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/binfmts.h>
32 #include <linux/personality.h>
34 #ifdef CONFIG_ANDROID_PARANOID_NETWORK
35 #include <linux/android_aid.h>
39 * If a non-root user executes a setuid-root binary in
40 * !secure(SECURE_NOROOT) mode, then we raise capabilities.
41 * However if fE is also set, then the intent is for only
42 * the file capabilities to be applied, and the setuid-root
43 * bit is left on either to change the uid (plausible) or
44 * to get full privilege on a kernel without file capabilities
45 * support. So in that case we do not raise capabilities.
47 * Warn if that happens, once per boot.
49 static void warn_setuid_and_fcaps_mixed(const char *fname
)
53 printk(KERN_INFO
"warning: `%s' has both setuid-root and"
54 " effective capabilities. Therefore not raising all"
55 " capabilities.\n", fname
);
60 int cap_netlink_send(struct sock
*sk
, struct sk_buff
*skb
)
66 * cap_capable - Determine whether a task has a particular effective capability
67 * @cred: The credentials to use
68 * @ns: The user namespace in which we need the capability
69 * @cap: The capability to check for
70 * @audit: Whether to write an audit message or not
72 * Determine whether the nominated task has the specified capability amongst
73 * its effective set, returning 0 if it does, -ve if it does not.
75 * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable()
76 * and has_capability() functions. That is, it has the reverse semantics:
77 * cap_has_capability() returns 0 when a task has a capability, but the
78 * kernel's capable() and has_capability() returns 1 for this case.
80 int cap_capable(const struct cred
*cred
, struct user_namespace
*targ_ns
,
83 struct user_namespace
*ns
= targ_ns
;
85 #ifdef CONFIG_ANDROID_PARANOID_NETWORK
86 if (cap
== CAP_NET_RAW
&& in_egroup_p(AID_NET_RAW
))
88 if (cap
== CAP_NET_ADMIN
&& in_egroup_p(AID_NET_ADMIN
))
92 /* See if cred has the capability in the target user namespace
93 * by examining the target user namespace and all of the target
94 * user namespace's parents.
97 /* Do we have the necessary capabilities? */
98 if (ns
== cred
->user_ns
)
99 return cap_raised(cred
->cap_effective
, cap
) ? 0 : -EPERM
;
101 /* Have we tried all of the parent namespaces? */
102 if (ns
== &init_user_ns
)
106 * The owner of the user namespace in the parent of the
107 * user namespace has all caps.
109 if ((ns
->parent
== cred
->user_ns
) && uid_eq(ns
->owner
, cred
->euid
))
113 * If you have a capability in a parent user ns, then you have
114 * it over all children user namespaces as well.
119 /* We never get here */
123 * cap_settime - Determine whether the current process may set the system clock
124 * @ts: The time to set
125 * @tz: The timezone to set
127 * Determine whether the current process may set the system clock and timezone
128 * information, returning 0 if permission granted, -ve if denied.
130 int cap_settime(const struct timespec
*ts
, const struct timezone
*tz
)
132 if (!capable(CAP_SYS_TIME
))
138 * cap_ptrace_access_check - Determine whether the current process may access
140 * @child: The process to be accessed
141 * @mode: The mode of attachment.
143 * If we are in the same or an ancestor user_ns and have all the target
144 * task's capabilities, then ptrace access is allowed.
145 * If we have the ptrace capability to the target user_ns, then ptrace
149 * Determine whether a process may access another, returning 0 if permission
150 * granted, -ve if denied.
152 int cap_ptrace_access_check(struct task_struct
*child
, unsigned int mode
)
155 const struct cred
*cred
, *child_cred
;
156 const kernel_cap_t
*caller_caps
;
159 cred
= current_cred();
160 child_cred
= __task_cred(child
);
161 if (mode
& PTRACE_MODE_FSCREDS
)
162 caller_caps
= &cred
->cap_effective
;
164 caller_caps
= &cred
->cap_permitted
;
165 if (cred
->user_ns
== child_cred
->user_ns
&&
166 cap_issubset(child_cred
->cap_permitted
, *caller_caps
))
168 if (ns_capable(child_cred
->user_ns
, CAP_SYS_PTRACE
))
177 * cap_ptrace_traceme - Determine whether another process may trace the current
178 * @parent: The task proposed to be the tracer
180 * If parent is in the same or an ancestor user_ns and has all current's
181 * capabilities, then ptrace access is allowed.
