1 /* Common capabilities, needed by capability.o and root_plug.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>
32 * If a non-root user executes a setuid-root binary in
33 * !secure(SECURE_NOROOT) mode, then we raise capabilities.
34 * However if fE is also set, then the intent is for only
35 * the file capabilities to be applied, and the setuid-root
36 * bit is left on either to change the uid (plausible) or
37 * to get full privilege on a kernel without file capabilities
38 * support. So in that case we do not raise capabilities.
40 * Warn if that happens, once per boot.
42 static void warn_setuid_and_fcaps_mixed(char *fname
)
46 printk(KERN_INFO
"warning: `%s' has both setuid-root and"
47 " effective capabilities. Therefore not raising all"
48 " capabilities.\n", fname
);
53 int cap_netlink_send(struct sock
*sk
, struct sk_buff
*skb
)
55 NETLINK_CB(skb
).eff_cap
= current_cap();
59 int cap_netlink_recv(struct sk_buff
*skb
, int cap
)
61 if (!cap_raised(NETLINK_CB(skb
).eff_cap
, cap
))
65 EXPORT_SYMBOL(cap_netlink_recv
);
68 * cap_capable - Determine whether a task has a particular effective capability
69 * @tsk: The task to query
70 * @cred: The credentials to use
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(struct task_struct
*tsk
, const struct cred
*cred
, int cap
,
85 return cap_raised(cred
->cap_effective
, cap
) ? 0 : -EPERM
;
89 * cap_settime - Determine whether the current process may set the system clock
90 * @ts: The time to set
91 * @tz: The timezone to set
93 * Determine whether the current process may set the system clock and timezone
94 * information, returning 0 if permission granted, -ve if denied.
96 int cap_settime(struct timespec
*ts
, struct timezone
*tz
)
98 if (!capable(CAP_SYS_TIME
))
104 * cap_ptrace_access_check - Determine whether the current process may access
106 * @child: The process to be accessed
107 * @mode: The mode of attachment.
109 * Determine whether a process may access another, returning 0 if permission
110 * granted, -ve if denied.
112 int cap_ptrace_access_check(struct task_struct
*child
, unsigned int mode
)
117 if (!cap_issubset(__task_cred(child
)->cap_permitted
,
118 current_cred()->cap_permitted
) &&
119 !capable(CAP_SYS_PTRACE
))
126 * cap_ptrace_traceme - Determine whether another process may trace the current
127 * @parent: The task proposed to be the tracer
129 * Determine whether the nominated task is permitted to trace the current
130 * process, returning 0 if permission is granted, -ve if denied.
132 int cap_ptrace_traceme(struct task_struct
*parent
)
137 if (!cap_issubset(current_cred()->cap_permitted
,
138 __task_cred(parent
)->cap_permitted
) &&
139 !has_capability(parent
, CAP_SYS_PTRACE
))
146 * cap_capget - Retrieve a task's capability sets
147 * @target: The task from which to retrieve the capability sets
148 * @effective: The place to record the effective set
149 * @inheritable: The place to record the inheritable set
150 * @permitted: The place to record the permitted set
152 * This function retrieves the capabilities of the nominated task and returns
153 * them to the caller.
155 int cap_capget(struct task_struct
*target
, kernel_cap_t
*effective
,
156 kernel_cap_t
*inheritable
, kernel_cap_t
*permitted
)
158 const struct cred
*cred
;
160 /* Derived from kernel/capability.c:sys_capget. */
162 cred
= __task_cred(target
);
163 *effective
= cred
->cap_effective
;
164 *inheritable
= cred
->cap_inheritable
;
165 *permitted
= cred
->cap_permitted
;
171 * Determine whether the inheritable capabilities are limited to the old
172 * permitted set. Returns 1 if they are limited, 0 if they are not.
174 static inline int cap_inh_is_capped(void)
176 #ifdef CONFIG_SECURITY_FILE_CAPABILITIES
178 /* they are so limited unless the current task has the CAP_SETPCAP
181 if (cap_capable(current
, current_cred(), CAP_SETPCAP
,
182 SECURITY_CAP_AUDIT
) == 0)
189 * cap_capset - Validate and apply proposed changes to current's capabilities
190 * @new: The proposed new credentials; alterations should be made here
191 * @old: The current task's current credentials
192 * @effective: A pointer to the proposed new effective capabilities set
193 * @inheritable: A pointer to the proposed new inheritable capabilities set
194 * @permitted: A pointer to the proposed new permitted capabilities set
196 * This function validates and applies a proposed mass change to the current
197 * process's capability sets. The changes are made to the proposed new
198 * credentials, and assuming no error, will be committed by the caller of LSM.
