5040 {
5041         ipc_free_security(&shp->shm_perm);
5042 }
5043
5044 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
5045 {
5046         struct ipc_security_struct *isec;
5047         struct common_audit_data ad;
5048         u32 sid = current_sid();
5049
5050         isec = shp->shm_perm.security;
5051
5052         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5053         ad.u.ipc_id = shp->shm_perm.key;
5054
5055         return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5056                             SHM__ASSOCIATE, &ad);
5057 }
5058
5059 /* Note, at this point, shp is locked down */
5060 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
5061 {
5062         int perms;
5063         int err;
5064
5065         switch (cmd) {
5066         case IPC_INFO:
5067         case SHM_INFO:
5068                 /* No specific object, just general system-wide information. */
5069                 return task_has_system(current, SYSTEM__IPC_INFO);
5070         case IPC_STAT:
5071         case SHM_STAT:
5072                 perms = SHM__GETATTR | SHM__ASSOCIATE;
5073                 break;
5074         case IPC_SET:
5075                 perms = SHM__SETATTR;
5076                 break;
5077         case SHM_LOCK:
5078         case SHM_UNLOCK:
5079                 perms = SHM__LOCK;
5080                 break;
5081         case IPC_RMID:
5082                 perms = SHM__DESTROY;
5083                 break;
5084         default:
5085                 return 0;
5086         }
5087
5088         err = ipc_has_perm(&shp->shm_perm, perms);
5089         return err;
5090 }
5091
5092 static int selinux_shm_shmat(struct shmid_kernel *shp,
5093                              char __user *shmaddr, int shmflg)
5094 {
5095         u32 perms;
5096
5097         if (shmflg & SHM_RDONLY)
5098                 perms = SHM__READ;
5099         else
5100                 perms = SHM__READ | SHM__WRITE;
5101
5102         return ipc_has_perm(&shp->shm_perm, perms);
5103 }
5104
5105 /* Semaphore security operations */
5106 static int selinux_sem_alloc_security(struct sem_array *sma)
5107 {
5108         struct ipc_security_struct *isec;
5109         struct common_audit_data ad;
5110         u32 sid = current_sid();
5111         int rc;
5112
5113         rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5114         if (rc)
5115                 return rc;
5116
5117         isec = sma->sem_perm.security;
5118
5119         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5120         ad.u.ipc_id = sma->sem_perm.key;
5121
5122         rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5123                           SEM__CREATE, &ad);
5124         if (rc) {
5125                 ipc_free_security(&sma->sem_perm);
5126                 return rc;
5127         }
5128         return 0;
5129 }
5130
5131 static void selinux_sem_free_security(struct sem_array *sma)
5132 {
5133         ipc_free_security(&sma->sem_perm);
5134 }
5135
5136 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5137 {
5138         struct ipc_security_struct *isec;
5139         struct common_audit_data ad;
5140         u32 sid = current_sid();
5141
5142         isec = sma->sem_perm.security;
5143
5144         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5145         ad.u.ipc_id = sma->sem_perm.key;
5146
5147         return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5148                             SEM__ASSOCIATE, &ad);
5149 }
5150
5151 /* Note, at this point, sma is locked down */
5152 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5153 {
5154         int err;
5155         u32 perms;
5156
5157         switch (cmd) {
5158         case IPC_INFO:
5159         case SEM_INFO:
5160                 /* No specific object, just general system-wide information. */
5161                 return task_has_system(current, SYSTEM__IPC_INFO);
5162         case GETPID:
5163         case GETNCNT:
5164         case GETZCNT:
5165                 perms = SEM__GETATTR;
5166                 break;
5167         case GETVAL:
5168         case GETALL:
