2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License as
4 * published by the Free Software Foundation, version 2 of the
8 #include <linux/export.h>
9 #include <linux/nsproxy.h>
10 #include <linux/slab.h>
11 #include <linux/user_namespace.h>
12 #include <linux/proc_ns.h>
13 #include <linux/highuid.h>
14 #include <linux/cred.h>
15 #include <linux/securebits.h>
16 #include <linux/keyctl.h>
17 #include <linux/key-type.h>
18 #include <keys/user-type.h>
19 #include <linux/seq_file.h>
21 #include <linux/uaccess.h>
22 #include <linux/ctype.h>
23 #include <linux/projid.h>
24 #include <linux/fs_struct.h>
26 static struct kmem_cache
*user_ns_cachep __read_mostly
;
28 static bool new_idmap_permitted(const struct file
*file
,
29 struct user_namespace
*ns
, int cap_setid
,
30 struct uid_gid_map
*map
);
32 static void set_cred_user_ns(struct cred
*cred
, struct user_namespace
*user_ns
)
34 /* Start with the same capabilities as init but useless for doing
35 * anything as the capabilities are bound to the new user namespace.
37 cred
->securebits
= SECUREBITS_DEFAULT
;
38 cred
->cap_inheritable
= CAP_EMPTY_SET
;
39 cred
->cap_permitted
= CAP_FULL_SET
;
40 cred
->cap_effective
= CAP_FULL_SET
;
41 cred
->cap_bset
= CAP_FULL_SET
;
43 key_put(cred
->request_key_auth
);
44 cred
->request_key_auth
= NULL
;
46 /* tgcred will be cleared in our caller bc CLONE_THREAD won't be set */
47 cred
->user_ns
= user_ns
;
51 * Create a new user namespace, deriving the creator from the user in the
52 * passed credentials, and replacing that user with the new root user for the
55 * This is called by copy_creds(), which will finish setting the target task's
58 int create_user_ns(struct cred
*new)
60 struct user_namespace
*ns
, *parent_ns
= new->user_ns
;
61 kuid_t owner
= new->euid
;
62 kgid_t group
= new->egid
;
66 * Verify that we can not violate the policy of which files
67 * may be accessed that is specified by the root directory,
68 * by verifing that the root directory is at the root of the
69 * mount namespace which allows all files to be accessed.
71 if (current_chrooted())
74 /* The creator needs a mapping in the parent user namespace
75 * or else we won't be able to reasonably tell userspace who
76 * created a user_namespace.
78 if (!kuid_has_mapping(parent_ns
, owner
) ||
79 !kgid_has_mapping(parent_ns
, group
))
82 ns
= kmem_cache_zalloc(user_ns_cachep
, GFP_KERNEL
);
86 ret
= proc_alloc_inum(&ns
->proc_inum
);
88 kmem_cache_free(user_ns_cachep
, ns
);
92 atomic_set(&ns
->count
, 1);
93 /* Leave the new->user_ns reference with the new user namespace. */
94 ns
->parent
= parent_ns
;
98 set_cred_user_ns(new, ns
);
100 update_mnt_policy(ns
);
105 int unshare_userns(unsigned long unshare_flags
, struct cred
**new_cred
)
110 if (!(unshare_flags
& CLONE_NEWUSER
))
113 cred
= prepare_creds();
115 err
= create_user_ns(cred
);
125 void free_user_ns(struct user_namespace
*ns
)
127 struct user_namespace
*parent
;
131 proc_free_inum(ns
->proc_inum
);
132 kmem_cache_free(user_ns_cachep
, ns
);
134 } while (atomic_dec_and_test(&parent
->count
));
136 EXPORT_SYMBOL(free_user_ns
);
138 static u32
map_id_range_down(struct uid_gid_map
*map
, u32 id
, u32 count
)
140 unsigned idx
, extents
;
141 u32 first
, last
, id2
;
143 id2
= id
+ count
- 1;
145 /* Find the matching extent */
146 extents
= map
->nr_extents
;
147 smp_read_barrier_depends();
148 for (idx
= 0; idx
< extents
; idx
++) {
149 first
= map
->extent
[idx
].first
;
150 last
= first
+ map
->extent
[idx
].count
- 1;
151 if (id
>= first
&& id
<= last
&&
152 (id2
>= first
&& id2
<= last
))
155 /* Map the id or note failure */
157 id
= (id
- first
) + map
->extent
[idx
].lower_first
;
164 static u32
map_id_down(struct uid_gid_map
*map
, u32 id
)
166 unsigned idx
, extents
;
169 /* Find the matching extent */
170 extents
= map
->nr_extents
;
171 smp_read_barrier_depends();
172 for (idx
= 0; idx
< extents
; idx
++) {
173 first
= map
->extent
[idx
].first
;
174 last
= first
+ map
->extent
[idx
].count
- 1;
175 if (id
>= first
&& id
<= last
)
178 /* Map the id or note failure */
180 id
= (id
- first
) + map
->extent
[idx
].lower_first
;
187 static u32
map_id_up(struct uid_gid_map
*map
, u32 id
)
189 unsigned idx
, extents
;
192 /* Find the matching extent */
193 extents
= map
->nr_extents
;
194 smp_read_barrier_depends();
195 for (idx
= 0; idx
< extents
; idx
++) {
196 first
= map
->extent
[idx
].lower_first
;
197 last
= first
+ map
->extent
[idx
].count
- 1;
198 if (id
>= first
&& id
<= last
)
201 /* Map the id or note failure */
203 id
= (id
- first
) + map
->extent
[idx
].first
;
211 * make_kuid - Map a user-namespace uid pair into a kuid.
