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 * @cred: The credentials to use
71 * @ns: The user namespace in which we need the capability
72 * @cap: The capability to check for
73 * @audit: Whether to write an audit message or not
75 * Determine whether the nominated task has the specified capability amongst
76 * its effective set, returning 0 if it does, -ve if it does not.
78 * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable()
79 * and has_capability() functions. That is, it has the reverse semantics:
80 * cap_has_capability() returns 0 when a task has a capability, but the
81 * kernel's capable() and has_capability() returns 1 for this case.
83 int cap_capable(const struct cred *cred, struct user_namespace *targ_ns,
87 /* The creator of the user namespace has all caps. */
88 if (targ_ns != &init_user_ns && targ_ns->creator == cred->user)
91 /* Do we have the necessary capabilities? */
92 if (targ_ns == cred->user->user_ns)
93 return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;
95 /* Have we tried all of the parent namespaces? */
96 if (targ_ns == &init_user_ns)
100 *If you have a capability in a parent user ns, then you have
101 * it over all children user namespaces as well.
103 targ_ns = targ_ns->creator->user_ns;
106 /* We never get here */
110 * cap_settime - Determine whether the current process may set the system clock
111 * @ts: The time to set
112 * @tz: The timezone to set
114 * Determine whether the current process may set the system clock and timezone
115 * information, returning 0 if permission granted, -ve if denied.
117 int cap_settime(const struct timespec *ts, const struct timezone *tz)
119 if (!capable(CAP_SYS_TIME))
125 * cap_ptrace_access_check - Determine whether the current process may access
127 * @child: The process to be accessed
128 * @mode: The mode of attachment.
130 * If we are in the same or an ancestor user_ns and have all the target
131 * task's capabilities, then ptrace access is allowed.
132 * If we have the ptrace capability to the target user_ns, then ptrace
136 * Determine whether a process may access another, returning 0 if permission
137 * granted, -ve if denied.
139 int cap_ptrace_access_check(struct task_struct *child, unsigned int mode)
142 const struct cred *cred, *child_cred;
145 cred = current_cred();
146 child_cred = __task_cred(child);
147 if (cred->user->user_ns == child_cred->user->user_ns &&
148 cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
150 if (ns_capable(child_cred->user->user_ns, CAP_SYS_PTRACE))
159 * cap_ptrace_traceme - Determine whether another process may trace the current
160 * @parent: The task proposed to be the tracer
162 * If parent is in the same or an ancestor user_ns and has all current's
163 * capabilities, then ptrace access is allowed.
164 * If parent has the ptrace capability to current's user_ns, then ptrace
168 * Determine whether the nominated task is permitted to trace the current
169 * process, returning 0 if permission is granted, -ve if denied.
171 int cap_ptrace_traceme(struct task_struct *parent)
174 const struct cred *cred, *child_cred;
177 cred = __task_cred(parent);
178 child_cred = current_cred();
179 if (cred->user->user_ns == child_cred->user->user_ns &&
180 cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
182 if (has_ns_capability(parent, child_cred->user->user_ns, CAP_SYS_PTRACE))
191 * cap_capget - Retrieve a task's capability sets
192 * @target: The task from which to retrieve the capability sets
193 * @effective: The place to record the effective set
194 * @inheritable: The place to record the inheritable set
195 * @permitted: The place to record the permitted set
197 * This function retrieves the capabilities of the nominated task and returns
198 * them to the caller.
200 int cap_capget(struct task_struct *target, kernel_cap_t *effective,
201 kernel_cap_t *inheritable, kernel_cap_t *permitted)
203 const struct cred *cred;
205 /* Derived from kernel/capability.c:sys_capget. */
207 cred = __task_cred(target);
208 *effective = cred->cap_effective;
209 *inheritable = cred->cap_inheritable;
210 *permitted = cred->cap_permitted;
216 * Determine whether the inheritable capabilities are limited to the old
217 * permitted set. Returns 1 if they are limited, 0 if they are not.
