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/sched/task.h>
16 #include <linux/slab.h>
17 #include <linux/syscalls.h>
18 #include <linux/key.h>
19 #include <linux/keyctl.h>
21 #include <linux/capability.h>
22 #include <linux/cred.h>
23 #include <linux/string.h>
24 #include <linux/err.h>
25 #include <linux/vmalloc.h>
26 #include <linux/security.h>
27 #include <linux/uio.h>
28 #include <linux/uaccess.h>
31 #define KEY_MAX_DESC_SIZE 4096
33 static int key_get_type_from_user(char *type
,
34 const char __user
*_type
,
39 ret
= strncpy_from_user(type
, _type
, len
);
42 if (ret
== 0 || ret
>= len
)
51 * Extract the description of a new key from userspace and either add it as a
52 * new key to the specified keyring or update a matching key in that keyring.
54 * If the description is NULL or an empty string, the key type is asked to
55 * generate one from the payload.
57 * The keyring must be writable so that we can attach the key to it.
59 * If successful, the new key's serial number is returned, otherwise an error
62 SYSCALL_DEFINE5(add_key
, const char __user
*, _type
,
63 const char __user
*, _description
,
64 const void __user
*, _payload
,
68 key_ref_t keyring_ref
, key_ref
;
69 char type
[32], *description
;
74 if (plen
> 1024 * 1024 - 1)
77 /* draw all the data into kernel space */
78 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
84 description
= strndup_user(_description
, KEY_MAX_DESC_SIZE
);
85 if (IS_ERR(description
)) {
86 ret
= PTR_ERR(description
);
92 } else if ((description
[0] == '.') &&
93 (strncmp(type
, "keyring", 7) == 0)) {
99 /* pull the payload in if one was supplied */
104 payload
= kmalloc(plen
, GFP_KERNEL
| __GFP_NOWARN
);
106 if (plen
<= PAGE_SIZE
)
108 payload
= vmalloc(plen
);
114 if (copy_from_user(payload
, _payload
, plen
) != 0)
118 /* find the target keyring (which must be writable) */
119 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
120 if (IS_ERR(keyring_ref
)) {
121 ret
= PTR_ERR(keyring_ref
);
125 /* create or update the requested key and add it to the target
127 key_ref
= key_create_or_update(keyring_ref
, type
, description
,
128 payload
, plen
, KEY_PERM_UNDEF
,
130 if (!IS_ERR(key_ref
)) {
131 ret
= key_ref_to_ptr(key_ref
)->serial
;
132 key_ref_put(key_ref
);
135 ret
= PTR_ERR(key_ref
);
138 key_ref_put(keyring_ref
);
148 * Search the process keyrings and keyring trees linked from those for a
149 * matching key. Keyrings must have appropriate Search permission to be
152 * If a key is found, it will be attached to the destination keyring if there's
153 * one specified and the serial number of the key will be returned.
155 * If no key is found, /sbin/request-key will be invoked if _callout_info is
156 * non-NULL in an attempt to create a key. The _callout_info string will be
157 * passed to /sbin/request-key to aid with completing the request. If the
158 * _callout_info string is "" then it will be changed to "-".
160 SYSCALL_DEFINE4(request_key
, const char __user
*, _type
,
161 const char __user
*, _description
,
162 const char __user
*, _callout_info
,
163 key_serial_t
, destringid
)
165 struct key_type
*ktype
;
169 char type
[32], *description
, *callout_info
;
172 /* pull the type into kernel space */
173 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
177 /* pull the description into kernel space */
178 description
= strndup_user(_description
, KEY_MAX_DESC_SIZE
);
179 if (IS_ERR(description
)) {
180 ret
= PTR_ERR(description
);
184 /* pull the callout info into kernel space */
188 callout_info
= strndup_user(_callout_info
, PAGE_SIZE
);
189 if (IS_ERR(callout_info
)) {
190 ret
= PTR_ERR(callout_info
);
193 callout_len
= strlen(callout_info
);
196 /* get the destination keyring if specified */
199 dest_ref
= lookup_user_key(destringid
, KEY_LOOKUP_CREATE
,
201 if (IS_ERR(dest_ref
)) {
202 ret
= PTR_ERR(dest_ref
);
207 /* find the key type */
208 ktype
= key_type_lookup(type
);
210 ret
= PTR_ERR(ktype
);
215 key
= request_key_and_link(ktype
, description
, callout_info
,
216 callout_len
, NULL
, key_ref_to_ptr(dest_ref
),
223 /* wait for the key to finish being constructed */
224 ret
= wait_for_key_construction(key
, 1);
235 key_ref_put(dest_ref
);
245 * Get the ID of the specified process keyring.
247 * The requested keyring must have search permission to be found.
249 * If successful, the ID of the requested keyring will be returned.
251 long keyctl_get_keyring_ID(key_serial_t id
, int create
)
254 unsigned long lflags
;
257 lflags
= create
? KEY_LOOKUP_CREATE
: 0;
258 key_ref
= lookup_user_key(id
, lflags
, KEY_NEED_SEARCH
);
259 if (IS_ERR(key_ref
)) {
260 ret
= PTR_ERR(key_ref
);
264 ret
= key_ref_to_ptr(key_ref
)->serial
;
265 key_ref_put(key_ref
);
271 * Join a (named) session keyring.