182 * If parent has the ptrace capability to current's user_ns, then ptrace
186 * Determine whether the nominated task is permitted to trace the current
187 * process, returning 0 if permission is granted, -ve if denied.
189 int cap_ptrace_traceme(struct task_struct
*parent
)
192 const struct cred
*cred
, *child_cred
;
195 cred
= __task_cred(parent
);
196 child_cred
= current_cred();
197 if (cred
->user_ns
== child_cred
->user_ns
&&
198 cap_issubset(child_cred
->cap_permitted
, cred
->cap_permitted
))
200 if (has_ns_capability(parent
, child_cred
->user_ns
, CAP_SYS_PTRACE
))
209 * cap_capget - Retrieve a task's capability sets
210 * @target: The task from which to retrieve the capability sets
211 * @effective: The place to record the effective set
212 * @inheritable: The place to record the inheritable set
213 * @permitted: The place to record the permitted set
215 * This function retrieves the capabilities of the nominated task and returns
216 * them to the caller.
218 int cap_capget(struct task_struct
*target
, kernel_cap_t
*effective
,
219 kernel_cap_t
*inheritable
, kernel_cap_t
*permitted
)
221 const struct cred
*cred
;
223 /* Derived from kernel/capability.c:sys_capget. */
225 cred
= __task_cred(target
);
226 *effective
= cred
->cap_effective
;
227 *inheritable
= cred
->cap_inheritable
;
228 *permitted
= cred
->cap_permitted
;
234 * Determine whether the inheritable capabilities are limited to the old
235 * permitted set. Returns 1 if they are limited, 0 if they are not.
237 static inline int cap_inh_is_capped(void)
240 /* they are so limited unless the current task has the CAP_SETPCAP
243 if (cap_capable(current_cred(), current_cred()->user_ns
,
244 CAP_SETPCAP
, SECURITY_CAP_AUDIT
) == 0)
250 * cap_capset - Validate and apply proposed changes to current's capabilities
251 * @new: The proposed new credentials; alterations should be made here
252 * @old: The current task's current credentials
253 * @effective: A pointer to the proposed new effective capabilities set
254 * @inheritable: A pointer to the proposed new inheritable capabilities set
255 * @permitted: A pointer to the proposed new permitted capabilities set
257 * This function validates and applies a proposed mass change to the current
258 * process's capability sets. The changes are made to the proposed new
259 * credentials, and assuming no error, will be committed by the caller of LSM.
261 int cap_capset(struct cred
*new,
262 const struct cred
*old
,
263 const kernel_cap_t
*effective
,
264 const kernel_cap_t
*inheritable
,
265 const kernel_cap_t
*permitted
)
267 if (cap_inh_is_capped() &&
268 !cap_issubset(*inheritable
,
269 cap_combine(old
->cap_inheritable
,
270 old
->cap_permitted
)))
271 /* incapable of using this inheritable set */
274 if (!cap_issubset(*inheritable
,
275 cap_combine(old
->cap_inheritable
,
277 /* no new pI capabilities outside bounding set */
280 /* verify restrictions on target's new Permitted set */
281 if (!cap_issubset(*permitted
, old
->cap_permitted
))
284 /* verify the _new_Effective_ is a subset of the _new_Permitted_ */
285 if (!cap_issubset(*effective
, *permitted
))
288 new->cap_effective
= *effective
;
289 new->cap_inheritable
= *inheritable
;
290 new->cap_permitted
= *permitted
;
295 * Clear proposed capability sets for execve().
297 static inline void bprm_clear_caps(struct linux_binprm
*bprm
)
299 cap_clear(bprm
->cred
->cap_permitted
);
300 bprm
->cap_effective
= false;
304 * cap_inode_need_killpriv - Determine if inode change affects privileges
305 * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV
307 * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV
308 * affects the security markings on that inode, and if it is, should
309 * inode_killpriv() be invoked or the change rejected?
311 * Returns 0 if granted; +ve if granted, but inode_killpriv() is required; and
312 * -ve to deny the change.