219 static inline int cap_inh_is_capped(void)
222 /* they are so limited unless the current task has the CAP_SETPCAP
225 if (cap_capable(current_cred(), current_cred()->user->user_ns,
226 CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0)
232 * cap_capset - Validate and apply proposed changes to current's capabilities
233 * @new: The proposed new credentials; alterations should be made here
234 * @old: The current task's current credentials
235 * @effective: A pointer to the proposed new effective capabilities set
236 * @inheritable: A pointer to the proposed new inheritable capabilities set
237 * @permitted: A pointer to the proposed new permitted capabilities set
239 * This function validates and applies a proposed mass change to the current
240 * process's capability sets. The changes are made to the proposed new
241 * credentials, and assuming no error, will be committed by the caller of LSM.
243 int cap_capset(struct cred *new,
244 const struct cred *old,
245 const kernel_cap_t *effective,
246 const kernel_cap_t *inheritable,
247 const kernel_cap_t *permitted)
249 if (cap_inh_is_capped() &&
250 !cap_issubset(*inheritable,
251 cap_combine(old->cap_inheritable,
252 old->cap_permitted)))
253 /* incapable of using this inheritable set */
256 if (!cap_issubset(*inheritable,
257 cap_combine(old->cap_inheritable,
259 /* no new pI capabilities outside bounding set */
262 /* verify restrictions on target's new Permitted set */
263 if (!cap_issubset(*permitted, old->cap_permitted))
266 /* verify the _new_Effective_ is a subset of the _new_Permitted_ */
267 if (!cap_issubset(*effective, *permitted))
270 new->cap_effective = *effective;
271 new->cap_inheritable = *inheritable;
272 new->cap_permitted = *permitted;
277 * Clear proposed capability sets for execve().
279 static inline void bprm_clear_caps(struct linux_binprm *bprm)
281 cap_clear(bprm->cred->cap_permitted);
282 bprm->cap_effective = false;
286 * cap_inode_need_killpriv - Determine if inode change affects privileges
287 * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV
289 * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV
290 * affects the security markings on that inode, and if it is, should
291 * inode_killpriv() be invoked or the change rejected?
293 * Returns 0 if granted; +ve if granted, but inode_killpriv() is required; and
294 * -ve to deny the change.
296 int cap_inode_need_killpriv(struct dentry *dentry)
298 struct inode *inode = dentry->d_inode;
301 if (!inode->i_op->getxattr)
304 error = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0);
311 * cap_inode_killpriv - Erase the security markings on an inode
312 * @dentry: The inode/dentry to alter
314 * Erase the privilege-enhancing security markings on an inode.
316 * Returns 0 if successful, -ve on error.
318 int cap_inode_killpriv(struct dentry *dentry)
320 struct inode *inode = dentry->d_inode;
322 if (!inode->i_op->removexattr)
325 return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
329 * Calculate the new process capability sets from the capability sets attached
332 static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
333 struct linux_binprm *bprm,
337 struct cred *new = bprm->cred;
341 if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE)
344 if (caps->magic_etc & VFS_CAP_REVISION_MASK)
347 CAP_FOR_EACH_U32(i) {
348 __u32 permitted = caps->permitted.cap[i];
349 __u32 inheritable = caps->inheritable.cap[i];
352 * pP' = (X & fP) | (pI & fI)
354 new->cap_permitted.cap[i] =
355 (new->cap_bset.cap[i] & permitted) |
356 (new->cap_inheritable.cap[i] & inheritable);
358 if (permitted & ~new->cap_permitted.cap[i])
359 /* insufficient to execute correctly */
364 * For legacy apps, with no internal support for recognizing they
365 * do not have enough capabilities, we return an error if they are
366 * missing some "forced" (aka file-permitted) capabilities.
368 return *effective ? ret : 0;
372 * Extract the on-exec-apply capability sets for an executable file.