200 int cap_capset(struct cred
*new,
201 const struct cred
*old
,
202 const kernel_cap_t
*effective
,
203 const kernel_cap_t
*inheritable
,
204 const kernel_cap_t
*permitted
)
206 if (cap_inh_is_capped() &&
207 !cap_issubset(*inheritable
,
208 cap_combine(old
->cap_inheritable
,
209 old
->cap_permitted
)))
210 /* incapable of using this inheritable set */
213 if (!cap_issubset(*inheritable
,
214 cap_combine(old
->cap_inheritable
,
216 /* no new pI capabilities outside bounding set */
219 /* verify restrictions on target's new Permitted set */
220 if (!cap_issubset(*permitted
, old
->cap_permitted
))
223 /* verify the _new_Effective_ is a subset of the _new_Permitted_ */
224 if (!cap_issubset(*effective
, *permitted
))
227 new->cap_effective
= *effective
;
228 new->cap_inheritable
= *inheritable
;
229 new->cap_permitted
= *permitted
;
234 * Clear proposed capability sets for execve().
236 static inline void bprm_clear_caps(struct linux_binprm
*bprm
)
238 cap_clear(bprm
->cred
->cap_permitted
);
239 bprm
->cap_effective
= false;
242 #ifdef CONFIG_SECURITY_FILE_CAPABILITIES
245 * cap_inode_need_killpriv - Determine if inode change affects privileges
246 * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV
248 * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV
249 * affects the security markings on that inode, and if it is, should
250 * inode_killpriv() be invoked or the change rejected?
252 * Returns 0 if granted; +ve if granted, but inode_killpriv() is required; and
253 * -ve to deny the change.
255 int cap_inode_need_killpriv(struct dentry
*dentry
)
257 struct inode
*inode
= dentry
->d_inode
;
260 if (!inode
->i_op
->getxattr
)
263 error
= inode
->i_op
->getxattr(dentry
, XATTR_NAME_CAPS
, NULL
, 0);
270 * cap_inode_killpriv - Erase the security markings on an inode
271 * @dentry: The inode/dentry to alter
273 * Erase the privilege-enhancing security markings on an inode.
275 * Returns 0 if successful, -ve on error.
277 int cap_inode_killpriv(struct dentry
*dentry
)
279 struct inode
*inode
= dentry
->d_inode
;
281 if (!inode
->i_op
->removexattr
)
284 return inode
->i_op
->removexattr(dentry
, XATTR_NAME_CAPS
);
288 * Calculate the new process capability sets from the capability sets attached
291 static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data
*caps
,
292 struct linux_binprm
*bprm
,
295 struct cred
*new = bprm
->cred
;
299 if (caps
->magic_etc
& VFS_CAP_FLAGS_EFFECTIVE
)
302 CAP_FOR_EACH_U32(i
) {
303 __u32 permitted
= caps
->permitted
.cap
[i
];
304 __u32 inheritable
= caps
->inheritable
.cap
[i
];
307 * pP' = (X & fP) | (pI & fI)
309 new->cap_permitted
.cap
[i
] =
310 (new->cap_bset
.cap
[i
] & permitted
) |
311 (new->cap_inheritable
.cap
[i
] & inheritable
);
313 if (permitted
& ~new->cap_permitted
.cap
[i
])
314 /* insufficient to execute correctly */
319 * For legacy apps, with no internal support for recognizing they
320 * do not have enough capabilities, we return an error if they are
321 * missing some "forced" (aka file-permitted) capabilities.
323 return *effective
? ret
: 0;
327 * Extract the on-exec-apply capability sets for an executable file.
