1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Userspace key control operations
4 * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #include <linux/init.h>
9 #include <linux/sched.h>
10 #include <linux/sched/task.h>
11 #include <linux/slab.h>
12 #include <linux/syscalls.h>
13 #include <linux/key.h>
14 #include <linux/keyctl.h>
16 #include <linux/capability.h>
17 #include <linux/cred.h>
18 #include <linux/string.h>
19 #include <linux/err.h>
20 #include <linux/vmalloc.h>
21 #include <linux/security.h>
22 #include <linux/uio.h>
23 #include <linux/uaccess.h>
24 #include <keys/request_key_auth-type.h>
27 #define KEY_MAX_DESC_SIZE 4096
29 static int key_get_type_from_user(char *type
,
30 const char __user
*_type
,
35 ret
= strncpy_from_user(type
, _type
, len
);
38 if (ret
== 0 || ret
>= len
)
47 * Extract the description of a new key from userspace and either add it as a
48 * new key to the specified keyring or update a matching key in that keyring.
50 * If the description is NULL or an empty string, the key type is asked to
51 * generate one from the payload.
53 * The keyring must be writable so that we can attach the key to it.
55 * If successful, the new key's serial number is returned, otherwise an error
58 SYSCALL_DEFINE5(add_key
, const char __user
*, _type
,
59 const char __user
*, _description
,
60 const void __user
*, _payload
,
64 key_ref_t keyring_ref
, key_ref
;
65 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
, KEY_MAX_DESC_SIZE
);
81 if (IS_ERR(description
)) {
82 ret
= PTR_ERR(description
);
88 } else if ((description
[0] == '.') &&
89 (strncmp(type
, "keyring", 7) == 0)) {
95 /* pull the payload in if one was supplied */
100 payload
= kvmalloc(plen
, GFP_KERNEL
);
105 if (copy_from_user(payload
, _payload
, plen
) != 0)
109 /* find the target keyring (which must be writable) */
110 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
111 if (IS_ERR(keyring_ref
)) {
112 ret
= PTR_ERR(keyring_ref
);
116 /* create or update the requested key and add it to the target
118 key_ref
= key_create_or_update(keyring_ref
, type
, description
,
119 payload
, plen
, KEY_PERM_UNDEF
,
121 if (!IS_ERR(key_ref
)) {
122 ret
= key_ref_to_ptr(key_ref
)->serial
;
123 key_ref_put(key_ref
);
126 ret
= PTR_ERR(key_ref
);
129 key_ref_put(keyring_ref
);
132 memzero_explicit(payload
, plen
);
142 * Search the process keyrings and keyring trees linked from those for a
143 * matching key. Keyrings must have appropriate Search permission to be
146 * If a key is found, it will be attached to the destination keyring if there's
147 * one specified and the serial number of the key will be returned.
149 * If no key is found, /sbin/request-key will be invoked if _callout_info is
150 * non-NULL in an attempt to create a key. The _callout_info string will be
151 * passed to /sbin/request-key to aid with completing the request. If the
152 * _callout_info string is "" then it will be changed to "-".
154 SYSCALL_DEFINE4(request_key
, const char __user
*, _type
,
155 const char __user
*, _description
,
156 const char __user
*, _callout_info
,
157 key_serial_t
, destringid
)
159 struct key_type
*ktype
;
163 char type
[32], *description
, *callout_info
;
166 /* pull the type into kernel space */
167 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
171 /* pull the description into kernel space */
172 description
= strndup_user(_description
, KEY_MAX_DESC_SIZE
);
173 if (IS_ERR(description
)) {
174 ret
= PTR_ERR(description
);
178 /* pull the callout info into kernel space */
182 callout_info
= strndup_user(_callout_info
, PAGE_SIZE
);
183 if (IS_ERR(callout_info
)) {
184 ret
= PTR_ERR(callout_info
);
187 callout_len
= strlen(callout_info
);
190 /* get the destination keyring if specified */
193 dest_ref
= lookup_user_key(destringid
, KEY_LOOKUP_CREATE
,
195 if (IS_ERR(dest_ref
)) {
196 ret
= PTR_ERR(dest_ref
);
201 /* find the key type */
202 ktype
= key_type_lookup(type
);
204 ret
= PTR_ERR(ktype
);
209 key
= request_key_and_link(ktype
, description
, callout_info
,
210 callout_len
, NULL
, key_ref_to_ptr(dest_ref
),
217 /* wait for the key to finish being constructed */
218 ret
= wait_for_key_construction(key
, 1);
229 key_ref_put(dest_ref
);
239 * Get the ID of the specified process keyring.
241 * The requested keyring must have search permission to be found.
243 * If successful, the ID of the requested keyring will be returned.