374 int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps)
376 struct inode *inode = dentry->d_inode;
380 struct vfs_cap_data caps;
382 memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data));
384 if (!inode || !inode->i_op->getxattr)
387 size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps,
389 if (size == -ENODATA || size == -EOPNOTSUPP)
390 /* no data, that's ok */
395 if (size < sizeof(magic_etc))
398 cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc);
400 switch (magic_etc & VFS_CAP_REVISION_MASK) {
401 case VFS_CAP_REVISION_1:
402 if (size != XATTR_CAPS_SZ_1)
404 tocopy = VFS_CAP_U32_1;
406 case VFS_CAP_REVISION_2:
407 if (size != XATTR_CAPS_SZ_2)
409 tocopy = VFS_CAP_U32_2;
415 CAP_FOR_EACH_U32(i) {
418 cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted);
419 cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable);
426 * Attempt to get the on-exec apply capability sets for an executable file from
427 * its xattrs and, if present, apply them to the proposed credentials being
428 * constructed by execve().
430 static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_cap)
432 struct dentry *dentry;
434 struct cpu_vfs_cap_data vcaps;
436 bprm_clear_caps(bprm);
438 if (!file_caps_enabled)
441 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
444 dentry = dget(bprm->file->f_dentry);
446 rc = get_vfs_caps_from_disk(dentry, &vcaps);
449 printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n",
450 __func__, rc, bprm->filename);
451 else if (rc == -ENODATA)
456 rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective, has_cap);
458 printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n",
459 __func__, rc, bprm->filename);
464 bprm_clear_caps(bprm);
470 * cap_bprm_set_creds - Set up the proposed credentials for execve().
471 * @bprm: The execution parameters, including the proposed creds
473 * Set up the proposed credentials for a new execution context being
474 * constructed by execve(). The proposed creds in @bprm->cred is altered,
475 * which won't take effect immediately. Returns 0 if successful, -ve on error.
477 int cap_bprm_set_creds(struct linux_binprm *bprm)
479 const struct cred *old = current_cred();
480 struct cred *new = bprm->cred;
481 bool effective, has_cap = false;
485 ret = get_file_caps(bprm, &effective, &has_cap);
489 if (!issecure(SECURE_NOROOT)) {
491 * If the legacy file capability is set, then don't set privs
492 * for a setuid root binary run by a non-root user. Do set it
493 * for a root user just to cause least surprise to an admin.
495 if (has_cap && new->uid != 0 && new->euid == 0) {
496 warn_setuid_and_fcaps_mixed(bprm->filename);
500 * To support inheritance of root-permissions and suid-root
501 * executables under compatibility mode, we override the
502 * capability sets for the file.
504 * If only the real uid is 0, we do not set the effective bit.
506 if (new->euid == 0 || new->uid == 0) {
507 /* pP' = (cap_bset & ~0) | (pI & ~0) */
508 new->cap_permitted = cap_combine(old->cap_bset,
509 old->cap_inheritable);
516 /* if we have fs caps, clear dangerous personality flags */
517 if (!cap_issubset(new->cap_permitted, old->cap_permitted))
518 bprm->per_clear |= PER_CLEAR_ON_SETID;
521 /* Don't let someone trace a set[ug]id/setpcap binary with the revised
522 * credentials unless they have the appropriate permit.
524 * In addition, if NO_NEW_PRIVS, then ensure we get no new privs.
