security/tomoyo/domain.c

   1 /*
   2  * security/tomoyo/domain.c
   3  *
   4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
   5  */
   6
   7 #include "common.h"
   8 #include <linux/binfmts.h>
   9 #include <linux/slab.h>
  10
  11 /* Variables definitions.*/
  12
  13 /* The initial domain. */
  14 struct tomoyo_domain_info tomoyo_kernel_domain;
  15
  16 /**
  17  * tomoyo_update_policy - Update an entry for exception policy.
  18  *
  19  * @new_entry:       Pointer to "struct tomoyo_acl_info".
  20  * @size:            Size of @new_entry in bytes.
  21  * @param:           Pointer to "struct tomoyo_acl_param".
  22  * @check_duplicate: Callback function to find duplicated entry.
  23  *
  24  * Returns 0 on success, negative value otherwise.
  25  *
  26  * Caller holds tomoyo_read_lock().
  27  */
  28 int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
  29                          struct tomoyo_acl_param *param,
  30                          bool (*check_duplicate) (const struct tomoyo_acl_head
  31                                                   *,
  32                                                   const struct tomoyo_acl_head
  33                                                   *))
  34 {
  35         int error = param->is_delete ? -ENOENT : -ENOMEM;
  36         struct tomoyo_acl_head *entry;
  37         struct list_head *list = param->list;
  38
  39         if (mutex_lock_interruptible(&tomoyo_policy_lock))
  40                 return -ENOMEM;
  41         list_for_each_entry_rcu(entry, list, list) {
  42                 if (!check_duplicate(entry, new_entry))
  43                         continue;
  44                 entry->is_deleted = param->is_delete;
  45                 error = 0;
  46                 break;
  47         }
  48         if (error && !param->is_delete) {
  49                 entry = tomoyo_commit_ok(new_entry, size);
  50                 if (entry) {
  51                         list_add_tail_rcu(&entry->list, list);
  52                         error = 0;
  53                 }
  54         }
  55         mutex_unlock(&tomoyo_policy_lock);
  56         return error;
  57 }
  58
  59 /**
  60  * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry.
  61  *
  62  * @a: Pointer to "struct tomoyo_acl_info".
  63  * @b: Pointer to "struct tomoyo_acl_info".
  64  *
  65  * Returns true if @a == @b, false otherwise.
  66  */
  67 static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
  68                                         const struct tomoyo_acl_info *b)
  69 {
  70         return a->type == b->type && a->cond == b->cond;
  71 }
  72
  73 /**
  74  * tomoyo_update_domain - Update an entry for domain policy.
  75  *
  76  * @new_entry:       Pointer to "struct tomoyo_acl_info".
  77  * @size:            Size of @new_entry in bytes.
  78  * @param:           Pointer to "struct tomoyo_acl_param".
  79  * @check_duplicate: Callback function to find duplicated entry.
  80  * @merge_duplicate: Callback function to merge duplicated entry.
  81  *
  82  * Returns 0 on success, negative value otherwise.
  83  *
  84  * Caller holds tomoyo_read_lock().
