1 /* Userspace key control operations
3 * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16 #include <linux/syscalls.h>
17 #include <linux/key.h>
18 #include <linux/keyctl.h>
20 #include <linux/capability.h>
21 #include <linux/string.h>
22 #include <linux/err.h>
23 #include <linux/vmalloc.h>
24 #include <linux/security.h>
25 #include <asm/uaccess.h>
28 static int key_get_type_from_user(char *type
,
29 const char __user
*_type
,
34 ret
= strncpy_from_user(type
, _type
, len
);
37 if (ret
== 0 || ret
>= len
)
46 * Extract the description of a new key from userspace and either add it as a
47 * new key to the specified keyring or update a matching key in that keyring.
49 * If the description is NULL or an empty string, the key type is asked to
50 * generate one from the payload.
52 * The keyring must be writable so that we can attach the key to it.
54 * If successful, the new key's serial number is returned, otherwise an error
57 SYSCALL_DEFINE5(add_key
, const char __user
*, _type
,
58 const char __user
*, _description
,
59 const void __user
*, _payload
,
63 key_ref_t keyring_ref
, key_ref
;
64 char type
[32], *description
;
70 if (plen
> 1024 * 1024 - 1)
73 /* draw all the data into kernel space */
74 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
80 description
= strndup_user(_description
, PAGE_SIZE
);
81 if (IS_ERR(description
)) {
82 ret
= PTR_ERR(description
);
91 /* pull the payload in if one was supplied */
97 payload
= kmalloc(plen
, GFP_KERNEL
| __GFP_NOWARN
);
99 if (plen
<= PAGE_SIZE
)
102 payload
= vmalloc(plen
);
108 if (copy_from_user(payload
, _payload
, plen
) != 0)
112 /* find the target keyring (which must be writable) */
113 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_WRITE
);
114 if (IS_ERR(keyring_ref
)) {
115 ret
= PTR_ERR(keyring_ref
);
119 /* create or update the requested key and add it to the target
121 key_ref
= key_create_or_update(keyring_ref
, type
, description
,
122 payload
, plen
, KEY_PERM_UNDEF
,
124 if (!IS_ERR(key_ref
)) {
125 ret
= key_ref_to_ptr(key_ref
)->serial
;
126 key_ref_put(key_ref
);
129 ret
= PTR_ERR(key_ref
);
132 key_ref_put(keyring_ref
);
145 * Search the process keyrings and keyring trees linked from those for a
146 * matching key. Keyrings must have appropriate Search permission to be
149 * If a key is found, it will be attached to the destination keyring if there's
150 * one specified and the serial number of the key will be returned.
152 * If no key is found, /sbin/request-key will be invoked if _callout_info is
153 * non-NULL in an attempt to create a key. The _callout_info string will be
154 * passed to /sbin/request-key to aid with completing the request. If the
155 * _callout_info string is "" then it will be changed to "-".
157 SYSCALL_DEFINE4(request_key
, const char __user
*, _type
,
158 const char __user
*, _description
,
159 const char __user
*, _callout_info
,
160 key_serial_t
, destringid
)
162 struct key_type
*ktype
;
166 char type
[32], *description
, *callout_info
;
169 /* pull the type into kernel space */
170 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
174 /* pull the description into kernel space */
175 description
= strndup_user(_description
, PAGE_SIZE
);
176 if (IS_ERR(description
)) {
177 ret
= PTR_ERR(description
);
181 /* pull the callout info into kernel space */
185 callout_info
= strndup_user(_callout_info
, PAGE_SIZE
);
186 if (IS_ERR(callout_info
)) {
187 ret
= PTR_ERR(callout_info
);
190 callout_len
= strlen(callout_info
);
193 /* get the destination keyring if specified */
196 dest_ref
= lookup_user_key(destringid
, KEY_LOOKUP_CREATE
,
198 if (IS_ERR(dest_ref
)) {
199 ret
= PTR_ERR(dest_ref
);
204 /* find the key type */
205 ktype
= key_type_lookup(type
);
207 ret
= PTR_ERR(ktype
);
212 key
= request_key_and_link(ktype
, description
, callout_info
,
213 callout_len
, NULL
, key_ref_to_ptr(dest_ref
),
220 /* wait for the key to finish being constructed */
221 ret
= wait_for_key_construction(key
, 1);
232 key_ref_put(dest_ref
);
242 * Get the ID of the specified process keyring.
244 * The requested keyring must have search permission to be found.
246 * If successful, the ID of the requested keyring will be returned.
248 long keyctl_get_keyring_ID(key_serial_t id
, int create
)
251 unsigned long lflags
;
254 lflags
= create
? KEY_LOOKUP_CREATE
: 0;
255 key_ref
= lookup_user_key(id
, lflags
, KEY_SEARCH
);
256 if (IS_ERR(key_ref
)) {
257 ret
= PTR_ERR(key_ref
);
261 ret
= key_ref_to_ptr(key_ref
)->serial
;
262 key_ref_put(key_ref
);
268 * Join a (named) session keyring.
