1 /* Common capabilities, needed by capability.o.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
10 #include <linux/capability.h>
11 #include <linux/audit.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/security.h>
16 #include <linux/file.h>
18 #include <linux/mman.h>
19 #include <linux/pagemap.h>
20 #include <linux/swap.h>
21 #include <linux/skbuff.h>
22 #include <linux/netlink.h>
23 #include <linux/ptrace.h>
24 #include <linux/xattr.h>
25 #include <linux/hugetlb.h>
26 #include <linux/mount.h>
27 #include <linux/sched.h>
28 #include <linux/prctl.h>
29 #include <linux/securebits.h>
30 #include <linux/user_namespace.h>
31 #include <linux/personality.h>
34 * If a non-root user executes a setuid-root binary in
35 * !secure(SECURE_NOROOT) mode, then we raise capabilities.
36 * However if fE is also set, then the intent is for only
37 * the file capabilities to be applied, and the setuid-root
38 * bit is left on either to change the uid (plausible) or
39 * to get full privilege on a kernel without file capabilities
40 * support. So in that case we do not raise capabilities.
42 * Warn if that happens, once per boot.
44 static void warn_setuid_and_fcaps_mixed(const char *fname)
48 printk(KERN_INFO "warning: `%s' has both setuid-root and"
49 " effective capabilities. Therefore not raising all"
50 " capabilities.\n", fname);
55 int cap_netlink_send(struct sock *sk, struct sk_buff *skb)
60 int cap_netlink_recv(struct sk_buff *skb, int cap)
62 if (!cap_raised(current_cap(), cap))
66 EXPORT_SYMBOL(cap_netlink_recv);
69 * cap_capable - Determine whether a task has a particular effective capability
70 * @tsk: The task to query
71 * @cred: The credentials to use
72 * @ns: The user namespace in which we need the capability
73 * @cap: The capability to check for
74 * @audit: Whether to write an audit message or not
76 * Determine whether the nominated task has the specified capability amongst
77 * its effective set, returning 0 if it does, -ve if it does not.
79 * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable()
80 * and has_capability() functions. That is, it has the reverse semantics:
81 * cap_has_capability() returns 0 when a task has a capability, but the
82 * kernel's capable() and has_capability() returns 1 for this case.
84 int cap_capable(struct task_struct *tsk, const struct cred *cred,
85 struct user_namespace *targ_ns, int cap, int audit)
88 /* The creator of the user namespace has all caps. */
89 if (targ_ns != &init_user_ns && targ_ns->creator == cred->user)
92 /* Do we have the necessary capabilities? */
93 if (targ_ns == cred->user->user_ns)
94 return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;
96 /* Have we tried all of the parent namespaces? */
97 if (targ_ns == &init_user_ns)
101 *If you have a capability in a parent user ns, then you have
102 * it over all children user namespaces as well.
104 targ_ns = targ_ns->creator->user_ns;
107 /* We never get here */
111 * cap_settime - Determine whether the current process may set the system clock
112 * @ts: The time to set
113 * @tz: The timezone to set
115 * Determine whether the current process may set the system clock and timezone
116 * information, returning 0 if permission granted, -ve if denied.
118 int cap_settime(const struct timespec *ts, const struct timezone *tz)
120 if (!capable(CAP_SYS_TIME))
126 * cap_ptrace_access_check - Determine whether the current process may access
128 * @child: The process to be accessed
129 * @mode: The mode of attachment.
131 * If we are in the same or an ancestor user_ns and have all the target
132 * task's capabilities, then ptrace access is allowed.
133 * If we have the ptrace capability to the target user_ns, then ptrace
137 * Determine whether a process may access another, returning 0 if permission
138 * granted, -ve if denied.
140 int cap_ptrace_access_check(struct task_struct *child, unsigned int mode)
143 const struct cred *cred, *child_cred;
144 const kernel_cap_t *caller_caps;
147 cred = current_cred();
148 child_cred = __task_cred(child);
149 if (mode & PTRACE_MODE_FSCREDS)
150 caller_caps = &cred->cap_effective;
152 caller_caps = &cred->cap_permitted;
153 if (cred->user->user_ns == child_cred->user->user_ns &&
154 cap_issubset(child_cred->cap_permitted, *caller_caps))
156 if (ns_capable(child_cred->user->user_ns, CAP_SYS_PTRACE))
165 * cap_ptrace_traceme - Determine whether another process may trace the current
166 * @parent: The task proposed to be the tracer
168 * If parent is in the same or an ancestor user_ns and has all current's
169 * capabilities, then ptrace access is allowed.