314 int cap_inode_need_killpriv(struct dentry
*dentry
)
316 struct inode
*inode
= dentry
->d_inode
;
319 if (!inode
->i_op
->getxattr
)
322 error
= inode
->i_op
->getxattr(dentry
, XATTR_NAME_CAPS
, NULL
, 0);
329 * cap_inode_killpriv - Erase the security markings on an inode
330 * @dentry: The inode/dentry to alter
332 * Erase the privilege-enhancing security markings on an inode.
334 * Returns 0 if successful, -ve on error.
336 int cap_inode_killpriv(struct dentry
*dentry
)
338 struct inode
*inode
= dentry
->d_inode
;
340 if (!inode
->i_op
->removexattr
)
343 return inode
->i_op
->removexattr(dentry
, XATTR_NAME_CAPS
);
347 * Calculate the new process capability sets from the capability sets attached
350 static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data
*caps
,
351 struct linux_binprm
*bprm
,
355 struct cred
*new = bprm
->cred
;
359 if (caps
->magic_etc
& VFS_CAP_FLAGS_EFFECTIVE
)
362 if (caps
->magic_etc
& VFS_CAP_REVISION_MASK
)
365 CAP_FOR_EACH_U32(i
) {
366 __u32 permitted
= caps
->permitted
.cap
[i
];
367 __u32 inheritable
= caps
->inheritable
.cap
[i
];
370 * pP' = (X & fP) | (pI & fI)
372 new->cap_permitted
.cap
[i
] =
373 (new->cap_bset
.cap
[i
] & permitted
) |
374 (new->cap_inheritable
.cap
[i
] & inheritable
);
376 if (permitted
& ~new->cap_permitted
.cap
[i
])
377 /* insufficient to execute correctly */
382 * For legacy apps, with no internal support for recognizing they
383 * do not have enough capabilities, we return an error if they are
384 * missing some "forced" (aka file-permitted) capabilities.
386 return *effective
? ret
: 0;
390 * Extract the on-exec-apply capability sets for an executable file.
392 int get_vfs_caps_from_disk(const struct dentry
*dentry
, struct cpu_vfs_cap_data
*cpu_caps
)
394 struct inode
*inode
= dentry
->d_inode
;
398 struct vfs_cap_data caps
;
400 memset(cpu_caps
, 0, sizeof(struct cpu_vfs_cap_data
));
402 if (!inode
|| !inode
->i_op
->getxattr
)
405 size
= inode
->i_op
->getxattr((struct dentry
*)dentry
, XATTR_NAME_CAPS
, &caps
,
407 if (size
== -ENODATA
|| size
== -EOPNOTSUPP
)
408 /* no data, that's ok */
413 if (size
< sizeof(magic_etc
))
416 cpu_caps
->magic_etc
= magic_etc
= le32_to_cpu(caps
.magic_etc
);
418 switch (magic_etc
& VFS_CAP_REVISION_MASK
) {
419 case VFS_CAP_REVISION_1
:
420 if (size
!= XATTR_CAPS_SZ_1
)
422 tocopy
= VFS_CAP_U32_1
;
424 case VFS_CAP_REVISION_2
:
425 if (size
!= XATTR_CAPS_SZ_2
)
427 tocopy
= VFS_CAP_U32_2
;
433 CAP_FOR_EACH_U32(i
) {
436 cpu_caps
->permitted
.cap
[i
] = le32_to_cpu(caps
.data
[i
].permitted
);
437 cpu_caps
->inheritable
.cap
[i
] = le32_to_cpu(caps
.data
[i
].inheritable
);
440 cpu_caps
->permitted
.cap
[CAP_LAST_U32
] &= CAP_LAST_U32_VALID_MASK
;
441 cpu_caps
->inheritable
.cap
[CAP_LAST_U32
] &= CAP_LAST_U32_VALID_MASK
;
447 * Attempt to get the on-exec apply capability sets for an executable file from
448 * its xattrs and, if present, apply them to the proposed credentials being
449 * constructed by execve().