270 * Create and join an anonymous session keyring or join a named session
271 * keyring, creating it if necessary. A named session keyring must have Search
272 * permission for it to be joined. Session keyrings without this permit will
275 * If successful, the ID of the joined session keyring will be returned.
277 long keyctl_join_session_keyring(const char __user
*_name
)
282 /* fetch the name from userspace */
285 name
= strndup_user(_name
, PAGE_SIZE
);
292 /* join the session */
293 ret
= join_session_keyring(name
);
301 * Update a key's data payload from the given data.
303 * The key must grant the caller Write permission and the key type must support
304 * updating for this to work. A negative key can be positively instantiated
307 * If successful, 0 will be returned. If the key type does not support
308 * updating, then -EOPNOTSUPP will be returned.
310 long keyctl_update_key(key_serial_t id
,
311 const void __user
*_payload
,
319 if (plen
> PAGE_SIZE
)
322 /* pull the payload in if one was supplied */
326 payload
= kmalloc(plen
, GFP_KERNEL
);
331 if (copy_from_user(payload
, _payload
, plen
) != 0)
335 /* find the target key (which must be writable) */
336 key_ref
= lookup_user_key(id
, 0, KEY_WRITE
);
337 if (IS_ERR(key_ref
)) {
338 ret
= PTR_ERR(key_ref
);
343 ret
= key_update(key_ref
, payload
, plen
);
345 key_ref_put(key_ref
);
355 * The key must be grant the caller Write or Setattr permission for this to
356 * work. The key type should give up its quota claim when revoked. The key
357 * and any links to the key will be automatically garbage collected after a
358 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
360 * If successful, 0 is returned.
362 long keyctl_revoke_key(key_serial_t id
)
367 key_ref
= lookup_user_key(id
, 0, KEY_WRITE
);
368 if (IS_ERR(key_ref
)) {
369 ret
= PTR_ERR(key_ref
);
372 key_ref
= lookup_user_key(id
, 0, KEY_SETATTR
);
373 if (IS_ERR(key_ref
)) {
374 ret
= PTR_ERR(key_ref
);
379 key_revoke(key_ref_to_ptr(key_ref
));
382 key_ref_put(key_ref
);
390 * The key must be grant the caller Invalidate permission for this to work.
391 * The key and any links to the key will be automatically garbage collected
394 * If successful, 0 is returned.
396 long keyctl_invalidate_key(key_serial_t id
)
403 key_ref
= lookup_user_key(id
, 0, KEY_SEARCH
);
404 if (IS_ERR(key_ref
)) {
405 ret
= PTR_ERR(key_ref
);
409 key_invalidate(key_ref_to_ptr(key_ref
));
412 key_ref_put(key_ref
);
414 kleave(" = %ld", ret
);
419 * Clear the specified keyring, creating an empty process keyring if one of the
420 * special keyring IDs is used.
422 * The keyring must grant the caller Write permission for this to work. If
423 * successful, 0 will be returned.
425 long keyctl_keyring_clear(key_serial_t ringid
)
427 key_ref_t keyring_ref
;
430 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_WRITE
);
431 if (IS_ERR(keyring_ref
)) {
432 ret
= PTR_ERR(keyring_ref
);
434 /* Root is permitted to invalidate certain special keyrings */
435 if (capable(CAP_SYS_ADMIN
)) {
436 keyring_ref
= lookup_user_key(ringid
, 0, 0);
437 if (IS_ERR(keyring_ref
))
439 if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR
,
440 &key_ref_to_ptr(keyring_ref
)->flags
))
449 ret
= keyring_clear(key_ref_to_ptr(keyring_ref
));
451 key_ref_put(keyring_ref
);
457 * Create a link from a keyring to a key if there's no matching key in the
458 * keyring, otherwise replace the link to the matching key with a link to the
461 * The key must grant the caller Link permission and the the keyring must grant
462 * the caller Write permission. Furthermore, if an additional link is created,
463 * the keyring's quota will be extended.
465 * If successful, 0 will be returned.
467 long keyctl_keyring_link(key_serial_t id
, key_serial_t ringid
)
469 key_ref_t keyring_ref
, key_ref
;
472 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_WRITE
);
473 if (IS_ERR(keyring_ref
)) {
474 ret
= PTR_ERR(keyring_ref
);
478 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
, KEY_LINK
);
479 if (IS_ERR(key_ref
)) {
480 ret
= PTR_ERR(key_ref
);
484 ret
= key_link(key_ref_to_ptr(keyring_ref
), key_ref_to_ptr(key_ref
));
486 key_ref_put(key_ref
);
488 key_ref_put(keyring_ref
);
494 * Unlink a key from a keyring.
496 * The keyring must grant the caller Write permission for this to work; the key
497 * itself need not grant the caller anything. If the last link to a key is
498 * removed then that key will be scheduled for destruction.