  85  */
  86 int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
  87                          struct tomoyo_acl_param *param,
  88                          bool (*check_duplicate) (const struct tomoyo_acl_info
  89                                                   *,
  90                                                   const struct tomoyo_acl_info
  91                                                   *),
  92                          bool (*merge_duplicate) (struct tomoyo_acl_info *,
  93                                                   struct tomoyo_acl_info *,
  94                                                   const bool))
  95 {
  96         const bool is_delete = param->is_delete;
  97         int error = is_delete ? -ENOENT : -ENOMEM;
  98         struct tomoyo_acl_info *entry;
  99         struct list_head * const list = param->list;
 100
 101         if (param->data[0]) {
 102                 new_entry->cond = tomoyo_get_condition(param);
 103                 if (!new_entry->cond)
 104                         return -EINVAL;
 105         }
 106         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 107                 goto out;
 108         list_for_each_entry_rcu(entry, list, list) {
 109                 if (!tomoyo_same_acl_head(entry, new_entry) ||
 110                     !check_duplicate(entry, new_entry))
 111                         continue;
 112                 if (merge_duplicate)
 113                         entry->is_deleted = merge_duplicate(entry, new_entry,
 114                                                             is_delete);
 115                 else
 116                         entry->is_deleted = is_delete;
 117                 error = 0;
 118                 break;
 119         }
 120         if (error && !is_delete) {
 121                 entry = tomoyo_commit_ok(new_entry, size);
 122                 if (entry) {
 123                         list_add_tail_rcu(&entry->list, list);
 124                         error = 0;
 125                 }
 126         }
 127         mutex_unlock(&tomoyo_policy_lock);
 128 out:
 129         tomoyo_put_condition(new_entry->cond);
 130         return error;
 131 }
 132
 133 /**
 134  * tomoyo_check_acl - Do permission check.
 135  *
 136  * @r:           Pointer to "struct tomoyo_request_info".
 137  * @check_entry: Callback function to check type specific parameters.
 138  *
 139  * Returns 0 on success, negative value otherwise.
 140  *
 141  * Caller holds tomoyo_read_lock().
 142  */
 143 void tomoyo_check_acl(struct tomoyo_request_info *r,
 144                       bool (*check_entry) (struct tomoyo_request_info *,
 145                                            const struct tomoyo_acl_info *))
 146 {
 147         const struct tomoyo_domain_info *domain = r->domain;
 148         struct tomoyo_acl_info *ptr;
 149         bool retried = false;
 150         const struct list_head *list = &domain->acl_info_list;
 151
 152 retry:
 153         list_for_each_entry_rcu(ptr, list, list) {
 154                 if (ptr->is_deleted || ptr->type != r->param_type)
 155                         continue;
 156                 if (!check_entry(r, ptr))
 157                         continue;
 158                 if (!tomoyo_condition(r, ptr->cond))
 159                         continue;
 160                 r->granted = true;
 161                 return;
 162         }
 163         if (!retried) {
 164                 retried = true;
 165                 list = &domain->ns->acl_group[domain->group];
 166                 goto retry;
 167         }
 168         r->granted = false;
 169 }
 170
 171 /* The list for "struct tomoyo_domain_info". */
 172 LIST_HEAD(tomoyo_domain_list);
 173
 174 /**
 175  * tomoyo_last_word - Get last component of a domainname.
 176  *
 177  * @name: Domainname to check.
 178  *
 179  * Returns the last word of @domainname.
 180  */
 181 static const char *tomoyo_last_word(const char *name)
 182 {
 183         const char *cp = strrchr(name, ' ');
 184         if (cp)
 185                 return cp + 1;
 186         return name;
 187 }
 188
 189 /**
 190  * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
 191  *
 192  * @a: Pointer to "struct tomoyo_acl_head".
 193  * @b: Pointer to "struct tomoyo_acl_head".
 194  *
 195  * Returns true if @a == @b, false otherwise.
 196  */
 197 static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
 198                                            const struct tomoyo_acl_head *b)
 199 {
 200         const struct tomoyo_transition_control *p1 = container_of(a,
 201                                                                   typeof(*p1),
 202                                                                   head);
 203         const struct tomoyo_transition_control *p2 = container_of(b,
 204                                                                   typeof(*p2),
 205                                                                   head);
 206         return p1->type == p2->type && p1->is_last_name == p2->is_last_name
 207                 && p1->domainname == p2->domainname
 208                 && p1->program == p2->program;
 209 }
 210
 211 /**
 212  * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
 213  *
 214  * @param: Pointer to "struct tomoyo_acl_param".
 215  * @type:  Type of this entry.
 216  *
 217  * Returns 0 on success, negative value otherwise.
