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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
,
335 struct cred
*new = bprm
->cred
;
339 if (caps
->magic_etc
& VFS_CAP_FLAGS_EFFECTIVE
)
342 CAP_FOR_EACH_U32(i
) {
343 __u32 permitted
= caps
->permitted
.cap
[i
];
344 __u32 inheritable
= caps
->inheritable
.cap
[i
];
347 * pP' = (X & fP) | (pI & fI)
349 new->cap_permitted
.cap
[i
] =
350 (new->cap_bset
.cap
[i
] & permitted
) |
351 (new->cap_inheritable
.cap
[i
] & inheritable
);
353 if (permitted
& ~new->cap_permitted
.cap
[i
])
354 /* insufficient to execute correctly */
359 * For legacy apps, with no internal support for recognizing they
360 * do not have enough capabilities, we return an error if they are
361 * missing some "forced" (aka file-permitted) capabilities.
363 return *effective
? ret
: 0;
367 * Extract the on-exec-apply capability sets for an executable file.
369 int get_vfs_caps_from_disk(const struct dentry
*dentry
, struct cpu_vfs_cap_data
*cpu_caps
)
371 struct inode
*inode
= dentry
->d_inode
;
375 struct vfs_cap_data caps
;
377 memset(cpu_caps
, 0, sizeof(struct cpu_vfs_cap_data
));
379 if (!inode
|| !inode
->i_op
->getxattr
)
382 size
= inode
->i_op
->getxattr((struct dentry
*)dentry
, XATTR_NAME_CAPS
, &caps
,
384 if (size
== -ENODATA
|| size
== -EOPNOTSUPP
)
385 /* no data, that's ok */
390 if (size
< sizeof(magic_etc
))
393 cpu_caps
->magic_etc
= magic_etc
= le32_to_cpu(caps
.magic_etc
);
395 switch (magic_etc
& VFS_CAP_REVISION_MASK
) {
396 case VFS_CAP_REVISION_1
:
397 if (size
!= XATTR_CAPS_SZ_1
)
399 tocopy
= VFS_CAP_U32_1
;
401 case VFS_CAP_REVISION_2
:
402 if (size
!= XATTR_CAPS_SZ_2
)
404 tocopy
= VFS_CAP_U32_2
;
410 CAP_FOR_EACH_U32(i
) {
413 cpu_caps
->permitted
.cap
[i
] = le32_to_cpu(caps
.data
[i
].permitted
);
414 cpu_caps
->inheritable
.cap
[i
] = le32_to_cpu(caps
.data
[i
].inheritable
);
421 * Attempt to get the on-exec apply capability sets for an executable file from
422 * its xattrs and, if present, apply them to the proposed credentials being
423 * constructed by execve().
425 static int get_file_caps(struct linux_binprm
*bprm
, bool *effective
)
427 struct dentry
*dentry
;
429 struct cpu_vfs_cap_data vcaps
;
431 bprm_clear_caps(bprm
);
433 if (!file_caps_enabled
)
436 if (bprm
->file
->f_vfsmnt
->mnt_flags
& MNT_NOSUID
)
439 dentry
= dget(bprm
->file
->f_dentry
);
441 rc
= get_vfs_caps_from_disk(dentry
, &vcaps
);
444 printk(KERN_NOTICE
"%s: get_vfs_caps_from_disk returned %d for %s\n",
445 __func__
, rc
, bprm
->filename
);
446 else if (rc
== -ENODATA
)
451 rc
= bprm_caps_from_vfs_caps(&vcaps
, bprm
, effective
);
453 printk(KERN_NOTICE
"%s: cap_from_disk returned %d for %s\n",
454 __func__
, rc
, bprm
->filename
);
459 bprm_clear_caps(bprm
);
465 * cap_bprm_set_creds - Set up the proposed credentials for execve().
466 * @bprm: The execution parameters, including the proposed creds
468 * Set up the proposed credentials for a new execution context being
469 * constructed by execve(). The proposed creds in @bprm->cred is altered,
470 * which won't take effect immediately. Returns 0 if successful, -ve on error.
472 int cap_bprm_set_creds(struct linux_binprm
*bprm
)
474 const struct cred
*old
= current_cred();
475 struct cred
*new = bprm
->cred
;
480 ret
= get_file_caps(bprm
, &effective
);
484 if (!issecure(SECURE_NOROOT
)) {
486 * If the legacy file capability is set, then don't set privs
487 * for a setuid root binary run by a non-root user. Do set it
488 * for a root user just to cause least surprise to an admin.