273 * Create and join an anonymous session keyring or join a named session
274 * keyring, creating it if necessary. A named session keyring must have Search
275 * permission for it to be joined. Session keyrings without this permit will
278 * If successful, the ID of the joined session keyring will be returned.
280 long keyctl_join_session_keyring(const char __user
*_name
)
285 /* fetch the name from userspace */
288 name
= strndup_user(_name
, KEY_MAX_DESC_SIZE
);
295 /* join the session */
296 ret
= join_session_keyring(name
);
304 * Update a key's data payload from the given data.
306 * The key must grant the caller Write permission and the key type must support
307 * updating for this to work. A negative key can be positively instantiated
310 * If successful, 0 will be returned. If the key type does not support
311 * updating, then -EOPNOTSUPP will be returned.
313 long keyctl_update_key(key_serial_t id
,
314 const void __user
*_payload
,
322 if (plen
> PAGE_SIZE
)
325 /* pull the payload in if one was supplied */
329 payload
= kmalloc(plen
, GFP_KERNEL
);
334 if (copy_from_user(payload
, _payload
, plen
) != 0)
338 /* find the target key (which must be writable) */
339 key_ref
= lookup_user_key(id
, 0, KEY_NEED_WRITE
);
340 if (IS_ERR(key_ref
)) {
341 ret
= PTR_ERR(key_ref
);
346 ret
= key_update(key_ref
, payload
, plen
);
348 key_ref_put(key_ref
);
358 * The key must be grant the caller Write or Setattr permission for this to
359 * work. The key type should give up its quota claim when revoked. The key
360 * and any links to the key will be automatically garbage collected after a
361 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
363 * Keys with KEY_FLAG_KEEP set should not be revoked.
365 * If successful, 0 is returned.
367 long keyctl_revoke_key(key_serial_t id
)
373 key_ref
= lookup_user_key(id
, 0, KEY_NEED_WRITE
);
374 if (IS_ERR(key_ref
)) {
375 ret
= PTR_ERR(key_ref
);
378 key_ref
= lookup_user_key(id
, 0, KEY_NEED_SETATTR
);
379 if (IS_ERR(key_ref
)) {
380 ret
= PTR_ERR(key_ref
);
385 key
= key_ref_to_ptr(key_ref
);
387 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
392 key_ref_put(key_ref
);
400 * The key must be grant the caller Invalidate permission for this to work.
401 * The key and any links to the key will be automatically garbage collected
404 * Keys with KEY_FLAG_KEEP set should not be invalidated.
406 * If successful, 0 is returned.
408 long keyctl_invalidate_key(key_serial_t id
)
416 key_ref
= lookup_user_key(id
, 0, KEY_NEED_SEARCH
);
417 if (IS_ERR(key_ref
)) {
418 ret
= PTR_ERR(key_ref
);
420 /* Root is permitted to invalidate certain special keys */
421 if (capable(CAP_SYS_ADMIN
)) {
422 key_ref
= lookup_user_key(id
, 0, 0);
425 if (test_bit(KEY_FLAG_ROOT_CAN_INVAL
,
426 &key_ref_to_ptr(key_ref
)->flags
))
435 key
= key_ref_to_ptr(key_ref
);
437 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
442 key_ref_put(key_ref
);
444 kleave(" = %ld", ret
);
449 * Clear the specified keyring, creating an empty process keyring if one of the
450 * special keyring IDs is used.
452 * The keyring must grant the caller Write permission and not have
453 * KEY_FLAG_KEEP set for this to work. If successful, 0 will be returned.
455 long keyctl_keyring_clear(key_serial_t ringid
)
457 key_ref_t keyring_ref
;
461 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
462 if (IS_ERR(keyring_ref
)) {
463 ret
= PTR_ERR(keyring_ref
);
465 /* Root is permitted to invalidate certain special keyrings */
466 if (capable(CAP_SYS_ADMIN
)) {
467 keyring_ref
= lookup_user_key(ringid
, 0, 0);
468 if (IS_ERR(keyring_ref
))
470 if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR
,
471 &key_ref_to_ptr(keyring_ref
)->flags
))
480 keyring
= key_ref_to_ptr(keyring_ref
);
481 if (test_bit(KEY_FLAG_KEEP
, &keyring
->flags
))
484 ret
= keyring_clear(keyring
);
486 key_ref_put(keyring_ref
);
492 * Create a link from a keyring to a key if there's no matching key in the
493 * keyring, otherwise replace the link to the matching key with a link to the
496 * The key must grant the caller Link permission and the the keyring must grant
497 * the caller Write permission. Furthermore, if an additional link is created,
498 * the keyring's quota will be extended.
500 * If successful, 0 will be returned.