526 if ((new->euid != old->uid ||
527 new->egid != old->gid ||
528 !cap_issubset(new->cap_permitted, old->cap_permitted)) &&
529 bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
530 /* downgrade; they get no more than they had, and maybe less */
531 if (!capable(CAP_SETUID) ||
532 (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) {
533 new->euid = new->uid;
534 new->egid = new->gid;
536 new->cap_permitted = cap_intersect(new->cap_permitted,
540 new->suid = new->fsuid = new->euid;
541 new->sgid = new->fsgid = new->egid;
544 new->cap_effective = new->cap_permitted;
546 cap_clear(new->cap_effective);
547 bprm->cap_effective = effective;
550 * Audit candidate if current->cap_effective is set
552 * We do not bother to audit if 3 things are true:
553 * 1) cap_effective has all caps
555 * 3) root is supposed to have all caps (SECURE_NOROOT)
556 * Since this is just a normal root execing a process.
558 * Number 1 above might fail if you don't have a full bset, but I think
559 * that is interesting information to audit.
561 if (!cap_isclear(new->cap_effective)) {
562 if (!cap_issubset(CAP_FULL_SET, new->cap_effective) ||
563 new->euid != 0 || new->uid != 0 ||
564 issecure(SECURE_NOROOT)) {
565 ret = audit_log_bprm_fcaps(bprm, new, old);
571 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
576 * cap_bprm_secureexec - Determine whether a secure execution is required
577 * @bprm: The execution parameters
579 * Determine whether a secure execution is required, return 1 if it is, and 0
582 * The credentials have been committed by this point, and so are no longer
583 * available through @bprm->cred.
585 int cap_bprm_secureexec(struct linux_binprm *bprm)
587 const struct cred *cred = current_cred();
589 if (cred->uid != 0) {
590 if (bprm->cap_effective)
592 if (!cap_isclear(cred->cap_permitted))
596 return (cred->euid != cred->uid ||
597 cred->egid != cred->gid);
601 * cap_inode_setxattr - Determine whether an xattr may be altered
602 * @dentry: The inode/dentry being altered
603 * @name: The name of the xattr to be changed
604 * @value: The value that the xattr will be changed to
605 * @size: The size of value
606 * @flags: The replacement flag
608 * Determine whether an xattr may be altered or set on an inode, returning 0 if
609 * permission is granted, -ve if denied.
611 * This is used to make sure security xattrs don't get updated or set by those
612 * who aren't privileged to do so.
614 int cap_inode_setxattr(struct dentry *dentry, const char *name,
615 const void *value, size_t size, int flags)
617 if (!strcmp(name, XATTR_NAME_CAPS)) {
618 if (!capable(CAP_SETFCAP))
623 if (!strncmp(name, XATTR_SECURITY_PREFIX,
624 sizeof(XATTR_SECURITY_PREFIX) - 1) &&
625 !capable(CAP_SYS_ADMIN))
631 * cap_inode_removexattr - Determine whether an xattr may be removed
632 * @dentry: The inode/dentry being altered
633 * @name: The name of the xattr to be changed
635 * Determine whether an xattr may be removed from an inode, returning 0 if
636 * permission is granted, -ve if denied.
638 * This is used to make sure security xattrs don't get removed by those who
639 * aren't privileged to remove them.
641 int cap_inode_removexattr(struct dentry *dentry, const char *name)
643 if (!strcmp(name, XATTR_NAME_CAPS)) {
644 if (!capable(CAP_SETFCAP))
649 if (!strncmp(name, XATTR_SECURITY_PREFIX,
650 sizeof(XATTR_SECURITY_PREFIX) - 1) &&
651 !capable(CAP_SYS_ADMIN))
657 * cap_emulate_setxuid() fixes the effective / permitted capabilities of
658 * a process after a call to setuid, setreuid, or setresuid.
660 * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
661 * {r,e,s}uid != 0, the permitted and effective capabilities are
664 * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
665 * capabilities of the process are cleared.
667 * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
668 * capabilities are set to the permitted capabilities.
670 * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should
675 * cevans - New behaviour, Oct '99
676 * A process may, via prctl(), elect to keep its capabilities when it
677 * calls setuid() and switches away from uid==0. Both permitted and
678 * effective sets will be retained.
679 * Without this change, it was impossible for a daemon to drop only some
680 * of its privilege. The call to setuid(!=0) would drop all privileges!