451 static int get_file_caps(struct linux_binprm
*bprm
, bool *effective
, bool *has_cap
)
453 struct dentry
*dentry
;
455 struct cpu_vfs_cap_data vcaps
;
457 bprm_clear_caps(bprm
);
459 if (!file_caps_enabled
)
462 if (bprm
->file
->f_path
.mnt
->mnt_flags
& MNT_NOSUID
)
465 dentry
= dget(bprm
->file
->f_dentry
);
467 rc
= get_vfs_caps_from_disk(dentry
, &vcaps
);
470 printk(KERN_NOTICE
"%s: get_vfs_caps_from_disk returned %d for %s\n",
471 __func__
, rc
, bprm
->filename
);
472 else if (rc
== -ENODATA
)
477 rc
= bprm_caps_from_vfs_caps(&vcaps
, bprm
, effective
, has_cap
);
479 printk(KERN_NOTICE
"%s: cap_from_disk returned %d for %s\n",
480 __func__
, rc
, bprm
->filename
);
485 bprm_clear_caps(bprm
);
491 * cap_bprm_set_creds - Set up the proposed credentials for execve().
492 * @bprm: The execution parameters, including the proposed creds
494 * Set up the proposed credentials for a new execution context being
495 * constructed by execve(). The proposed creds in @bprm->cred is altered,
496 * which won't take effect immediately. Returns 0 if successful, -ve on error.
498 int cap_bprm_set_creds(struct linux_binprm
*bprm
)
500 const struct cred
*old
= current_cred();
501 struct cred
*new = bprm
->cred
;
502 bool effective
, has_cap
= false;
507 ret
= get_file_caps(bprm
, &effective
, &has_cap
);
511 root_uid
= make_kuid(new->user_ns
, 0);
513 if (!issecure(SECURE_NOROOT
)) {
515 * If the legacy file capability is set, then don't set privs
516 * for a setuid root binary run by a non-root user. Do set it
517 * for a root user just to cause least surprise to an admin.
519 if (has_cap
&& !uid_eq(new->uid
, root_uid
) && uid_eq(new->euid
, root_uid
)) {
520 warn_setuid_and_fcaps_mixed(bprm
->filename
);
524 * To support inheritance of root-permissions and suid-root
525 * executables under compatibility mode, we override the
526 * capability sets for the file.
528 * If only the real uid is 0, we do not set the effective bit.
530 if (uid_eq(new->euid
, root_uid
) || uid_eq(new->uid
, root_uid
)) {
531 /* pP' = (cap_bset & ~0) | (pI & ~0) */
532 new->cap_permitted
= cap_combine(old
->cap_bset
,
533 old
->cap_inheritable
);
535 if (uid_eq(new->euid
, root_uid
))
540 /* if we have fs caps, clear dangerous personality flags */
541 if (!cap_issubset(new->cap_permitted
, old
->cap_permitted
))
542 bprm
->per_clear
|= PER_CLEAR_ON_SETID
;
545 /* Don't let someone trace a set[ug]id/setpcap binary with the revised
546 * credentials unless they have the appropriate permit.
548 * In addition, if NO_NEW_PRIVS, then ensure we get no new privs.
550 if ((!uid_eq(new->euid
, old
->uid
) ||
551 !gid_eq(new->egid
, old
->gid
) ||
552 !cap_issubset(new->cap_permitted
, old
->cap_permitted
)) &&
553 bprm
->unsafe
& ~LSM_UNSAFE_PTRACE_CAP
) {
554 /* downgrade; they get no more than they had, and maybe less */
555 if (!capable(CAP_SETUID
) ||
556 (bprm
->unsafe
& LSM_UNSAFE_NO_NEW_PRIVS
)) {
557 new->euid
= new->uid
;
558 new->egid
= new->gid
;
560 new->cap_permitted
= cap_intersect(new->cap_permitted
,
564 new->suid
= new->fsuid
= new->euid
;
565 new->sgid
= new->fsgid
= new->egid
;
568 new->cap_effective
= new->cap_permitted
;
570 cap_clear(new->cap_effective
);
571 bprm
->cap_effective
= effective
;
574 * Audit candidate if current->cap_effective is set
576 * We do not bother to audit if 3 things are true:
577 * 1) cap_effective has all caps
579 * 3) root is supposed to have all caps (SECURE_NOROOT)
580 * Since this is just a normal root execing a process.
582 * Number 1 above might fail if you don't have a full bset, but I think
583 * that is interesting information to audit.