500 * If successful, 0 will be returned.
502 long keyctl_keyring_unlink(key_serial_t id
, key_serial_t ringid
)
504 key_ref_t keyring_ref
, key_ref
;
507 keyring_ref
= lookup_user_key(ringid
, 0, KEY_WRITE
);
508 if (IS_ERR(keyring_ref
)) {
509 ret
= PTR_ERR(keyring_ref
);
513 key_ref
= lookup_user_key(id
, KEY_LOOKUP_FOR_UNLINK
, 0);
514 if (IS_ERR(key_ref
)) {
515 ret
= PTR_ERR(key_ref
);
519 ret
= key_unlink(key_ref_to_ptr(keyring_ref
), key_ref_to_ptr(key_ref
));
521 key_ref_put(key_ref
);
523 key_ref_put(keyring_ref
);
529 * Return a description of a key to userspace.
531 * The key must grant the caller View permission for this to work.
533 * If there's a buffer, we place up to buflen bytes of data into it formatted
534 * in the following way:
536 * type;uid;gid;perm;description<NUL>
538 * If successful, we return the amount of description available, irrespective
539 * of how much we may have copied into the buffer.
541 long keyctl_describe_key(key_serial_t keyid
,
545 struct key
*key
, *instkey
;
550 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, KEY_VIEW
);
551 if (IS_ERR(key_ref
)) {
552 /* viewing a key under construction is permitted if we have the
553 * authorisation token handy */
554 if (PTR_ERR(key_ref
) == -EACCES
) {
555 instkey
= key_get_instantiation_authkey(keyid
);
556 if (!IS_ERR(instkey
)) {
558 key_ref
= lookup_user_key(keyid
,
561 if (!IS_ERR(key_ref
))
566 ret
= PTR_ERR(key_ref
);
571 /* calculate how much description we're going to return */
573 tmpbuf
= kmalloc(PAGE_SIZE
, GFP_KERNEL
);
577 key
= key_ref_to_ptr(key_ref
);
579 ret
= snprintf(tmpbuf
, PAGE_SIZE
- 1,
582 from_kuid_munged(current_user_ns(), key
->uid
),
583 from_kgid_munged(current_user_ns(), key
->gid
),
585 key
->description
?: "");
587 /* include a NUL char at the end of the data */
588 if (ret
> PAGE_SIZE
- 1)
593 /* consider returning the data */
594 if (buffer
&& buflen
> 0) {
598 if (copy_to_user(buffer
, tmpbuf
, buflen
) != 0)
604 key_ref_put(key_ref
);
610 * Search the specified keyring and any keyrings it links to for a matching
611 * key. Only keyrings that grant the caller Search permission will be searched
612 * (this includes the starting keyring). Only keys with Search permission can
615 * If successful, the found key will be linked to the destination keyring if
616 * supplied and the key has Link permission, and the found key ID will be
619 long keyctl_keyring_search(key_serial_t ringid
,
620 const char __user
*_type
,
621 const char __user
*_description
,
622 key_serial_t destringid
)
624 struct key_type
*ktype
;
625 key_ref_t keyring_ref
, key_ref
, dest_ref
;
626 char type
[32], *description
;
629 /* pull the type and description into kernel space */
630 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
634 description
= strndup_user(_description
, PAGE_SIZE
);
635 if (IS_ERR(description
)) {
636 ret
= PTR_ERR(description
);
640 /* get the keyring at which to begin the search */
641 keyring_ref
= lookup_user_key(ringid
, 0, KEY_SEARCH
);
642 if (IS_ERR(keyring_ref
)) {
643 ret
= PTR_ERR(keyring_ref
);
647 /* get the destination keyring if specified */
650 dest_ref
= lookup_user_key(destringid
, KEY_LOOKUP_CREATE
,
652 if (IS_ERR(dest_ref
)) {
653 ret
= PTR_ERR(dest_ref
);
658 /* find the key type */
659 ktype
= key_type_lookup(type
);
661 ret
= PTR_ERR(ktype
);
666 key_ref
= keyring_search(keyring_ref
, ktype
, description
);
667 if (IS_ERR(key_ref
)) {
668 ret
= PTR_ERR(key_ref
);
670 /* treat lack or presence of a negative key the same */
676 /* link the resulting key to the destination keyring if we can */
678 ret
= key_permission(key_ref
, KEY_LINK
);
682 ret
= key_link(key_ref_to_ptr(dest_ref
), key_ref_to_ptr(key_ref
));
687 ret
= key_ref_to_ptr(key_ref
)->serial
;
690 key_ref_put(key_ref
);
694 key_ref_put(dest_ref
);
696 key_ref_put(keyring_ref
);
704 * Read a key's payload.
706 * The key must either grant the caller Read permission, or it must grant the
707 * caller Search permission when searched for from the process keyrings.
709 * If successful, we place up to buflen bytes of data into the buffer, if one
710 * is provided, and return the amount of data that is available in the key,
711 * irrespective of how much we copied into the buffer.