502 long keyctl_keyring_link(key_serial_t id
, key_serial_t ringid
)
504 key_ref_t keyring_ref
, key_ref
;
507 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
508 if (IS_ERR(keyring_ref
)) {
509 ret
= PTR_ERR(keyring_ref
);
513 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
, KEY_NEED_LINK
);
514 if (IS_ERR(key_ref
)) {
515 ret
= PTR_ERR(key_ref
);
519 ret
= key_link(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 * Unlink a key from a keyring.
531 * The keyring must grant the caller Write permission for this to work; the key
532 * itself need not grant the caller anything. If the last link to a key is
533 * removed then that key will be scheduled for destruction.
535 * Keys or keyrings with KEY_FLAG_KEEP set should not be unlinked.
537 * If successful, 0 will be returned.
539 long keyctl_keyring_unlink(key_serial_t id
, key_serial_t ringid
)
541 key_ref_t keyring_ref
, key_ref
;
542 struct key
*keyring
, *key
;
545 keyring_ref
= lookup_user_key(ringid
, 0, KEY_NEED_WRITE
);
546 if (IS_ERR(keyring_ref
)) {
547 ret
= PTR_ERR(keyring_ref
);
551 key_ref
= lookup_user_key(id
, KEY_LOOKUP_FOR_UNLINK
, 0);
552 if (IS_ERR(key_ref
)) {
553 ret
= PTR_ERR(key_ref
);
557 keyring
= key_ref_to_ptr(keyring_ref
);
558 key
= key_ref_to_ptr(key_ref
);
559 if (test_bit(KEY_FLAG_KEEP
, &keyring
->flags
) &&
560 test_bit(KEY_FLAG_KEEP
, &key
->flags
))
563 ret
= key_unlink(keyring
, key
);
565 key_ref_put(key_ref
);
567 key_ref_put(keyring_ref
);
573 * Return a description of a key to userspace.
575 * The key must grant the caller View permission for this to work.
577 * If there's a buffer, we place up to buflen bytes of data into it formatted
578 * in the following way:
580 * type;uid;gid;perm;description<NUL>
582 * If successful, we return the amount of description available, irrespective
583 * of how much we may have copied into the buffer.
585 long keyctl_describe_key(key_serial_t keyid
,
589 struct key
*key
, *instkey
;
593 int desclen
, infolen
;
595 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, KEY_NEED_VIEW
);
596 if (IS_ERR(key_ref
)) {
597 /* viewing a key under construction is permitted if we have the
598 * authorisation token handy */
599 if (PTR_ERR(key_ref
) == -EACCES
) {
600 instkey
= key_get_instantiation_authkey(keyid
);
601 if (!IS_ERR(instkey
)) {
603 key_ref
= lookup_user_key(keyid
,
606 if (!IS_ERR(key_ref
))
611 ret
= PTR_ERR(key_ref
);
616 key
= key_ref_to_ptr(key_ref
);
617 desclen
= strlen(key
->description
);
619 /* calculate how much information we're going to return */
621 infobuf
= kasprintf(GFP_KERNEL
,
624 from_kuid_munged(current_user_ns(), key
->uid
),
625 from_kgid_munged(current_user_ns(), key
->gid
),
629 infolen
= strlen(infobuf
);
630 ret
= infolen
+ desclen
+ 1;
632 /* consider returning the data */
633 if (buffer
&& buflen
>= ret
) {
634 if (copy_to_user(buffer
, infobuf
, infolen
) != 0 ||
635 copy_to_user(buffer
+ infolen
, key
->description
,
642 key_ref_put(key_ref
);
648 * Search the specified keyring and any keyrings it links to for a matching
649 * key. Only keyrings that grant the caller Search permission will be searched
650 * (this includes the starting keyring). Only keys with Search permission can
653 * If successful, the found key will be linked to the destination keyring if
654 * supplied and the key has Link permission, and the found key ID will be
657 long keyctl_keyring_search(key_serial_t ringid
,
658 const char __user
*_type
,
659 const char __user
*_description
,
660 key_serial_t destringid
)
662 struct key_type
*ktype
;
663 key_ref_t keyring_ref
, key_ref
, dest_ref
;
664 char type
[32], *description
;
667 /* pull the type and description into kernel space */
668 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
672 description
= strndup_user(_description
, KEY_MAX_DESC_SIZE
);
673 if (IS_ERR(description
)) {
674 ret
= PTR_ERR(description
);
678 /* get the keyring at which to begin the search */
679 keyring_ref
= lookup_user_key(ringid
, 0, KEY_NEED_SEARCH
);
680 if (IS_ERR(keyring_ref
)) {
681 ret
= PTR_ERR(keyring_ref
);
685 /* get the destination keyring if specified */
688 dest_ref
= lookup_user_key(destringid
, KEY_LOOKUP_CREATE
,
690 if (IS_ERR(dest_ref
)) {
691 ret
= PTR_ERR(dest_ref
);
696 /* find the key type */
697 ktype
= key_type_lookup(type
);
699 ret
= PTR_ERR(ktype
);
704 key_ref
= keyring_search(keyring_ref
, ktype
, description
);
705 if (IS_ERR(key_ref
)) {
706 ret
= PTR_ERR(key_ref
);
708 /* treat lack or presence of a negative key the same */
714 /* link the resulting key to the destination keyring if we can */
716 ret
= key_permission(key_ref
, KEY_NEED_LINK
);
720 ret
= key_link(key_ref_to_ptr(dest_ref
), key_ref_to_ptr(key_ref
));
725 ret
= key_ref_to_ptr(key_ref
)->serial
;
728 key_ref_put(key_ref
);
732 key_ref_put(dest_ref
);
734 key_ref_put(keyring_ref
);
742 * Read a key's payload.