585 if (!cap_isclear(new->cap_effective
)) {
586 if (!cap_issubset(CAP_FULL_SET
, new->cap_effective
) ||
587 !uid_eq(new->euid
, root_uid
) || !uid_eq(new->uid
, root_uid
) ||
588 issecure(SECURE_NOROOT
)) {
589 ret
= audit_log_bprm_fcaps(bprm
, new, old
);
595 new->securebits
&= ~issecure_mask(SECURE_KEEP_CAPS
);
600 * cap_bprm_secureexec - Determine whether a secure execution is required
601 * @bprm: The execution parameters
603 * Determine whether a secure execution is required, return 1 if it is, and 0
606 * The credentials have been committed by this point, and so are no longer
607 * available through @bprm->cred.
609 int cap_bprm_secureexec(struct linux_binprm
*bprm
)
611 const struct cred
*cred
= current_cred();
612 kuid_t root_uid
= make_kuid(cred
->user_ns
, 0);
614 if (!uid_eq(cred
->uid
, root_uid
)) {
615 if (bprm
->cap_effective
)
617 if (!cap_isclear(cred
->cap_permitted
))
621 return (!uid_eq(cred
->euid
, cred
->uid
) ||
622 !gid_eq(cred
->egid
, cred
->gid
));
626 * cap_inode_setxattr - Determine whether an xattr may be altered
627 * @dentry: The inode/dentry being altered
628 * @name: The name of the xattr to be changed
629 * @value: The value that the xattr will be changed to
630 * @size: The size of value
631 * @flags: The replacement flag
633 * Determine whether an xattr may be altered or set on an inode, returning 0 if
634 * permission is granted, -ve if denied.
636 * This is used to make sure security xattrs don't get updated or set by those
637 * who aren't privileged to do so.
639 int cap_inode_setxattr(struct dentry
*dentry
, const char *name
,
640 const void *value
, size_t size
, int flags
)
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_inode_removexattr - Determine whether an xattr may be removed
657 * @dentry: The inode/dentry being altered
658 * @name: The name of the xattr to be changed
660 * Determine whether an xattr may be removed from an inode, returning 0 if
661 * permission is granted, -ve if denied.
663 * This is used to make sure security xattrs don't get removed by those who
664 * aren't privileged to remove them.
666 int cap_inode_removexattr(struct dentry
*dentry
, const char *name
)
668 if (!strcmp(name
, XATTR_NAME_CAPS
)) {
669 if (!capable(CAP_SETFCAP
))
674 if (!strncmp(name
, XATTR_SECURITY_PREFIX
,
675 sizeof(XATTR_SECURITY_PREFIX
) - 1) &&
676 !capable(CAP_SYS_ADMIN
))
682 * cap_emulate_setxuid() fixes the effective / permitted capabilities of
683 * a process after a call to setuid, setreuid, or setresuid.
685 * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
686 * {r,e,s}uid != 0, the permitted and effective capabilities are
689 * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
690 * capabilities of the process are cleared.
692 * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
693 * capabilities are set to the permitted capabilities.
695 * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should
700 * cevans - New behaviour, Oct '99
701 * A process may, via prctl(), elect to keep its capabilities when it
702 * calls setuid() and switches away from uid==0. Both permitted and
703 * effective sets will be retained.
704 * Without this change, it was impossible for a daemon to drop only some
705 * of its privilege. The call to setuid(!=0) would drop all privileges!
706 * Keeping uid 0 is not an option because uid 0 owns too many vital
708 * Thanks to Olaf Kirch and Peter Benie for spotting this.