170 * If parent has the ptrace capability to current's user_ns, then ptrace
174 * Determine whether the nominated task is permitted to trace the current
175 * process, returning 0 if permission is granted, -ve if denied.
177 int cap_ptrace_traceme(struct task_struct *parent)
180 const struct cred *cred, *child_cred;
183 cred = __task_cred(parent);
184 child_cred = current_cred();
185 if (cred->user->user_ns == child_cred->user->user_ns &&
186 cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
188 if (has_ns_capability(parent, child_cred->user->user_ns, CAP_SYS_PTRACE))
197 * cap_capget - Retrieve a task's capability sets
198 * @target: The task from which to retrieve the capability sets
199 * @effective: The place to record the effective set
200 * @inheritable: The place to record the inheritable set
201 * @permitted: The place to record the permitted set
203 * This function retrieves the capabilities of the nominated task and returns
204 * them to the caller.
206 int cap_capget(struct task_struct *target, kernel_cap_t *effective,
207 kernel_cap_t *inheritable, kernel_cap_t *permitted)
209 const struct cred *cred;
211 /* Derived from kernel/capability.c:sys_capget. */
213 cred = __task_cred(target);
214 *effective = cred->cap_effective;
215 *inheritable = cred->cap_inheritable;
216 *permitted = cred->cap_permitted;
222 * Determine whether the inheritable capabilities are limited to the old
223 * permitted set. Returns 1 if they are limited, 0 if they are not.
225 static inline int cap_inh_is_capped(void)
228 /* they are so limited unless the current task has the CAP_SETPCAP
231 if (cap_capable(current, current_cred(),
232 current_cred()->user->user_ns, CAP_SETPCAP,
233 SECURITY_CAP_AUDIT) == 0)
239 * cap_capset - Validate and apply proposed changes to current's capabilities
240 * @new: The proposed new credentials; alterations should be made here
241 * @old: The current task's current credentials
242 * @effective: A pointer to the proposed new effective capabilities set
243 * @inheritable: A pointer to the proposed new inheritable capabilities set
244 * @permitted: A pointer to the proposed new permitted capabilities set
246 * This function validates and applies a proposed mass change to the current
247 * process's capability sets. The changes are made to the proposed new
248 * credentials, and assuming no error, will be committed by the caller of LSM.
250 int cap_capset(struct cred *new,
251 const struct cred *old,
252 const kernel_cap_t *effective,
253 const kernel_cap_t *inheritable,
254 const kernel_cap_t *permitted)
256 if (cap_inh_is_capped() &&
257 !cap_issubset(*inheritable,
258 cap_combine(old->cap_inheritable,
259 old->cap_permitted)))
260 /* incapable of using this inheritable set */
263 if (!cap_issubset(*inheritable,
264 cap_combine(old->cap_inheritable,
266 /* no new pI capabilities outside bounding set */
269 /* verify restrictions on target's new Permitted set */
270 if (!cap_issubset(*permitted, old->cap_permitted))
273 /* verify the _new_Effective_ is a subset of the _new_Permitted_ */
274 if (!cap_issubset(*effective, *permitted))
277 new->cap_effective = *effective;
278 new->cap_inheritable = *inheritable;
279 new->cap_permitted = *permitted;
284 * Clear proposed capability sets for execve().
286 static inline void bprm_clear_caps(struct linux_binprm *bprm)
288 cap_clear(bprm->cred->cap_permitted);
289 bprm->cap_effective = false;
293 * cap_inode_need_killpriv - Determine if inode change affects privileges
294 * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV
296 * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV
297 * affects the security markings on that inode, and if it is, should
298 * inode_killpriv() be invoked or the change rejected?
300 * Returns 0 if granted; +ve if granted, but inode_killpriv() is required; and
301 * -ve to deny the change.