681 * Keeping uid 0 is not an option because uid 0 owns too many vital
683 * Thanks to Olaf Kirch and Peter Benie for spotting this.
685 static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old)
687 if ((old->uid == 0 || old->euid == 0 || old->suid == 0) &&
688 (new->uid != 0 && new->euid != 0 && new->suid != 0) &&
689 !issecure(SECURE_KEEP_CAPS)) {
690 cap_clear(new->cap_permitted);
691 cap_clear(new->cap_effective);
693 if (old->euid == 0 && new->euid != 0)
694 cap_clear(new->cap_effective);
695 if (old->euid != 0 && new->euid == 0)
696 new->cap_effective = new->cap_permitted;
700 * cap_task_fix_setuid - Fix up the results of setuid() call
701 * @new: The proposed credentials
702 * @old: The current task's current credentials
703 * @flags: Indications of what has changed
705 * Fix up the results of setuid() call before the credential changes are
706 * actually applied, returning 0 to grant the changes, -ve to deny them.
708 int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
714 /* juggle the capabilities to follow [RES]UID changes unless
715 * otherwise suppressed */
716 if (!issecure(SECURE_NO_SETUID_FIXUP))
717 cap_emulate_setxuid(new, old);
721 /* juggle the capabilties to follow FSUID changes, unless
722 * otherwise suppressed
724 * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
725 * if not, we might be a bit too harsh here.
727 if (!issecure(SECURE_NO_SETUID_FIXUP)) {
728 if (old->fsuid == 0 && new->fsuid != 0)
730 cap_drop_fs_set(new->cap_effective);
732 if (old->fsuid != 0 && new->fsuid == 0)
734 cap_raise_fs_set(new->cap_effective,
747 * Rationale: code calling task_setscheduler, task_setioprio, and
748 * task_setnice, assumes that
749 * . if capable(cap_sys_nice), then those actions should be allowed
750 * . if not capable(cap_sys_nice), but acting on your own processes,
751 * then those actions should be allowed
752 * This is insufficient now since you can call code without suid, but
753 * yet with increased caps.
754 * So we check for increased caps on the target process.
756 static int cap_safe_nice(struct task_struct *p)
761 is_subset = cap_issubset(__task_cred(p)->cap_permitted,
762 current_cred()->cap_permitted);
765 if (!is_subset && !capable(CAP_SYS_NICE))
771 * cap_task_setscheduler - Detemine if scheduler policy change is permitted
772 * @p: The task to affect
774 * Detemine if the requested scheduler policy change is permitted for the
775 * specified task, returning 0 if permission is granted, -ve if denied.
777 int cap_task_setscheduler(struct task_struct *p)
779 return cap_safe_nice(p);
783 * cap_task_ioprio - Detemine if I/O priority change is permitted
784 * @p: The task to affect
785 * @ioprio: The I/O priority to set
787 * Detemine if the requested I/O priority change is permitted for the specified
788 * task, returning 0 if permission is granted, -ve if denied.
790 int cap_task_setioprio(struct task_struct *p, int ioprio)
792 return cap_safe_nice(p);
796 * cap_task_ioprio - Detemine if task priority change is permitted
797 * @p: The task to affect
798 * @nice: The nice value to set
800 * Detemine if the requested task priority change is permitted for the
801 * specified task, returning 0 if permission is granted, -ve if denied.
803 int cap_task_setnice(struct task_struct *p, int nice)
805 return cap_safe_nice(p);
809 * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from
810 * the current task's bounding set. Returns 0 on success, -ve on error.
812 static long cap_prctl_drop(struct cred *new, unsigned long cap)
814 if (!capable(CAP_SETPCAP))
819 cap_lower(new->cap_bset, cap);
824 * cap_task_prctl - Implement process control functions for this security module
825 * @option: The process control function requested
826 * @arg2, @arg3, @arg4, @arg5: The argument data for this function
828 * Allow process control functions (sys_prctl()) to alter capabilities; may
829 * also deny access to other functions not otherwise implemented here.
