Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
commoncap.c
Go to the documentation of this file.
1 /* Common capabilities, needed by capability.o.
2  *
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.
7  *
8  */
9 
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>
17 #include <linux/mm.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>
33 
34 /*
35  * If a non-root user executes a setuid-root binary in
36  * !secure(SECURE_NOROOT) mode, then we raise capabilities.
37  * However if fE is also set, then the intent is for only
38  * the file capabilities to be applied, and the setuid-root
39  * bit is left on either to change the uid (plausible) or
40  * to get full privilege on a kernel without file capabilities
41  * support. So in that case we do not raise capabilities.
42  *
43  * Warn if that happens, once per boot.
44  */
45 static void warn_setuid_and_fcaps_mixed(const char *fname)
46 {
47  static int warned;
48  if (!warned) {
49  printk(KERN_INFO "warning: `%s' has both setuid-root and"
50  " effective capabilities. Therefore not raising all"
51  " capabilities.\n", fname);
52  warned = 1;
53  }
54 }
55 
56 int cap_netlink_send(struct sock *sk, struct sk_buff *skb)
57 {
58  return 0;
59 }
60 
76 int cap_capable(const struct cred *cred, struct user_namespace *targ_ns,
77  int cap, int audit)
78 {
79  for (;;) {
80  /* The owner of the user namespace has all caps. */
81  if (targ_ns != &init_user_ns && uid_eq(targ_ns->owner, cred->euid))
82  return 0;
83 
84  /* Do we have the necessary capabilities? */
85  if (targ_ns == cred->user_ns)
86  return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;
87 
88  /* Have we tried all of the parent namespaces? */
89  if (targ_ns == &init_user_ns)
90  return -EPERM;
91 
92  /*
93  *If you have a capability in a parent user ns, then you have
94  * it over all children user namespaces as well.
95  */
96  targ_ns = targ_ns->parent;
97  }
98 
99  /* We never get here */
100 }
101 
110 int cap_settime(const struct timespec *ts, const struct timezone *tz)
111 {
112  if (!capable(CAP_SYS_TIME))
113  return -EPERM;
114  return 0;
115 }
116 
132 int cap_ptrace_access_check(struct task_struct *child, unsigned int mode)
133 {
134  int ret = 0;
135  const struct cred *cred, *child_cred;
136 
137  rcu_read_lock();
138  cred = current_cred();
139  child_cred = __task_cred(child);
140  if (cred->user_ns == child_cred->user_ns &&
141  cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
142  goto out;
143  if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE))
144  goto out;
145  ret = -EPERM;
146 out:
147  rcu_read_unlock();
148  return ret;
149 }
150 
164 int cap_ptrace_traceme(struct task_struct *parent)
165 {
166  int ret = 0;
167  const struct cred *cred, *child_cred;
168 
169  rcu_read_lock();
170  cred = __task_cred(parent);
171  child_cred = current_cred();
172  if (cred->user_ns == child_cred->user_ns &&
173  cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
174  goto out;
175  if (has_ns_capability(parent, child_cred->user_ns, CAP_SYS_PTRACE))
176  goto out;
177  ret = -EPERM;
178 out:
179  rcu_read_unlock();
180  return ret;
181 }
182 
193 int cap_capget(struct task_struct *target, kernel_cap_t *effective,
194  kernel_cap_t *inheritable, kernel_cap_t *permitted)
195 {
196  const struct cred *cred;
197 
198  /* Derived from kernel/capability.c:sys_capget. */
199  rcu_read_lock();
200  cred = __task_cred(target);
201  *effective = cred->cap_effective;
202  *inheritable = cred->cap_inheritable;
203  *permitted = cred->cap_permitted;
204  rcu_read_unlock();
205  return 0;
206 }
207 
208 /*
209  * Determine whether the inheritable capabilities are limited to the old
210  * permitted set. Returns 1 if they are limited, 0 if they are not.