245 long keyctl_get_keyring_ID(key_serial_t id
, int create
)
248 unsigned long lflags
;
251 lflags
= create
? KEY_LOOKUP_CREATE
: 0;
252 key_ref
= lookup_user_key(id
, lflags
, KEY_NEED_SEARCH
);
253 if (IS_ERR(key_ref
)) {
254 ret
= PTR_ERR(key_ref
);
258 ret
= key_ref_to_ptr(key_ref
)->serial
;
259 key_ref_put(key_ref
);
265 * Join a (named) session keyring.
267 * Create and join an anonymous session keyring or join a named session
268 * keyring, creating it if necessary. A named session keyring must have Search
269 * permission for it to be joined. Session keyrings without this permit will
270 * be skipped over. It is not permitted for userspace to create or join
271 * keyrings whose name begin with a dot.
273 * If successful, the ID of the joined session keyring will be returned.
275 long keyctl_join_session_keyring(const char __user
*_name
)
280 /* fetch the name from userspace */
283 name
= strndup_user(_name
, KEY_MAX_DESC_SIZE
);
294 /* join the session */
295 ret
= join_session_keyring(name
);
303 * Update a key's data payload from the given data.
305 * The key must grant the caller Write permission and the key type must support
306 * updating for this to work. A negative key can be positively instantiated
309 * If successful, 0 will be returned. If the key type does not support
310 * updating, then -EOPNOTSUPP will be returned.
312 long keyctl_update_key(key_serial_t id
,
313 const void __user
*_payload
,
321 if (plen
> PAGE_SIZE
)
324 /* pull the payload in if one was supplied */
328 payload
= kmalloc(plen
, GFP_KERNEL
);
333 if (copy_from_user(payload
, _payload
, plen
) != 0)
337 /* find the target key (which must be writable) */
338 key_ref
= lookup_user_key(id
, 0, KEY_NEED_WRITE
);
339 if (IS_ERR(key_ref
)) {
340 ret
= PTR_ERR(key_ref
);
345 ret
= key_update(key_ref
, payload
, plen
);
347 key_ref_put(key_ref
);
357 * The key must be grant the caller Write or Setattr permission for this to
358 * work. The key type should give up its quota claim when revoked. The key
359 * and any links to the key will be automatically garbage collected after a
360 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
362 * Keys with KEY_FLAG_KEEP set should not be revoked.
364 * If successful, 0 is returned.
366 long keyctl_revoke_key(key_serial_t id
)
372 key_ref
= lookup_user_key(id
, 0, KEY_NEED_WRITE
);
373 if (IS_ERR(key_ref
)) {
374 ret
= PTR_ERR(key_ref
);
377 key_ref
= lookup_user_key(id
, 0, KEY_NEED_SETATTR
);
378 if (IS_ERR(key_ref
)) {
379 ret
= PTR_ERR(key_ref
);
384 key
= key_ref_to_ptr(key_ref
);
386 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
391 key_ref_put(key_ref
);
399 * The key must be grant the caller Invalidate permission for this to work.
400 * The key and any links to the key will be automatically garbage collected
403 * Keys with KEY_FLAG_KEEP set should not be invalidated.
405 * If successful, 0 is returned.
407 long keyctl_invalidate_key(key_serial_t id
)
415 key_ref
= lookup_user_key(id
, 0, KEY_NEED_SEARCH
);
416 if (IS_ERR(key_ref
)) {
417 ret
= PTR_ERR(key_ref
);
419 /* Root is permitted to invalidate certain special keys */
420 if (capable(CAP_SYS_ADMIN
)) {
421 key_ref
= lookup_user_key(id
, 0, 0);
424 if (test_bit(KEY_FLAG_ROOT_CAN_INVAL
,
425 &key_ref_to_ptr(key_ref
)->flags
))
434 key
= key_ref_to_ptr(key_ref
);
436 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
441 key_ref_put(key_ref
);
443 kleave(" = %ld", ret
);
448 * Clear the specified keyring, creating an empty process keyring if one of the
449 * special keyring IDs is used.
451 * The keyring must grant the caller Write permission and not have
452 * KEY_FLAG_KEEP set for this to work. If successful, 0 will be returned.
454 long keyctl_keyring_clear(key_serial_t ringid
)
456 key_ref_t keyring_ref
;
460 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
461 if (IS_ERR(keyring_ref
)) {
462 ret
= PTR_ERR(keyring_ref
);
464 /* Root is permitted to invalidate certain special keyrings */
465 if (capable(CAP_SYS_ADMIN
)) {
466 keyring_ref
= lookup_user_key(ringid
, 0, 0);
467 if (IS_ERR(keyring_ref
))
469 if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR
,
470 &key_ref_to_ptr(keyring_ref
)->flags
))
479 keyring
= key_ref_to_ptr(keyring_ref
);
480 if (test_bit(KEY_FLAG_KEEP
, &keyring
->flags
))
483 ret
= keyring_clear(keyring
);
485 key_ref_put(keyring_ref
);
491 * Create a link from a keyring to a key if there's no matching key in the
492 * keyring, otherwise replace the link to the matching key with a link to the
495 * The key must grant the caller Link permission and the the keyring must grant
496 * the caller Write permission. Furthermore, if an additional link is created,
497 * the keyring's quota will be extended.