 218  */
 219 int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
 220                                     const u8 type)
 221 {
 222         struct tomoyo_transition_control e = { .type = type };
 223         int error = param->is_delete ? -ENOENT : -ENOMEM;
 224         char *program = param->data;
 225         char *domainname = strstr(program, " from ");
 226         if (domainname) {
 227                 *domainname = '\0';
 228                 domainname += 6;
 229         } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
 230                    type == TOMOYO_TRANSITION_CONTROL_KEEP) {
 231                 domainname = program;
 232                 program = NULL;
 233         }
 234         if (program && strcmp(program, "any")) {
 235                 if (!tomoyo_correct_path(program))
 236                         return -EINVAL;
 237                 e.program = tomoyo_get_name(program);
 238                 if (!e.program)
 239                         goto out;
 240         }
 241         if (domainname && strcmp(domainname, "any")) {
 242                 if (!tomoyo_correct_domain(domainname)) {
 243                         if (!tomoyo_correct_path(domainname))
 244                                 goto out;
 245                         e.is_last_name = true;
 246                 }
 247                 e.domainname = tomoyo_get_name(domainname);
 248                 if (!e.domainname)
 249                         goto out;
 250         }
 251         param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
 252         error = tomoyo_update_policy(&e.head, sizeof(e), param,
 253                                      tomoyo_same_transition_control);
 254 out:
 255         tomoyo_put_name(e.domainname);
 256         tomoyo_put_name(e.program);
 257         return error;
 258 }
 259
 260 /**
 261  * tomoyo_scan_transition - Try to find specific domain transition type.
 262  *
 263  * @list:       Pointer to "struct list_head".
 264  * @domainname: The name of current domain.
 265  * @program:    The name of requested program.
 266  * @last_name:  The last component of @domainname.
 267  * @type:       One of values in "enum tomoyo_transition_type".
 268  *
 269  * Returns true if found one, false otherwise.
 270  *
 271  * Caller holds tomoyo_read_lock().
 272  */
 273 static inline bool tomoyo_scan_transition
 274 (const struct list_head *list, const struct tomoyo_path_info *domainname,
 275  const struct tomoyo_path_info *program, const char *last_name,
 276  const enum tomoyo_transition_type type)
 277 {
 278         const struct tomoyo_transition_control *ptr;
 279         list_for_each_entry_rcu(ptr, list, head.list) {
 280                 if (ptr->head.is_deleted || ptr->type != type)
 281                         continue;
 282                 if (ptr->domainname) {
 283                         if (!ptr->is_last_name) {
 284                                 if (ptr->domainname != domainname)
 285                                         continue;
 286                         } else {
 287                                 /*
 288                                  * Use direct strcmp() since this is
 289                                  * unlikely used.
 290                                  */
 291                                 if (strcmp(ptr->domainname->name, last_name))
 292                                         continue;
 293                         }
 294                 }
 295                 if (ptr->program && tomoyo_pathcmp(ptr->program, program))
 296                         continue;
 297                 return true;
 298         }
 299         return false;
 300 }
 301
 302 /**
 303  * tomoyo_transition_type - Get domain transition type.
 304  *
 305  * @ns:         Pointer to "struct tomoyo_policy_namespace".
 306  * @domainname: The name of current domain.
 307  * @program:    The name of requested program.
 308  *
 309  * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
 310  * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
 311  * executing @program reinitializes domain transition within that namespace,
 312  * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
 313  * others otherwise.
 314  *
 315  * Caller holds tomoyo_read_lock().
 316  */
 317 static enum tomoyo_transition_type tomoyo_transition_type
 318 (const struct tomoyo_policy_namespace *ns,
 319  const struct tomoyo_path_info *domainname,
 320  const struct tomoyo_path_info *program)
 321 {
 322         const char *last_name = tomoyo_last_word(domainname->name);
 323         enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
 324         while (type < TOMOYO_MAX_TRANSITION_TYPE) {
 325                 const struct list_head * const list =
 326                         &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
 327                 if (!tomoyo_scan_transition(list, domainname, program,
 328                                             last_name, type)) {
 329                         type++;
 330                         continue;
 331                 }
 332                 if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
 333                     type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
 334                         break;
 335                 /*
 336                  * Do not check for reset_domain if no_reset_domain matched.