212 * @ns: User namespace that the uid is in
213 * @uid: User identifier
215 * Maps a user-namespace uid pair into a kernel internal kuid,
216 * and returns that kuid.
218 * When there is no mapping defined for the user-namespace uid
219 * pair INVALID_UID is returned. Callers are expected to test
220 * for and handle handle INVALID_UID being returned. INVALID_UID
221 * may be tested for using uid_valid().
223 kuid_t
make_kuid(struct user_namespace
*ns
, uid_t uid
)
225 /* Map the uid to a global kernel uid */
226 return KUIDT_INIT(map_id_down(&ns
->uid_map
, uid
));
228 EXPORT_SYMBOL(make_kuid
);
231 * from_kuid - Create a uid from a kuid user-namespace pair.
232 * @targ: The user namespace we want a uid in.
233 * @kuid: The kernel internal uid to start with.
235 * Map @kuid into the user-namespace specified by @targ and
236 * return the resulting uid.
238 * There is always a mapping into the initial user_namespace.
240 * If @kuid has no mapping in @targ (uid_t)-1 is returned.
242 uid_t
from_kuid(struct user_namespace
*targ
, kuid_t kuid
)
244 /* Map the uid from a global kernel uid */
245 return map_id_up(&targ
->uid_map
, __kuid_val(kuid
));
247 EXPORT_SYMBOL(from_kuid
);
250 * from_kuid_munged - Create a uid from a kuid user-namespace pair.
251 * @targ: The user namespace we want a uid in.
252 * @kuid: The kernel internal uid to start with.
254 * Map @kuid into the user-namespace specified by @targ and
255 * return the resulting uid.
257 * There is always a mapping into the initial user_namespace.
259 * Unlike from_kuid from_kuid_munged never fails and always
260 * returns a valid uid. This makes from_kuid_munged appropriate
261 * for use in syscalls like stat and getuid where failing the
262 * system call and failing to provide a valid uid are not an
265 * If @kuid has no mapping in @targ overflowuid is returned.
267 uid_t
from_kuid_munged(struct user_namespace
*targ
, kuid_t kuid
)
270 uid
= from_kuid(targ
, kuid
);
272 if (uid
== (uid_t
) -1)
276 EXPORT_SYMBOL(from_kuid_munged
);
279 * make_kgid - Map a user-namespace gid pair into a kgid.
280 * @ns: User namespace that the gid is in
281 * @uid: group identifier
283 * Maps a user-namespace gid pair into a kernel internal kgid,
284 * and returns that kgid.
286 * When there is no mapping defined for the user-namespace gid
287 * pair INVALID_GID is returned. Callers are expected to test
288 * for and handle INVALID_GID being returned. INVALID_GID may be
289 * tested for using gid_valid().
291 kgid_t
make_kgid(struct user_namespace
*ns
, gid_t gid
)
293 /* Map the gid to a global kernel gid */
294 return KGIDT_INIT(map_id_down(&ns
->gid_map
, gid
));
296 EXPORT_SYMBOL(make_kgid
);
299 * from_kgid - Create a gid from a kgid user-namespace pair.