499 * If successful, 0 will be returned.
501 long keyctl_keyring_link(key_serial_t id
, key_serial_t ringid
)
503 key_ref_t keyring_ref
, key_ref
;
506 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
507 if (IS_ERR(keyring_ref
)) {
508 ret
= PTR_ERR(keyring_ref
);
512 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
, KEY_NEED_LINK
);
513 if (IS_ERR(key_ref
)) {
514 ret
= PTR_ERR(key_ref
);
518 ret
= key_link(key_ref_to_ptr(keyring_ref
), key_ref_to_ptr(key_ref
));
520 key_ref_put(key_ref
);
522 key_ref_put(keyring_ref
);
528 * Unlink a key from a keyring.
530 * The keyring must grant the caller Write permission for this to work; the key
531 * itself need not grant the caller anything. If the last link to a key is
532 * removed then that key will be scheduled for destruction.
534 * Keys or keyrings with KEY_FLAG_KEEP set should not be unlinked.
536 * If successful, 0 will be returned.
538 long keyctl_keyring_unlink(key_serial_t id
, key_serial_t ringid
)
540 key_ref_t keyring_ref
, key_ref
;
541 struct key
*keyring
, *key
;
544 keyring_ref
= lookup_user_key(ringid
, 0, KEY_NEED_WRITE
);
545 if (IS_ERR(keyring_ref
)) {
546 ret
= PTR_ERR(keyring_ref
);
550 key_ref
= lookup_user_key(id
, KEY_LOOKUP_FOR_UNLINK
, 0);
551 if (IS_ERR(key_ref
)) {
552 ret
= PTR_ERR(key_ref
);
556 keyring
= key_ref_to_ptr(keyring_ref
);
557 key
= key_ref_to_ptr(key_ref
);
558 if (test_bit(KEY_FLAG_KEEP
, &keyring
->flags
) &&
559 test_bit(KEY_FLAG_KEEP
, &key
->flags
))
562 ret
= key_unlink(keyring
, key
);
564 key_ref_put(key_ref
);
566 key_ref_put(keyring_ref
);
572 * Return a description of a key to userspace.
574 * The key must grant the caller View permission for this to work.
576 * If there's a buffer, we place up to buflen bytes of data into it formatted
577 * in the following way:
579 * type;uid;gid;perm;description<NUL>
581 * If successful, we return the amount of description available, irrespective
582 * of how much we may have copied into the buffer.
584 long keyctl_describe_key(key_serial_t keyid
,
588 struct key
*key
, *instkey
;
592 int desclen
, infolen
;
594 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, KEY_NEED_VIEW
);
595 if (IS_ERR(key_ref
)) {
596 /* viewing a key under construction is permitted if we have the
597 * authorisation token handy */
598 if (PTR_ERR(key_ref
) == -EACCES
) {
599 instkey
= key_get_instantiation_authkey(keyid
);
600 if (!IS_ERR(instkey
)) {
602 key_ref
= lookup_user_key(keyid
,
605 if (!IS_ERR(key_ref
))
610 ret
= PTR_ERR(key_ref
);
615 key
= key_ref_to_ptr(key_ref
);
616 desclen
= strlen(key
->description
);
618 /* calculate how much information we're going to return */
620 infobuf
= kasprintf(GFP_KERNEL
,
623 from_kuid_munged(current_user_ns(), key
->uid
),
624 from_kgid_munged(current_user_ns(), key
->gid
),
628 infolen
= strlen(infobuf
);
629 ret
= infolen
+ desclen
+ 1;
631 /* consider returning the data */
632 if (buffer
&& buflen
>= ret
) {
633 if (copy_to_user(buffer
, infobuf
, infolen
) != 0 ||
634 copy_to_user(buffer
+ infolen
, key
->description
,
641 key_ref_put(key_ref
);
647 * Search the specified keyring and any keyrings it links to for a matching
648 * key. Only keyrings that grant the caller Search permission will be searched
649 * (this includes the starting keyring). Only keys with Search permission can
652 * If successful, the found key will be linked to the destination keyring if
653 * supplied and the key has Link permission, and the found key ID will be
656 long keyctl_keyring_search(key_serial_t ringid
,
657 const char __user
*_type
,
658 const char __user
*_description
,
659 key_serial_t destringid
)
661 struct key_type
*ktype
;
662 key_ref_t keyring_ref
, key_ref
, dest_ref
;
663 char type
[32], *description
;
666 /* pull the type and description into kernel space */
667 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
671 description
= strndup_user(_description
, KEY_MAX_DESC_SIZE
);
672 if (IS_ERR(description
)) {
673 ret
= PTR_ERR(description
);
677 /* get the keyring at which to begin the search */
678 keyring_ref
= lookup_user_key(ringid
, 0, KEY_NEED_SEARCH
);
679 if (IS_ERR(keyring_ref
)) {
680 ret
= PTR_ERR(keyring_ref
);
684 /* get the destination keyring if specified */
687 dest_ref
= lookup_user_key(destringid
, KEY_LOOKUP_CREATE
,
689 if (IS_ERR(dest_ref
)) {
690 ret
= PTR_ERR(dest_ref
);
695 /* find the key type */
696 ktype
= key_type_lookup(type
);
698 ret
= PTR_ERR(ktype
);
703 key_ref
= keyring_search(keyring_ref
, ktype
, description
);
704 if (IS_ERR(key_ref
)) {
705 ret
= PTR_ERR(key_ref
);
707 /* treat lack or presence of a negative key the same */
713 /* link the resulting key to the destination keyring if we can */
715 ret
= key_permission(key_ref
, KEY_NEED_LINK
);
719 ret
= key_link(key_ref_to_ptr(dest_ref
), key_ref_to_ptr(key_ref
));
724 ret
= key_ref_to_ptr(key_ref
)->serial
;
727 key_ref_put(key_ref
);
731 key_ref_put(dest_ref
);
733 key_ref_put(keyring_ref
);
741 * Read a key's payload.
