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>
33 * If a non-root user executes a setuid-root binary in
34 * !secure(SECURE_NOROOT) mode, then we raise capabilities.
35 * However if fE is also set, then the intent is for only
36 * the file capabilities to be applied, and the setuid-root
37 * bit is left on either to change the uid (plausible) or
38 * to get full privilege on a kernel without file capabilities
39 * support. So in that case we do not raise capabilities.
41 * Warn if that happens, once per boot.
43 static void warn_setuid_and_fcaps_mixed(const char *fname)
47 printk(KERN_INFO "warning: `%s' has both setuid-root and"
48 " effective capabilities. Therefore not raising all"
49 " capabilities.\n", fname);
54 int cap_netlink_send(struct sock *sk, struct sk_buff *skb)
59 int cap_netlink_recv(struct sk_buff *skb, int cap)
61 if (!cap_raised(current_cap(), cap))
65 EXPORT_SYMBOL(cap_netlink_recv);
68 * cap_capable - Determine whether a task has a particular effective capability
69 * @cred: The credentials to use
70 * @ns: The user namespace in which we need the capability
71 * @cap: The capability to check for
72 * @audit: Whether to write an audit message or not
74 * Determine whether the nominated task has the specified capability amongst
75 * its effective set, returning 0 if it does, -ve if it does not.
77 * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable()
78 * and has_capability() functions. That is, it has the reverse semantics:
79 * cap_has_capability() returns 0 when a task has a capability, but the
80 * kernel's capable() and has_capability() returns 1 for this case.
82 int cap_capable(const struct cred *cred, struct user_namespace *targ_ns,
86 /* The creator of the user namespace has all caps. */
87 if (targ_ns != &init_user_ns && targ_ns->creator == cred->user)
90 /* Do we have the necessary capabilities? */
91 if (targ_ns == cred->user->user_ns)
92 return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;
94 /* Have we tried all of the parent namespaces? */
95 if (targ_ns == &init_user_ns)
99 *If you have a capability in a parent user ns, then you have
100 * it over all children user namespaces as well.
102 targ_ns = targ_ns->creator->user_ns;
105 /* We never get here */
109 * cap_settime - Determine whether the current process may set the system clock
110 * @ts: The time to set
111 * @tz: The timezone to set
113 * Determine whether the current process may set the system clock and timezone
114 * information, returning 0 if permission granted, -ve if denied.
116 int cap_settime(const struct timespec *ts, const struct timezone *tz)
118 if (!capable(CAP_SYS_TIME))
124 * cap_ptrace_access_check - Determine whether the current process may access
126 * @child: The process to be accessed
127 * @mode: The mode of attachment.
129 * If we are in the same or an ancestor user_ns and have all the target
130 * task's capabilities, then ptrace access is allowed.
131 * If we have the ptrace capability to the target user_ns, then ptrace
135 * Determine whether a process may access another, returning 0 if permission
136 * granted, -ve if denied.
138 int cap_ptrace_access_check(struct task_struct *child, unsigned int mode)
141 const struct cred *cred, *child_cred;
144 cred = current_cred();
145 child_cred = __task_cred(child);
146 if (cred->user->user_ns == child_cred->user->user_ns &&
147 cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
149 if (ns_capable(child_cred->user->user_ns, CAP_SYS_PTRACE))
158 * cap_ptrace_traceme - Determine whether another process may trace the current
159 * @parent: The task proposed to be the tracer
161 * If parent is in the same or an ancestor user_ns and has all current's
162 * capabilities, then ptrace access is allowed.
163 * If parent has the ptrace capability to current's user_ns, then ptrace
167 * Determine whether the nominated task is permitted to trace the current
168 * process, returning 0 if permission is granted, -ve if denied.