5169                 perms = SEM__READ;
5170                 break;
5171         case SETVAL:
5172         case SETALL:
5173                 perms = SEM__WRITE;
5174                 break;
5175         case IPC_RMID:
5176                 perms = SEM__DESTROY;
5177                 break;
5178         case IPC_SET:
5179                 perms = SEM__SETATTR;
5180                 break;
5181         case IPC_STAT:
5182         case SEM_STAT:
5183                 perms = SEM__GETATTR | SEM__ASSOCIATE;
5184                 break;
5185         default:
5186                 return 0;
5187         }
5188
5189         err = ipc_has_perm(&sma->sem_perm, perms);
5190         return err;
5191 }
5192
5193 static int selinux_sem_semop(struct sem_array *sma,
5194                              struct sembuf *sops, unsigned nsops, int alter)
5195 {
5196         u32 perms;
5197
5198         if (alter)
5199                 perms = SEM__READ | SEM__WRITE;
5200         else
5201                 perms = SEM__READ;
5202
5203         return ipc_has_perm(&sma->sem_perm, perms);
5204 }
5205
5206 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5207 {
5208         u32 av = 0;
5209
5210         av = 0;
5211         if (flag & S_IRUGO)
5212                 av |= IPC__UNIX_READ;
5213         if (flag & S_IWUGO)
5214                 av |= IPC__UNIX_WRITE;
5215
5216         if (av == 0)
5217                 return 0;
5218
5219         return ipc_has_perm(ipcp, av);
5220 }
5221
5222 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5223 {
5224         struct ipc_security_struct *isec = ipcp->security;
5225         *secid = isec->sid;
5226 }
5227
5228 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5229 {
5230         if (inode)
5231                 inode_doinit_with_dentry(inode, dentry);
5232 }
5233
5234 static int selinux_getprocattr(struct task_struct *p,
5235                                char *name, char **value)
5236 {
5237         const struct task_security_struct *__tsec;
5238         u32 sid;
5239         int error;
5240         unsigned len;
5241
5242         if (current != p) {
5243                 error = current_has_perm(p, PROCESS__GETATTR);
5244                 if (error)
5245                         return error;
5246         }
5247
5248         rcu_read_lock();
5249         __tsec = __task_cred(p)->security;
5250
5251         if (!strcmp(name, "current"))
5252                 sid = __tsec->sid;
5253         else if (!strcmp(name, "prev"))
5254                 sid = __tsec->osid;
5255         else if (!strcmp(name, "exec"))
5256                 sid = __tsec->exec_sid;
5257         else if (!strcmp(name, "fscreate"))
5258                 sid = __tsec->create_sid;
5259         else if (!strcmp(name, "keycreate"))
5260                 sid = __tsec->keycreate_sid;
5261         else if (!strcmp(name, "sockcreate"))
5262                 sid = __tsec->sockcreate_sid;
5263         else
5264                 goto invalid;
5265         rcu_read_unlock();
5266
5267         if (!sid)
5268                 return 0;
5269
5270         error = security_sid_to_context(sid, value, &len);
5271         if (error)
5272                 return error;
5273         return len;
5274
5275 invalid:
5276         rcu_read_unlock();
5277         return -EINVAL;
5278 }
5279
5280 static int selinux_setprocattr(struct task_struct *p,
5281                                char *name, void *value, size_t size)
5282 {
5283         struct task_security_struct *tsec;
5284         struct task_struct *tracer;
5285         struct cred *new;
5286         u32 sid = 0, ptsid;
5287         int error;
5288         char *str = value;
5289
5290         if (current != p) {
5291                 /* SELinux only allows a process to change its own
5292                    security attributes. */
5293                 return -EACCES;
5294         }
5295
5296         /*
5297          * Basic control over ability to set these attributes at all.
5298          * current == p, but we'll pass them separately in case the
5299          * above restriction is ever removed.