743 * The key must either grant the caller Read permission, or it must grant the
744 * caller Search permission when searched for from the process keyrings.
746 * If successful, we place up to buflen bytes of data into the buffer, if one
747 * is provided, and return the amount of data that is available in the key,
748 * irrespective of how much we copied into the buffer.
750 long keyctl_read_key(key_serial_t keyid
, char __user
*buffer
, size_t buflen
)
756 /* find the key first */
757 key_ref
= lookup_user_key(keyid
, 0, 0);
758 if (IS_ERR(key_ref
)) {
763 key
= key_ref_to_ptr(key_ref
);
765 ret
= key_read_state(key
);
767 goto error2
; /* Negatively instantiated */
769 /* see if we can read it directly */
770 ret
= key_permission(key_ref
, KEY_NEED_READ
);
776 /* we can't; see if it's searchable from this process's keyrings
777 * - we automatically take account of the fact that it may be
778 * dangling off an instantiation key
780 if (!is_key_possessed(key_ref
)) {
785 /* the key is probably readable - now try to read it */
788 if (key
->type
->read
) {
789 /* Read the data with the semaphore held (since we might sleep)
790 * to protect against the key being updated or revoked.
792 down_read(&key
->sem
);
793 ret
= key_validate(key
);
795 ret
= key
->type
->read(key
, buffer
, buflen
);
806 * Change the ownership of a key
808 * The key must grant the caller Setattr permission for this to work, though
809 * the key need not be fully instantiated yet. For the UID to be changed, or
810 * for the GID to be changed to a group the caller is not a member of, the
811 * caller must have sysadmin capability. If either uid or gid is -1 then that
812 * attribute is not changed.
814 * If the UID is to be changed, the new user must have sufficient quota to
815 * accept the key. The quota deduction will be removed from the old user to
816 * the new user should the attribute be changed.
818 * If successful, 0 will be returned.
820 long keyctl_chown_key(key_serial_t id
, uid_t user
, gid_t group
)
822 struct key_user
*newowner
, *zapowner
= NULL
;
829 uid
= make_kuid(current_user_ns(), user
);
830 gid
= make_kgid(current_user_ns(), group
);
832 if ((user
!= (uid_t
) -1) && !uid_valid(uid
))
834 if ((group
!= (gid_t
) -1) && !gid_valid(gid
))
838 if (user
== (uid_t
) -1 && group
== (gid_t
) -1)
841 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
843 if (IS_ERR(key_ref
)) {
844 ret
= PTR_ERR(key_ref
);
848 key
= key_ref_to_ptr(key_ref
);
850 /* make the changes with the locks held to prevent chown/chown races */
852 down_write(&key
->sem
);
854 if (!capable(CAP_SYS_ADMIN
)) {
855 /* only the sysadmin can chown a key to some other UID */
856 if (user
!= (uid_t
) -1 && !uid_eq(key
->uid
, uid
))
859 /* only the sysadmin can set the key's GID to a group other
860 * than one of those that the current process subscribes to */
861 if (group
!= (gid_t
) -1 && !gid_eq(gid
, key
->gid
) && !in_group_p(gid
))
866 if (user
!= (uid_t
) -1 && !uid_eq(uid
, key
->uid
)) {
868 newowner
= key_user_lookup(uid
);
872 /* transfer the quota burden to the new user */
873 if (test_bit(KEY_FLAG_IN_QUOTA
, &key
->flags
)) {
874 unsigned maxkeys
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
875 key_quota_root_maxkeys
: key_quota_maxkeys
;
876 unsigned maxbytes
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
877 key_quota_root_maxbytes
: key_quota_maxbytes
;
879 spin_lock(&newowner
->lock
);
880 if (newowner
->qnkeys
+ 1 >= maxkeys
||
881 newowner
->qnbytes
+ key
->quotalen
>= maxbytes
||
882 newowner
->qnbytes
+ key
->quotalen
<
887 newowner
->qnbytes
+= key
->quotalen
;
888 spin_unlock(&newowner
->lock
);
890 spin_lock(&key
->user
->lock
);
892 key
->user
->qnbytes
-= key
->quotalen
;
893 spin_unlock(&key
->user
->lock
);
896 atomic_dec(&key
->user
->nkeys
);
897 atomic_inc(&newowner
->nkeys
);
899 if (key
->state
!= KEY_IS_UNINSTANTIATED
) {
900 atomic_dec(&key
->user
->nikeys
);
901 atomic_inc(&newowner
->nikeys
);
904 zapowner
= key
->user
;
905 key
->user
= newowner
;
910 if (group
!= (gid_t
) -1)
919 key_user_put(zapowner
);
924 spin_unlock(&newowner
->lock
);
931 * Change the permission mask on a key.