170 int cap_ptrace_traceme(struct task_struct *parent)
173 const struct cred *cred, *child_cred;
176 cred = __task_cred(parent);
177 child_cred = current_cred();
178 if (cred->user->user_ns == child_cred->user->user_ns &&
179 cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
181 if (has_ns_capability(parent, child_cred->user->user_ns, CAP_SYS_PTRACE))
190 * cap_capget - Retrieve a task's capability sets
191 * @target: The task from which to retrieve the capability sets
192 * @effective: The place to record the effective set
193 * @inheritable: The place to record the inheritable set
194 * @permitted: The place to record the permitted set
196 * This function retrieves the capabilities of the nominated task and returns
197 * them to the caller.
199 int cap_capget(struct task_struct *target, kernel_cap_t *effective,
200 kernel_cap_t *inheritable, kernel_cap_t *permitted)
202 const struct cred *cred;
204 /* Derived from kernel/capability.c:sys_capget. */
206 cred = __task_cred(target);
207 *effective = cred->cap_effective;
208 *inheritable = cred->cap_inheritable;
209 *permitted = cred->cap_permitted;
215 * Determine whether the inheritable capabilities are limited to the old
216 * permitted set. Returns 1 if they are limited, 0 if they are not.
218 static inline int cap_inh_is_capped(void)
221 /* they are so limited unless the current task has the CAP_SETPCAP
224 if (cap_capable(current_cred(), current_cred()->user->user_ns,
225 CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0)
231 * cap_capset - Validate and apply proposed changes to current's capabilities
232 * @new: The proposed new credentials; alterations should be made here
233 * @old: The current task's current credentials
234 * @effective: A pointer to the proposed new effective capabilities set
235 * @inheritable: A pointer to the proposed new inheritable capabilities set
236 * @permitted: A pointer to the proposed new permitted capabilities set
238 * This function validates and applies a proposed mass change to the current
239 * process's capability sets. The changes are made to the proposed new
240 * credentials, and assuming no error, will be committed by the caller of LSM.
242 int cap_capset(struct cred *new,
243 const struct cred *old,
244 const kernel_cap_t *effective,
245 const kernel_cap_t *inheritable,
246 const kernel_cap_t *permitted)
248 if (cap_inh_is_capped() &&
249 !cap_issubset(*inheritable,
250 cap_combine(old->cap_inheritable,
251 old->cap_permitted)))
252 /* incapable of using this inheritable set */
255 if (!cap_issubset(*inheritable,
256 cap_combine(old->cap_inheritable,
258 /* no new pI capabilities outside bounding set */
261 /* verify restrictions on target's new Permitted set */
262 if (!cap_issubset(*permitted, old->cap_permitted))
265 /* verify the _new_Effective_ is a subset of the _new_Permitted_ */
266 if (!cap_issubset(*effective, *permitted))
269 new->cap_effective = *effective;
270 new->cap_inheritable = *inheritable;
271 new->cap_permitted = *permitted;
276 * Clear proposed capability sets for execve().
278 static inline void bprm_clear_caps(struct linux_binprm *bprm)
280 cap_clear(bprm->cred->cap_permitted);
281 bprm->cap_effective = false;
285 * cap_inode_need_killpriv - Determine if inode change affects privileges
286 * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV
288 * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV
289 * affects the security markings on that inode, and if it is, should
290 * inode_killpriv() be invoked or the change rejected?
292 * Returns 0 if granted; +ve if granted, but inode_killpriv() is required; and
293 * -ve to deny the change.
295 int cap_inode_need_killpriv(struct dentry *dentry)
297 struct inode *inode = dentry->d_inode;
300 if (!inode->i_op->getxattr)
303 error = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0);
310 * cap_inode_killpriv - Erase the security markings on an inode
311 * @dentry: The inode/dentry to alter
313 * Erase the privilege-enhancing security markings on an inode.
315 * Returns 0 if successful, -ve on error.