5300          */
5301         if (!strcmp(name, "exec"))
5302                 error = current_has_perm(p, PROCESS__SETEXEC);
5303         else if (!strcmp(name, "fscreate"))
5304                 error = current_has_perm(p, PROCESS__SETFSCREATE);
5305         else if (!strcmp(name, "keycreate"))
5306                 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5307         else if (!strcmp(name, "sockcreate"))
5308                 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5309         else if (!strcmp(name, "current"))
5310                 error = current_has_perm(p, PROCESS__SETCURRENT);
5311         else
5312                 error = -EINVAL;
5313         if (error)
5314                 return error;
5315
5316         /* Obtain a SID for the context, if one was specified. */
5317         if (size && str[1] && str[1] != '\n') {
5318                 if (str[size-1] == '\n') {
5319                         str[size-1] = 0;
5320                         size--;
5321                 }
5322                 error = security_context_to_sid(value, size, &sid);
5323                 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5324                         if (!capable(CAP_MAC_ADMIN))
5325                                 return error;
5326                         error = security_context_to_sid_force(value, size,
5327                                                               &sid);
5328                 }
5329                 if (error)
5330                         return error;
5331         }
5332
5333         new = prepare_creds();
5334         if (!new)
5335                 return -ENOMEM;
5336
5337         /* Permission checking based on the specified context is
5338            performed during the actual operation (execve,
5339            open/mkdir/...), when we know the full context of the
5340            operation.  See selinux_bprm_set_creds for the execve
5341            checks and may_create for the file creation checks. The
5342            operation will then fail if the context is not permitted. */
5343         tsec = new->security;
5344         if (!strcmp(name, "exec")) {
5345                 tsec->exec_sid = sid;
5346         } else if (!strcmp(name, "fscreate")) {
5347                 tsec->create_sid = sid;
5348         } else if (!strcmp(name, "keycreate")) {
5349                 error = may_create_key(sid, p);
5350                 if (error)
5351                         goto abort_change;
5352                 tsec->keycreate_sid = sid;
5353         } else if (!strcmp(name, "sockcreate")) {
5354                 tsec->sockcreate_sid = sid;
5355         } else if (!strcmp(name, "current")) {
5356                 error = -EINVAL;
5357                 if (sid == 0)
5358                         goto abort_change;
5359
5360                 /* Only allow single threaded processes to change context */
5361                 error = -EPERM;
5362                 if (!current_is_single_threaded()) {
5363                         error = security_bounded_transition(tsec->sid, sid);
5364                         if (error)
5365                                 goto abort_change;
5366                 }
5367
5368                 /* Check permissions for the transition. */
5369                 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5370                                      PROCESS__DYNTRANSITION, NULL);
5371                 if (error)
5372                         goto abort_change;
5373
5374                 /* Check for ptracing, and update the task SID if ok.
5375                    Otherwise, leave SID unchanged and fail. */
5376                 ptsid = 0;
5377                 rcu_read_lock();
5378                 tracer = ptrace_parent(p);
5379                 if (tracer)
5380                         ptsid = task_sid(tracer);
5381                 rcu_read_unlock();
5382
5383                 if (tracer) {
5384                         error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5385                                              PROCESS__PTRACE, NULL);
5386                         if (error)
5387                                 goto abort_change;
5388                 }
5389
5390                 tsec->sid = sid;
5391         } else {
5392                 error = -EINVAL;
5393                 goto abort_change;
5394         }
5395
5396         commit_creds(new);
5397         return size;
5398
5399 abort_change:
5400         abort_creds(new);
5401         return error;
5402 }
5403
5404 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5405 {
5406         return security_sid_to_context(secid, secdata, seclen);
5407 }
5408
5409 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5410 {
5411         return security_context_to_sid(secdata, seclen, secid);
5412 }
5413
5414 static void selinux_release_secctx(char *secdata, u32 seclen)
5415 {
5416         kfree(secdata);
5417 }
5418
5419 /*
5420  *      called with inode->i_mutex locked
5421  */
5422 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5423 {
5424         return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5425 }