713 long keyctl_read_key(key_serial_t keyid
, char __user
*buffer
, size_t buflen
)
719 /* find the key first */
720 key_ref
= lookup_user_key(keyid
, 0, 0);
721 if (IS_ERR(key_ref
)) {
726 key
= key_ref_to_ptr(key_ref
);
728 /* see if we can read it directly */
729 ret
= key_permission(key_ref
, KEY_READ
);
735 /* we can't; see if it's searchable from this process's keyrings
736 * - we automatically take account of the fact that it may be
737 * dangling off an instantiation key
739 if (!is_key_possessed(key_ref
)) {
744 /* the key is probably readable - now try to read it */
746 ret
= key_validate(key
);
749 if (key
->type
->read
) {
750 /* read the data with the semaphore held (since we
752 down_read(&key
->sem
);
753 ret
= key
->type
->read(key
, buffer
, buflen
);
765 * Change the ownership of a key
767 * The key must grant the caller Setattr permission for this to work, though
768 * the key need not be fully instantiated yet. For the UID to be changed, or
769 * for the GID to be changed to a group the caller is not a member of, the
770 * caller must have sysadmin capability. If either uid or gid is -1 then that
771 * attribute is not changed.
773 * If the UID is to be changed, the new user must have sufficient quota to
774 * accept the key. The quota deduction will be removed from the old user to
775 * the new user should the attribute be changed.
777 * If successful, 0 will be returned.
779 long keyctl_chown_key(key_serial_t id
, uid_t user
, gid_t group
)
781 struct key_user
*newowner
, *zapowner
= NULL
;
788 uid
= make_kuid(current_user_ns(), user
);
789 gid
= make_kgid(current_user_ns(), group
);
791 if ((user
!= (uid_t
) -1) && !uid_valid(uid
))
793 if ((group
!= (gid_t
) -1) && !gid_valid(gid
))
797 if (user
== (uid_t
) -1 && group
== (gid_t
) -1)
800 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
802 if (IS_ERR(key_ref
)) {
803 ret
= PTR_ERR(key_ref
);
807 key
= key_ref_to_ptr(key_ref
);
809 /* make the changes with the locks held to prevent chown/chown races */
811 down_write(&key
->sem
);
813 if (!capable(CAP_SYS_ADMIN
)) {
814 /* only the sysadmin can chown a key to some other UID */
815 if (user
!= (uid_t
) -1 && !uid_eq(key
->uid
, uid
))
818 /* only the sysadmin can set the key's GID to a group other
819 * than one of those that the current process subscribes to */
820 if (group
!= (gid_t
) -1 && !gid_eq(gid
, key
->gid
) && !in_group_p(gid
))
825 if (user
!= (uid_t
) -1 && !uid_eq(uid
, key
->uid
)) {
827 newowner
= key_user_lookup(uid
);
831 /* transfer the quota burden to the new user */
832 if (test_bit(KEY_FLAG_IN_QUOTA
, &key
->flags
)) {
833 unsigned maxkeys
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
834 key_quota_root_maxkeys
: key_quota_maxkeys
;
835 unsigned maxbytes
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
836 key_quota_root_maxbytes
: key_quota_maxbytes
;
838 spin_lock(&newowner
->lock
);
839 if (newowner
->qnkeys
+ 1 >= maxkeys
||
840 newowner
->qnbytes
+ key
->quotalen
>= maxbytes
||
841 newowner
->qnbytes
+ key
->quotalen
<
846 newowner
->qnbytes
+= key
->quotalen
;
847 spin_unlock(&newowner
->lock
);
849 spin_lock(&key
->user
->lock
);
851 key
->user
->qnbytes
-= key
->quotalen
;
852 spin_unlock(&key
->user
->lock
);
855 atomic_dec(&key
->user
->nkeys
);
856 atomic_inc(&newowner
->nkeys
);
858 if (test_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
)) {
859 atomic_dec(&key
->user
->nikeys
);
860 atomic_inc(&newowner
->nikeys
);
863 zapowner
= key
->user
;
864 key
->user
= newowner
;
869 if (group
!= (gid_t
) -1)
878 key_user_put(zapowner
);
883 spin_unlock(&newowner
->lock
);
890 * Change the permission mask on a key.
892 * The key must grant the caller Setattr permission for this to work, though
893 * the key need not be fully instantiated yet. If the caller does not have
894 * sysadmin capability, it may only change the permission on keys that it owns.
896 long keyctl_setperm_key(key_serial_t id
, key_perm_t perm
)
903 if (perm
& ~(KEY_POS_ALL
| KEY_USR_ALL
| KEY_GRP_ALL
| KEY_OTH_ALL
))
906 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
908 if (IS_ERR(key_ref
)) {
909 ret
= PTR_ERR(key_ref
);
913 key
= key_ref_to_ptr(key_ref
);
915 /* make the changes with the locks held to prevent chown/chmod races */
917 down_write(&key
->sem
);
919 /* if we're not the sysadmin, we can only change a key that we own */
920 if (capable(CAP_SYS_ADMIN
) || uid_eq(key
->uid
, current_fsuid())) {
932 * Get the destination keyring for instantiation and check that the caller has
933 * Write permission on it.