710 static inline void cap_emulate_setxuid(struct cred
*new, const struct cred
*old
)
712 kuid_t root_uid
= make_kuid(old
->user_ns
, 0);
714 if ((uid_eq(old
->uid
, root_uid
) ||
715 uid_eq(old
->euid
, root_uid
) ||
716 uid_eq(old
->suid
, root_uid
)) &&
717 (!uid_eq(new->uid
, root_uid
) &&
718 !uid_eq(new->euid
, root_uid
) &&
719 !uid_eq(new->suid
, root_uid
)) &&
720 !issecure(SECURE_KEEP_CAPS
)) {
721 cap_clear(new->cap_permitted
);
722 cap_clear(new->cap_effective
);
724 if (uid_eq(old
->euid
, root_uid
) && !uid_eq(new->euid
, root_uid
))
725 cap_clear(new->cap_effective
);
726 if (!uid_eq(old
->euid
, root_uid
) && uid_eq(new->euid
, root_uid
))
727 new->cap_effective
= new->cap_permitted
;
731 * cap_task_fix_setuid - Fix up the results of setuid() call
732 * @new: The proposed credentials
733 * @old: The current task's current credentials
734 * @flags: Indications of what has changed
736 * Fix up the results of setuid() call before the credential changes are
737 * actually applied, returning 0 to grant the changes, -ve to deny them.
739 int cap_task_fix_setuid(struct cred
*new, const struct cred
*old
, int flags
)
745 /* juggle the capabilities to follow [RES]UID changes unless
746 * otherwise suppressed */
747 if (!issecure(SECURE_NO_SETUID_FIXUP
))
748 cap_emulate_setxuid(new, old
);
752 /* juggle the capabilties to follow FSUID changes, unless
753 * otherwise suppressed
755 * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
756 * if not, we might be a bit too harsh here.
758 if (!issecure(SECURE_NO_SETUID_FIXUP
)) {
759 kuid_t root_uid
= make_kuid(old
->user_ns
, 0);
760 if (uid_eq(old
->fsuid
, root_uid
) && !uid_eq(new->fsuid
, root_uid
))
762 cap_drop_fs_set(new->cap_effective
);
764 if (!uid_eq(old
->fsuid
, root_uid
) && uid_eq(new->fsuid
, root_uid
))
766 cap_raise_fs_set(new->cap_effective
,
779 * Rationale: code calling task_setscheduler, task_setioprio, and
780 * task_setnice, assumes that
781 * . if capable(cap_sys_nice), then those actions should be allowed
782 * . if not capable(cap_sys_nice), but acting on your own processes,
783 * then those actions should be allowed
784 * This is insufficient now since you can call code without suid, but
785 * yet with increased caps.
786 * So we check for increased caps on the target process.
788 static int cap_safe_nice(struct task_struct
*p
)
793 is_subset
= cap_issubset(__task_cred(p
)->cap_permitted
,
794 current_cred()->cap_permitted
);
797 if (!is_subset
&& !capable(CAP_SYS_NICE
))
803 * cap_task_setscheduler - Detemine if scheduler policy change is permitted
804 * @p: The task to affect
806 * Detemine if the requested scheduler policy change is permitted for the
807 * specified task, returning 0 if permission is granted, -ve if denied.
809 int cap_task_setscheduler(struct task_struct
*p
)
811 return cap_safe_nice(p
);
815 * cap_task_ioprio - Detemine if I/O priority change is permitted
816 * @p: The task to affect
817 * @ioprio: The I/O priority to set
819 * Detemine if the requested I/O priority change is permitted for the specified
820 * task, returning 0 if permission is granted, -ve if denied.
822 int cap_task_setioprio(struct task_struct
*p
, int ioprio
)
824 return cap_safe_nice(p
);
828 * cap_task_ioprio - Detemine if task priority change is permitted
829 * @p: The task to affect
830 * @nice: The nice value to set
832 * Detemine if the requested task priority change is permitted for the
833 * specified task, returning 0 if permission is granted, -ve if denied.
835 int cap_task_setnice(struct task_struct
*p
, int nice
)
837 return cap_safe_nice(p
);
841 * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from
842 * the current task's bounding set. Returns 0 on success, -ve on error.
844 static long cap_prctl_drop(struct cred
*new, unsigned long cap
)
846 if (!capable(CAP_SETPCAP
))
851 cap_lower(new->cap_bset
, cap
);
856 * cap_task_prctl - Implement process control functions for this security module
857 * @option: The process control function requested
858 * @arg2, @arg3, @arg4, @arg5: The argument data for this function
860 * Allow process control functions (sys_prctl()) to alter capabilities; may
861 * also deny access to other functions not otherwise implemented here.
863 * Returns 0 or +ve on success, -ENOSYS if this function is not implemented
864 * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM
865 * modules will consider performing the function.