744 * The key must either grant the caller Read permission, or it must grant the
745 * caller Search permission when searched for from the process keyrings.
747 * If successful, we place up to buflen bytes of data into the buffer, if one
748 * is provided, and return the amount of data that is available in the key,
749 * irrespective of how much we copied into the buffer.
751 long keyctl_read_key(key_serial_t keyid
, char __user
*buffer
, size_t buflen
)
757 /* find the key first */
758 key_ref
= lookup_user_key(keyid
, 0, 0);
759 if (IS_ERR(key_ref
)) {
764 key
= key_ref_to_ptr(key_ref
);
766 /* see if we can read it directly */
767 ret
= key_permission(key_ref
, KEY_NEED_READ
);
773 /* we can't; see if it's searchable from this process's keyrings
774 * - we automatically take account of the fact that it may be
775 * dangling off an instantiation key
777 if (!is_key_possessed(key_ref
)) {
782 /* the key is probably readable - now try to read it */
785 if (key
->type
->read
) {
786 /* Read the data with the semaphore held (since we might sleep)
787 * to protect against the key being updated or revoked.
789 down_read(&key
->sem
);
790 ret
= key_validate(key
);
792 ret
= key
->type
->read(key
, buffer
, buflen
);
803 * Change the ownership of a key
805 * The key must grant the caller Setattr permission for this to work, though
806 * the key need not be fully instantiated yet. For the UID to be changed, or
807 * for the GID to be changed to a group the caller is not a member of, the
808 * caller must have sysadmin capability. If either uid or gid is -1 then that
809 * attribute is not changed.
811 * If the UID is to be changed, the new user must have sufficient quota to
812 * accept the key. The quota deduction will be removed from the old user to
813 * the new user should the attribute be changed.
815 * If successful, 0 will be returned.
817 long keyctl_chown_key(key_serial_t id
, uid_t user
, gid_t group
)
819 struct key_user
*newowner
, *zapowner
= NULL
;
826 uid
= make_kuid(current_user_ns(), user
);
827 gid
= make_kgid(current_user_ns(), group
);
829 if ((user
!= (uid_t
) -1) && !uid_valid(uid
))
831 if ((group
!= (gid_t
) -1) && !gid_valid(gid
))
835 if (user
== (uid_t
) -1 && group
== (gid_t
) -1)
838 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
840 if (IS_ERR(key_ref
)) {
841 ret
= PTR_ERR(key_ref
);
845 key
= key_ref_to_ptr(key_ref
);
847 /* make the changes with the locks held to prevent chown/chown races */
849 down_write(&key
->sem
);
851 if (!capable(CAP_SYS_ADMIN
)) {
852 /* only the sysadmin can chown a key to some other UID */
853 if (user
!= (uid_t
) -1 && !uid_eq(key
->uid
, uid
))
856 /* only the sysadmin can set the key's GID to a group other
857 * than one of those that the current process subscribes to */
858 if (group
!= (gid_t
) -1 && !gid_eq(gid
, key
->gid
) && !in_group_p(gid
))
863 if (user
!= (uid_t
) -1 && !uid_eq(uid
, key
->uid
)) {
865 newowner
= key_user_lookup(uid
);
869 /* transfer the quota burden to the new user */
870 if (test_bit(KEY_FLAG_IN_QUOTA
, &key
->flags
)) {
871 unsigned maxkeys
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
872 key_quota_root_maxkeys
: key_quota_maxkeys
;
873 unsigned maxbytes
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
874 key_quota_root_maxbytes
: key_quota_maxbytes
;
876 spin_lock(&newowner
->lock
);
877 if (newowner
->qnkeys
+ 1 >= maxkeys
||
878 newowner
->qnbytes
+ key
->quotalen
>= maxbytes
||
879 newowner
->qnbytes
+ key
->quotalen
<
884 newowner
->qnbytes
+= key
->quotalen
;
885 spin_unlock(&newowner
->lock
);
887 spin_lock(&key
->user
->lock
);
889 key
->user
->qnbytes
-= key
->quotalen
;
890 spin_unlock(&key
->user
->lock
);
893 atomic_dec(&key
->user
->nkeys
);
894 atomic_inc(&newowner
->nkeys
);
896 if (test_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
)) {
897 atomic_dec(&key
->user
->nikeys
);
898 atomic_inc(&newowner
->nikeys
);
901 zapowner
= key
->user
;
902 key
->user
= newowner
;
907 if (group
!= (gid_t
) -1)
916 key_user_put(zapowner
);
921 spin_unlock(&newowner
->lock
);
928 * Change the permission mask on a key.