303 int cap_inode_need_killpriv(struct dentry *dentry)
305 struct inode *inode = dentry->d_inode;
308 if (!inode->i_op->getxattr)
311 error = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0);
318 * cap_inode_killpriv - Erase the security markings on an inode
319 * @dentry: The inode/dentry to alter
321 * Erase the privilege-enhancing security markings on an inode.
323 * Returns 0 if successful, -ve on error.
325 int cap_inode_killpriv(struct dentry *dentry)
327 struct inode *inode = dentry->d_inode;
329 if (!inode->i_op->removexattr)
332 return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
336 * Calculate the new process capability sets from the capability sets attached
339 static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
340 struct linux_binprm *bprm,
344 struct cred *new = bprm->cred;
348 if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE)
351 if (caps->magic_etc & VFS_CAP_REVISION_MASK)
354 CAP_FOR_EACH_U32(i) {
355 __u32 permitted = caps->permitted.cap[i];
356 __u32 inheritable = caps->inheritable.cap[i];
359 * pP' = (X & fP) | (pI & fI)
361 new->cap_permitted.cap[i] =
362 (new->cap_bset.cap[i] & permitted) |
363 (new->cap_inheritable.cap[i] & inheritable);
365 if (permitted & ~new->cap_permitted.cap[i])
366 /* insufficient to execute correctly */
371 * For legacy apps, with no internal support for recognizing they
372 * do not have enough capabilities, we return an error if they are
373 * missing some "forced" (aka file-permitted) capabilities.
375 return *effective ? ret : 0;
379 * Extract the on-exec-apply capability sets for an executable file.
381 int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps)
383 struct inode *inode = dentry->d_inode;
387 struct vfs_cap_data caps;
389 memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data));
391 if (!inode || !inode->i_op->getxattr)
394 size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps,
396 if (size == -ENODATA || size == -EOPNOTSUPP)
397 /* no data, that's ok */
402 if (size < sizeof(magic_etc))
405 cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc);
407 switch (magic_etc & VFS_CAP_REVISION_MASK) {
408 case VFS_CAP_REVISION_1:
409 if (size != XATTR_CAPS_SZ_1)
411 tocopy = VFS_CAP_U32_1;
413 case VFS_CAP_REVISION_2:
414 if (size != XATTR_CAPS_SZ_2)
416 tocopy = VFS_CAP_U32_2;
422 CAP_FOR_EACH_U32(i) {
425 cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted);
426 cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable);
433 * Attempt to get the on-exec apply capability sets for an executable file from
434 * its xattrs and, if present, apply them to the proposed credentials being
435 * constructed by execve().
437 static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_cap)
439 struct dentry *dentry;
441 struct cpu_vfs_cap_data vcaps;
443 bprm_clear_caps(bprm);
445 if (!file_caps_enabled)
448 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
451 dentry = dget(bprm->file->f_dentry);
453 rc = get_vfs_caps_from_disk(dentry, &vcaps);
456 printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n",
457 __func__, rc, bprm->filename);
458 else if (rc == -ENODATA)
463 rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective, has_cap);
465 printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n",
466 __func__, rc, bprm->filename);
471 bprm_clear_caps(bprm);
477 * cap_bprm_set_creds - Set up the proposed credentials for execve().
478 * @bprm: The execution parameters, including the proposed creds
480 * Set up the proposed credentials for a new execution context being
481 * constructed by execve(). The proposed creds in @bprm->cred is altered,
482 * which won't take effect immediately. Returns 0 if successful, -ve on error.
484 int cap_bprm_set_creds(struct linux_binprm *bprm)
486 const struct cred *old = current_cred();
487 struct cred *new = bprm->cred;
488 bool effective, has_cap = false;
492 ret = get_file_caps(bprm, &effective, &has_cap);
496 if (!issecure(SECURE_NOROOT)) {
498 * If the legacy file capability is set, then don't set privs
499 * for a setuid root binary run by a non-root user. Do set it
500 * for a root user just to cause least surprise to an admin.
502 if (has_cap && new->uid != 0 && new->euid == 0) {
503 warn_setuid_and_fcaps_mixed(bprm->filename);
507 * To support inheritance of root-permissions and suid-root
508 * executables under compatibility mode, we override the
509 * capability sets for the file.
511 * If only the real uid is 0, we do not set the effective bit.