211  */
212 static inline int cap_inh_is_capped(void)
213 {
214 
215  /* they are so limited unless the current task has the CAP_SETPCAP
216  * capability
217  */
220  return 0;
221  return 1;
222 }
223 
236 int cap_capset(struct cred *new,
237  const struct cred *old,
238  const kernel_cap_t *effective,
239  const kernel_cap_t *inheritable,
240  const kernel_cap_t *permitted)
241 {
242  if (cap_inh_is_capped() &&
243  !cap_issubset(*inheritable,
244  cap_combine(old->cap_inheritable,
245  old->cap_permitted)))
246  /* incapable of using this inheritable set */
247  return -EPERM;
248 
249  if (!cap_issubset(*inheritable,
250  cap_combine(old->cap_inheritable,
251  old->cap_bset)))
252  /* no new pI capabilities outside bounding set */
253  return -EPERM;
254 
255  /* verify restrictions on target's new Permitted set */
256  if (!cap_issubset(*permitted, old->cap_permitted))
257  return -EPERM;
258 
259  /* verify the _new_Effective_ is a subset of the _new_Permitted_ */
260  if (!cap_issubset(*effective, *permitted))
261  return -EPERM;
262 
263  new->cap_effective = *effective;
264  new->cap_inheritable = *inheritable;
265  new->cap_permitted = *permitted;
266  return 0;
267 }
268 
269 /*
270  * Clear proposed capability sets for execve().
271  */
272 static inline void bprm_clear_caps(struct linux_binprm *bprm)
273 {
274  cap_clear(bprm->cred->cap_permitted);
275  bprm->cap_effective = false;
276 }
277 
290 {
291  struct inode *inode = dentry->d_inode;
292  int error;
293 
294  if (!inode->i_op->getxattr)
295  return 0;
296 
297  error = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0);
298  if (error <= 0)
299  return 0;
300  return 1;
301 }
302 
312 {
313  struct inode *inode = dentry->d_inode;
314 
315  if (!inode->i_op->removexattr)
316  return 0;
317 
318  return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
319 }
320 
321 /*
322  * Calculate the new process capability sets from the capability sets attached
323  * to a file.
324  */
325 static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
326  struct linux_binprm *bprm,
327  bool *effective,
328  bool *has_cap)
329 {
330  struct cred *new = bprm->cred;
331  unsigned i;
332  int ret = 0;
333 
335  *effective = true;
336 
337  if (caps->magic_etc & VFS_CAP_REVISION_MASK)
338  *has_cap = true;
339 
340  CAP_FOR_EACH_U32(i) {
341  __u32 permitted = caps->permitted.cap[i];
342  __u32 inheritable = caps->inheritable.cap[i];
343 
344  /*
345  * pP' = (X & fP) | (pI & fI)
346  */
347  new->cap_permitted.cap[i] =
348  (new->cap_bset.cap[i] & permitted) |
349  (new->cap_inheritable.cap[i] & inheritable);
350 
351  if (permitted & ~new->cap_permitted.cap[i])
352  /* insufficient to execute correctly */
353  ret = -EPERM;
354  }
355 
356  /*
357  * For legacy apps, with no internal support for recognizing they
358  * do not have enough capabilities, we return an error if they are
359  * missing some "forced" (aka file-permitted) capabilities.
360  */
361  return *effective ? ret : 0;
362 }
363 
364 /*
365  * Extract the on-exec-apply capability sets for an executable file.