300 * @targ: The user namespace we want a gid in.
301 * @kgid: The kernel internal gid to start with.
303 * Map @kgid into the user-namespace specified by @targ and
304 * return the resulting gid.
306 * There is always a mapping into the initial user_namespace.
308 * If @kgid has no mapping in @targ (gid_t)-1 is returned.
310 gid_t
from_kgid(struct user_namespace
*targ
, kgid_t kgid
)
312 /* Map the gid from a global kernel gid */
313 return map_id_up(&targ
->gid_map
, __kgid_val(kgid
));
315 EXPORT_SYMBOL(from_kgid
);
318 * from_kgid_munged - Create a gid from a kgid user-namespace pair.
319 * @targ: The user namespace we want a gid in.
320 * @kgid: The kernel internal gid to start with.
322 * Map @kgid into the user-namespace specified by @targ and
323 * return the resulting gid.
325 * There is always a mapping into the initial user_namespace.
327 * Unlike from_kgid from_kgid_munged never fails and always
328 * returns a valid gid. This makes from_kgid_munged appropriate
329 * for use in syscalls like stat and getgid where failing the
330 * system call and failing to provide a valid gid are not options.
332 * If @kgid has no mapping in @targ overflowgid is returned.
334 gid_t
from_kgid_munged(struct user_namespace
*targ
, kgid_t kgid
)
337 gid
= from_kgid(targ
, kgid
);
339 if (gid
== (gid_t
) -1)
343 EXPORT_SYMBOL(from_kgid_munged
);
346 * make_kprojid - Map a user-namespace projid pair into a kprojid.
347 * @ns: User namespace that the projid is in
348 * @projid: Project identifier
350 * Maps a user-namespace uid pair into a kernel internal kuid,
351 * and returns that kuid.
353 * When there is no mapping defined for the user-namespace projid
354 * pair INVALID_PROJID is returned. Callers are expected to test
355 * for and handle handle INVALID_PROJID being returned. INVALID_PROJID
356 * may be tested for using projid_valid().
358 kprojid_t
make_kprojid(struct user_namespace
*ns
, projid_t projid
)
360 /* Map the uid to a global kernel uid */
361 return KPROJIDT_INIT(map_id_down(&ns
->projid_map
, projid
));
363 EXPORT_SYMBOL(make_kprojid
);
366 * from_kprojid - Create a projid from a kprojid user-namespace pair.
367 * @targ: The user namespace we want a projid in.
368 * @kprojid: The kernel internal project identifier to start with.
370 * Map @kprojid into the user-namespace specified by @targ and
371 * return the resulting projid.
373 * There is always a mapping into the initial user_namespace.
375 * If @kprojid has no mapping in @targ (projid_t)-1 is returned.
377 projid_t
from_kprojid(struct user_namespace
*targ
, kprojid_t kprojid
)
379 /* Map the uid from a global kernel uid */
380 return map_id_up(&targ
->projid_map
, __kprojid_val(kprojid
));
382 EXPORT_SYMBOL(from_kprojid
);
385 * from_kprojid_munged - Create a projiid from a kprojid user-namespace pair.
386 * @targ: The user namespace we want a projid in.
387 * @kprojid: The kernel internal projid to start with.
389 * Map @kprojid into the user-namespace specified by @targ and
390 * return the resulting projid.
392 * There is always a mapping into the initial user_namespace.
394 * Unlike from_kprojid from_kprojid_munged never fails and always
395 * returns a valid projid. This makes from_kprojid_munged
396 * appropriate for use in syscalls like stat and where
397 * failing the system call and failing to provide a valid projid are
400 * If @kprojid has no mapping in @targ OVERFLOW_PROJID is returned.