490 if (effective
&& new->uid
!= 0 && new->euid
== 0) {
491 warn_setuid_and_fcaps_mixed(bprm
->filename
);
495 * To support inheritance of root-permissions and suid-root
496 * executables under compatibility mode, we override the
497 * capability sets for the file.
499 * If only the real uid is 0, we do not set the effective bit.
501 if (new->euid
== 0 || new->uid
== 0) {
502 /* pP' = (cap_bset & ~0) | (pI & ~0) */
503 new->cap_permitted
= cap_combine(old
->cap_bset
,
504 old
->cap_inheritable
);
511 /* Don't let someone trace a set[ug]id/setpcap binary with the revised
512 * credentials unless they have the appropriate permit
514 if ((new->euid
!= old
->uid
||
515 new->egid
!= old
->gid
||
516 !cap_issubset(new->cap_permitted
, old
->cap_permitted
)) &&
517 bprm
->unsafe
& ~LSM_UNSAFE_PTRACE_CAP
) {
518 /* downgrade; they get no more than they had, and maybe less */
519 if (!capable(CAP_SETUID
)) {
520 new->euid
= new->uid
;
521 new->egid
= new->gid
;
523 new->cap_permitted
= cap_intersect(new->cap_permitted
,
527 new->suid
= new->fsuid
= new->euid
;
528 new->sgid
= new->fsgid
= new->egid
;
531 new->cap_effective
= new->cap_permitted
;
533 cap_clear(new->cap_effective
);
534 bprm
->cap_effective
= effective
;
537 * Audit candidate if current->cap_effective is set
539 * We do not bother to audit if 3 things are true:
540 * 1) cap_effective has all caps
542 * 3) root is supposed to have all caps (SECURE_NOROOT)
543 * Since this is just a normal root execing a process.
545 * Number 1 above might fail if you don't have a full bset, but I think
546 * that is interesting information to audit.
548 if (!cap_isclear(new->cap_effective
)) {
549 if (!cap_issubset(CAP_FULL_SET
, new->cap_effective
) ||
550 new->euid
!= 0 || new->uid
!= 0 ||
551 issecure(SECURE_NOROOT
)) {
552 ret
= audit_log_bprm_fcaps(bprm
, new, old
);
558 new->securebits
&= ~issecure_mask(SECURE_KEEP_CAPS
);
563 * cap_bprm_secureexec - Determine whether a secure execution is required
564 * @bprm: The execution parameters
566 * Determine whether a secure execution is required, return 1 if it is, and 0
569 * The credentials have been committed by this point, and so are no longer
570 * available through @bprm->cred.
572 int cap_bprm_secureexec(struct linux_binprm
*bprm
)
574 const struct cred
*cred
= current_cred();
576 if (cred
->uid
!= 0) {
577 if (bprm
->cap_effective
)
579 if (!cap_isclear(cred
->cap_permitted
))
583 return (cred
->euid
!= cred
->uid
||
584 cred
->egid
!= cred
->gid
);
588 * cap_inode_setxattr - Determine whether an xattr may be altered
589 * @dentry: The inode/dentry being altered
590 * @name: The name of the xattr to be changed
591 * @value: The value that the xattr will be changed to
592 * @size: The size of value
593 * @flags: The replacement flag
595 * Determine whether an xattr may be altered or set on an inode, returning 0 if
596 * permission is granted, -ve if denied.
598 * This is used to make sure security xattrs don't get updated or set by those
599 * who aren't privileged to do so.
601 int cap_inode_setxattr(struct dentry
*dentry
, const char *name
,
602 const void *value
, size_t size
, int flags
)
604 if (!strcmp(name
, XATTR_NAME_CAPS
)) {
605 if (!capable(CAP_SETFCAP
))
610 if (!strncmp(name
, XATTR_SECURITY_PREFIX
,
611 sizeof(XATTR_SECURITY_PREFIX
) - 1) &&
612 !capable(CAP_SYS_ADMIN
))
618 * cap_inode_removexattr - Determine whether an xattr may be removed
619 * @dentry: The inode/dentry being altered
620 * @name: The name of the xattr to be changed
622 * Determine whether an xattr may be removed from an inode, returning 0 if
623 * permission is granted, -ve if denied.
625 * This is used to make sure security xattrs don't get removed by those who
626 * aren't privileged to remove them.
628 int cap_inode_removexattr(struct dentry
*dentry
, const char *name
)
630 if (!strcmp(name
, XATTR_NAME_CAPS
)) {
631 if (!capable(CAP_SETFCAP
))
636 if (!strncmp(name
, XATTR_SECURITY_PREFIX
,
637 sizeof(XATTR_SECURITY_PREFIX
) - 1) &&
638 !capable(CAP_SYS_ADMIN
))
644 * cap_emulate_setxuid() fixes the effective / permitted capabilities of
645 * a process after a call to setuid, setreuid, or setresuid.