366  */
367 int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps)
368 {
369  struct inode *inode = dentry->d_inode;
370  __u32 magic_etc;
371  unsigned tocopy, i;
372  int size;
373  struct vfs_cap_data caps;
374 
375  memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data));
376 
377  if (!inode || !inode->i_op->getxattr)
378  return -ENODATA;
379 
380  size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps,
381  XATTR_CAPS_SZ);
382  if (size == -ENODATA || size == -EOPNOTSUPP)
383  /* no data, that's ok */
384  return -ENODATA;
385  if (size < 0)
386  return size;
387 
388  if (size < sizeof(magic_etc))
389  return -EINVAL;
390 
391  cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc);
392 
393  switch (magic_etc & VFS_CAP_REVISION_MASK) {
394  case VFS_CAP_REVISION_1:
395  if (size != XATTR_CAPS_SZ_1)
396  return -EINVAL;
397  tocopy = VFS_CAP_U32_1;
398  break;
399  case VFS_CAP_REVISION_2:
400  if (size != XATTR_CAPS_SZ_2)
401  return -EINVAL;
402  tocopy = VFS_CAP_U32_2;
403  break;
404  default:
405  return -EINVAL;
406  }
407 
408  CAP_FOR_EACH_U32(i) {
409  if (i >= tocopy)
410  break;
411  cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted);
412  cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable);
413  }
414 
415  return 0;
416 }
417 
418 /*
419  * Attempt to get the on-exec apply capability sets for an executable file from
420  * its xattrs and, if present, apply them to the proposed credentials being
421  * constructed by execve().
422  */
423 static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_cap)
424 {
425  struct dentry *dentry;
426  int rc = 0;
427  struct cpu_vfs_cap_data vcaps;
428 
429  bprm_clear_caps(bprm);
430 
431  if (!file_caps_enabled)
432  return 0;
433 
434  if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
435  return 0;
436 
437  dentry = dget(bprm->file->f_dentry);
438 
439  rc = get_vfs_caps_from_disk(dentry, &vcaps);
440  if (rc < 0) {
441  if (rc == -EINVAL)
442  printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n",
443  __func__, rc, bprm->filename);
444  else if (rc == -ENODATA)
445  rc = 0;
446  goto out;
447  }
448 
449  rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective, has_cap);
450  if (rc == -EINVAL)
451  printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n",
452  __func__, rc, bprm->filename);
453 
454 out:
455  dput(dentry);
456  if (rc)
457  bprm_clear_caps(bprm);
458 
459  return rc;
460 }
461 
471 {
472  const struct cred *old = current_cred();
473  struct cred *new = bprm->cred;
474  bool effective, has_cap = false;
475  int ret;
476  kuid_t root_uid;
477 
478  effective = false;
479  ret = get_file_caps(bprm, &effective, &has_cap);
480  if (ret < 0)
481  return ret;
482 
483  root_uid = make_kuid(new->user_ns, 0);
484 
485  if (!issecure(SECURE_NOROOT)) {
486  /*
487  * If the legacy file capability is set, then don't set privs
488  * for a setuid root binary run by a non-root user. Do set it
489  * for a root user just to cause least surprise to an admin.
490  */
491  if (has_cap && !uid_eq(new->uid, root_uid) && uid_eq(new->euid, root_uid)) {
492  warn_setuid_and_fcaps_mixed(bprm->filename);
493  goto skip;
494  }
495  /*
496  * To support inheritance of root-permissions and suid-root
497  * executables under compatibility mode, we override the
498  * capability sets for the file.
499  *
500  * If only the real uid is 0, we do not set the effective bit.
501  */
502  if (uid_eq(new->euid, root_uid) || uid_eq(new->uid, root_uid)) {
503  /* pP' = (cap_bset & ~0) | (pI & ~0) */
504  new->cap_permitted = cap_combine(old->cap_bset,
505  old->cap_inheritable);
506  }
507  if (uid_eq(new->euid, root_uid))
508  effective = true;
509  }
510 skip:
511 
512  /* if we have fs caps, clear dangerous personality flags */
513  if (!cap_issubset(new->cap_permitted, old->cap_permitted))
514  bprm->per_clear |= PER_CLEAR_ON_SETID;
515 
516 
517  /* Don't let someone trace a set[ug]id/setpcap binary with the revised
518  * credentials unless they have the appropriate permit.
519  *
520  * In addition, if NO_NEW_PRIVS, then ensure we get no new privs.