 337                  * Do not check for initialize_domain if no_initialize_domain
 338                  * matched.
 339                  */
 340                 type++;
 341                 type++;
 342         }
 343         return type;
 344 }
 345
 346 /**
 347  * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
 348  *
 349  * @a: Pointer to "struct tomoyo_acl_head".
 350  * @b: Pointer to "struct tomoyo_acl_head".
 351  *
 352  * Returns true if @a == @b, false otherwise.
 353  */
 354 static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
 355                                    const struct tomoyo_acl_head *b)
 356 {
 357         const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
 358                                                           head);
 359         const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
 360                                                           head);
 361         return p1->original_name == p2->original_name &&
 362                 p1->aggregated_name == p2->aggregated_name;
 363 }
 364
 365 /**
 366  * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
 367  *
 368  * @param: Pointer to "struct tomoyo_acl_param".
 369  *
 370  * Returns 0 on success, negative value otherwise.
 371  *
 372  * Caller holds tomoyo_read_lock().
 373  */
 374 int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
 375 {
 376         struct tomoyo_aggregator e = { };
 377         int error = param->is_delete ? -ENOENT : -ENOMEM;
 378         const char *original_name = tomoyo_read_token(param);
 379         const char *aggregated_name = tomoyo_read_token(param);
 380         if (!tomoyo_correct_word(original_name) ||
 381             !tomoyo_correct_path(aggregated_name))
 382                 return -EINVAL;
 383         e.original_name = tomoyo_get_name(original_name);
 384         e.aggregated_name = tomoyo_get_name(aggregated_name);
 385         if (!e.original_name || !e.aggregated_name ||
 386             e.aggregated_name->is_patterned) /* No patterns allowed. */
 387                 goto out;
 388         param->list = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
 389         error = tomoyo_update_policy(&e.head, sizeof(e), param,
 390                                      tomoyo_same_aggregator);
 391 out:
 392         tomoyo_put_name(e.original_name);
 393         tomoyo_put_name(e.aggregated_name);
 394         return error;
 395 }
 396
 397 /**
 398  * tomoyo_find_namespace - Find specified namespace.
 399  *
 400  * @name: Name of namespace to find.
 401  * @len:  Length of @name.
 402  *
 403  * Returns pointer to "struct tomoyo_policy_namespace" if found,
 404  * NULL otherwise.
 405  *
 406  * Caller holds tomoyo_read_lock().
 407  */
 408 static struct tomoyo_policy_namespace *tomoyo_find_namespace
 409 (const char *name, const unsigned int len)
 410 {
 411         struct tomoyo_policy_namespace *ns;
 412         list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
 413                 if (strncmp(name, ns->name, len) ||
 414                     (name[len] && name[len] != ' '))
 415                         continue;
 416                 return ns;
 417         }
 418         return NULL;
 419 }
 420
 421 /**
 422  * tomoyo_assign_namespace - Create a new namespace.
 423  *
 424  * @domainname: Name of namespace to create.
 425  *
 426  * Returns pointer to "struct tomoyo_policy_namespace" on success,
 427  * NULL otherwise.
 428  *
 429  * Caller holds tomoyo_read_lock().