5426
5427 /*
5428  *      called with inode->i_mutex locked
5429  */
5430 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5431 {
5432         return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5433 }
5434
5435 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5436 {
5437         int len = 0;
5438         len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5439                                                 ctx, true);
5440         if (len < 0)
5441                 return len;
5442         *ctxlen = len;
5443         return 0;
5444 }
5445 #ifdef CONFIG_KEYS
5446
5447 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5448                              unsigned long flags)
5449 {
5450         const struct task_security_struct *tsec;
5451         struct key_security_struct *ksec;
5452
5453         ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5454         if (!ksec)
5455                 return -ENOMEM;
5456
5457         tsec = cred->security;
5458         if (tsec->keycreate_sid)
5459                 ksec->sid = tsec->keycreate_sid;
5460         else
5461                 ksec->sid = tsec->sid;
5462
5463         k->security = ksec;
5464         return 0;
5465 }
5466
5467 static void selinux_key_free(struct key *k)
5468 {
5469         struct key_security_struct *ksec = k->security;
5470
5471         k->security = NULL;
5472         kfree(ksec);
5473 }
5474
5475 static int selinux_key_permission(key_ref_t key_ref,
5476                                   const struct cred *cred,
5477                                   key_perm_t perm)
5478 {
5479         struct key *key;
5480         struct key_security_struct *ksec;
5481         u32 sid;
5482
5483         /* if no specific permissions are requested, we skip the
5484            permission check. No serious, additional covert channels
5485            appear to be created. */
5486         if (perm == 0)
5487                 return 0;
5488
5489         sid = cred_sid(cred);
5490
5491         key = key_ref_to_ptr(key_ref);
5492         ksec = key->security;
5493
5494         return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5495 }
5496
5497 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5498 {
5499         struct key_security_struct *ksec = key->security;
5500         char *context = NULL;
5501         unsigned len;
5502         int rc;
5503
5504         rc = security_sid_to_context(ksec->sid, &context, &len);
5505         if (!rc)
5506                 rc = len;
5507         *_buffer = context;
5508         return rc;
5509 }
5510
5511 #endif
5512
5513 static struct security_operations selinux_ops = {
5514         .name =                         "selinux",
5515
5516         .ptrace_access_check =          selinux_ptrace_access_check,
5517         .ptrace_traceme =               selinux_ptrace_traceme,
5518         .capget =                       selinux_capget,
5519         .capset =                       selinux_capset,
5520         .capable =                      selinux_capable,
5521         .quotactl =                     selinux_quotactl,
5522         .quota_on =                     selinux_quota_on,
5523         .syslog =                       selinux_syslog,
5524         .vm_enough_memory =             selinux_vm_enough_memory,
5525
5526         .netlink_send =                 selinux_netlink_send,
5527         .netlink_recv =                 selinux_netlink_recv,
5528
5529         .bprm_set_creds =               selinux_bprm_set_creds,
5530         .bprm_committing_creds =        selinux_bprm_committing_creds,
5531         .bprm_committed_creds =         selinux_bprm_committed_creds,
5532         .bprm_secureexec =              selinux_bprm_secureexec,
5533
5534         .sb_alloc_security =            selinux_sb_alloc_security,
5535         .sb_free_security =             selinux_sb_free_security,
5536         .sb_copy_data =                 selinux_sb_copy_data,
5537         .sb_remount =                   selinux_sb_remount,
5538         .sb_kern_mount =                selinux_sb_kern_mount,
5539         .sb_show_options =              selinux_sb_show_options,
5540         .sb_statfs =                    selinux_sb_statfs,
5541         .sb_mount =                     selinux_mount,
5542         .sb_umount =                    selinux_umount,
5543         .sb_set_mnt_opts =              selinux_set_mnt_opts,
5544         .sb_clone_mnt_opts =            selinux_sb_clone_mnt_opts,
5545         .sb_parse_opts_str =            selinux_parse_opts_str,
5546
5547
5548         .inode_alloc_security =         selinux_inode_alloc_security,
5549         .inode_free_security =          selinux_inode_free_security,
5550         .inode_init_security =          selinux_inode_init_security,
5551         .inode_create =                 selinux_inode_create,
5552         .inode_link =                   selinux_inode_link,
5553         .inode_unlink =                 selinux_inode_unlink,
5554         .inode_symlink =                selinux_inode_symlink,
5555         .inode_mkdir =                  selinux_inode_mkdir,
5556         .inode_rmdir =                  selinux_inode_rmdir,