935 static long get_instantiation_keyring(key_serial_t ringid
,
936 struct request_key_auth
*rka
,
937 struct key
**_dest_keyring
)
941 *_dest_keyring
= NULL
;
943 /* just return a NULL pointer if we weren't asked to make a link */
947 /* if a specific keyring is nominated by ID, then use that */
949 dkref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_WRITE
);
951 return PTR_ERR(dkref
);
952 *_dest_keyring
= key_ref_to_ptr(dkref
);
956 if (ringid
== KEY_SPEC_REQKEY_AUTH_KEY
)
959 /* otherwise specify the destination keyring recorded in the
960 * authorisation key (any KEY_SPEC_*_KEYRING) */
961 if (ringid
>= KEY_SPEC_REQUESTOR_KEYRING
) {
962 *_dest_keyring
= key_get(rka
->dest_keyring
);
970 * Change the request_key authorisation key on the current process.
972 static int keyctl_change_reqkey_auth(struct key
*key
)
976 new = prepare_creds();
980 key_put(new->request_key_auth
);
981 new->request_key_auth
= key_get(key
);
983 return commit_creds(new);
987 * Copy the iovec data from userspace
989 static long copy_from_user_iovec(void *buffer
, const struct iovec
*iov
,
992 for (; ioc
> 0; ioc
--) {
993 if (copy_from_user(buffer
, iov
->iov_base
, iov
->iov_len
) != 0)
995 buffer
+= iov
->iov_len
;
1002 * Instantiate a key with the specified payload and link the key into the
1003 * destination keyring if one is given.
1005 * The caller must have the appropriate instantiation permit set for this to
1006 * work (see keyctl_assume_authority). No other permissions are required.
1008 * If successful, 0 will be returned.
1010 long keyctl_instantiate_key_common(key_serial_t id
,
1011 const struct iovec
*payload_iov
,
1014 key_serial_t ringid
)
1016 const struct cred
*cred
= current_cred();
1017 struct request_key_auth
*rka
;
1018 struct key
*instkey
, *dest_keyring
;
1023 kenter("%d,,%zu,%d", id
, plen
, ringid
);
1026 if (plen
> 1024 * 1024 - 1)
1029 /* the appropriate instantiation authorisation key must have been
1030 * assumed before calling this */
1032 instkey
= cred
->request_key_auth
;
1036 rka
= instkey
->payload
.data
;
1037 if (rka
->target_key
->serial
!= id
)
1040 /* pull the payload in if one was supplied */
1045 payload
= kmalloc(plen
, GFP_KERNEL
);
1047 if (plen
<= PAGE_SIZE
)
1050 payload
= vmalloc(plen
);
1055 ret
= copy_from_user_iovec(payload
, payload_iov
, ioc
);
1060 /* find the destination keyring amongst those belonging to the
1061 * requesting task */
1062 ret
= get_instantiation_keyring(ringid
, rka
, &dest_keyring
);
1066 /* instantiate the key and link it into a keyring */
1067 ret
= key_instantiate_and_link(rka
->target_key
, payload
, plen
,
1068 dest_keyring
, instkey
);
1070 key_put(dest_keyring
);
1072 /* discard the assumed authority if it's just been disabled by
1073 * instantiation of the key */
1075 keyctl_change_reqkey_auth(NULL
);
1087 * Instantiate a key with the specified payload and link the key into the
1088 * destination keyring if one is given.
1090 * The caller must have the appropriate instantiation permit set for this to
1091 * work (see keyctl_assume_authority). No other permissions are required.
1093 * If successful, 0 will be returned.
1095 long keyctl_instantiate_key(key_serial_t id
,
1096 const void __user
*_payload
,
1098 key_serial_t ringid
)
1100 if (_payload
&& plen
) {
1101 struct iovec iov
[1] = {
1102 [0].iov_base
= (void __user
*)_payload
,
1106 return keyctl_instantiate_key_common(id
, iov
, 1, plen
, ringid
);
1109 return keyctl_instantiate_key_common(id
, NULL
, 0, 0, ringid
);
1113 * Instantiate a key with the specified multipart payload and link the key into
1114 * the destination keyring if one is given.
1116 * The caller must have the appropriate instantiation permit set for this to
1117 * work (see keyctl_assume_authority). No other permissions are required.
1119 * If successful, 0 will be returned.