930 * The key must grant the caller Setattr permission for this to work, though
931 * the key need not be fully instantiated yet. If the caller does not have
932 * sysadmin capability, it may only change the permission on keys that it owns.
934 long keyctl_setperm_key(key_serial_t id
, key_perm_t perm
)
941 if (perm
& ~(KEY_POS_ALL
| KEY_USR_ALL
| KEY_GRP_ALL
| KEY_OTH_ALL
))
944 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
946 if (IS_ERR(key_ref
)) {
947 ret
= PTR_ERR(key_ref
);
951 key
= key_ref_to_ptr(key_ref
);
953 /* make the changes with the locks held to prevent chown/chmod races */
955 down_write(&key
->sem
);
957 /* if we're not the sysadmin, we can only change a key that we own */
958 if (capable(CAP_SYS_ADMIN
) || uid_eq(key
->uid
, current_fsuid())) {
970 * Get the destination keyring for instantiation and check that the caller has
971 * Write permission on it.
973 static long get_instantiation_keyring(key_serial_t ringid
,
974 struct request_key_auth
*rka
,
975 struct key
**_dest_keyring
)
979 *_dest_keyring
= NULL
;
981 /* just return a NULL pointer if we weren't asked to make a link */
985 /* if a specific keyring is nominated by ID, then use that */
987 dkref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
989 return PTR_ERR(dkref
);
990 *_dest_keyring
= key_ref_to_ptr(dkref
);
994 if (ringid
== KEY_SPEC_REQKEY_AUTH_KEY
)
997 /* otherwise specify the destination keyring recorded in the
998 * authorisation key (any KEY_SPEC_*_KEYRING) */
999 if (ringid
>= KEY_SPEC_REQUESTOR_KEYRING
) {
1000 *_dest_keyring
= key_get(rka
->dest_keyring
);
1008 * Change the request_key authorisation key on the current process.
1010 static int keyctl_change_reqkey_auth(struct key
*key
)
1014 new = prepare_creds();
1018 key_put(new->request_key_auth
);
1019 new->request_key_auth
= key_get(key
);
1021 return commit_creds(new);
1025 * Instantiate a key with the specified payload and link the key into the
1026 * destination keyring if one is given.
1028 * The caller must have the appropriate instantiation permit set for this to
1029 * work (see keyctl_assume_authority). No other permissions are required.
1031 * If successful, 0 will be returned.
1033 long keyctl_instantiate_key_common(key_serial_t id
,
1034 struct iov_iter
*from
,
1035 key_serial_t ringid
)
1037 const struct cred
*cred
= current_cred();
1038 struct request_key_auth
*rka
;
1039 struct key
*instkey
, *dest_keyring
;
1040 size_t plen
= from
? iov_iter_count(from
) : 0;
1044 kenter("%d,,%zu,%d", id
, plen
, ringid
);
1050 if (plen
> 1024 * 1024 - 1)
1053 /* the appropriate instantiation authorisation key must have been
1054 * assumed before calling this */
1056 instkey
= cred
->request_key_auth
;
1060 rka
= instkey
->payload
.data
[0];
1061 if (rka
->target_key
->serial
!= id
)
1064 /* pull the payload in if one was supplied */
1069 payload
= kmalloc(plen
, GFP_KERNEL
);
1071 if (plen
<= PAGE_SIZE
)
1073 payload
= vmalloc(plen
);
1079 if (!copy_from_iter_full(payload
, plen
, from
))
1083 /* find the destination keyring amongst those belonging to the
1084 * requesting task */
1085 ret
= get_instantiation_keyring(ringid
, rka
, &dest_keyring
);
1089 /* instantiate the key and link it into a keyring */
1090 ret
= key_instantiate_and_link(rka
->target_key
, payload
, plen
,
1091 dest_keyring
, instkey
);
1093 key_put(dest_keyring
);
1095 /* discard the assumed authority if it's just been disabled by
1096 * instantiation of the key */
1098 keyctl_change_reqkey_auth(NULL
);
1107 * Instantiate a key with the specified payload and link the key into the
1108 * destination keyring if one is given.
1110 * The caller must have the appropriate instantiation permit set for this to
1111 * work (see keyctl_assume_authority). No other permissions are required.
1113 * If successful, 0 will be returned.
1115 long keyctl_instantiate_key(key_serial_t id
,
1116 const void __user
*_payload
,
1118 key_serial_t ringid
)
1120 if (_payload
&& plen
) {
1122 struct iov_iter from
;
1125 ret
= import_single_range(WRITE
, (void __user
*)_payload
, plen
,
1130 return keyctl_instantiate_key_common(id
, &from
, ringid
);
1133 return keyctl_instantiate_key_common(id
, NULL
, ringid
);
1137 * Instantiate a key with the specified multipart payload and link the key into
1138 * the destination keyring if one is given.
1140 * The caller must have the appropriate instantiation permit set for this to
1141 * work (see keyctl_assume_authority). No other permissions are required.
1143 * If successful, 0 will be returned.