933 * The key must grant the caller Setattr permission for this to work, though
934 * the key need not be fully instantiated yet. If the caller does not have
935 * sysadmin capability, it may only change the permission on keys that it owns.
937 long keyctl_setperm_key(key_serial_t id
, key_perm_t perm
)
944 if (perm
& ~(KEY_POS_ALL
| KEY_USR_ALL
| KEY_GRP_ALL
| KEY_OTH_ALL
))
947 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
949 if (IS_ERR(key_ref
)) {
950 ret
= PTR_ERR(key_ref
);
954 key
= key_ref_to_ptr(key_ref
);
956 /* make the changes with the locks held to prevent chown/chmod races */
958 down_write(&key
->sem
);
960 /* if we're not the sysadmin, we can only change a key that we own */
961 if (capable(CAP_SYS_ADMIN
) || uid_eq(key
->uid
, current_fsuid())) {
973 * Get the destination keyring for instantiation and check that the caller has
974 * Write permission on it.
976 static long get_instantiation_keyring(key_serial_t ringid
,
977 struct request_key_auth
*rka
,
978 struct key
**_dest_keyring
)
982 *_dest_keyring
= NULL
;
984 /* just return a NULL pointer if we weren't asked to make a link */
988 /* if a specific keyring is nominated by ID, then use that */
990 dkref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
992 return PTR_ERR(dkref
);
993 *_dest_keyring
= key_ref_to_ptr(dkref
);
997 if (ringid
== KEY_SPEC_REQKEY_AUTH_KEY
)
1000 /* otherwise specify the destination keyring recorded in the
1001 * authorisation key (any KEY_SPEC_*_KEYRING) */
1002 if (ringid
>= KEY_SPEC_REQUESTOR_KEYRING
) {
1003 *_dest_keyring
= key_get(rka
->dest_keyring
);
1011 * Change the request_key authorisation key on the current process.
1013 static int keyctl_change_reqkey_auth(struct key
*key
)
1017 new = prepare_creds();
1021 key_put(new->request_key_auth
);
1022 new->request_key_auth
= key_get(key
);
1024 return commit_creds(new);
1028 * Instantiate a key with the specified payload and link the key into the
1029 * destination keyring if one is given.
1031 * The caller must have the appropriate instantiation permit set for this to
1032 * work (see keyctl_assume_authority). No other permissions are required.
1034 * If successful, 0 will be returned.
1036 long keyctl_instantiate_key_common(key_serial_t id
,
1037 struct iov_iter
*from
,
1038 key_serial_t ringid
)
1040 const struct cred
*cred
= current_cred();
1041 struct request_key_auth
*rka
;
1042 struct key
*instkey
, *dest_keyring
;
1043 size_t plen
= from
? iov_iter_count(from
) : 0;
1047 kenter("%d,,%zu,%d", id
, plen
, ringid
);
1053 if (plen
> 1024 * 1024 - 1)
1056 /* the appropriate instantiation authorisation key must have been
1057 * assumed before calling this */
1059 instkey
= cred
->request_key_auth
;
1063 rka
= instkey
->payload
.data
[0];
1064 if (rka
->target_key
->serial
!= id
)
1067 /* pull the payload in if one was supplied */
1072 payload
= kvmalloc(plen
, GFP_KERNEL
);
1077 if (!copy_from_iter_full(payload
, plen
, from
))
1081 /* find the destination keyring amongst those belonging to the
1082 * requesting task */
1083 ret
= get_instantiation_keyring(ringid
, rka
, &dest_keyring
);
1087 /* instantiate the key and link it into a keyring */
1088 ret
= key_instantiate_and_link(rka
->target_key
, payload
, plen
,
1089 dest_keyring
, instkey
);
1091 key_put(dest_keyring
);
1093 /* discard the assumed authority if it's just been disabled by
1094 * instantiation of the key */
1096 keyctl_change_reqkey_auth(NULL
);
1100 memzero_explicit(payload
, plen
);
1108 * Instantiate a key with the specified payload and link the key into the
1109 * destination keyring if one is given.