402 projid_t
from_kprojid_munged(struct user_namespace
*targ
, kprojid_t kprojid
)
405 projid
= from_kprojid(targ
, kprojid
);
407 if (projid
== (projid_t
) -1)
408 projid
= OVERFLOW_PROJID
;
411 EXPORT_SYMBOL(from_kprojid_munged
);
414 static int uid_m_show(struct seq_file
*seq
, void *v
)
416 struct user_namespace
*ns
= seq
->private;
417 struct uid_gid_extent
*extent
= v
;
418 struct user_namespace
*lower_ns
;
421 lower_ns
= seq_user_ns(seq
);
422 if ((lower_ns
== ns
) && lower_ns
->parent
)
423 lower_ns
= lower_ns
->parent
;
425 lower
= from_kuid(lower_ns
, KUIDT_INIT(extent
->lower_first
));
427 seq_printf(seq
, "%10u %10u %10u\n",
435 static int gid_m_show(struct seq_file
*seq
, void *v
)
437 struct user_namespace
*ns
= seq
->private;
438 struct uid_gid_extent
*extent
= v
;
439 struct user_namespace
*lower_ns
;
442 lower_ns
= seq_user_ns(seq
);
443 if ((lower_ns
== ns
) && lower_ns
->parent
)
444 lower_ns
= lower_ns
->parent
;
446 lower
= from_kgid(lower_ns
, KGIDT_INIT(extent
->lower_first
));
448 seq_printf(seq
, "%10u %10u %10u\n",
456 static int projid_m_show(struct seq_file
*seq
, void *v
)
458 struct user_namespace
*ns
= seq
->private;
459 struct uid_gid_extent
*extent
= v
;
460 struct user_namespace
*lower_ns
;
463 lower_ns
= seq_user_ns(seq
);
464 if ((lower_ns
== ns
) && lower_ns
->parent
)
465 lower_ns
= lower_ns
->parent
;
467 lower
= from_kprojid(lower_ns
, KPROJIDT_INIT(extent
->lower_first
));
469 seq_printf(seq
, "%10u %10u %10u\n",
477 static void *m_start(struct seq_file
*seq
, loff_t
*ppos
, struct uid_gid_map
*map
)
479 struct uid_gid_extent
*extent
= NULL
;
482 if (pos
< map
->nr_extents
)
483 extent
= &map
->extent
[pos
];
488 static void *uid_m_start(struct seq_file
*seq
, loff_t
*ppos
)
490 struct user_namespace
*ns
= seq
->private;
492 return m_start(seq
, ppos
, &ns
->uid_map
);
495 static void *gid_m_start(struct seq_file
*seq
, loff_t
*ppos
)
497 struct user_namespace
*ns
= seq
->private;
499 return m_start(seq
, ppos
, &ns
->gid_map
);
502 static void *projid_m_start(struct seq_file
*seq
, loff_t
*ppos
)
504 struct user_namespace
*ns
= seq
->private;
506 return m_start(seq
, ppos
, &ns
->projid_map
);
509 static void *m_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
512 return seq
->op
->start(seq
, pos
);
515 static void m_stop(struct seq_file
*seq
, void *v
)
520 struct seq_operations proc_uid_seq_operations
= {
521 .start
= uid_m_start
,
527 struct seq_operations proc_gid_seq_operations
= {
528 .start
= gid_m_start
,
534 struct seq_operations proc_projid_seq_operations
= {
535 .start
= projid_m_start
,
538 .show
= projid_m_show
,
541 static bool mappings_overlap(struct uid_gid_map
*new_map
, struct uid_gid_extent
*extent
)
543 u32 upper_first
, lower_first
, upper_last
, lower_last
;
546 upper_first
= extent
->first
;
547 lower_first
= extent
->lower_first
;
548 upper_last
= upper_first
+ extent
->count
- 1;
549 lower_last
= lower_first
+ extent
->count
- 1;
551 for (idx
= 0; idx
< new_map
->nr_extents
; idx
++) {
552 u32 prev_upper_first
, prev_lower_first
;
553 u32 prev_upper_last
, prev_lower_last
;
554 struct uid_gid_extent
*prev
;
556 prev
= &new_map
->extent
[idx
];
558 prev_upper_first
= prev
->first
;
559 prev_lower_first
= prev
->lower_first
;
560 prev_upper_last
= prev_upper_first
+ prev
->count
- 1;
561 prev_lower_last
= prev_lower_first
+ prev
->count
- 1;
563 /* Does the upper range intersect a previous extent? */
564 if ((prev_upper_first
<= upper_last
) &&
565 (prev_upper_last
>= upper_first
))
568 /* Does the lower range intersect a previous extent? */
569 if ((prev_lower_first
<= lower_last
) &&
570 (prev_lower_last
>= lower_first
))
577 static DEFINE_MUTEX(id_map_mutex
);
579 static ssize_t
map_write(struct file
*file
, const char __user
*buf
,
580 size_t count
, loff_t
*ppos
,
582 struct uid_gid_map
*map
,
583 struct uid_gid_map
*parent_map
)
585 struct seq_file
*seq
= file
->private_data
;
586 struct user_namespace
*ns
= seq
->private;
587 struct uid_gid_map new_map
;
589 struct uid_gid_extent
*extent
= NULL
;
590 unsigned long page
= 0;
591 char *kbuf
, *pos
, *next_line
;
592 ssize_t ret
= -EINVAL
;
595 * The id_map_mutex serializes all writes to any given map.