1121 long keyctl_instantiate_key_iov(key_serial_t id
,
1122 const struct iovec __user
*_payload_iov
,
1124 key_serial_t ringid
)
1126 struct iovec iovstack
[UIO_FASTIOV
], *iov
= iovstack
;
1129 if (!_payload_iov
|| !ioc
)
1132 ret
= rw_copy_check_uvector(WRITE
, _payload_iov
, ioc
,
1133 ARRAY_SIZE(iovstack
), iovstack
, &iov
);
1137 goto no_payload_free
;
1139 ret
= keyctl_instantiate_key_common(id
, iov
, ioc
, ret
, ringid
);
1141 if (iov
!= iovstack
)
1146 if (iov
!= iovstack
)
1149 return keyctl_instantiate_key_common(id
, NULL
, 0, 0, ringid
);
1153 * Negatively instantiate the key with the given timeout (in seconds) and link
1154 * the key into the destination keyring if one is given.
1156 * The caller must have the appropriate instantiation permit set for this to
1157 * work (see keyctl_assume_authority). No other permissions are required.
1159 * The key and any links to the key will be automatically garbage collected
1160 * after the timeout expires.
1162 * Negative keys are used to rate limit repeated request_key() calls by causing
1163 * them to return -ENOKEY until the negative key expires.
1165 * If successful, 0 will be returned.
1167 long keyctl_negate_key(key_serial_t id
, unsigned timeout
, key_serial_t ringid
)
1169 return keyctl_reject_key(id
, timeout
, ENOKEY
, ringid
);
1173 * Negatively instantiate the key with the given timeout (in seconds) and error
1174 * code and link the key into the destination keyring if one is given.
1176 * The caller must have the appropriate instantiation permit set for this to
1177 * work (see keyctl_assume_authority). No other permissions are required.
1179 * The key and any links to the key will be automatically garbage collected
1180 * after the timeout expires.
1182 * Negative keys are used to rate limit repeated request_key() calls by causing
1183 * them to return the specified error code until the negative key expires.
1185 * If successful, 0 will be returned.
1187 long keyctl_reject_key(key_serial_t id
, unsigned timeout
, unsigned error
,
1188 key_serial_t ringid
)
1190 const struct cred
*cred
= current_cred();
1191 struct request_key_auth
*rka
;
1192 struct key
*instkey
, *dest_keyring
;
1195 kenter("%d,%u,%u,%d", id
, timeout
, error
, ringid
);
1197 /* must be a valid error code and mustn't be a kernel special */
1199 error
>= MAX_ERRNO
||
1200 error
== ERESTARTSYS
||
1201 error
== ERESTARTNOINTR
||
1202 error
== ERESTARTNOHAND
||
1203 error
== ERESTART_RESTARTBLOCK
)
1206 /* the appropriate instantiation authorisation key must have been
1207 * assumed before calling this */
1209 instkey
= cred
->request_key_auth
;
1213 rka
= instkey
->payload
.data
;
1214 if (rka
->target_key
->serial
!= id
)
1217 /* find the destination keyring if present (which must also be
1219 ret
= get_instantiation_keyring(ringid
, rka
, &dest_keyring
);
1223 /* instantiate the key and link it into a keyring */
1224 ret
= key_reject_and_link(rka
->target_key
, timeout
, error
,
1225 dest_keyring
, instkey
);
1227 key_put(dest_keyring
);
1229 /* discard the assumed authority if it's just been disabled by
1230 * instantiation of the key */
1232 keyctl_change_reqkey_auth(NULL
);
1239 * Read or set the default keyring in which request_key() will cache keys and
1240 * return the old setting.
1242 * If a process keyring is specified then this will be created if it doesn't
1243 * yet exist. The old setting will be returned if successful.
1245 long keyctl_set_reqkey_keyring(int reqkey_defl
)
1248 int ret
, old_setting
;
1250 old_setting
= current_cred_xxx(jit_keyring
);
1252 if (reqkey_defl
== KEY_REQKEY_DEFL_NO_CHANGE
)
1255 new = prepare_creds();
1259 switch (reqkey_defl
) {
1260 case KEY_REQKEY_DEFL_THREAD_KEYRING
:
1261 ret
= install_thread_keyring_to_cred(new);
1266 case KEY_REQKEY_DEFL_PROCESS_KEYRING
:
1267 ret
= install_process_keyring_to_cred(new);
1275 case KEY_REQKEY_DEFL_DEFAULT
:
1276 case KEY_REQKEY_DEFL_SESSION_KEYRING
:
1277 case KEY_REQKEY_DEFL_USER_KEYRING
:
1278 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING
:
1279 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING
:
1282 case KEY_REQKEY_DEFL_NO_CHANGE
:
1283 case KEY_REQKEY_DEFL_GROUP_KEYRING
:
1290 new->jit_keyring
= reqkey_defl
;
1299 * Set or clear the timeout on a key.
1301 * Either the key must grant the caller Setattr permission or else the caller
1302 * must hold an instantiation authorisation token for the key.
1304 * The timeout is either 0 to clear the timeout, or a number of seconds from
1305 * the current time. The key and any links to the key will be automatically
1306 * garbage collected after the timeout expires.
1308 * If successful, 0 is returned.