513 if (new->euid == 0 || new->uid == 0) {
514 /* pP' = (cap_bset & ~0) | (pI & ~0) */
515 new->cap_permitted = cap_combine(old->cap_bset,
516 old->cap_inheritable);
523 /* if we have fs caps, clear dangerous personality flags */
524 if (!cap_issubset(new->cap_permitted, old->cap_permitted))
525 bprm->per_clear |= PER_CLEAR_ON_SETID;
528 /* Don't let someone trace a set[ug]id/setpcap binary with the revised
529 * credentials unless they have the appropriate permit
531 if ((new->euid != old->uid ||
532 new->egid != old->gid ||
533 !cap_issubset(new->cap_permitted, old->cap_permitted)) &&
534 bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
535 /* downgrade; they get no more than they had, and maybe less */
536 if (!capable(CAP_SETUID)) {
537 new->euid = new->uid;
538 new->egid = new->gid;
540 new->cap_permitted = cap_intersect(new->cap_permitted,
544 new->suid = new->fsuid = new->euid;
545 new->sgid = new->fsgid = new->egid;
548 new->cap_effective = new->cap_permitted;
550 cap_clear(new->cap_effective);
551 bprm->cap_effective = effective;
554 * Audit candidate if current->cap_effective is set
556 * We do not bother to audit if 3 things are true:
557 * 1) cap_effective has all caps
559 * 3) root is supposed to have all caps (SECURE_NOROOT)
560 * Since this is just a normal root execing a process.
562 * Number 1 above might fail if you don't have a full bset, but I think
563 * that is interesting information to audit.
565 if (!cap_isclear(new->cap_effective)) {
566 if (!cap_issubset(CAP_FULL_SET, new->cap_effective) ||
567 new->euid != 0 || new->uid != 0 ||
568 issecure(SECURE_NOROOT)) {
569 ret = audit_log_bprm_fcaps(bprm, new, old);
575 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
580 * cap_bprm_secureexec - Determine whether a secure execution is required
581 * @bprm: The execution parameters
583 * Determine whether a secure execution is required, return 1 if it is, and 0
586 * The credentials have been committed by this point, and so are no longer
587 * available through @bprm->cred.
589 int cap_bprm_secureexec(struct linux_binprm *bprm)
591 const struct cred *cred = current_cred();
593 if (cred->uid != 0) {
594 if (bprm->cap_effective)
596 if (!cap_isclear(cred->cap_permitted))
600 return (cred->euid != cred->uid ||
601 cred->egid != cred->gid);
605 * cap_inode_setxattr - Determine whether an xattr may be altered
606 * @dentry: The inode/dentry being altered
607 * @name: The name of the xattr to be changed
608 * @value: The value that the xattr will be changed to
609 * @size: The size of value
610 * @flags: The replacement flag
612 * Determine whether an xattr may be altered or set on an inode, returning 0 if
613 * permission is granted, -ve if denied.
615 * This is used to make sure security xattrs don't get updated or set by those
616 * who aren't privileged to do so.
618 int cap_inode_setxattr(struct dentry *dentry, const char *name,
619 const void *value, size_t size, int flags)
621 if (!strcmp(name, XATTR_NAME_CAPS)) {
622 if (!capable(CAP_SETFCAP))
627 if (!strncmp(name, XATTR_SECURITY_PREFIX,
628 sizeof(XATTR_SECURITY_PREFIX) - 1) &&
629 !capable(CAP_SYS_ADMIN))
635 * cap_inode_removexattr - Determine whether an xattr may be removed
636 * @dentry: The inode/dentry being altered
637 * @name: The name of the xattr to be changed
639 * Determine whether an xattr may be removed from an inode, returning 0 if
640 * permission is granted, -ve if denied.
642 * This is used to make sure security xattrs don't get removed by those who
643 * aren't privileged to remove them.
645 int cap_inode_removexattr(struct dentry *dentry, const char *name)
647 if (!strcmp(name, XATTR_NAME_CAPS)) {
648 if (!capable(CAP_SETFCAP))
653 if (!strncmp(name, XATTR_SECURITY_PREFIX,
654 sizeof(XATTR_SECURITY_PREFIX) - 1) &&
655 !capable(CAP_SYS_ADMIN))
661 * cap_emulate_setxuid() fixes the effective / permitted capabilities of
662 * a process after a call to setuid, setreuid, or setresuid.