867 int cap_task_prctl(int option
, unsigned long arg2
, unsigned long arg3
,
868 unsigned long arg4
, unsigned long arg5
)
873 new = prepare_creds();
878 case PR_CAPBSET_READ
:
880 if (!cap_valid(arg2
))
882 error
= !!cap_raised(new->cap_bset
, arg2
);
885 case PR_CAPBSET_DROP
:
886 error
= cap_prctl_drop(new, arg2
);
892 * The next four prctl's remain to assist with transitioning a
893 * system from legacy UID=0 based privilege (when filesystem
894 * capabilities are not in use) to a system using filesystem
895 * capabilities only - as the POSIX.1e draft intended.
899 * PR_SET_SECUREBITS =
900 * issecure_mask(SECURE_KEEP_CAPS_LOCKED)
901 * | issecure_mask(SECURE_NOROOT)
902 * | issecure_mask(SECURE_NOROOT_LOCKED)
903 * | issecure_mask(SECURE_NO_SETUID_FIXUP)
904 * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
906 * will ensure that the current process and all of its
907 * children will be locked into a pure
908 * capability-based-privilege environment.
910 case PR_SET_SECUREBITS
:
912 if ((((new->securebits
& SECURE_ALL_LOCKS
) >> 1)
913 & (new->securebits
^ arg2
)) /*[1]*/
914 || ((new->securebits
& SECURE_ALL_LOCKS
& ~arg2
)) /*[2]*/
915 || (arg2
& ~(SECURE_ALL_LOCKS
| SECURE_ALL_BITS
)) /*[3]*/
916 || (cap_capable(current_cred(),
917 current_cred()->user_ns
, CAP_SETPCAP
,
918 SECURITY_CAP_AUDIT
) != 0) /*[4]*/
920 * [1] no changing of bits that are locked
921 * [2] no unlocking of locks
922 * [3] no setting of unsupported bits
923 * [4] doing anything requires privilege (go read about
924 * the "sendmail capabilities bug")
927 /* cannot change a locked bit */
929 new->securebits
= arg2
;
932 case PR_GET_SECUREBITS
:
933 error
= new->securebits
;
936 case PR_GET_KEEPCAPS
:
937 if (issecure(SECURE_KEEP_CAPS
))
941 case PR_SET_KEEPCAPS
:
943 if (arg2
> 1) /* Note, we rely on arg2 being unsigned here */
946 if (issecure(SECURE_KEEP_CAPS_LOCKED
))
949 new->securebits
|= issecure_mask(SECURE_KEEP_CAPS
);
951 new->securebits
&= ~issecure_mask(SECURE_KEEP_CAPS
);
955 /* No functionality available - continue with default */
960 /* Functionality provided */
962 return commit_creds(new);
971 * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted
972 * @mm: The VM space in which the new mapping is to be made
973 * @pages: The size of the mapping
975 * Determine whether the allocation of a new virtual mapping by the current
976 * task is permitted, returning 0 if permission is granted, -ve if not.
978 int cap_vm_enough_memory(struct mm_struct
*mm
, long pages
)
980 int cap_sys_admin
= 0;
982 if (cap_capable(current_cred(), &init_user_ns
, CAP_SYS_ADMIN
,
983 SECURITY_CAP_NOAUDIT
) == 0)
985 return __vm_enough_memory(mm
, pages
, cap_sys_admin
);
989 * cap_mmap_addr - check if able to map given addr
990 * @addr: address attempting to be mapped
992 * If the process is attempting to map memory below dac_mmap_min_addr they need
993 * CAP_SYS_RAWIO. The other parameters to this function are unused by the
994 * capability security module. Returns 0 if this mapping should be allowed
997 int cap_mmap_addr(unsigned long addr
)
1001 if (addr
< dac_mmap_min_addr
) {
1002 ret
= cap_capable(current_cred(), &init_user_ns
, CAP_SYS_RAWIO
,
1003 SECURITY_CAP_AUDIT
);
1004 /* set PF_SUPERPRIV if it turns out we allow the low mmap */
1006 current
->flags
|= PF_SUPERPRIV
;
1011 int cap_mmap_file(struct file
*file
, unsigned long reqprot
,
1012 unsigned long prot
, unsigned long flags
)