5557         .inode_mknod =                  selinux_inode_mknod,
5558         .inode_rename =                 selinux_inode_rename,
5559         .inode_readlink =               selinux_inode_readlink,
5560         .inode_follow_link =            selinux_inode_follow_link,
5561         .inode_permission =             selinux_inode_permission,
5562         .inode_setattr =                selinux_inode_setattr,
5563         .inode_getattr =                selinux_inode_getattr,
5564         .inode_setxattr =               selinux_inode_setxattr,
5565         .inode_post_setxattr =          selinux_inode_post_setxattr,
5566         .inode_getxattr =               selinux_inode_getxattr,
5567         .inode_listxattr =              selinux_inode_listxattr,
5568         .inode_removexattr =            selinux_inode_removexattr,
5569         .inode_getsecurity =            selinux_inode_getsecurity,
5570         .inode_setsecurity =            selinux_inode_setsecurity,
5571         .inode_listsecurity =           selinux_inode_listsecurity,
5572         .inode_getsecid =               selinux_inode_getsecid,
5573
5574         .file_permission =              selinux_file_permission,
5575         .file_alloc_security =          selinux_file_alloc_security,
5576         .file_free_security =           selinux_file_free_security,
5577         .file_ioctl =                   selinux_file_ioctl,
5578         .file_mmap =                    selinux_file_mmap,
5579         .file_mprotect =                selinux_file_mprotect,
5580         .file_lock =                    selinux_file_lock,
5581         .file_fcntl =                   selinux_file_fcntl,
5582         .file_set_fowner =              selinux_file_set_fowner,
5583         .file_send_sigiotask =          selinux_file_send_sigiotask,
5584         .file_receive =                 selinux_file_receive,
5585
5586         .dentry_open =                  selinux_dentry_open,
5587
5588         .task_create =                  selinux_task_create,
5589         .cred_alloc_blank =             selinux_cred_alloc_blank,
5590         .cred_free =                    selinux_cred_free,
5591         .cred_prepare =                 selinux_cred_prepare,
5592         .cred_transfer =                selinux_cred_transfer,
5593         .kernel_act_as =                selinux_kernel_act_as,
5594         .kernel_create_files_as =       selinux_kernel_create_files_as,
5595         .kernel_module_request =        selinux_kernel_module_request,
5596         .task_setpgid =                 selinux_task_setpgid,
5597         .task_getpgid =                 selinux_task_getpgid,
5598         .task_getsid =                  selinux_task_getsid,
5599         .task_getsecid =                selinux_task_getsecid,
5600         .task_setnice =                 selinux_task_setnice,
5601         .task_setioprio =               selinux_task_setioprio,
5602         .task_getioprio =               selinux_task_getioprio,
5603         .task_setrlimit =               selinux_task_setrlimit,
5604         .task_setscheduler =            selinux_task_setscheduler,
5605         .task_getscheduler =            selinux_task_getscheduler,
5606         .task_movememory =              selinux_task_movememory,
5607         .task_kill =                    selinux_task_kill,
5608         .task_wait =                    selinux_task_wait,
5609         .task_to_inode =                selinux_task_to_inode,
5610
5611         .ipc_permission =               selinux_ipc_permission,
5612         .ipc_getsecid =                 selinux_ipc_getsecid,
5613
5614         .msg_msg_alloc_security =       selinux_msg_msg_alloc_security,
5615         .msg_msg_free_security =        selinux_msg_msg_free_security,
5616
5617         .msg_queue_alloc_security =     selinux_msg_queue_alloc_security,
5618         .msg_queue_free_security =      selinux_msg_queue_free_security,
5619         .msg_queue_associate =          selinux_msg_queue_associate,
5620         .msg_queue_msgctl =             selinux_msg_queue_msgctl,
5621         .msg_queue_msgsnd =             selinux_msg_queue_msgsnd,
5622         .msg_queue_msgrcv =             selinux_msg_queue_msgrcv,
5623
5624         .shm_alloc_security =           selinux_shm_alloc_security,
5625         .shm_free_security =            selinux_shm_free_security,
5626         .shm_associate =                selinux_shm_associate,
5627         .shm_shmctl =                   selinux_shm_shmctl,
5628         .shm_shmat =                    selinux_shm_shmat,
5629
5630         .sem_alloc_security =           selinux_sem_alloc_security,
5631         .sem_free_security =            selinux_sem_free_security,
5632         .sem_associate =                selinux_sem_associate,
5633         .sem_semctl =                   selinux_sem_semctl,
5634         .sem_semop =                    selinux_sem_semop,
5635
5636         .d_instantiate =                selinux_d_instantiate,
5637
5638         .getprocattr =                  selinux_getprocattr,
5639         .setprocattr =                  selinux_setprocattr,