 430  */
 431 struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
 432 {
 433         struct tomoyo_policy_namespace *ptr;
 434         struct tomoyo_policy_namespace *entry;
 435         const char *cp = domainname;
 436         unsigned int len = 0;
 437         while (*cp && *cp++ != ' ')
 438                 len++;
 439         ptr = tomoyo_find_namespace(domainname, len);
 440         if (ptr)
 441                 return ptr;
 442         if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
 443                 return NULL;
 444         entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS);
 445         if (!entry)
 446                 return NULL;
 447         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 448                 goto out;
 449         ptr = tomoyo_find_namespace(domainname, len);
 450         if (!ptr && tomoyo_memory_ok(entry)) {
 451                 char *name = (char *) (entry + 1);
 452                 ptr = entry;
 453                 memmove(name, domainname, len);
 454                 name[len] = '\0';
 455                 entry->name = name;
 456                 tomoyo_init_policy_namespace(entry);
 457                 entry = NULL;
 458         }
 459         mutex_unlock(&tomoyo_policy_lock);
 460 out:
 461         kfree(entry);
 462         return ptr;
 463 }
 464
 465 /**
 466  * tomoyo_namespace_jump - Check for namespace jump.
 467  *
 468  * @domainname: Name of domain.
 469  *
 470  * Returns true if namespace differs, false otherwise.
 471  */
 472 static bool tomoyo_namespace_jump(const char *domainname)
 473 {
 474         const char *namespace = tomoyo_current_namespace()->name;
 475         const int len = strlen(namespace);
 476         return strncmp(domainname, namespace, len) ||
 477                 (domainname[len] && domainname[len] != ' ');
 478 }
 479
 480 /**
 481  * tomoyo_assign_domain - Create a domain or a namespace.
 482  *
 483  * @domainname: The name of domain.
 484  * @transit:    True if transit to domain found or created.
 485  *
 486  * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
 487  *
 488  * Caller holds tomoyo_read_lock().
 489  */
 490 struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
 491                                                 const bool transit)
 492 {
 493         struct tomoyo_domain_info e = { };
 494         struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
 495         bool created = false;
 496         if (entry) {
 497                 if (transit) {
 498                         /*
 499                          * Since namespace is created at runtime, profiles may
 500                          * not be created by the moment the process transits to
 501                          * that domain. Do not perform domain transition if
 502                          * profile for that domain is not yet created.
 503                          */
 504                         if (!entry->ns->profile_ptr[entry->profile])
 505                                 return NULL;
 506                 }
 507                 return entry;
 508         }
 509         /* Requested domain does not exist. */
 510         /* Don't create requested domain if domainname is invalid. */
 511         if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
 512             !tomoyo_correct_domain(domainname))
 513                 return NULL;
 514         /*
 515          * Since definition of profiles and acl_groups may differ across
 516          * namespaces, do not inherit "use_profile" and "use_group" settings
 517          * by automatically creating requested domain upon domain transition.
 518          */
 519         if (transit && tomoyo_namespace_jump(domainname))
 520                 return NULL;
 521         e.ns = tomoyo_assign_namespace(domainname);
 522         if (!e.ns)
 523                 return NULL;
 524         /*
 525          * "use_profile" and "use_group" settings for automatically created
 526          * domains are inherited from current domain. These are 0 for manually
 527          * created domains.
 528          */
 529         if (transit) {
 530                 const struct tomoyo_domain_info *domain = tomoyo_domain();
 531                 e.profile = domain->profile;
 532                 e.group = domain->group;
 533         }
 534         e.domainname = tomoyo_get_name(domainname);
 535         if (!e.domainname)
 536                 return NULL;
 537         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 538                 goto out;
 539         entry = tomoyo_find_domain(domainname);
 540         if (!entry) {
 541                 entry = tomoyo_commit_ok(&e, sizeof(e));
 542                 if (entry) {
 543                         INIT_LIST_HEAD(&entry->acl_info_list);
 544                         list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
 545                         created = true;
 546                 }
 547         }
 548         mutex_unlock(&tomoyo_policy_lock);
 549 out:
 550         tomoyo_put_name(e.domainname);
 551         if (entry && transit) {
 552                 if (created) {
 553                         struct tomoyo_request_info r;
 554                         tomoyo_init_request_info(&r, entry,
 555                                                  TOMOYO_MAC_FILE_EXECUTE);
 556                         r.granted = false;
 557                         tomoyo_write_log(&r, "use_profile %u\n",
 558                                          entry->profile);
 559                         tomoyo_write_log(&r, "use_group %u\n", entry->group);
 560                 }
 561         }
 562         return entry;
 563 }
 564
 565 /**
 566  * tomoyo_find_next_domain - Find a domain.