831 * Returns 0 or +ve on success, -ENOSYS if this function is not implemented
832 * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM
833 * modules will consider performing the function.
835 int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
836 unsigned long arg4, unsigned long arg5)
841 new = prepare_creds();
846 case PR_CAPBSET_READ:
848 if (!cap_valid(arg2))
850 error = !!cap_raised(new->cap_bset, arg2);
853 case PR_CAPBSET_DROP:
854 error = cap_prctl_drop(new, arg2);
860 * The next four prctl's remain to assist with transitioning a
861 * system from legacy UID=0 based privilege (when filesystem
862 * capabilities are not in use) to a system using filesystem
863 * capabilities only - as the POSIX.1e draft intended.
867 * PR_SET_SECUREBITS =
868 * issecure_mask(SECURE_KEEP_CAPS_LOCKED)
869 * | issecure_mask(SECURE_NOROOT)
870 * | issecure_mask(SECURE_NOROOT_LOCKED)
871 * | issecure_mask(SECURE_NO_SETUID_FIXUP)
872 * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
874 * will ensure that the current process and all of its
875 * children will be locked into a pure
876 * capability-based-privilege environment.
878 case PR_SET_SECUREBITS:
880 if ((((new->securebits & SECURE_ALL_LOCKS) >> 1)
881 & (new->securebits ^ arg2)) /*[1]*/
882 || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/
883 || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
884 || (cap_capable(current_cred(),
885 current_cred()->user->user_ns, CAP_SETPCAP,
886 SECURITY_CAP_AUDIT) != 0) /*[4]*/
888 * [1] no changing of bits that are locked
889 * [2] no unlocking of locks
890 * [3] no setting of unsupported bits
891 * [4] doing anything requires privilege (go read about
892 * the "sendmail capabilities bug")
895 /* cannot change a locked bit */
897 new->securebits = arg2;
900 case PR_GET_SECUREBITS:
901 error = new->securebits;
904 case PR_GET_KEEPCAPS:
905 if (issecure(SECURE_KEEP_CAPS))
909 case PR_SET_KEEPCAPS:
911 if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */
914 if (issecure(SECURE_KEEP_CAPS_LOCKED))
917 new->securebits |= issecure_mask(SECURE_KEEP_CAPS);
919 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
923 /* No functionality available - continue with default */
928 /* Functionality provided */
930 return commit_creds(new);
939 * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted
940 * @mm: The VM space in which the new mapping is to be made
941 * @pages: The size of the mapping
943 * Determine whether the allocation of a new virtual mapping by the current
944 * task is permitted, returning 0 if permission is granted, -ve if not.
946 int cap_vm_enough_memory(struct mm_struct *mm, long pages)
948 int cap_sys_admin = 0;
950 if (cap_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
951 SECURITY_CAP_NOAUDIT) == 0)
953 return __vm_enough_memory(mm, pages, cap_sys_admin);
957 * cap_file_mmap - check if able to map given addr
962 * @addr: address attempting to be mapped
965 * If the process is attempting to map memory below dac_mmap_min_addr they need
966 * CAP_SYS_RAWIO. The other parameters to this function are unused by the
967 * capability security module. Returns 0 if this mapping should be allowed
970 int cap_file_mmap(struct file *file, unsigned long reqprot,
971 unsigned long prot, unsigned long flags,
972 unsigned long addr, unsigned long addr_only)
976 if (addr < dac_mmap_min_addr) {
977 ret = cap_capable(current_cred(), &init_user_ns, CAP_SYS_RAWIO,
979 /* set PF_SUPERPRIV if it turns out we allow the low mmap */
981 current->flags |= PF_SUPERPRIV;
985 EXPORT_SYMBOL(cap_file_mmap);