647 * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
648 * {r,e,s}uid != 0, the permitted and effective capabilities are
651 * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
652 * capabilities of the process are cleared.
654 * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
655 * capabilities are set to the permitted capabilities.
657 * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should
662 * cevans - New behaviour, Oct '99
663 * A process may, via prctl(), elect to keep its capabilities when it
664 * calls setuid() and switches away from uid==0. Both permitted and
665 * effective sets will be retained.
666 * Without this change, it was impossible for a daemon to drop only some
667 * of its privilege. The call to setuid(!=0) would drop all privileges!
668 * Keeping uid 0 is not an option because uid 0 owns too many vital
670 * Thanks to Olaf Kirch and Peter Benie for spotting this.
672 static inline void cap_emulate_setxuid(struct cred
*new, const struct cred
*old
)
674 if ((old
->uid
== 0 || old
->euid
== 0 || old
->suid
== 0) &&
675 (new->uid
!= 0 && new->euid
!= 0 && new->suid
!= 0) &&
676 !issecure(SECURE_KEEP_CAPS
)) {
677 cap_clear(new->cap_permitted
);
678 cap_clear(new->cap_effective
);
680 if (old
->euid
== 0 && new->euid
!= 0)
681 cap_clear(new->cap_effective
);
682 if (old
->euid
!= 0 && new->euid
== 0)
683 new->cap_effective
= new->cap_permitted
;
687 * cap_task_fix_setuid - Fix up the results of setuid() call
688 * @new: The proposed credentials
689 * @old: The current task's current credentials
690 * @flags: Indications of what has changed
692 * Fix up the results of setuid() call before the credential changes are
693 * actually applied, returning 0 to grant the changes, -ve to deny them.
695 int cap_task_fix_setuid(struct cred
*new, const struct cred
*old
, int flags
)
701 /* juggle the capabilities to follow [RES]UID changes unless
702 * otherwise suppressed */
703 if (!issecure(SECURE_NO_SETUID_FIXUP
))
704 cap_emulate_setxuid(new, old
);
708 /* juggle the capabilties to follow FSUID changes, unless
709 * otherwise suppressed
711 * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
712 * if not, we might be a bit too harsh here.
714 if (!issecure(SECURE_NO_SETUID_FIXUP
)) {
715 if (old
->fsuid
== 0 && new->fsuid
!= 0)
717 cap_drop_fs_set(new->cap_effective
);
719 if (old
->fsuid
!= 0 && new->fsuid
== 0)
721 cap_raise_fs_set(new->cap_effective
,
734 * Rationale: code calling task_setscheduler, task_setioprio, and
735 * task_setnice, assumes that
736 * . if capable(cap_sys_nice), then those actions should be allowed
737 * . if not capable(cap_sys_nice), but acting on your own processes,
738 * then those actions should be allowed
739 * This is insufficient now since you can call code without suid, but
740 * yet with increased caps.
741 * So we check for increased caps on the target process.
743 static int cap_safe_nice(struct task_struct
*p
)
748 is_subset
= cap_issubset(__task_cred(p
)->cap_permitted
,
749 current_cred()->cap_permitted
);
752 if (!is_subset
&& !capable(CAP_SYS_NICE
))
758 * cap_task_setscheduler - Detemine if scheduler policy change is permitted
759 * @p: The task to affect
761 * Detemine if the requested scheduler policy change is permitted for the
762 * specified task, returning 0 if permission is granted, -ve if denied.
764 int cap_task_setscheduler(struct task_struct
*p
)
766 return cap_safe_nice(p
);
770 * cap_task_ioprio - Detemine if I/O priority change is permitted
771 * @p: The task to affect
772 * @ioprio: The I/O priority to set
774 * Detemine if the requested I/O priority change is permitted for the specified
775 * task, returning 0 if permission is granted, -ve if denied.
777 int cap_task_setioprio(struct task_struct
*p
, int ioprio
)
779 return cap_safe_nice(p
);
783 * cap_task_ioprio - Detemine if task priority change is permitted
784 * @p: The task to affect
785 * @nice: The nice value to set
787 * Detemine if the requested task priority change is permitted for the
788 * specified task, returning 0 if permission is granted, -ve if denied.
790 int cap_task_setnice(struct task_struct
*p
, int nice
)
792 return cap_safe_nice(p
);
796 * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from
797 * the current task's bounding set. Returns 0 on success, -ve on error.