5640
5641         .secid_to_secctx =              selinux_secid_to_secctx,
5642         .secctx_to_secid =              selinux_secctx_to_secid,
5643         .release_secctx =               selinux_release_secctx,
5644         .inode_notifysecctx =           selinux_inode_notifysecctx,
5645         .inode_setsecctx =              selinux_inode_setsecctx,
5646         .inode_getsecctx =              selinux_inode_getsecctx,
5647
5648         .unix_stream_connect =          selinux_socket_unix_stream_connect,
5649         .unix_may_send =                selinux_socket_unix_may_send,
5650
5651         .socket_create =                selinux_socket_create,
5652         .socket_post_create =           selinux_socket_post_create,
5653         .socket_bind =                  selinux_socket_bind,
5654         .socket_connect =               selinux_socket_connect,
5655         .socket_listen =                selinux_socket_listen,
5656         .socket_accept =                selinux_socket_accept,
5657         .socket_sendmsg =               selinux_socket_sendmsg,
5658         .socket_recvmsg =               selinux_socket_recvmsg,
5659         .socket_getsockname =           selinux_socket_getsockname,
5660         .socket_getpeername =           selinux_socket_getpeername,
5661         .socket_getsockopt =            selinux_socket_getsockopt,
5662         .socket_setsockopt =            selinux_socket_setsockopt,
5663         .socket_shutdown =              selinux_socket_shutdown,
5664         .socket_sock_rcv_skb =          selinux_socket_sock_rcv_skb,
5665         .socket_getpeersec_stream =     selinux_socket_getpeersec_stream,
5666         .socket_getpeersec_dgram =      selinux_socket_getpeersec_dgram,
5667         .sk_alloc_security =            selinux_sk_alloc_security,
5668         .sk_free_security =             selinux_sk_free_security,
5669         .sk_clone_security =            selinux_sk_clone_security,
5670         .sk_getsecid =                  selinux_sk_getsecid,
5671         .sock_graft =                   selinux_sock_graft,
5672         .inet_conn_request =            selinux_inet_conn_request,
5673         .inet_csk_clone =               selinux_inet_csk_clone,
5674         .inet_conn_established =        selinux_inet_conn_established,
5675         .secmark_relabel_packet =       selinux_secmark_relabel_packet,
5676         .secmark_refcount_inc =         selinux_secmark_refcount_inc,
5677         .secmark_refcount_dec =         selinux_secmark_refcount_dec,
5678         .req_classify_flow =            selinux_req_classify_flow,
5679         .tun_dev_create =               selinux_tun_dev_create,
5680         .tun_dev_post_create =          selinux_tun_dev_post_create,
5681         .tun_dev_attach =               selinux_tun_dev_attach,
5682
5683 #ifdef CONFIG_SECURITY_NETWORK_XFRM
5684         .xfrm_policy_alloc_security =   selinux_xfrm_policy_alloc,
5685         .xfrm_policy_clone_security =   selinux_xfrm_policy_clone,
5686         .xfrm_policy_free_security =    selinux_xfrm_policy_free,
5687         .xfrm_policy_delete_security =  selinux_xfrm_policy_delete,
5688         .xfrm_state_alloc_security =    selinux_xfrm_state_alloc,
5689         .xfrm_state_free_security =     selinux_xfrm_state_free,
5690         .xfrm_state_delete_security =   selinux_xfrm_state_delete,
5691         .xfrm_policy_lookup =           selinux_xfrm_policy_lookup,
5692         .xfrm_state_pol_flow_match =    selinux_xfrm_state_pol_flow_match,
5693         .xfrm_decode_session =          selinux_xfrm_decode_session,
5694 #endif
5695
5696 #ifdef CONFIG_KEYS
5697         .key_alloc =                    selinux_key_alloc,
5698         .key_free =                     selinux_key_free,
5699         .key_permission =               selinux_key_permission,
5700         .key_getsecurity =              selinux_key_getsecurity,
5701 #endif
5702
5703 #ifdef CONFIG_AUDIT
5704         .audit_rule_init =              selinux_audit_rule_init,
5705         .audit_rule_known =             selinux_audit_rule_known,
5706         .audit_rule_match =             selinux_audit_rule_match,
5707         .audit_rule_free =              selinux_audit_rule_free,
5708 #endif
5709 };
5710
5711 static __init int selinux_init(void)
5712 {
5713         if (!security_module_enable(&selinux_ops)) {
5714                 selinux_enabled = 0;
5715                 return 0;
5716         }
5717
5718         if (!selinux_enabled) {
5719                 printk(KERN_INFO "SELinux:  Disabled at boot.\n");
5720                 return 0;
5721         }
5722
5723         printk(KERN_INFO "SELinux:  Initializing.\n");
5724
5725         /* Set the security state for the initial task. */
5726         cred_init_security();
5727
5728         default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
5729
5730         sel_inode_cache = kmem_cache_create("selinux_inode_security",
5731                                             sizeof(struct inode_security_struct),
5732                                             0, SLAB_PANIC, NULL);