521  */
522  if ((!uid_eq(new->euid, old->uid) ||
523  !gid_eq(new->egid, old->gid) ||
524  !cap_issubset(new->cap_permitted, old->cap_permitted)) &&
525  bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
526  /* downgrade; they get no more than they had, and maybe less */
527  if (!capable(CAP_SETUID) ||
528  (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) {
529  new->euid = new->uid;
530  new->egid = new->gid;
531  }
532  new->cap_permitted = cap_intersect(new->cap_permitted,
533  old->cap_permitted);
534  }
535 
536  new->suid = new->fsuid = new->euid;
537  new->sgid = new->fsgid = new->egid;
538 
539  if (effective)
540  new->cap_effective = new->cap_permitted;
541  else
542  cap_clear(new->cap_effective);
543  bprm->cap_effective = effective;
544 
545  /*
546  * Audit candidate if current->cap_effective is set
547  *
548  * We do not bother to audit if 3 things are true:
549  * 1) cap_effective has all caps
550  * 2) we are root
551  * 3) root is supposed to have all caps (SECURE_NOROOT)
552  * Since this is just a normal root execing a process.
553  *
554  * Number 1 above might fail if you don't have a full bset, but I think
555  * that is interesting information to audit.
556  */
557  if (!cap_isclear(new->cap_effective)) {
558  if (!cap_issubset(CAP_FULL_SET, new->cap_effective) ||
559  !uid_eq(new->euid, root_uid) || !uid_eq(new->uid, root_uid) ||
561  ret = audit_log_bprm_fcaps(bprm, new, old);
562  if (ret < 0)
563  return ret;
564  }
565  }
566 
567  new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
568  return 0;
569 }
570 
582 {
583  const struct cred *cred = current_cred();
584  kuid_t root_uid = make_kuid(cred->user_ns, 0);
585 
586  if (!uid_eq(cred->uid, root_uid)) {
587  if (bprm->cap_effective)
588  return 1;
589  if (!cap_isclear(cred->cap_permitted))
590  return 1;
591  }
592 
593  return (!uid_eq(cred->euid, cred->uid) ||
594  !gid_eq(cred->egid, cred->gid));
595 }
596 
611 int cap_inode_setxattr(struct dentry *dentry, const char *name,
612  const void *value, size_t size, int flags)
613 {
614  if (!strcmp(name, XATTR_NAME_CAPS)) {
615  if (!capable(CAP_SETFCAP))
616  return -EPERM;
617  return 0;
618  }
619 
620  if (!strncmp(name, XATTR_SECURITY_PREFIX,
621  sizeof(XATTR_SECURITY_PREFIX) - 1) &&
623  return -EPERM;
624  return 0;
625 }
626 
638 int cap_inode_removexattr(struct dentry *dentry, const char *name)
639 {
640  if (!strcmp(name, XATTR_NAME_CAPS)) {
641  if (!capable(CAP_SETFCAP))
642  return -EPERM;
643  return 0;
644  }
645 
646  if (!strncmp(name, XATTR_SECURITY_PREFIX,
647  sizeof(XATTR_SECURITY_PREFIX) - 1) &&
649  return -EPERM;
650  return 0;
651 }
652 
653 /*
654  * cap_emulate_setxuid() fixes the effective / permitted capabilities of
655  * a process after a call to setuid, setreuid, or setresuid.
656  *
657  * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
658  * {r,e,s}uid != 0, the permitted and effective capabilities are
659  * cleared.
660  *
661  * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
662  * capabilities of the process are cleared.
663  *
664  * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
665  * capabilities are set to the permitted capabilities.
666  *
667  * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should
668  * never happen.
669  *
670  * -astor
671  *
672  * cevans - New behaviour, Oct '99
673  * A process may, via prctl(), elect to keep its capabilities when it
674  * calls setuid() and switches away from uid==0. Both permitted and
675  * effective sets will be retained.
676  * Without this change, it was impossible for a daemon to drop only some
677  * of its privilege. The call to setuid(!=0) would drop all privileges!