1310 long keyctl_set_timeout(key_serial_t id
, unsigned timeout
)
1312 struct key
*key
, *instkey
;
1316 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
1318 if (IS_ERR(key_ref
)) {
1319 /* setting the timeout on a key under construction is permitted
1320 * if we have the authorisation token handy */
1321 if (PTR_ERR(key_ref
) == -EACCES
) {
1322 instkey
= key_get_instantiation_authkey(id
);
1323 if (!IS_ERR(instkey
)) {
1325 key_ref
= lookup_user_key(id
,
1328 if (!IS_ERR(key_ref
))
1333 ret
= PTR_ERR(key_ref
);
1338 key
= key_ref_to_ptr(key_ref
);
1339 key_set_timeout(key
, timeout
);
1348 * Assume (or clear) the authority to instantiate the specified key.
1350 * This sets the authoritative token currently in force for key instantiation.
1351 * This must be done for a key to be instantiated. It has the effect of making
1352 * available all the keys from the caller of the request_key() that created a
1353 * key to request_key() calls made by the caller of this function.
1355 * The caller must have the instantiation key in their process keyrings with a
1356 * Search permission grant available to the caller.
1358 * If the ID given is 0, then the setting will be cleared and 0 returned.
1360 * If the ID given has a matching an authorisation key, then that key will be
1361 * set and its ID will be returned. The authorisation key can be read to get
1362 * the callout information passed to request_key().
1364 long keyctl_assume_authority(key_serial_t id
)
1366 struct key
*authkey
;
1369 /* special key IDs aren't permitted */
1374 /* we divest ourselves of authority if given an ID of 0 */
1376 ret
= keyctl_change_reqkey_auth(NULL
);
1380 /* attempt to assume the authority temporarily granted to us whilst we
1381 * instantiate the specified key
1382 * - the authorisation key must be in the current task's keyrings
1385 authkey
= key_get_instantiation_authkey(id
);
1386 if (IS_ERR(authkey
)) {
1387 ret
= PTR_ERR(authkey
);
1391 ret
= keyctl_change_reqkey_auth(authkey
);
1396 ret
= authkey
->serial
;
1402 * Get a key's the LSM security label.
1404 * The key must grant the caller View permission for this to work.
1406 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1408 * If successful, the amount of information available will be returned,
1409 * irrespective of how much was copied (including the terminal NUL).
1411 long keyctl_get_security(key_serial_t keyid
,
1412 char __user
*buffer
,
1415 struct key
*key
, *instkey
;
1420 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, KEY_VIEW
);
1421 if (IS_ERR(key_ref
)) {
1422 if (PTR_ERR(key_ref
) != -EACCES
)
1423 return PTR_ERR(key_ref
);
1425 /* viewing a key under construction is also permitted if we
1426 * have the authorisation token handy */
1427 instkey
= key_get_instantiation_authkey(keyid
);
1428 if (IS_ERR(instkey
))
1429 return PTR_ERR(instkey
);
1432 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, 0);
1433 if (IS_ERR(key_ref
))
1434 return PTR_ERR(key_ref
);
1437 key
= key_ref_to_ptr(key_ref
);
1438 ret
= security_key_getsecurity(key
, &context
);
1440 /* if no information was returned, give userspace an empty
1443 if (buffer
&& buflen
> 0 &&
1444 copy_to_user(buffer
, "", 1) != 0)
1446 } else if (ret
> 0) {
1447 /* return as much data as there's room for */
1448 if (buffer
&& buflen
> 0) {
1452 if (copy_to_user(buffer
, context
, buflen
) != 0)
1459 key_ref_put(key_ref
);
1464 * Attempt to install the calling process's session keyring on the process's
1467 * The keyring must exist and must grant the caller LINK permission, and the
1468 * parent process must be single-threaded and must have the same effective
1469 * ownership as this process and mustn't be SUID/SGID.
1471 * The keyring will be emplaced on the parent when it next resumes userspace.
1473 * If successful, 0 will be returned.