1145 long keyctl_instantiate_key_iov(key_serial_t id
,
1146 const struct iovec __user
*_payload_iov
,
1148 key_serial_t ringid
)
1150 struct iovec iovstack
[UIO_FASTIOV
], *iov
= iovstack
;
1151 struct iov_iter from
;
1157 ret
= import_iovec(WRITE
, _payload_iov
, ioc
,
1158 ARRAY_SIZE(iovstack
), &iov
, &from
);
1161 ret
= keyctl_instantiate_key_common(id
, &from
, ringid
);
1167 * Negatively instantiate the key with the given timeout (in seconds) and link
1168 * the key into the destination keyring if one is given.
1170 * The caller must have the appropriate instantiation permit set for this to
1171 * work (see keyctl_assume_authority). No other permissions are required.
1173 * The key and any links to the key will be automatically garbage collected
1174 * after the timeout expires.
1176 * Negative keys are used to rate limit repeated request_key() calls by causing
1177 * them to return -ENOKEY until the negative key expires.
1179 * If successful, 0 will be returned.
1181 long keyctl_negate_key(key_serial_t id
, unsigned timeout
, key_serial_t ringid
)
1183 return keyctl_reject_key(id
, timeout
, ENOKEY
, ringid
);
1187 * Negatively instantiate the key with the given timeout (in seconds) and error
1188 * code and link the key into the destination keyring if one is given.
1190 * The caller must have the appropriate instantiation permit set for this to
1191 * work (see keyctl_assume_authority). No other permissions are required.
1193 * The key and any links to the key will be automatically garbage collected
1194 * after the timeout expires.
1196 * Negative keys are used to rate limit repeated request_key() calls by causing
1197 * them to return the specified error code until the negative key expires.
1199 * If successful, 0 will be returned.
1201 long keyctl_reject_key(key_serial_t id
, unsigned timeout
, unsigned error
,
1202 key_serial_t ringid
)
1204 const struct cred
*cred
= current_cred();
1205 struct request_key_auth
*rka
;
1206 struct key
*instkey
, *dest_keyring
;
1209 kenter("%d,%u,%u,%d", id
, timeout
, error
, ringid
);
1211 /* must be a valid error code and mustn't be a kernel special */
1213 error
>= MAX_ERRNO
||
1214 error
== ERESTARTSYS
||
1215 error
== ERESTARTNOINTR
||
1216 error
== ERESTARTNOHAND
||
1217 error
== ERESTART_RESTARTBLOCK
)
1220 /* the appropriate instantiation authorisation key must have been
1221 * assumed before calling this */
1223 instkey
= cred
->request_key_auth
;
1227 rka
= instkey
->payload
.data
[0];
1228 if (rka
->target_key
->serial
!= id
)
1231 /* find the destination keyring if present (which must also be
1233 ret
= get_instantiation_keyring(ringid
, rka
, &dest_keyring
);
1237 /* instantiate the key and link it into a keyring */
1238 ret
= key_reject_and_link(rka
->target_key
, timeout
, error
,
1239 dest_keyring
, instkey
);
1241 key_put(dest_keyring
);
1243 /* discard the assumed authority if it's just been disabled by
1244 * instantiation of the key */
1246 keyctl_change_reqkey_auth(NULL
);
1253 * Read or set the default keyring in which request_key() will cache keys and
1254 * return the old setting.
1256 * If a process keyring is specified then this will be created if it doesn't
1257 * yet exist. The old setting will be returned if successful.
1259 long keyctl_set_reqkey_keyring(int reqkey_defl
)
1262 int ret
, old_setting
;
1264 old_setting
= current_cred_xxx(jit_keyring
);
1266 if (reqkey_defl
== KEY_REQKEY_DEFL_NO_CHANGE
)
1269 new = prepare_creds();
1273 switch (reqkey_defl
) {
1274 case KEY_REQKEY_DEFL_THREAD_KEYRING
:
1275 ret
= install_thread_keyring_to_cred(new);
1280 case KEY_REQKEY_DEFL_PROCESS_KEYRING
:
1281 ret
= install_process_keyring_to_cred(new);
1289 case KEY_REQKEY_DEFL_DEFAULT
:
1290 case KEY_REQKEY_DEFL_SESSION_KEYRING
:
1291 case KEY_REQKEY_DEFL_USER_KEYRING
:
1292 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING
:
1293 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING
:
1296 case KEY_REQKEY_DEFL_NO_CHANGE
:
1297 case KEY_REQKEY_DEFL_GROUP_KEYRING
:
1304 new->jit_keyring
= reqkey_defl
;
1313 * Set or clear the timeout on a key.
1315 * Either the key must grant the caller Setattr permission or else the caller
1316 * must hold an instantiation authorisation token for the key.
1318 * The timeout is either 0 to clear the timeout, or a number of seconds from
1319 * the current time. The key and any links to the key will be automatically
1320 * garbage collected after the timeout expires.
1322 * Keys with KEY_FLAG_KEEP set should not be timed out.
1324 * If successful, 0 is returned.