317 int cap_inode_killpriv(struct dentry *dentry)
319 struct inode *inode = dentry->d_inode;
321 if (!inode->i_op->removexattr)
324 return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
328 * Calculate the new process capability sets from the capability sets attached
331 static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
332 struct linux_binprm *bprm,
336 struct cred *new = bprm->cred;
340 if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE)
343 if (caps->magic_etc & VFS_CAP_REVISION_MASK)
346 CAP_FOR_EACH_U32(i) {
347 __u32 permitted = caps->permitted.cap[i];
348 __u32 inheritable = caps->inheritable.cap[i];
351 * pP' = (X & fP) | (pI & fI)
353 new->cap_permitted.cap[i] =
354 (new->cap_bset.cap[i] & permitted) |
355 (new->cap_inheritable.cap[i] & inheritable);
357 if (permitted & ~new->cap_permitted.cap[i])
358 /* insufficient to execute correctly */
363 * For legacy apps, with no internal support for recognizing they
364 * do not have enough capabilities, we return an error if they are
365 * missing some "forced" (aka file-permitted) capabilities.
367 return *effective ? ret : 0;
371 * Extract the on-exec-apply capability sets for an executable file.
373 int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps)
375 struct inode *inode = dentry->d_inode;
379 struct vfs_cap_data caps;
381 memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data));
383 if (!inode || !inode->i_op->getxattr)
386 size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps,
388 if (size == -ENODATA || size == -EOPNOTSUPP)
389 /* no data, that's ok */
394 if (size < sizeof(magic_etc))
397 cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc);
399 switch (magic_etc & VFS_CAP_REVISION_MASK) {
400 case VFS_CAP_REVISION_1:
401 if (size != XATTR_CAPS_SZ_1)
403 tocopy = VFS_CAP_U32_1;
405 case VFS_CAP_REVISION_2:
406 if (size != XATTR_CAPS_SZ_2)
408 tocopy = VFS_CAP_U32_2;
414 CAP_FOR_EACH_U32(i) {
417 cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted);
418 cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable);
425 * Attempt to get the on-exec apply capability sets for an executable file from
426 * its xattrs and, if present, apply them to the proposed credentials being
427 * constructed by execve().
429 static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_cap)
431 struct dentry *dentry;
433 struct cpu_vfs_cap_data vcaps;
435 bprm_clear_caps(bprm);
437 if (!file_caps_enabled)
440 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
443 dentry = dget(bprm->file->f_dentry);
445 rc = get_vfs_caps_from_disk(dentry, &vcaps);
448 printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n",
449 __func__, rc, bprm->filename);
450 else if (rc == -ENODATA)
455 rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective, has_cap);
457 printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n",
458 __func__, rc, bprm->filename);
463 bprm_clear_caps(bprm);
469 * cap_bprm_set_creds - Set up the proposed credentials for execve().
470 * @bprm: The execution parameters, including the proposed creds
472 * Set up the proposed credentials for a new execution context being
473 * constructed by execve(). The proposed creds in @bprm->cred is altered,
474 * which won't take effect immediately. Returns 0 if successful, -ve on error.
476 int cap_bprm_set_creds(struct linux_binprm *bprm)
478 const struct cred *old = current_cred();
479 struct cred *new = bprm->cred;
480 bool effective, has_cap = false;
484 ret = get_file_caps(bprm, &effective, &has_cap);
488 if (!issecure(SECURE_NOROOT)) {
490 * If the legacy file capability is set, then don't set privs
491 * for a setuid root binary run by a non-root user. Do set it
492 * for a root user just to cause least surprise to an admin.
494 if (has_cap && new->uid != 0 && new->euid == 0) {
495 warn_setuid_and_fcaps_mixed(bprm->filename);
499 * To support inheritance of root-permissions and suid-root
500 * executables under compatibility mode, we override the
501 * capability sets for the file.
503 * If only the real uid is 0, we do not set the effective bit.
505 if (new->euid == 0 || new->uid == 0) {
506 /* pP' = (cap_bset & ~0) | (pI & ~0) */
507 new->cap_permitted = cap_combine(old->cap_bset,
508 old->cap_inheritable);
515 /* if we have fs caps, clear dangerous personality flags */
516 if (!cap_issubset(new->cap_permitted, old->cap_permitted))
517 bprm->per_clear |= PER_CLEAR_ON_SETID;
520 /* Don't let someone trace a set[ug]id/setpcap binary with the revised
521 * credentials unless they have the appropriate permit.