329 int get_vfs_caps_from_disk(const struct dentry
*dentry
, struct cpu_vfs_cap_data
*cpu_caps
)
331 struct inode
*inode
= dentry
->d_inode
;
335 struct vfs_cap_data caps
;
337 memset(cpu_caps
, 0, sizeof(struct cpu_vfs_cap_data
));
339 if (!inode
|| !inode
->i_op
->getxattr
)
342 size
= inode
->i_op
->getxattr((struct dentry
*)dentry
, XATTR_NAME_CAPS
, &caps
,
344 if (size
== -ENODATA
|| size
== -EOPNOTSUPP
)
345 /* no data, that's ok */
350 if (size
< sizeof(magic_etc
))
353 cpu_caps
->magic_etc
= magic_etc
= le32_to_cpu(caps
.magic_etc
);
355 switch (magic_etc
& VFS_CAP_REVISION_MASK
) {
356 case VFS_CAP_REVISION_1
:
357 if (size
!= XATTR_CAPS_SZ_1
)
359 tocopy
= VFS_CAP_U32_1
;
361 case VFS_CAP_REVISION_2
:
362 if (size
!= XATTR_CAPS_SZ_2
)
364 tocopy
= VFS_CAP_U32_2
;
370 CAP_FOR_EACH_U32(i
) {
373 cpu_caps
->permitted
.cap
[i
] = le32_to_cpu(caps
.data
[i
].permitted
);
374 cpu_caps
->inheritable
.cap
[i
] = le32_to_cpu(caps
.data
[i
].inheritable
);
381 * Attempt to get the on-exec apply capability sets for an executable file from
382 * its xattrs and, if present, apply them to the proposed credentials being
383 * constructed by execve().
385 static int get_file_caps(struct linux_binprm
*bprm
, bool *effective
)
387 struct dentry
*dentry
;
389 struct cpu_vfs_cap_data vcaps
;
391 bprm_clear_caps(bprm
);
393 if (!file_caps_enabled
)
396 if (bprm
->file
->f_vfsmnt
->mnt_flags
& MNT_NOSUID
)
399 dentry
= dget(bprm
->file
->f_dentry
);
401 rc
= get_vfs_caps_from_disk(dentry
, &vcaps
);
404 printk(KERN_NOTICE
"%s: get_vfs_caps_from_disk returned %d for %s\n",
405 __func__
, rc
, bprm
->filename
);
406 else if (rc
== -ENODATA
)
411 rc
= bprm_caps_from_vfs_caps(&vcaps
, bprm
, effective
);
413 printk(KERN_NOTICE
"%s: cap_from_disk returned %d for %s\n",
414 __func__
, rc
, bprm
->filename
);
419 bprm_clear_caps(bprm
);
425 int cap_inode_need_killpriv(struct dentry
*dentry
)
430 int cap_inode_killpriv(struct dentry
*dentry
)
435 int get_vfs_caps_from_disk(const struct dentry
*dentry
, struct cpu_vfs_cap_data
*cpu_caps
)
437 memset(cpu_caps
, 0, sizeof(struct cpu_vfs_cap_data
));
441 static inline int get_file_caps(struct linux_binprm
*bprm
, bool *effective
)
443 bprm_clear_caps(bprm
);
449 * Determine whether a exec'ing process's new permitted capabilities should be
450 * limited to just what it already has.
452 * This prevents processes that are being ptraced from gaining access to
453 * CAP_SETPCAP, unless the process they're tracing already has it, and the
454 * binary they're executing has filecaps that elevate it.
456 * Returns 1 if they should be limited, 0 if they are not.
458 static inline int cap_limit_ptraced_target(void)
460 #ifndef CONFIG_SECURITY_FILE_CAPABILITIES
461 if (capable(CAP_SETPCAP
))
468 * cap_bprm_set_creds - Set up the proposed credentials for execve().
469 * @bprm: The execution parameters, including the proposed creds
471 * Set up the proposed credentials for a new execution context being
472 * constructed by execve(). The proposed creds in @bprm->cred is altered,
473 * which won't take effect immediately. Returns 0 if successful, -ve on error.
475 int cap_bprm_set_creds(struct linux_binprm
*bprm
)
477 const struct cred
*old
= current_cred();
478 struct cred
*new = bprm
->cred
;
483 ret
= get_file_caps(bprm
, &effective
);
487 if (!issecure(SECURE_NOROOT
)) {
489 * If the legacy file capability is set, then don't set privs
490 * for a setuid root binary run by a non-root user. Do set it
491 * for a root user just to cause least surprise to an admin.
493 if (effective
&& new->uid
!= 0 && new->euid
== 0) {
494 warn_setuid_and_fcaps_mixed(bprm
->filename
);
498 * To support inheritance of root-permissions and suid-root
499 * executables under compatibility mode, we override the
500 * capability sets for the file.
502 * If only the real uid is 0, we do not set the effective bit.