1111 * The caller must have the appropriate instantiation permit set for this to
1112 * work (see keyctl_assume_authority). No other permissions are required.
1114 * If successful, 0 will be returned.
1116 long keyctl_instantiate_key(key_serial_t id
,
1117 const void __user
*_payload
,
1119 key_serial_t ringid
)
1121 if (_payload
&& plen
) {
1123 struct iov_iter from
;
1126 ret
= import_single_range(WRITE
, (void __user
*)_payload
, plen
,
1131 return keyctl_instantiate_key_common(id
, &from
, ringid
);
1134 return keyctl_instantiate_key_common(id
, NULL
, ringid
);
1138 * Instantiate a key with the specified multipart payload and link the key into
1139 * the destination keyring if one is given.
1141 * The caller must have the appropriate instantiation permit set for this to
1142 * work (see keyctl_assume_authority). No other permissions are required.
1144 * If successful, 0 will be returned.
1146 long keyctl_instantiate_key_iov(key_serial_t id
,
1147 const struct iovec __user
*_payload_iov
,
1149 key_serial_t ringid
)
1151 struct iovec iovstack
[UIO_FASTIOV
], *iov
= iovstack
;
1152 struct iov_iter from
;
1158 ret
= import_iovec(WRITE
, _payload_iov
, ioc
,
1159 ARRAY_SIZE(iovstack
), &iov
, &from
);
1162 ret
= keyctl_instantiate_key_common(id
, &from
, ringid
);
1168 * Negatively instantiate the key with the given timeout (in seconds) and link
1169 * the key into the destination keyring if one is given.
1171 * The caller must have the appropriate instantiation permit set for this to
1172 * work (see keyctl_assume_authority). No other permissions are required.
1174 * The key and any links to the key will be automatically garbage collected
1175 * after the timeout expires.
1177 * Negative keys are used to rate limit repeated request_key() calls by causing
1178 * them to return -ENOKEY until the negative key expires.
1180 * If successful, 0 will be returned.
1182 long keyctl_negate_key(key_serial_t id
, unsigned timeout
, key_serial_t ringid
)
1184 return keyctl_reject_key(id
, timeout
, ENOKEY
, ringid
);
1188 * Negatively instantiate the key with the given timeout (in seconds) and error
1189 * code and link the key into the destination keyring if one is given.
1191 * The caller must have the appropriate instantiation permit set for this to
1192 * work (see keyctl_assume_authority). No other permissions are required.
1194 * The key and any links to the key will be automatically garbage collected
1195 * after the timeout expires.
1197 * Negative keys are used to rate limit repeated request_key() calls by causing
1198 * them to return the specified error code until the negative key expires.
1200 * If successful, 0 will be returned.
1202 long keyctl_reject_key(key_serial_t id
, unsigned timeout
, unsigned error
,
1203 key_serial_t ringid
)
1205 const struct cred
*cred
= current_cred();
1206 struct request_key_auth
*rka
;
1207 struct key
*instkey
, *dest_keyring
;
1210 kenter("%d,%u,%u,%d", id
, timeout
, error
, ringid
);
1212 /* must be a valid error code and mustn't be a kernel special */
1214 error
>= MAX_ERRNO
||
1215 error
== ERESTARTSYS
||
1216 error
== ERESTARTNOINTR
||
1217 error
== ERESTARTNOHAND
||
1218 error
== ERESTART_RESTARTBLOCK
)
1221 /* the appropriate instantiation authorisation key must have been
1222 * assumed before calling this */
1224 instkey
= cred
->request_key_auth
;
1228 rka
= instkey
->payload
.data
[0];
1229 if (rka
->target_key
->serial
!= id
)
1232 /* find the destination keyring if present (which must also be
1234 ret
= get_instantiation_keyring(ringid
, rka
, &dest_keyring
);
1238 /* instantiate the key and link it into a keyring */
1239 ret
= key_reject_and_link(rka
->target_key
, timeout
, error
,
1240 dest_keyring
, instkey
);
1242 key_put(dest_keyring
);
1244 /* discard the assumed authority if it's just been disabled by
1245 * instantiation of the key */
1247 keyctl_change_reqkey_auth(NULL
);
1254 * Read or set the default keyring in which request_key() will cache keys and
1255 * return the old setting.
1257 * If a thread or process keyring is specified then it will be created if it
1258 * doesn't yet exist. The old setting will be returned if successful.