523 * In addition, if NO_NEW_PRIVS, then ensure we get no new privs.
525 if ((new->euid != old->uid ||
526 new->egid != old->gid ||
527 !cap_issubset(new->cap_permitted, old->cap_permitted)) &&
528 bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
529 /* downgrade; they get no more than they had, and maybe less */
530 if (!capable(CAP_SETUID) ||
531 (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) {
532 new->euid = new->uid;
533 new->egid = new->gid;
535 new->cap_permitted = cap_intersect(new->cap_permitted,
539 new->suid = new->fsuid = new->euid;
540 new->sgid = new->fsgid = new->egid;
543 new->cap_effective = new->cap_permitted;
545 cap_clear(new->cap_effective);
546 bprm->cap_effective = effective;
549 * Audit candidate if current->cap_effective is set
551 * We do not bother to audit if 3 things are true:
552 * 1) cap_effective has all caps
554 * 3) root is supposed to have all caps (SECURE_NOROOT)
555 * Since this is just a normal root execing a process.
557 * Number 1 above might fail if you don't have a full bset, but I think
558 * that is interesting information to audit.
560 if (!cap_isclear(new->cap_effective)) {
561 if (!cap_issubset(CAP_FULL_SET, new->cap_effective) ||
562 new->euid != 0 || new->uid != 0 ||
563 issecure(SECURE_NOROOT)) {
564 ret = audit_log_bprm_fcaps(bprm, new, old);
570 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
575 * cap_bprm_secureexec - Determine whether a secure execution is required
576 * @bprm: The execution parameters
578 * Determine whether a secure execution is required, return 1 if it is, and 0
581 * The credentials have been committed by this point, and so are no longer
582 * available through @bprm->cred.
584 int cap_bprm_secureexec(struct linux_binprm *bprm)
586 const struct cred *cred = current_cred();
588 if (cred->uid != 0) {
589 if (bprm->cap_effective)
591 if (!cap_isclear(cred->cap_permitted))
595 return (cred->euid != cred->uid ||
596 cred->egid != cred->gid);
600 * cap_inode_setxattr - Determine whether an xattr may be altered
601 * @dentry: The inode/dentry being altered
602 * @name: The name of the xattr to be changed
603 * @value: The value that the xattr will be changed to
604 * @size: The size of value
605 * @flags: The replacement flag
607 * Determine whether an xattr may be altered or set on an inode, returning 0 if
608 * permission is granted, -ve if denied.
610 * This is used to make sure security xattrs don't get updated or set by those
611 * who aren't privileged to do so.
613 int cap_inode_setxattr(struct dentry *dentry, const char *name,
614 const void *value, size_t size, int flags)
616 if (!strcmp(name, XATTR_NAME_CAPS)) {
617 if (!capable(CAP_SETFCAP))
622 if (!strncmp(name, XATTR_SECURITY_PREFIX,
623 sizeof(XATTR_SECURITY_PREFIX) - 1) &&
624 !capable(CAP_SYS_ADMIN))
630 * cap_inode_removexattr - Determine whether an xattr may be removed
631 * @dentry: The inode/dentry being altered
632 * @name: The name of the xattr to be changed
634 * Determine whether an xattr may be removed from an inode, returning 0 if
635 * permission is granted, -ve if denied.
637 * This is used to make sure security xattrs don't get removed by those who
638 * aren't privileged to remove them.
640 int cap_inode_removexattr(struct dentry *dentry, const char *name)
642 if (!strcmp(name, XATTR_NAME_CAPS)) {
643 if (!capable(CAP_SETFCAP))
648 if (!strncmp(name, XATTR_SECURITY_PREFIX,
649 sizeof(XATTR_SECURITY_PREFIX) - 1) &&
650 !capable(CAP_SYS_ADMIN))
656 * cap_emulate_setxuid() fixes the effective / permitted capabilities of
657 * a process after a call to setuid, setreuid, or setresuid.
659 * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
660 * {r,e,s}uid != 0, the permitted and effective capabilities are
663 * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
664 * capabilities of the process are cleared.
666 * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
667 * capabilities are set to the permitted capabilities.