5733         avc_init();
5734
5735         if (register_security(&selinux_ops))
5736                 panic("SELinux: Unable to register with kernel.\n");
5737
5738         if (selinux_enforcing)
5739                 printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
5740         else
5741                 printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
5742
5743         return 0;
5744 }
5745
5746 static void delayed_superblock_init(struct super_block *sb, void *unused)
5747 {
5748         superblock_doinit(sb, NULL);
5749 }
5750
5751 void selinux_complete_init(void)
5752 {
5753         printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
5754
5755         /* Set up any superblocks initialized prior to the policy load. */
5756         printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
5757         iterate_supers(delayed_superblock_init, NULL);
5758 }
5759
5760 /* SELinux requires early initialization in order to label
5761    all processes and objects when they are created. */
5762 security_initcall(selinux_init);
5763
5764 #if defined(CONFIG_NETFILTER)
5765
5766 static struct nf_hook_ops selinux_ipv4_ops[] = {
5767         {
5768                 .hook =         selinux_ipv4_postroute,
5769                 .owner =        THIS_MODULE,
5770                 .pf =           PF_INET,
5771                 .hooknum =      NF_INET_POST_ROUTING,
5772                 .priority =     NF_IP_PRI_SELINUX_LAST,
5773         },
5774         {
5775                 .hook =         selinux_ipv4_forward,
5776                 .owner =        THIS_MODULE,
5777                 .pf =           PF_INET,
5778                 .hooknum =      NF_INET_FORWARD,
5779                 .priority =     NF_IP_PRI_SELINUX_FIRST,
5780         },
5781         {
5782                 .hook =         selinux_ipv4_output,
5783                 .owner =        THIS_MODULE,
5784                 .pf =           PF_INET,
5785                 .hooknum =      NF_INET_LOCAL_OUT,
5786                 .priority =     NF_IP_PRI_SELINUX_FIRST,
5787         }
5788 };
5789
5790 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5791
5792 static struct nf_hook_ops selinux_ipv6_ops[] = {
5793         {
5794                 .hook =         selinux_ipv6_postroute,
5795                 .owner =        THIS_MODULE,
5796                 .pf =           PF_INET6,
5797                 .hooknum =      NF_INET_POST_ROUTING,
5798                 .priority =     NF_IP6_PRI_SELINUX_LAST,
5799         },
5800         {
5801                 .hook =         selinux_ipv6_forward,
5802                 .owner =        THIS_MODULE,
5803                 .pf =           PF_INET6,
5804                 .hooknum =      NF_INET_FORWARD,
5805                 .priority =     NF_IP6_PRI_SELINUX_FIRST,
5806         }
5807 };
5808
5809 #endif  /* IPV6 */
5810
5811 static int __init selinux_nf_ip_init(void)
5812 {
5813         int err = 0;
5814
5815         if (!selinux_enabled)
5816                 goto out;
5817
5818         printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");
5819
5820         err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5821         if (err)
5822                 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
5823
5824 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5825         err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5826         if (err)
5827                 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
5828 #endif  /* IPV6 */
5829
5830 out:
5831         return err;
5832 }
5833
5834 __initcall(selinux_nf_ip_init);
5835
5836 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5837 static void selinux_nf_ip_exit(void)
5838 {
5839         printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
5840
5841         nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5842 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5843         nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5844 #endif  /* IPV6 */
5845 }
5846 #endif
5847
5848 #else /* CONFIG_NETFILTER */
5849
5850 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5851 #define selinux_nf_ip_exit()
5852 #endif
5853
5854 #endif /* CONFIG_NETFILTER */
5855
5856 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5857 static int selinux_disabled;
5858
5859 int selinux_disable(void)
5860 {
5861         if (ss_initialized) {
5862                 /* Not permitted after initial policy load. */
5863                 return -EINVAL;
5864         }
5865
5866         if (selinux_disabled) {
5867                 /* Only do this once. */
5868                 return -EINVAL;
5869         }
5870
5871         printk(KERN_INFO "SELinux:  Disabled at runtime.\n");
5872
5873         selinux_disabled = 1;
5874         selinux_enabled = 0;
5875
5876         reset_security_ops();
5877
5878         /* Try to destroy the avc node cache */
5879         avc_disable();
5880
5881         /* Unregister netfilter hooks. */
5882         selinux_nf_ip_exit();
5883
5884         /* Unregister selinuxfs. */
5885         exit_sel_fs();
5886
5887         return 0;
5888 }
5889 #endif