597 * Any map is only ever written once.
599 * An id map fits within 1 cache line on most architectures.
601 * On read nothing needs to be done unless you are on an
602 * architecture with a crazy cache coherency model like alpha.
604 * There is a one time data dependency between reading the
605 * count of the extents and the values of the extents. The
606 * desired behavior is to see the values of the extents that
607 * were written before the count of the extents.
609 * To achieve this smp_wmb() is used on guarantee the write
610 * order and smp_read_barrier_depends() is guaranteed that we
611 * don't have crazy architectures returning stale data.
614 mutex_lock(&id_map_mutex
);
617 /* Only allow one successful write to the map */
618 if (map
->nr_extents
!= 0)
622 * Adjusting namespace settings requires capabilities on the target.
624 if (cap_valid(cap_setid
) && !file_ns_capable(file
, ns
, CAP_SYS_ADMIN
))
629 page
= __get_free_page(GFP_TEMPORARY
);
630 kbuf
= (char *) page
;
634 /* Only allow <= page size writes at the beginning of the file */
636 if ((*ppos
!= 0) || (count
>= PAGE_SIZE
))
639 /* Slurp in the user data */
641 if (copy_from_user(kbuf
, buf
, count
))
645 /* Parse the user data */
648 new_map
.nr_extents
= 0;
649 for (;pos
; pos
= next_line
) {
650 extent
= &new_map
.extent
[new_map
.nr_extents
];
652 /* Find the end of line and ensure I don't look past it */
653 next_line
= strchr(pos
, '\n');
657 if (*next_line
== '\0')
661 pos
= skip_spaces(pos
);
662 extent
->first
= simple_strtoul(pos
, &pos
, 10);
666 pos
= skip_spaces(pos
);
667 extent
->lower_first
= simple_strtoul(pos
, &pos
, 10);
671 pos
= skip_spaces(pos
);
672 extent
->count
= simple_strtoul(pos
, &pos
, 10);
673 if (*pos
&& !isspace(*pos
))
676 /* Verify there is not trailing junk on the line */
677 pos
= skip_spaces(pos
);
681 /* Verify we have been given valid starting values */
682 if ((extent
->first
== (u32
) -1) ||
683 (extent
->lower_first
== (u32
) -1 ))
686 /* Verify count is not zero and does not cause the extent to wrap */
687 if ((extent
->first
+ extent
->count
) <= extent
->first
)
689 if ((extent
->lower_first
+ extent
->count
) <= extent
->lower_first
)
692 /* Do the ranges in extent overlap any previous extents? */
693 if (mappings_overlap(&new_map
, extent
))
696 new_map
.nr_extents
++;
698 /* Fail if the file contains too many extents */
699 if ((new_map
.nr_extents
== UID_GID_MAP_MAX_EXTENTS
) &&
703 /* Be very certaint the new map actually exists */
704 if (new_map
.nr_extents
== 0)
708 /* Validate the user is allowed to use user id's mapped to. */
709 if (!new_idmap_permitted(file
, ns
, cap_setid
, &new_map
))
712 /* Map the lower ids from the parent user namespace to the
713 * kernel global id space.
715 for (idx
= 0; idx
< new_map
.nr_extents
; idx
++) {
717 extent
= &new_map
.extent
[idx
];
719 lower_first
= map_id_range_down(parent_map
,
723 /* Fail if we can not map the specified extent to
724 * the kernel global id space.