1260 long keyctl_set_reqkey_keyring(int reqkey_defl
)
1263 int ret
, old_setting
;
1265 old_setting
= current_cred_xxx(jit_keyring
);
1267 if (reqkey_defl
== KEY_REQKEY_DEFL_NO_CHANGE
)
1270 new = prepare_creds();
1274 switch (reqkey_defl
) {
1275 case KEY_REQKEY_DEFL_THREAD_KEYRING
:
1276 ret
= install_thread_keyring_to_cred(new);
1281 case KEY_REQKEY_DEFL_PROCESS_KEYRING
:
1282 ret
= install_process_keyring_to_cred(new);
1287 case KEY_REQKEY_DEFL_DEFAULT
:
1288 case KEY_REQKEY_DEFL_SESSION_KEYRING
:
1289 case KEY_REQKEY_DEFL_USER_KEYRING
:
1290 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING
:
1291 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING
:
1294 case KEY_REQKEY_DEFL_NO_CHANGE
:
1295 case KEY_REQKEY_DEFL_GROUP_KEYRING
:
1302 new->jit_keyring
= reqkey_defl
;
1311 * Set or clear the timeout on a key.
1313 * Either the key must grant the caller Setattr permission or else the caller
1314 * must hold an instantiation authorisation token for the key.
1316 * The timeout is either 0 to clear the timeout, or a number of seconds from
1317 * the current time. The key and any links to the key will be automatically
1318 * garbage collected after the timeout expires.
1320 * Keys with KEY_FLAG_KEEP set should not be timed out.
1322 * If successful, 0 is returned.
1324 long keyctl_set_timeout(key_serial_t id
, unsigned timeout
)
1326 struct key
*key
, *instkey
;
1330 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
1332 if (IS_ERR(key_ref
)) {
1333 /* setting the timeout on a key under construction is permitted
1334 * if we have the authorisation token handy */
1335 if (PTR_ERR(key_ref
) == -EACCES
) {
1336 instkey
= key_get_instantiation_authkey(id
);
1337 if (!IS_ERR(instkey
)) {
1339 key_ref
= lookup_user_key(id
,
1342 if (!IS_ERR(key_ref
))
1347 ret
= PTR_ERR(key_ref
);
1352 key
= key_ref_to_ptr(key_ref
);
1354 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
1357 key_set_timeout(key
, timeout
);
1365 * Assume (or clear) the authority to instantiate the specified key.
1367 * This sets the authoritative token currently in force for key instantiation.
1368 * This must be done for a key to be instantiated. It has the effect of making
1369 * available all the keys from the caller of the request_key() that created a
1370 * key to request_key() calls made by the caller of this function.
1372 * The caller must have the instantiation key in their process keyrings with a
1373 * Search permission grant available to the caller.
1375 * If the ID given is 0, then the setting will be cleared and 0 returned.
1377 * If the ID given has a matching an authorisation key, then that key will be
1378 * set and its ID will be returned. The authorisation key can be read to get
1379 * the callout information passed to request_key().
1381 long keyctl_assume_authority(key_serial_t id
)
1383 struct key
*authkey
;
1386 /* special key IDs aren't permitted */
1391 /* we divest ourselves of authority if given an ID of 0 */
1393 ret
= keyctl_change_reqkey_auth(NULL
);
1397 /* attempt to assume the authority temporarily granted to us whilst we
1398 * instantiate the specified key
1399 * - the authorisation key must be in the current task's keyrings
1402 authkey
= key_get_instantiation_authkey(id
);
1403 if (IS_ERR(authkey
)) {
1404 ret
= PTR_ERR(authkey
);
1408 ret
= keyctl_change_reqkey_auth(authkey
);
1410 ret
= authkey
->serial
;
1417 * Get a key's the LSM security label.
1419 * The key must grant the caller View permission for this to work.
1421 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1423 * If successful, the amount of information available will be returned,
1424 * irrespective of how much was copied (including the terminal NUL).
1426 long keyctl_get_security(key_serial_t keyid
,
1427 char __user
*buffer
,
1430 struct key
*key
, *instkey
;
1435 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, KEY_NEED_VIEW
);
1436 if (IS_ERR(key_ref
)) {
1437 if (PTR_ERR(key_ref
) != -EACCES
)
1438 return PTR_ERR(key_ref
);
1440 /* viewing a key under construction is also permitted if we
1441 * have the authorisation token handy */
1442 instkey
= key_get_instantiation_authkey(keyid
);
1443 if (IS_ERR(instkey
))
1444 return PTR_ERR(instkey
);
1447 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, 0);
1448 if (IS_ERR(key_ref
))
1449 return PTR_ERR(key_ref
);
1452 key
= key_ref_to_ptr(key_ref
);
1453 ret
= security_key_getsecurity(key
, &context
);
1455 /* if no information was returned, give userspace an empty
1458 if (buffer
&& buflen
> 0 &&
1459 copy_to_user(buffer
, "", 1) != 0)
1461 } else if (ret
> 0) {
1462 /* return as much data as there's room for */
1463 if (buffer
&& buflen
> 0) {
1467 if (copy_to_user(buffer
, context
, buflen
) != 0)
1474 key_ref_put(key_ref
);
1479 * Attempt to install the calling process's session keyring on the process's
1482 * The keyring must exist and must grant the caller LINK permission, and the
1483 * parent process must be single-threaded and must have the same effective
1484 * ownership as this process and mustn't be SUID/SGID.