504 if (new->euid
== 0 || new->uid
== 0) {
505 /* pP' = (cap_bset & ~0) | (pI & ~0) */
506 new->cap_permitted
= cap_combine(old
->cap_bset
,
507 old
->cap_inheritable
);
514 /* Don't let someone trace a set[ug]id/setpcap binary with the revised
515 * credentials unless they have the appropriate permit
517 if ((new->euid
!= old
->uid
||
518 new->egid
!= old
->gid
||
519 !cap_issubset(new->cap_permitted
, old
->cap_permitted
)) &&
520 bprm
->unsafe
& ~LSM_UNSAFE_PTRACE_CAP
) {
521 /* downgrade; they get no more than they had, and maybe less */
522 if (!capable(CAP_SETUID
)) {
523 new->euid
= new->uid
;
524 new->egid
= new->gid
;
526 if (cap_limit_ptraced_target())
527 new->cap_permitted
= cap_intersect(new->cap_permitted
,
531 new->suid
= new->fsuid
= new->euid
;
532 new->sgid
= new->fsgid
= new->egid
;
534 /* For init, we want to retain the capabilities set in the initial
535 * task. Thus we skip the usual capability rules
537 if (!is_global_init(current
)) {
539 new->cap_effective
= new->cap_permitted
;
541 cap_clear(new->cap_effective
);
543 bprm
->cap_effective
= effective
;
546 * Audit candidate if current->cap_effective is set
548 * We do not bother to audit if 3 things are true:
549 * 1) cap_effective has all caps
551 * 3) root is supposed to have all caps (SECURE_NOROOT)
552 * Since this is just a normal root execing a process.
554 * Number 1 above might fail if you don't have a full bset, but I think
555 * that is interesting information to audit.
557 if (!cap_isclear(new->cap_effective
)) {
558 if (!cap_issubset(CAP_FULL_SET
, new->cap_effective
) ||
559 new->euid
!= 0 || new->uid
!= 0 ||
560 issecure(SECURE_NOROOT
)) {
561 ret
= audit_log_bprm_fcaps(bprm
, new, old
);
567 new->securebits
&= ~issecure_mask(SECURE_KEEP_CAPS
);
572 * cap_bprm_secureexec - Determine whether a secure execution is required
573 * @bprm: The execution parameters
575 * Determine whether a secure execution is required, return 1 if it is, and 0
578 * The credentials have been committed by this point, and so are no longer
579 * available through @bprm->cred.
581 int cap_bprm_secureexec(struct linux_binprm
*bprm
)
583 const struct cred
*cred
= current_cred();
585 if (cred
->uid
!= 0) {
586 if (bprm
->cap_effective
)
588 if (!cap_isclear(cred
->cap_permitted
))
592 return (cred
->euid
!= cred
->uid
||
593 cred
->egid
!= cred
->gid
);
597 * cap_inode_setxattr - Determine whether an xattr may be altered
598 * @dentry: The inode/dentry being altered
599 * @name: The name of the xattr to be changed
600 * @value: The value that the xattr will be changed to
601 * @size: The size of value
602 * @flags: The replacement flag
604 * Determine whether an xattr may be altered or set on an inode, returning 0 if
605 * permission is granted, -ve if denied.
607 * This is used to make sure security xattrs don't get updated or set by those
608 * who aren't privileged to do so.
610 int cap_inode_setxattr(struct dentry
*dentry
, const char *name
,
611 const void *value
, size_t size
, int flags
)
613 if (!strcmp(name
, XATTR_NAME_CAPS
)) {
614 if (!capable(CAP_SETFCAP
))
619 if (!strncmp(name
, XATTR_SECURITY_PREFIX
,
620 sizeof(XATTR_SECURITY_PREFIX
) - 1) &&
621 !capable(CAP_SYS_ADMIN
))
627 * cap_inode_removexattr - Determine whether an xattr may be removed
628 * @dentry: The inode/dentry being altered
629 * @name: The name of the xattr to be changed
631 * Determine whether an xattr may be removed from an inode, returning 0 if
632 * permission is granted, -ve if denied.
634 * This is used to make sure security xattrs don't get removed by those who
635 * aren't privileged to remove them.