664 * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
665 * {r,e,s}uid != 0, the permitted and effective capabilities are
668 * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
669 * capabilities of the process are cleared.
671 * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
672 * capabilities are set to the permitted capabilities.
674 * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should
679 * cevans - New behaviour, Oct '99
680 * A process may, via prctl(), elect to keep its capabilities when it
681 * calls setuid() and switches away from uid==0. Both permitted and
682 * effective sets will be retained.
683 * Without this change, it was impossible for a daemon to drop only some
684 * of its privilege. The call to setuid(!=0) would drop all privileges!
685 * Keeping uid 0 is not an option because uid 0 owns too many vital
687 * Thanks to Olaf Kirch and Peter Benie for spotting this.
689 static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old)
691 if ((old->uid == 0 || old->euid == 0 || old->suid == 0) &&
692 (new->uid != 0 && new->euid != 0 && new->suid != 0) &&
693 !issecure(SECURE_KEEP_CAPS)) {
694 cap_clear(new->cap_permitted);
695 cap_clear(new->cap_effective);
697 if (old->euid == 0 && new->euid != 0)
698 cap_clear(new->cap_effective);
699 if (old->euid != 0 && new->euid == 0)
700 new->cap_effective = new->cap_permitted;
704 * cap_task_fix_setuid - Fix up the results of setuid() call
705 * @new: The proposed credentials
706 * @old: The current task's current credentials
707 * @flags: Indications of what has changed
709 * Fix up the results of setuid() call before the credential changes are
710 * actually applied, returning 0 to grant the changes, -ve to deny them.
712 int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
718 /* juggle the capabilities to follow [RES]UID changes unless
719 * otherwise suppressed */
720 if (!issecure(SECURE_NO_SETUID_FIXUP))
721 cap_emulate_setxuid(new, old);
725 /* juggle the capabilties to follow FSUID changes, unless
726 * otherwise suppressed
728 * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
729 * if not, we might be a bit too harsh here.
731 if (!issecure(SECURE_NO_SETUID_FIXUP)) {
732 if (old->fsuid == 0 && new->fsuid != 0)
734 cap_drop_fs_set(new->cap_effective);
736 if (old->fsuid != 0 && new->fsuid == 0)
738 cap_raise_fs_set(new->cap_effective,
751 * Rationale: code calling task_setscheduler, task_setioprio, and
752 * task_setnice, assumes that
753 * . if capable(cap_sys_nice), then those actions should be allowed
754 * . if not capable(cap_sys_nice), but acting on your own processes,
755 * then those actions should be allowed
756 * This is insufficient now since you can call code without suid, but
757 * yet with increased caps.
758 * So we check for increased caps on the target process.
760 static int cap_safe_nice(struct task_struct *p)
765 is_subset = cap_issubset(__task_cred(p)->cap_permitted,
766 current_cred()->cap_permitted);
769 if (!is_subset && !capable(CAP_SYS_NICE))
775 * cap_task_setscheduler - Detemine if scheduler policy change is permitted
776 * @p: The task to affect
778 * Detemine if the requested scheduler policy change is permitted for the
779 * specified task, returning 0 if permission is granted, -ve if denied.
781 int cap_task_setscheduler(struct task_struct *p)
783 return cap_safe_nice(p);
787 * cap_task_ioprio - Detemine if I/O priority change is permitted
788 * @p: The task to affect
789 * @ioprio: The I/O priority to set
791 * Detemine if the requested I/O priority change is permitted for the specified
792 * task, returning 0 if permission is granted, -ve if denied.
794 int cap_task_setioprio(struct task_struct *p, int ioprio)
796 return cap_safe_nice(p);
800 * cap_task_ioprio - Detemine if task priority change is permitted
801 * @p: The task to affect
802 * @nice: The nice value to set
804 * Detemine if the requested task priority change is permitted for the
805 * specified task, returning 0 if permission is granted, -ve if denied.
807 int cap_task_setnice(struct task_struct *p, int nice)
809 return cap_safe_nice(p);
813 * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from
814 * the current task's bounding set. Returns 0 on success, -ve on error.