 567  *
 568  * @bprm: Pointer to "struct linux_binprm".
 569  *
 570  * Returns 0 on success, negative value otherwise.
 571  *
 572  * Caller holds tomoyo_read_lock().
 573  */
 574 int tomoyo_find_next_domain(struct linux_binprm *bprm)
 575 {
 576         struct tomoyo_domain_info *old_domain = tomoyo_domain();
 577         struct tomoyo_domain_info *domain = NULL;
 578         const char *original_name = bprm->filename;
 579         int retval = -ENOMEM;
 580         bool need_kfree = false;
 581         bool reject_on_transition_failure = false;
 582         struct tomoyo_path_info rn = { }; /* real name */
 583         struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
 584         if (!ee)
 585                 return -ENOMEM;
 586         ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
 587         if (!ee->tmp) {
 588                 kfree(ee);
 589                 return -ENOMEM;
 590         }
 591         /* ee->dump->data is allocated by tomoyo_dump_page(). */
 592         tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
 593         ee->r.ee = ee;
 594         ee->bprm = bprm;
 595         ee->r.obj = &ee->obj;
 596         ee->obj.path1 = bprm->file->f_path;
 597  retry:
 598         if (need_kfree) {
 599                 kfree(rn.name);
 600                 need_kfree = false;
 601         }
 602         /* Get symlink's pathname of program. */
 603         retval = -ENOENT;
 604         rn.name = tomoyo_realpath_nofollow(original_name);
 605         if (!rn.name)
 606                 goto out;
 607         tomoyo_fill_path_info(&rn);
 608         need_kfree = true;
 609
 610         /* Check 'aggregator' directive. */
 611         {
 612                 struct tomoyo_aggregator *ptr;
 613                 struct list_head *list =
 614                         &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
 615                 /* Check 'aggregator' directive. */
 616                 list_for_each_entry_rcu(ptr, list, head.list) {
 617                         if (ptr->head.is_deleted ||
 618                             !tomoyo_path_matches_pattern(&rn,
 619                                                          ptr->original_name))
 620                                 continue;
 621                         kfree(rn.name);
 622                         need_kfree = false;
 623                         /* This is OK because it is read only. */
 624                         rn = *ptr->aggregated_name;
 625                         break;
 626                 }
 627         }
 628
 629         /* Check execute permission. */
 630         retval = tomoyo_path_permission(&ee->r, TOMOYO_TYPE_EXECUTE, &rn);
 631         if (retval == TOMOYO_RETRY_REQUEST)
 632                 goto retry;
 633         if (retval < 0)
 634                 goto out;
 635         /*
 636          * To be able to specify domainnames with wildcards, use the
 637          * pathname specified in the policy (which may contain
 638          * wildcard) rather than the pathname passed to execve()
 639          * (which never contains wildcard).
 640          */
 641         if (ee->r.param.path.matched_path) {
 642                 if (need_kfree)
 643                         kfree(rn.name);
 644                 need_kfree = false;
 645                 /* This is OK because it is read only. */
 646                 rn = *ee->r.param.path.matched_path;
 647         }
 648
 649         /* Calculate domain to transit to. */
 650         switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
 651                                        &rn)) {
 652         case TOMOYO_TRANSITION_CONTROL_RESET:
 653                 /* Transit to the root of specified namespace. */
 654                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>", rn.name);
 655                 /*
 656                  * Make do_execve() fail if domain transition across namespaces
 657                  * has failed.