678  * Keeping uid 0 is not an option because uid 0 owns too many vital
679  * files..
680  * Thanks to Olaf Kirch and Peter Benie for spotting this.
681  */
682 static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old)
683 {
684  kuid_t root_uid = make_kuid(old->user_ns, 0);
685 
686  if ((uid_eq(old->uid, root_uid) ||
687  uid_eq(old->euid, root_uid) ||
688  uid_eq(old->suid, root_uid)) &&
689  (!uid_eq(new->uid, root_uid) &&
690  !uid_eq(new->euid, root_uid) &&
691  !uid_eq(new->suid, root_uid)) &&
693  cap_clear(new->cap_permitted);
694  cap_clear(new->cap_effective);
695  }
696  if (uid_eq(old->euid, root_uid) && !uid_eq(new->euid, root_uid))
697  cap_clear(new->cap_effective);
698  if (!uid_eq(old->euid, root_uid) && uid_eq(new->euid, root_uid))
699  new->cap_effective = new->cap_permitted;
700 }
701 
711 int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags)
712 {
713  switch (flags) {
714  case LSM_SETID_RE:
715  case LSM_SETID_ID:
716  case LSM_SETID_RES:
717  /* juggle the capabilities to follow [RES]UID changes unless
718  * otherwise suppressed */
720  cap_emulate_setxuid(new, old);
721  break;
722 
723  case LSM_SETID_FS:
724  /* juggle the capabilties to follow FSUID changes, unless
725  * otherwise suppressed
726  *
727  * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
728  * if not, we might be a bit too harsh here.
729  */
731  kuid_t root_uid = make_kuid(old->user_ns, 0);
732  if (uid_eq(old->fsuid, root_uid) && !uid_eq(new->fsuid, root_uid))
733  new->cap_effective =
734  cap_drop_fs_set(new->cap_effective);
735 
736  if (!uid_eq(old->fsuid, root_uid) && uid_eq(new->fsuid, root_uid))
737  new->cap_effective =
738  cap_raise_fs_set(new->cap_effective,
739  new->cap_permitted);
740  }
741  break;
742 
743  default:
744  return -EINVAL;
745  }
746 
747  return 0;
748 }
749 
750 /*
751  * Rationale: code calling task_setscheduler, task_setioprio, and
752  * task_setnice, assumes that
753  * . if capable(cap_sys_nice), then those actions should be allowed
754  * . if not capable(cap_sys_nice), but acting on your own processes,
755  * then those actions should be allowed
756  * This is insufficient now since you can call code without suid, but
757  * yet with increased caps.
758  * So we check for increased caps on the target process.
759  */
760 static int cap_safe_nice(struct task_struct *p)
761 {
762  int is_subset;
763 
764  rcu_read_lock();
765  is_subset = cap_issubset(__task_cred(p)->cap_permitted,
767  rcu_read_unlock();
768 
769  if (!is_subset && !capable(CAP_SYS_NICE))
770  return -EPERM;
771  return 0;
772 }
773 
782 {
783  return cap_safe_nice(p);
784 }
785 
794 int cap_task_setioprio(struct task_struct *p, int ioprio)
795 {
796  return cap_safe_nice(p);
797 }
798 
807 int cap_task_setnice(struct task_struct *p, int nice)
808 {
809  return cap_safe_nice(p);
810 }
811 
812 /*
813  * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from
814  * the current task's bounding set. Returns 0 on success, -ve on error.