816 static long cap_prctl_drop(struct cred *new, unsigned long cap)
818 if (!capable(CAP_SETPCAP))
823 cap_lower(new->cap_bset, cap);
828 * cap_task_prctl - Implement process control functions for this security module
829 * @option: The process control function requested
830 * @arg2, @arg3, @arg4, @arg5: The argument data for this function
832 * Allow process control functions (sys_prctl()) to alter capabilities; may
833 * also deny access to other functions not otherwise implemented here.
835 * Returns 0 or +ve on success, -ENOSYS if this function is not implemented
836 * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM
837 * modules will consider performing the function.
839 int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
840 unsigned long arg4, unsigned long arg5)
845 new = prepare_creds();
850 case PR_CAPBSET_READ:
852 if (!cap_valid(arg2))
854 error = !!cap_raised(new->cap_bset, arg2);
857 case PR_CAPBSET_DROP:
858 error = cap_prctl_drop(new, arg2);
864 * The next four prctl's remain to assist with transitioning a
865 * system from legacy UID=0 based privilege (when filesystem
866 * capabilities are not in use) to a system using filesystem
867 * capabilities only - as the POSIX.1e draft intended.
871 * PR_SET_SECUREBITS =
872 * issecure_mask(SECURE_KEEP_CAPS_LOCKED)
873 * | issecure_mask(SECURE_NOROOT)
874 * | issecure_mask(SECURE_NOROOT_LOCKED)
875 * | issecure_mask(SECURE_NO_SETUID_FIXUP)
876 * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
878 * will ensure that the current process and all of its
879 * children will be locked into a pure
880 * capability-based-privilege environment.
882 case PR_SET_SECUREBITS:
884 if ((((new->securebits & SECURE_ALL_LOCKS) >> 1)
885 & (new->securebits ^ arg2)) /*[1]*/
886 || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/
887 || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
888 || (cap_capable(current, current_cred(),
889 current_cred()->user->user_ns, CAP_SETPCAP,
890 SECURITY_CAP_AUDIT) != 0) /*[4]*/
892 * [1] no changing of bits that are locked
893 * [2] no unlocking of locks
894 * [3] no setting of unsupported bits
895 * [4] doing anything requires privilege (go read about
896 * the "sendmail capabilities bug")
899 /* cannot change a locked bit */
901 new->securebits = arg2;
904 case PR_GET_SECUREBITS:
905 error = new->securebits;
908 case PR_GET_KEEPCAPS:
909 if (issecure(SECURE_KEEP_CAPS))
913 case PR_SET_KEEPCAPS:
915 if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */
918 if (issecure(SECURE_KEEP_CAPS_LOCKED))
921 new->securebits |= issecure_mask(SECURE_KEEP_CAPS);
923 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
927 /* No functionality available - continue with default */
932 /* Functionality provided */
934 return commit_creds(new);
943 * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted
944 * @mm: The VM space in which the new mapping is to be made
945 * @pages: The size of the mapping
947 * Determine whether the allocation of a new virtual mapping by the current
948 * task is permitted, returning 0 if permission is granted, -ve if not.
950 int cap_vm_enough_memory(struct mm_struct *mm, long pages)
952 int cap_sys_admin = 0;
954 if (cap_capable(current, current_cred(), &init_user_ns, CAP_SYS_ADMIN,
955 SECURITY_CAP_NOAUDIT) == 0)
957 return __vm_enough_memory(mm, pages, cap_sys_admin);
961 * cap_file_mmap - check if able to map given addr
966 * @addr: address attempting to be mapped
969 * If the process is attempting to map memory below dac_mmap_min_addr they need
970 * CAP_SYS_RAWIO. The other parameters to this function are unused by the
971 * capability security module. Returns 0 if this mapping should be allowed
974 int cap_file_mmap(struct file *file, unsigned long reqprot,
975 unsigned long prot, unsigned long flags,
976 unsigned long addr, unsigned long addr_only)
980 if (addr < dac_mmap_min_addr) {
981 ret = cap_capable(current, current_cred(), &init_user_ns, CAP_SYS_RAWIO,
983 /* set PF_SUPERPRIV if it turns out we allow the low mmap */
985 current->flags |= PF_SUPERPRIV;