 658                  */
 659                 reject_on_transition_failure = true;
 660                 break;
 661         case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
 662                 /* Transit to the child of current namespace's root. */
 663                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
 664                          old_domain->ns->name, rn.name);
 665                 break;
 666         case TOMOYO_TRANSITION_CONTROL_KEEP:
 667                 /* Keep current domain. */
 668                 domain = old_domain;
 669                 break;
 670         default:
 671                 if (old_domain == &tomoyo_kernel_domain &&
 672                     !tomoyo_policy_loaded) {
 673                         /*
 674                          * Needn't to transit from kernel domain before
 675                          * starting /sbin/init. But transit from kernel domain
 676                          * if executing initializers because they might start
 677                          * before /sbin/init.
 678                          */
 679                         domain = old_domain;
 680                 } else {
 681                         /* Normal domain transition. */
 682                         snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
 683                                  old_domain->domainname->name, rn.name);
 684                 }
 685                 break;
 686         }
 687         if (!domain)
 688                 domain = tomoyo_assign_domain(ee->tmp, true);
 689         if (domain)
 690                 retval = 0;
 691         else if (reject_on_transition_failure) {
 692                 printk(KERN_WARNING "ERROR: Domain '%s' not ready.\n",
 693                        ee->tmp);
 694                 retval = -ENOMEM;
 695         } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
 696                 retval = -ENOMEM;
 697         else {
 698                 retval = 0;
 699                 if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
 700                         old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
 701                         ee->r.granted = false;
 702                         tomoyo_write_log(&ee->r, "%s", tomoyo_dif
 703                                          [TOMOYO_DIF_TRANSITION_FAILED]);
 704                         printk(KERN_WARNING
 705                                "ERROR: Domain '%s' not defined.\n", ee->tmp);
 706                 }
 707         }
 708  out:
 709         if (!domain)
 710                 domain = old_domain;
 711         /* Update reference count on "struct tomoyo_domain_info". */
 712         atomic_inc(&domain->users);
 713         bprm->cred->security = domain;
 714         if (need_kfree)
 715                 kfree(rn.name);
 716         kfree(ee->tmp);
 717         kfree(ee->dump.data);
 718         kfree(ee);
 719         return retval;
 720 }
 721
 722 /**
 723  * tomoyo_dump_page - Dump a page to buffer.
 724  *
 725  * @bprm: Pointer to "struct linux_binprm".
 726  * @pos:  Location to dump.
 727  * @dump: Poiner to "struct tomoyo_page_dump".
 728  *
 729  * Returns true on success, false otherwise.
 730  */
 731 bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
 732                       struct tomoyo_page_dump *dump)
 733 {
 734         struct page *page;
 735         /* dump->data is released by tomoyo_finish_execve(). */
 736         if (!dump->data) {
 737                 dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
 738                 if (!dump->data)
 739                         return false;
 740         }
 741         /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
 742 #ifdef CONFIG_MMU
 743         if (get_user_pages(current, bprm->mm, pos, 1, 0, 1, &page, NULL) <= 0)
 744                 return false;
 745 #else
 746         page = bprm->page[pos / PAGE_SIZE];
 747 #endif
 748         if (page != dump->page) {
 749                 const unsigned int offset = pos % PAGE_SIZE;
 750                 /*
 751                  * Maybe kmap()/kunmap() should be used here.
 752                  * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
 753                  * So do I.
 754                  */
 755                 char *kaddr = kmap_atomic(page, KM_USER0);
 756                 dump->page = page;
 757                 memcpy(dump->data + offset, kaddr + offset,
 758                        PAGE_SIZE - offset);
 759                 kunmap_atomic(kaddr, KM_USER0);
 760         }
 761         /* Same with put_arg_page(page) in fs/exec.c */
 762 #ifdef CONFIG_MMU
 763         put_page(page);
 764 #endif
 765         return true;
 766 }