669 * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should
674 * cevans - New behaviour, Oct '99
675 * A process may, via prctl(), elect to keep its capabilities when it
676 * calls setuid() and switches away from uid==0. Both permitted and
677 * effective sets will be retained.
678 * Without this change, it was impossible for a daemon to drop only some
679 * of its privilege. The call to setuid(!=0) would drop all privileges!
680 * Keeping uid 0 is not an option because uid 0 owns too many vital
682 * Thanks to Olaf Kirch and Peter Benie for spotting this.
684 static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old)
686 if ((old->uid == 0 || old->euid == 0 || old->suid == 0) &&
687 (new->uid != 0 && new->euid != 0 && new->suid != 0) &&
688 !issecure(SECURE_KEEP_CAPS)) {
689 cap_clear(new->cap_permitted);
690 cap_clear(new->cap_effective);
692 if (old->euid == 0 && new->euid != 0)
693 cap_clear(new->cap_effective);
694 if (old->euid != 0 && new->euid == 0)
695 new->cap_effective = new->cap_permitted;
699 * cap_task_fix_setuid - Fix up the results of setuid() call
700 * @new: The proposed credentials
701 * @old: The current task's current credentials
702 * @flags: Indications of what has changed
704 * Fix up the results of setuid() call before the credential changes are
705 * actually applied, returning 0 to grant the changes, -ve to deny them.
707 int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
713 /* juggle the capabilities to follow [RES]UID changes unless
714 * otherwise suppressed */
715 if (!issecure(SECURE_NO_SETUID_FIXUP))
716 cap_emulate_setxuid(new, old);
720 /* juggle the capabilties to follow FSUID changes, unless
721 * otherwise suppressed
723 * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
724 * if not, we might be a bit too harsh here.
726 if (!issecure(SECURE_NO_SETUID_FIXUP)) {
727 if (old->fsuid == 0 && new->fsuid != 0)
729 cap_drop_fs_set(new->cap_effective);
731 if (old->fsuid != 0 && new->fsuid == 0)
733 cap_raise_fs_set(new->cap_effective,
746 * Rationale: code calling task_setscheduler, task_setioprio, and
747 * task_setnice, assumes that
748 * . if capable(cap_sys_nice), then those actions should be allowed
749 * . if not capable(cap_sys_nice), but acting on your own processes,
750 * then those actions should be allowed
751 * This is insufficient now since you can call code without suid, but
752 * yet with increased caps.
753 * So we check for increased caps on the target process.
755 static int cap_safe_nice(struct task_struct *p)
760 is_subset = cap_issubset(__task_cred(p)->cap_permitted,
761 current_cred()->cap_permitted);
764 if (!is_subset && !capable(CAP_SYS_NICE))
770 * cap_task_setscheduler - Detemine if scheduler policy change is permitted
771 * @p: The task to affect
773 * Detemine if the requested scheduler policy change is permitted for the
774 * specified task, returning 0 if permission is granted, -ve if denied.
776 int cap_task_setscheduler(struct task_struct *p)
778 return cap_safe_nice(p);
782 * cap_task_ioprio - Detemine if I/O priority change is permitted
783 * @p: The task to affect
784 * @ioprio: The I/O priority to set
786 * Detemine if the requested I/O priority change is permitted for the specified
787 * task, returning 0 if permission is granted, -ve if denied.
789 int cap_task_setioprio(struct task_struct *p, int ioprio)
791 return cap_safe_nice(p);
795 * cap_task_ioprio - Detemine if task priority change is permitted
796 * @p: The task to affect
797 * @nice: The nice value to set
799 * Detemine if the requested task priority change is permitted for the
800 * specified task, returning 0 if permission is granted, -ve if denied.
802 int cap_task_setnice(struct task_struct *p, int nice)
804 return cap_safe_nice(p);
808 * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from
809 * the current task's bounding set. Returns 0 on success, -ve on error.