637 int cap_inode_removexattr(struct dentry
*dentry
, const char *name
)
639 if (!strcmp(name
, XATTR_NAME_CAPS
)) {
640 if (!capable(CAP_SETFCAP
))
645 if (!strncmp(name
, XATTR_SECURITY_PREFIX
,
646 sizeof(XATTR_SECURITY_PREFIX
) - 1) &&
647 !capable(CAP_SYS_ADMIN
))
653 * cap_emulate_setxuid() fixes the effective / permitted capabilities of
654 * a process after a call to setuid, setreuid, or setresuid.
656 * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
657 * {r,e,s}uid != 0, the permitted and effective capabilities are
660 * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
661 * capabilities of the process are cleared.
663 * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
664 * capabilities are set to the permitted capabilities.
666 * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should
671 * cevans - New behaviour, Oct '99
672 * A process may, via prctl(), elect to keep its capabilities when it
673 * calls setuid() and switches away from uid==0. Both permitted and
674 * effective sets will be retained.
675 * Without this change, it was impossible for a daemon to drop only some
676 * of its privilege. The call to setuid(!=0) would drop all privileges!
677 * Keeping uid 0 is not an option because uid 0 owns too many vital
679 * Thanks to Olaf Kirch and Peter Benie for spotting this.
681 static inline void cap_emulate_setxuid(struct cred
*new, const struct cred
*old
)
683 if ((old
->uid
== 0 || old
->euid
== 0 || old
->suid
== 0) &&
684 (new->uid
!= 0 && new->euid
!= 0 && new->suid
!= 0) &&
685 !issecure(SECURE_KEEP_CAPS
)) {
686 cap_clear(new->cap_permitted
);
687 cap_clear(new->cap_effective
);
689 if (old
->euid
== 0 && new->euid
!= 0)
690 cap_clear(new->cap_effective
);
691 if (old
->euid
!= 0 && new->euid
== 0)
692 new->cap_effective
= new->cap_permitted
;
696 * cap_task_fix_setuid - Fix up the results of setuid() call
697 * @new: The proposed credentials
698 * @old: The current task's current credentials
699 * @flags: Indications of what has changed
701 * Fix up the results of setuid() call before the credential changes are
702 * actually applied, returning 0 to grant the changes, -ve to deny them.
704 int cap_task_fix_setuid(struct cred
*new, const struct cred
*old
, int flags
)
710 /* juggle the capabilities to follow [RES]UID changes unless
711 * otherwise suppressed */
712 if (!issecure(SECURE_NO_SETUID_FIXUP
))
713 cap_emulate_setxuid(new, old
);
717 /* juggle the capabilties to follow FSUID changes, unless
718 * otherwise suppressed
720 * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
721 * if not, we might be a bit too harsh here.
723 if (!issecure(SECURE_NO_SETUID_FIXUP
)) {
724 if (old
->fsuid
== 0 && new->fsuid
!= 0)
726 cap_drop_fs_set(new->cap_effective
);
728 if (old
->fsuid
!= 0 && new->fsuid
== 0)
730 cap_raise_fs_set(new->cap_effective
,
742 #ifdef CONFIG_SECURITY_FILE_CAPABILITIES
744 * Rationale: code calling task_setscheduler, task_setioprio, and
745 * task_setnice, assumes that
746 * . if capable(cap_sys_nice), then those actions should be allowed
747 * . if not capable(cap_sys_nice), but acting on your own processes,
748 * then those actions should be allowed
749 * This is insufficient now since you can call code without suid, but
750 * yet with increased caps.
751 * So we check for increased caps on the target process.
753 static int cap_safe_nice(struct task_struct
*p
)
758 is_subset
= cap_issubset(__task_cred(p
)->cap_permitted
,
759 current_cred()->cap_permitted
);
762 if (!is_subset
&& !capable(CAP_SYS_NICE
))
768 * cap_task_setscheduler - Detemine if scheduler policy change is permitted
769 * @p: The task to affect
770 * @policy: The policy to effect
771 * @lp: The parameters to the scheduling policy
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
, int policy
,
777 struct sched_param
*lp
)
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 int cap_task_setscheduler (struct task_struct
*p
, int policy
,
825 struct sched_param
*lp
)
829 int cap_task_setioprio (struct task_struct
*p
, int ioprio
)
833 int cap_task_setnice (struct task_struct
*p
, int nice
)
840 * cap_task_prctl - Implement process control functions for this security module
841 * @option: The process control function requested
842 * @arg2, @arg3, @arg4, @arg5: The argument data for this function
844 * Allow process control functions (sys_prctl()) to alter capabilities; may
845 * also deny access to other functions not otherwise implemented here.