799 static long cap_prctl_drop(struct cred
*new, unsigned long cap
)
801 if (!capable(CAP_SETPCAP
))
806 cap_lower(new->cap_bset
, cap
);
811 * cap_task_prctl - Implement process control functions for this security module
812 * @option: The process control function requested
813 * @arg2, @arg3, @arg4, @arg5: The argument data for this function
815 * Allow process control functions (sys_prctl()) to alter capabilities; may
816 * also deny access to other functions not otherwise implemented here.
818 * Returns 0 or +ve on success, -ENOSYS if this function is not implemented
819 * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM
820 * modules will consider performing the function.
822 int cap_task_prctl(int option
, unsigned long arg2
, unsigned long arg3
,
823 unsigned long arg4
, unsigned long arg5
)
828 new = prepare_creds();
833 case PR_CAPBSET_READ
:
835 if (!cap_valid(arg2
))
837 error
= !!cap_raised(new->cap_bset
, arg2
);
840 case PR_CAPBSET_DROP
:
841 error
= cap_prctl_drop(new, arg2
);
847 * The next four prctl's remain to assist with transitioning a
848 * system from legacy UID=0 based privilege (when filesystem
849 * capabilities are not in use) to a system using filesystem
850 * capabilities only - as the POSIX.1e draft intended.
854 * PR_SET_SECUREBITS =
855 * issecure_mask(SECURE_KEEP_CAPS_LOCKED)
856 * | issecure_mask(SECURE_NOROOT)
857 * | issecure_mask(SECURE_NOROOT_LOCKED)
858 * | issecure_mask(SECURE_NO_SETUID_FIXUP)
859 * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
861 * will ensure that the current process and all of its
862 * children will be locked into a pure
863 * capability-based-privilege environment.
865 case PR_SET_SECUREBITS
:
867 if ((((new->securebits
& SECURE_ALL_LOCKS
) >> 1)
868 & (new->securebits
^ arg2
)) /*[1]*/
869 || ((new->securebits
& SECURE_ALL_LOCKS
& ~arg2
)) /*[2]*/
870 || (arg2
& ~(SECURE_ALL_LOCKS
| SECURE_ALL_BITS
)) /*[3]*/
871 || (cap_capable(current_cred(),
872 current_cred()->user
->user_ns
, CAP_SETPCAP
,
873 SECURITY_CAP_AUDIT
) != 0) /*[4]*/
875 * [1] no changing of bits that are locked
876 * [2] no unlocking of locks
877 * [3] no setting of unsupported bits
878 * [4] doing anything requires privilege (go read about
879 * the "sendmail capabilities bug")
882 /* cannot change a locked bit */
884 new->securebits
= arg2
;
887 case PR_GET_SECUREBITS
:
888 error
= new->securebits
;
891 case PR_GET_KEEPCAPS
:
892 if (issecure(SECURE_KEEP_CAPS
))
896 case PR_SET_KEEPCAPS
:
898 if (arg2
> 1) /* Note, we rely on arg2 being unsigned here */
901 if (issecure(SECURE_KEEP_CAPS_LOCKED
))
904 new->securebits
|= issecure_mask(SECURE_KEEP_CAPS
);
906 new->securebits
&= ~issecure_mask(SECURE_KEEP_CAPS
);
910 /* No functionality available - continue with default */
915 /* Functionality provided */
917 return commit_creds(new);
926 * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted
927 * @mm: The VM space in which the new mapping is to be made
928 * @pages: The size of the mapping
930 * Determine whether the allocation of a new virtual mapping by the current
931 * task is permitted, returning 0 if permission is granted, -ve if not.
933 int cap_vm_enough_memory(struct mm_struct
*mm
, long pages
)
935 int cap_sys_admin
= 0;
937 if (cap_capable(current_cred(), &init_user_ns
, CAP_SYS_ADMIN
,
938 SECURITY_CAP_NOAUDIT
) == 0)
940 return __vm_enough_memory(mm
, pages
, cap_sys_admin
);
944 * cap_file_mmap - check if able to map given addr
949 * @addr: address attempting to be mapped
952 * If the process is attempting to map memory below dac_mmap_min_addr they need
953 * CAP_SYS_RAWIO. The other parameters to this function are unused by the
954 * capability security module. Returns 0 if this mapping should be allowed
957 int cap_file_mmap(struct file
*file
, unsigned long reqprot
,
958 unsigned long prot
, unsigned long flags
,
959 unsigned long addr
, unsigned long addr_only
)
963 if (addr
< dac_mmap_min_addr
) {
964 ret
= cap_capable(current_cred(), &init_user_ns
, CAP_SYS_RAWIO
,
966 /* set PF_SUPERPRIV if it turns out we allow the low mmap */
968 current
->flags
|= PF_SUPERPRIV
;