811 static long cap_prctl_drop(struct cred *new, unsigned long cap)
813 if (!capable(CAP_SETPCAP))
818 cap_lower(new->cap_bset, cap);
823 * cap_task_prctl - Implement process control functions for this security module
824 * @option: The process control function requested
825 * @arg2, @arg3, @arg4, @arg5: The argument data for this function
827 * Allow process control functions (sys_prctl()) to alter capabilities; may
828 * also deny access to other functions not otherwise implemented here.
830 * Returns 0 or +ve on success, -ENOSYS if this function is not implemented
831 * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM
832 * modules will consider performing the function.
834 int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
835 unsigned long arg4, unsigned long arg5)
840 new = prepare_creds();
845 case PR_CAPBSET_READ:
847 if (!cap_valid(arg2))
849 error = !!cap_raised(new->cap_bset, arg2);
852 case PR_CAPBSET_DROP:
853 error = cap_prctl_drop(new, arg2);
859 * The next four prctl's remain to assist with transitioning a
860 * system from legacy UID=0 based privilege (when filesystem
861 * capabilities are not in use) to a system using filesystem
862 * capabilities only - as the POSIX.1e draft intended.
866 * PR_SET_SECUREBITS =
867 * issecure_mask(SECURE_KEEP_CAPS_LOCKED)
868 * | issecure_mask(SECURE_NOROOT)
869 * | issecure_mask(SECURE_NOROOT_LOCKED)
870 * | issecure_mask(SECURE_NO_SETUID_FIXUP)
871 * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
873 * will ensure that the current process and all of its
874 * children will be locked into a pure
875 * capability-based-privilege environment.
877 case PR_SET_SECUREBITS:
879 if ((((new->securebits & SECURE_ALL_LOCKS) >> 1)
880 & (new->securebits ^ arg2)) /*[1]*/
881 || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/
882 || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
883 || (cap_capable(current_cred(),
884 current_cred()->user->user_ns, CAP_SETPCAP,
885 SECURITY_CAP_AUDIT) != 0) /*[4]*/
887 * [1] no changing of bits that are locked
888 * [2] no unlocking of locks
889 * [3] no setting of unsupported bits
890 * [4] doing anything requires privilege (go read about
891 * the "sendmail capabilities bug")
894 /* cannot change a locked bit */
896 new->securebits = arg2;
899 case PR_GET_SECUREBITS:
900 error = new->securebits;
903 case PR_GET_KEEPCAPS:
904 if (issecure(SECURE_KEEP_CAPS))
908 case PR_SET_KEEPCAPS:
910 if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */
913 if (issecure(SECURE_KEEP_CAPS_LOCKED))
916 new->securebits |= issecure_mask(SECURE_KEEP_CAPS);
918 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
922 /* No functionality available - continue with default */
927 /* Functionality provided */
929 return commit_creds(new);
938 * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted
939 * @mm: The VM space in which the new mapping is to be made
940 * @pages: The size of the mapping
942 * Determine whether the allocation of a new virtual mapping by the current
943 * task is permitted, returning 0 if permission is granted, -ve if not.
945 int cap_vm_enough_memory(struct mm_struct *mm, long pages)
947 int cap_sys_admin = 0;
949 if (cap_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
950 SECURITY_CAP_NOAUDIT) == 0)
952 return __vm_enough_memory(mm, pages, cap_sys_admin);
956 * cap_file_mmap - check if able to map given addr
961 * @addr: address attempting to be mapped
964 * If the process is attempting to map memory below dac_mmap_min_addr they need
965 * CAP_SYS_RAWIO. The other parameters to this function are unused by the
966 * capability security module. Returns 0 if this mapping should be allowed
969 int cap_file_mmap(struct file *file, unsigned long reqprot,
970 unsigned long prot, unsigned long flags,
971 unsigned long addr, unsigned long addr_only)
975 if (addr < dac_mmap_min_addr) {
976 ret = cap_capable(current_cred(), &init_user_ns, CAP_SYS_RAWIO,
978 /* set PF_SUPERPRIV if it turns out we allow the low mmap */
980 current->flags |= PF_SUPERPRIV;
984 EXPORT_SYMBOL(cap_file_mmap);