1326 long keyctl_set_timeout(key_serial_t id
, unsigned timeout
)
1328 struct key
*key
, *instkey
;
1332 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
1334 if (IS_ERR(key_ref
)) {
1335 /* setting the timeout on a key under construction is permitted
1336 * if we have the authorisation token handy */
1337 if (PTR_ERR(key_ref
) == -EACCES
) {
1338 instkey
= key_get_instantiation_authkey(id
);
1339 if (!IS_ERR(instkey
)) {
1341 key_ref
= lookup_user_key(id
,
1344 if (!IS_ERR(key_ref
))
1349 ret
= PTR_ERR(key_ref
);
1354 key
= key_ref_to_ptr(key_ref
);
1356 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
1359 key_set_timeout(key
, timeout
);
1367 * Assume (or clear) the authority to instantiate the specified key.
1369 * This sets the authoritative token currently in force for key instantiation.
1370 * This must be done for a key to be instantiated. It has the effect of making
1371 * available all the keys from the caller of the request_key() that created a
1372 * key to request_key() calls made by the caller of this function.
1374 * The caller must have the instantiation key in their process keyrings with a
1375 * Search permission grant available to the caller.
1377 * If the ID given is 0, then the setting will be cleared and 0 returned.
1379 * If the ID given has a matching an authorisation key, then that key will be
1380 * set and its ID will be returned. The authorisation key can be read to get
1381 * the callout information passed to request_key().
1383 long keyctl_assume_authority(key_serial_t id
)
1385 struct key
*authkey
;
1388 /* special key IDs aren't permitted */
1393 /* we divest ourselves of authority if given an ID of 0 */
1395 ret
= keyctl_change_reqkey_auth(NULL
);
1399 /* attempt to assume the authority temporarily granted to us whilst we
1400 * instantiate the specified key
1401 * - the authorisation key must be in the current task's keyrings
1404 authkey
= key_get_instantiation_authkey(id
);
1405 if (IS_ERR(authkey
)) {
1406 ret
= PTR_ERR(authkey
);
1410 ret
= keyctl_change_reqkey_auth(authkey
);
1415 ret
= authkey
->serial
;
1421 * Get a key's the LSM security label.
1423 * The key must grant the caller View permission for this to work.
1425 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1427 * If successful, the amount of information available will be returned,
1428 * irrespective of how much was copied (including the terminal NUL).
1430 long keyctl_get_security(key_serial_t keyid
,
1431 char __user
*buffer
,
1434 struct key
*key
, *instkey
;
1439 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, KEY_NEED_VIEW
);
1440 if (IS_ERR(key_ref
)) {
1441 if (PTR_ERR(key_ref
) != -EACCES
)
1442 return PTR_ERR(key_ref
);
1444 /* viewing a key under construction is also permitted if we
1445 * have the authorisation token handy */
1446 instkey
= key_get_instantiation_authkey(keyid
);
1447 if (IS_ERR(instkey
))
1448 return PTR_ERR(instkey
);
1451 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, 0);
1452 if (IS_ERR(key_ref
))
1453 return PTR_ERR(key_ref
);
1456 key
= key_ref_to_ptr(key_ref
);
1457 ret
= security_key_getsecurity(key
, &context
);
1459 /* if no information was returned, give userspace an empty
1462 if (buffer
&& buflen
> 0 &&
1463 copy_to_user(buffer
, "", 1) != 0)
1465 } else if (ret
> 0) {
1466 /* return as much data as there's room for */
1467 if (buffer
&& buflen
> 0) {
1471 if (copy_to_user(buffer
, context
, buflen
) != 0)
1478 key_ref_put(key_ref
);
1483 * Attempt to install the calling process's session keyring on the process's
1486 * The keyring must exist and must grant the caller LINK permission, and the
1487 * parent process must be single-threaded and must have the same effective
1488 * ownership as this process and mustn't be SUID/SGID.
1490 * The keyring will be emplaced on the parent when it next resumes userspace.
1492 * If successful, 0 will be returned.