726 if (lower_first
== (u32
) -1)
729 extent
->lower_first
= lower_first
;
732 /* Install the map */
733 memcpy(map
->extent
, new_map
.extent
,
734 new_map
.nr_extents
*sizeof(new_map
.extent
[0]));
736 map
->nr_extents
= new_map
.nr_extents
;
741 mutex_unlock(&id_map_mutex
);
747 ssize_t
proc_uid_map_write(struct file
*file
, const char __user
*buf
, size_t size
, loff_t
*ppos
)
749 struct seq_file
*seq
= file
->private_data
;
750 struct user_namespace
*ns
= seq
->private;
751 struct user_namespace
*seq_ns
= seq_user_ns(seq
);
756 if ((seq_ns
!= ns
) && (seq_ns
!= ns
->parent
))
759 return map_write(file
, buf
, size
, ppos
, CAP_SETUID
,
760 &ns
->uid_map
, &ns
->parent
->uid_map
);
763 ssize_t
proc_gid_map_write(struct file
*file
, const char __user
*buf
, size_t size
, loff_t
*ppos
)
765 struct seq_file
*seq
= file
->private_data
;
766 struct user_namespace
*ns
= seq
->private;
767 struct user_namespace
*seq_ns
= seq_user_ns(seq
);
772 if ((seq_ns
!= ns
) && (seq_ns
!= ns
->parent
))
775 return map_write(file
, buf
, size
, ppos
, CAP_SETGID
,
776 &ns
->gid_map
, &ns
->parent
->gid_map
);
779 ssize_t
proc_projid_map_write(struct file
*file
, const char __user
*buf
, size_t size
, loff_t
*ppos
)
781 struct seq_file
*seq
= file
->private_data
;
782 struct user_namespace
*ns
= seq
->private;
783 struct user_namespace
*seq_ns
= seq_user_ns(seq
);
788 if ((seq_ns
!= ns
) && (seq_ns
!= ns
->parent
))
791 /* Anyone can set any valid project id no capability needed */
792 return map_write(file
, buf
, size
, ppos
, -1,
793 &ns
->projid_map
, &ns
->parent
->projid_map
);
796 static bool new_idmap_permitted(const struct file
*file
,
797 struct user_namespace
*ns
, int cap_setid
,
798 struct uid_gid_map
*new_map
)
800 /* Allow mapping to your own filesystem ids */
801 if ((new_map
->nr_extents
== 1) && (new_map
->extent
[0].count
== 1)) {
802 u32 id
= new_map
->extent
[0].lower_first
;
803 if (cap_setid
== CAP_SETUID
) {
804 kuid_t uid
= make_kuid(ns
->parent
, id
);
805 if (uid_eq(uid
, file
->f_cred
->fsuid
))
808 else if (cap_setid
== CAP_SETGID
) {
809 kgid_t gid
= make_kgid(ns
->parent
, id
);
810 if (gid_eq(gid
, file
->f_cred
->fsgid
))
815 /* Allow anyone to set a mapping that doesn't require privilege */
816 if (!cap_valid(cap_setid
))
819 /* Allow the specified ids if we have the appropriate capability
820 * (CAP_SETUID or CAP_SETGID) over the parent user namespace.
821 * And the opener of the id file also had the approprpiate capability.
823 if (ns_capable(ns
->parent
, cap_setid
) &&
824 file_ns_capable(file
, ns
->parent
, cap_setid
))
830 static void *userns_get(struct task_struct
*task
)
832 struct user_namespace
*user_ns
;
835 user_ns
= get_user_ns(__task_cred(task
)->user_ns
);
841 static void userns_put(void *ns
)
846 static int userns_install(struct nsproxy
*nsproxy
, void *ns
)
848 struct user_namespace
*user_ns
= ns
;
851 /* Don't allow gaining capabilities by reentering
852 * the same user namespace.
854 if (user_ns
== current_user_ns())
857 /* Threaded processes may not enter a different user namespace */
858 if (atomic_read(¤t
->mm
->mm_users
) > 1)
861 if (current
->fs
->users
!= 1)
864 if (!ns_capable(user_ns
, CAP_SYS_ADMIN
))
867 cred
= prepare_creds();
871 put_user_ns(cred
->user_ns
);
872 set_cred_user_ns(cred
, get_user_ns(user_ns
));
874 return commit_creds(cred
);
877 static unsigned int userns_inum(void *ns
)
879 struct user_namespace
*user_ns
= ns
;
880 return user_ns
->proc_inum
;
883 const struct proc_ns_operations userns_operations
= {
885 .type
= CLONE_NEWUSER
,
888 .install
= userns_install
,
892 static __init
int user_namespaces_init(void)
894 user_ns_cachep
= KMEM_CACHE(user_namespace
, SLAB_PANIC
);
897 module_init(user_namespaces_init
);