815  */
816 static long cap_prctl_drop(struct cred *new, unsigned long cap)
817 {
818  if (!capable(CAP_SETPCAP))
819  return -EPERM;
820  if (!cap_valid(cap))
821  return -EINVAL;
822 
823  cap_lower(new->cap_bset, cap);
824  return 0;
825 }
826 
839 int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
840  unsigned long arg4, unsigned long arg5)
841 {
842  struct cred *new;
843  long error = 0;
844 
845  new = prepare_creds();
846  if (!new)
847  return -ENOMEM;
848 
849  switch (option) {
850  case PR_CAPBSET_READ:
851  error = -EINVAL;
852  if (!cap_valid(arg2))
853  goto error;
854  error = !!cap_raised(new->cap_bset, arg2);
855  goto no_change;
856 
857  case PR_CAPBSET_DROP:
858  error = cap_prctl_drop(new, arg2);
859  if (error < 0)
860  goto error;
861  goto changed;
862 
863  /*
864  * The next four prctl's remain to assist with transitioning a
865  * system from legacy UID=0 based privilege (when filesystem
866  * capabilities are not in use) to a system using filesystem
867  * capabilities only - as the POSIX.1e draft intended.
868  *
869  * Note:
870  *
871  * PR_SET_SECUREBITS =
872  * issecure_mask(SECURE_KEEP_CAPS_LOCKED)
873  * | issecure_mask(SECURE_NOROOT)
874  * | issecure_mask(SECURE_NOROOT_LOCKED)
875  * | issecure_mask(SECURE_NO_SETUID_FIXUP)
876  * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
877  *
878  * will ensure that the current process and all of its
879  * children will be locked into a pure
880  * capability-based-privilege environment.
881  */
882  case PR_SET_SECUREBITS:
883  error = -EPERM;
884  if ((((new->securebits & SECURE_ALL_LOCKS) >> 1)
885  & (new->securebits ^ arg2)) /*[1]*/
886  || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/
887  || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
890  SECURITY_CAP_AUDIT) != 0) /*[4]*/
891  /*
892  * [1] no changing of bits that are locked
893  * [2] no unlocking of locks
894  * [3] no setting of unsupported bits
895  * [4] doing anything requires privilege (go read about
896  * the "sendmail capabilities bug")
897  */
898  )
899  /* cannot change a locked bit */
900  goto error;
901  new->securebits = arg2;
902  goto changed;
903 
904  case PR_GET_SECUREBITS:
905  error = new->securebits;
906  goto no_change;
907 
908  case PR_GET_KEEPCAPS:
910  error = 1;
911  goto no_change;
912 
913  case PR_SET_KEEPCAPS:
914  error = -EINVAL;
915  if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */
916  goto error;
917  error = -EPERM;
919  goto error;
920  if (arg2)
921  new->securebits |= issecure_mask(SECURE_KEEP_CAPS);
922  else
923  new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
924  goto changed;
925 
926  default:
927  /* No functionality available - continue with default */
928  error = -ENOSYS;
929  goto error;
930  }
931 
932  /* Functionality provided */
933 changed:
934  return commit_creds(new);
935 
936 no_change:
937 error:
938  abort_creds(new);
939  return error;
940 }
941 
950 int cap_vm_enough_memory(struct mm_struct *mm, long pages)
951 {
952  int cap_sys_admin = 0;
953 
955  SECURITY_CAP_NOAUDIT) == 0)
956  cap_sys_admin = 1;
957  return __vm_enough_memory(mm, pages, cap_sys_admin);
958 }
959 
960 /*
961  * cap_mmap_addr - check if able to map given addr
962  * @addr: address attempting to be mapped
963  *
964  * If the process is attempting to map memory below dac_mmap_min_addr they need
965  * CAP_SYS_RAWIO. The other parameters to this function are unused by the
966  * capability security module. Returns 0 if this mapping should be allowed
967  * -EPERM if not.
968  */
969 int cap_mmap_addr(unsigned long addr)
970 {
971  int ret = 0;
972 
973  if (addr < dac_mmap_min_addr) {
976  /* set PF_SUPERPRIV if it turns out we allow the low mmap */
977  if (ret == 0)
978  current->flags |= PF_SUPERPRIV;
979  }
980  return ret;
981 }
982 
983 int cap_mmap_file(struct file *file, unsigned long reqprot,
984  unsigned long prot, unsigned long flags)
985 {
986  return 0;
987 }