1494 long keyctl_session_to_parent(void)
1496 struct task_struct
*me
, *parent
;
1497 const struct cred
*mycred
, *pcred
;
1498 struct callback_head
*newwork
, *oldwork
;
1499 key_ref_t keyring_r
;
1503 keyring_r
= lookup_user_key(KEY_SPEC_SESSION_KEYRING
, 0, KEY_NEED_LINK
);
1504 if (IS_ERR(keyring_r
))
1505 return PTR_ERR(keyring_r
);
1509 /* our parent is going to need a new cred struct, a new tgcred struct
1510 * and new security data, so we allocate them here to prevent ENOMEM in
1512 cred
= cred_alloc_blank();
1515 newwork
= &cred
->rcu
;
1517 cred
->session_keyring
= key_ref_to_ptr(keyring_r
);
1519 init_task_work(newwork
, key_change_session_keyring
);
1523 write_lock_irq(&tasklist_lock
);
1527 parent
= me
->real_parent
;
1529 /* the parent mustn't be init and mustn't be a kernel thread */
1530 if (parent
->pid
<= 1 || !parent
->mm
)
1533 /* the parent must be single threaded */
1534 if (!thread_group_empty(parent
))
1537 /* the parent and the child must have different session keyrings or
1538 * there's no point */
1539 mycred
= current_cred();
1540 pcred
= __task_cred(parent
);
1541 if (mycred
== pcred
||
1542 mycred
->session_keyring
== pcred
->session_keyring
) {
1547 /* the parent must have the same effective ownership and mustn't be
1549 if (!uid_eq(pcred
->uid
, mycred
->euid
) ||
1550 !uid_eq(pcred
->euid
, mycred
->euid
) ||
1551 !uid_eq(pcred
->suid
, mycred
->euid
) ||
1552 !gid_eq(pcred
->gid
, mycred
->egid
) ||
1553 !gid_eq(pcred
->egid
, mycred
->egid
) ||
1554 !gid_eq(pcred
->sgid
, mycred
->egid
))
1557 /* the keyrings must have the same UID */
1558 if ((pcred
->session_keyring
&&
1559 !uid_eq(pcred
->session_keyring
->uid
, mycred
->euid
)) ||
1560 !uid_eq(mycred
->session_keyring
->uid
, mycred
->euid
))
1563 /* cancel an already pending keyring replacement */
1564 oldwork
= task_work_cancel(parent
, key_change_session_keyring
);
1566 /* the replacement session keyring is applied just prior to userspace
1568 ret
= task_work_add(parent
, newwork
, true);
1572 write_unlock_irq(&tasklist_lock
);
1575 put_cred(container_of(oldwork
, struct cred
, rcu
));
1581 key_ref_put(keyring_r
);
1586 * The key control system call
1588 SYSCALL_DEFINE5(keyctl
, int, option
, unsigned long, arg2
, unsigned long, arg3
,
1589 unsigned long, arg4
, unsigned long, arg5
)
1592 case KEYCTL_GET_KEYRING_ID
:
1593 return keyctl_get_keyring_ID((key_serial_t
) arg2
,
1596 case KEYCTL_JOIN_SESSION_KEYRING
:
1597 return keyctl_join_session_keyring((const char __user
*) arg2
);
1600 return keyctl_update_key((key_serial_t
) arg2
,
1601 (const void __user
*) arg3
,
1605 return keyctl_revoke_key((key_serial_t
) arg2
);
1607 case KEYCTL_DESCRIBE
:
1608 return keyctl_describe_key((key_serial_t
) arg2
,
1609 (char __user
*) arg3
,
1613 return keyctl_keyring_clear((key_serial_t
) arg2
);
1616 return keyctl_keyring_link((key_serial_t
) arg2
,
1617 (key_serial_t
) arg3
);
1620 return keyctl_keyring_unlink((key_serial_t
) arg2
,
1621 (key_serial_t
) arg3
);
1624 return keyctl_keyring_search((key_serial_t
) arg2
,
1625 (const char __user
*) arg3
,
1626 (const char __user
*) arg4
,
1627 (key_serial_t
) arg5
);
1630 return keyctl_read_key((key_serial_t
) arg2
,
1631 (char __user
*) arg3
,
1635 return keyctl_chown_key((key_serial_t
) arg2
,
1639 case KEYCTL_SETPERM
:
1640 return keyctl_setperm_key((key_serial_t
) arg2
,
1643 case KEYCTL_INSTANTIATE
:
1644 return keyctl_instantiate_key((key_serial_t
) arg2
,
1645 (const void __user
*) arg3
,
1647 (key_serial_t
) arg5
);
1650 return keyctl_negate_key((key_serial_t
) arg2
,
1652 (key_serial_t
) arg4
);
1654 case KEYCTL_SET_REQKEY_KEYRING
:
1655 return keyctl_set_reqkey_keyring(arg2
);
1657 case KEYCTL_SET_TIMEOUT
:
1658 return keyctl_set_timeout((key_serial_t
) arg2
,
1661 case KEYCTL_ASSUME_AUTHORITY
:
1662 return keyctl_assume_authority((key_serial_t
) arg2
);
1664 case KEYCTL_GET_SECURITY
:
1665 return keyctl_get_security((key_serial_t
) arg2
,
1666 (char __user
*) arg3
,
1669 case KEYCTL_SESSION_TO_PARENT
:
1670 return keyctl_session_to_parent();
1673 return keyctl_reject_key((key_serial_t
) arg2
,
1676 (key_serial_t
) arg5
);
1678 case KEYCTL_INSTANTIATE_IOV
:
1679 return keyctl_instantiate_key_iov(
1680 (key_serial_t
) arg2
,
1681 (const struct iovec __user
*) arg3
,
1683 (key_serial_t
) arg5
);
1685 case KEYCTL_INVALIDATE
:
1686 return keyctl_invalidate_key((key_serial_t
) arg2
);
1688 case KEYCTL_GET_PERSISTENT
:
1689 return keyctl_get_persistent((uid_t
)arg2
, (key_serial_t
)arg3
);
1691 case KEYCTL_DH_COMPUTE
:
1692 return keyctl_dh_compute((struct keyctl_dh_params __user
*) arg2
,
1693 (char __user
*) arg3
, (size_t) arg4
,
1694 (void __user
*) arg5
);