847 * Returns 0 or +ve on success, -ENOSYS if this function is not implemented
848 * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM
849 * modules will consider performing the function.
851 int cap_task_prctl(int option
, unsigned long arg2
, unsigned long arg3
,
852 unsigned long arg4
, unsigned long arg5
)
857 new = prepare_creds();
862 case PR_CAPBSET_READ
:
864 if (!cap_valid(arg2
))
866 error
= !!cap_raised(new->cap_bset
, arg2
);
869 #ifdef CONFIG_SECURITY_FILE_CAPABILITIES
870 case PR_CAPBSET_DROP
:
871 error
= cap_prctl_drop(new, arg2
);
877 * The next four prctl's remain to assist with transitioning a
878 * system from legacy UID=0 based privilege (when filesystem
879 * capabilities are not in use) to a system using filesystem
880 * capabilities only - as the POSIX.1e draft intended.
884 * PR_SET_SECUREBITS =
885 * issecure_mask(SECURE_KEEP_CAPS_LOCKED)
886 * | issecure_mask(SECURE_NOROOT)
887 * | issecure_mask(SECURE_NOROOT_LOCKED)
888 * | issecure_mask(SECURE_NO_SETUID_FIXUP)
889 * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
891 * will ensure that the current process and all of its
892 * children will be locked into a pure
893 * capability-based-privilege environment.
895 case PR_SET_SECUREBITS
:
897 if ((((new->securebits
& SECURE_ALL_LOCKS
) >> 1)
898 & (new->securebits
^ arg2
)) /*[1]*/
899 || ((new->securebits
& SECURE_ALL_LOCKS
& ~arg2
)) /*[2]*/
900 || (arg2
& ~(SECURE_ALL_LOCKS
| SECURE_ALL_BITS
)) /*[3]*/
901 || (cap_capable(current
, current_cred(), CAP_SETPCAP
,
902 SECURITY_CAP_AUDIT
) != 0) /*[4]*/
904 * [1] no changing of bits that are locked
905 * [2] no unlocking of locks
906 * [3] no setting of unsupported bits
907 * [4] doing anything requires privilege (go read about
908 * the "sendmail capabilities bug")
911 /* cannot change a locked bit */
913 new->securebits
= arg2
;
916 case PR_GET_SECUREBITS
:
917 error
= new->securebits
;
920 #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */
922 case PR_GET_KEEPCAPS
:
923 if (issecure(SECURE_KEEP_CAPS
))
927 case PR_SET_KEEPCAPS
:
929 if (arg2
> 1) /* Note, we rely on arg2 being unsigned here */
932 if (issecure(SECURE_KEEP_CAPS_LOCKED
))
935 new->securebits
|= issecure_mask(SECURE_KEEP_CAPS
);
937 new->securebits
&= ~issecure_mask(SECURE_KEEP_CAPS
);
941 /* No functionality available - continue with default */
946 /* Functionality provided */
948 return commit_creds(new);
957 * cap_syslog - Determine whether syslog function is permitted
958 * @type: Function requested
960 * Determine whether the current process is permitted to use a particular
961 * syslog function, returning 0 if permission is granted, -ve if not.
963 int cap_syslog(int type
)
965 if ((type
!= 3 && type
!= 10) && !capable(CAP_SYS_ADMIN
))
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
, current_cred(), CAP_SYS_ADMIN
,
983 SECURITY_CAP_NOAUDIT
) == 0)
985 return __vm_enough_memory(mm
, pages
, cap_sys_admin
);
989 * cap_file_mmap - check if able to map given addr
994 * @addr: address attempting to be mapped
997 * If the process is attempting to map memory below mmap_min_addr they need
998 * CAP_SYS_RAWIO. The other parameters to this function are unused by the
999 * capability security module. Returns 0 if this mapping should be allowed
1002 int cap_file_mmap(struct file
*file
, unsigned long reqprot
,
1003 unsigned long prot
, unsigned long flags
,
1004 unsigned long addr
, unsigned long addr_only
)
1008 if (addr
< dac_mmap_min_addr
) {
1009 ret
= cap_capable(current
, current_cred(), CAP_SYS_RAWIO
,
1010 SECURITY_CAP_AUDIT
);
1011 /* set PF_SUPERPRIV if it turns out we allow the low mmap */
1013 current
->flags
|= PF_SUPERPRIV
;
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