1475 long keyctl_session_to_parent(void)
1477 struct task_struct
*me
, *parent
;
1478 const struct cred
*mycred
, *pcred
;
1479 struct callback_head
*newwork
, *oldwork
;
1480 key_ref_t keyring_r
;
1484 keyring_r
= lookup_user_key(KEY_SPEC_SESSION_KEYRING
, 0, KEY_LINK
);
1485 if (IS_ERR(keyring_r
))
1486 return PTR_ERR(keyring_r
);
1490 /* our parent is going to need a new cred struct, a new tgcred struct
1491 * and new security data, so we allocate them here to prevent ENOMEM in
1493 cred
= cred_alloc_blank();
1496 newwork
= &cred
->rcu
;
1498 cred
->session_keyring
= key_ref_to_ptr(keyring_r
);
1500 init_task_work(newwork
, key_change_session_keyring
);
1504 write_lock_irq(&tasklist_lock
);
1508 parent
= me
->real_parent
;
1510 /* the parent mustn't be init and mustn't be a kernel thread */
1511 if (parent
->pid
<= 1 || !parent
->mm
)
1514 /* the parent must be single threaded */
1515 if (!thread_group_empty(parent
))
1518 /* the parent and the child must have different session keyrings or
1519 * there's no point */
1520 mycred
= current_cred();
1521 pcred
= __task_cred(parent
);
1522 if (mycred
== pcred
||
1523 mycred
->session_keyring
== pcred
->session_keyring
) {
1528 /* the parent must have the same effective ownership and mustn't be
1530 if (!uid_eq(pcred
->uid
, mycred
->euid
) ||
1531 !uid_eq(pcred
->euid
, mycred
->euid
) ||
1532 !uid_eq(pcred
->suid
, mycred
->euid
) ||
1533 !gid_eq(pcred
->gid
, mycred
->egid
) ||
1534 !gid_eq(pcred
->egid
, mycred
->egid
) ||
1535 !gid_eq(pcred
->sgid
, mycred
->egid
))
1538 /* the keyrings must have the same UID */
1539 if ((pcred
->session_keyring
&&
1540 !uid_eq(pcred
->session_keyring
->uid
, mycred
->euid
)) ||
1541 !uid_eq(mycred
->session_keyring
->uid
, mycred
->euid
))
1544 /* cancel an already pending keyring replacement */
1545 oldwork
= task_work_cancel(parent
, key_change_session_keyring
);
1547 /* the replacement session keyring is applied just prior to userspace
1549 ret
= task_work_add(parent
, newwork
, true);
1553 write_unlock_irq(&tasklist_lock
);
1556 put_cred(container_of(oldwork
, struct cred
, rcu
));
1562 key_ref_put(keyring_r
);
1567 * The key control system call
1569 SYSCALL_DEFINE5(keyctl
, int, option
, unsigned long, arg2
, unsigned long, arg3
,
1570 unsigned long, arg4
, unsigned long, arg5
)
1573 case KEYCTL_GET_KEYRING_ID
:
1574 return keyctl_get_keyring_ID((key_serial_t
) arg2
,
1577 case KEYCTL_JOIN_SESSION_KEYRING
:
1578 return keyctl_join_session_keyring((const char __user
*) arg2
);
1581 return keyctl_update_key((key_serial_t
) arg2
,
1582 (const void __user
*) arg3
,
1586 return keyctl_revoke_key((key_serial_t
) arg2
);
1588 case KEYCTL_DESCRIBE
:
1589 return keyctl_describe_key((key_serial_t
) arg2
,
1590 (char __user
*) arg3
,
1594 return keyctl_keyring_clear((key_serial_t
) arg2
);
1597 return keyctl_keyring_link((key_serial_t
) arg2
,
1598 (key_serial_t
) arg3
);
1601 return keyctl_keyring_unlink((key_serial_t
) arg2
,
1602 (key_serial_t
) arg3
);
1605 return keyctl_keyring_search((key_serial_t
) arg2
,
1606 (const char __user
*) arg3
,
1607 (const char __user
*) arg4
,
1608 (key_serial_t
) arg5
);
1611 return keyctl_read_key((key_serial_t
) arg2
,
1612 (char __user
*) arg3
,
1616 return keyctl_chown_key((key_serial_t
) arg2
,
1620 case KEYCTL_SETPERM
:
1621 return keyctl_setperm_key((key_serial_t
) arg2
,
1624 case KEYCTL_INSTANTIATE
:
1625 return keyctl_instantiate_key((key_serial_t
) arg2
,
1626 (const void __user
*) arg3
,
1628 (key_serial_t
) arg5
);
1631 return keyctl_negate_key((key_serial_t
) arg2
,
1633 (key_serial_t
) arg4
);
1635 case KEYCTL_SET_REQKEY_KEYRING
:
1636 return keyctl_set_reqkey_keyring(arg2
);
1638 case KEYCTL_SET_TIMEOUT
:
1639 return keyctl_set_timeout((key_serial_t
) arg2
,
1642 case KEYCTL_ASSUME_AUTHORITY
:
1643 return keyctl_assume_authority((key_serial_t
) arg2
);
1645 case KEYCTL_GET_SECURITY
:
1646 return keyctl_get_security((key_serial_t
) arg2
,
1647 (char __user
*) arg3
,
1650 case KEYCTL_SESSION_TO_PARENT
:
1651 return keyctl_session_to_parent();
1654 return keyctl_reject_key((key_serial_t
) arg2
,
1657 (key_serial_t
) arg5
);
1659 case KEYCTL_INSTANTIATE_IOV
:
1660 return keyctl_instantiate_key_iov(
1661 (key_serial_t
) arg2
,
1662 (const struct iovec __user
*) arg3
,
1664 (key_serial_t
) arg5
);
1666 case KEYCTL_INVALIDATE
:
1667 return keyctl_invalidate_key((key_serial_t
) arg2
);