1486 * The keyring will be emplaced on the parent when it next resumes userspace.
1488 * If successful, 0 will be returned.
1490 long keyctl_session_to_parent(void)
1492 struct task_struct
*me
, *parent
;
1493 const struct cred
*mycred
, *pcred
;
1494 struct callback_head
*newwork
, *oldwork
;
1495 key_ref_t keyring_r
;
1499 keyring_r
= lookup_user_key(KEY_SPEC_SESSION_KEYRING
, 0, KEY_NEED_LINK
);
1500 if (IS_ERR(keyring_r
))
1501 return PTR_ERR(keyring_r
);
1505 /* our parent is going to need a new cred struct, a new tgcred struct
1506 * and new security data, so we allocate them here to prevent ENOMEM in
1508 cred
= cred_alloc_blank();
1511 newwork
= &cred
->rcu
;
1513 cred
->session_keyring
= key_ref_to_ptr(keyring_r
);
1515 init_task_work(newwork
, key_change_session_keyring
);
1519 write_lock_irq(&tasklist_lock
);
1523 parent
= me
->real_parent
;
1525 /* the parent mustn't be init and mustn't be a kernel thread */
1526 if (parent
->pid
<= 1 || !parent
->mm
)
1529 /* the parent must be single threaded */
1530 if (!thread_group_empty(parent
))
1533 /* the parent and the child must have different session keyrings or
1534 * there's no point */
1535 mycred
= current_cred();
1536 pcred
= __task_cred(parent
);
1537 if (mycred
== pcred
||
1538 mycred
->session_keyring
== pcred
->session_keyring
) {
1543 /* the parent must have the same effective ownership and mustn't be
1545 if (!uid_eq(pcred
->uid
, mycred
->euid
) ||
1546 !uid_eq(pcred
->euid
, mycred
->euid
) ||
1547 !uid_eq(pcred
->suid
, mycred
->euid
) ||
1548 !gid_eq(pcred
->gid
, mycred
->egid
) ||
1549 !gid_eq(pcred
->egid
, mycred
->egid
) ||
1550 !gid_eq(pcred
->sgid
, mycred
->egid
))
1553 /* the keyrings must have the same UID */
1554 if ((pcred
->session_keyring
&&
1555 !uid_eq(pcred
->session_keyring
->uid
, mycred
->euid
)) ||
1556 !uid_eq(mycred
->session_keyring
->uid
, mycred
->euid
))
1559 /* cancel an already pending keyring replacement */
1560 oldwork
= task_work_cancel(parent
, key_change_session_keyring
);
1562 /* the replacement session keyring is applied just prior to userspace
1564 ret
= task_work_add(parent
, newwork
, true);
1568 write_unlock_irq(&tasklist_lock
);
1571 put_cred(container_of(oldwork
, struct cred
, rcu
));
1577 key_ref_put(keyring_r
);
1582 * Apply a restriction to a given keyring.
1584 * The caller must have Setattr permission to change keyring restrictions.
1586 * The requested type name may be a NULL pointer to reject all attempts
1587 * to link to the keyring. In this case, _restriction must also be NULL.
1588 * Otherwise, both _type and _restriction must be non-NULL.
1590 * Returns 0 if successful.
1592 long keyctl_restrict_keyring(key_serial_t id
, const char __user
*_type
,
1593 const char __user
*_restriction
)
1597 char *restriction
= NULL
;
1600 key_ref
= lookup_user_key(id
, 0, KEY_NEED_SETATTR
);
1601 if (IS_ERR(key_ref
))
1602 return PTR_ERR(key_ref
);
1609 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
1613 restriction
= strndup_user(_restriction
, PAGE_SIZE
);
1614 if (IS_ERR(restriction
)) {
1615 ret
= PTR_ERR(restriction
);
1623 ret
= keyring_restrict(key_ref
, _type
? type
: NULL
, restriction
);
1626 key_ref_put(key_ref
);
1631 * The key control system call
1633 SYSCALL_DEFINE5(keyctl
, int, option
, unsigned long, arg2
, unsigned long, arg3
,
1634 unsigned long, arg4
, unsigned long, arg5
)
1637 case KEYCTL_GET_KEYRING_ID
:
1638 return keyctl_get_keyring_ID((key_serial_t
) arg2
,
1641 case KEYCTL_JOIN_SESSION_KEYRING
:
1642 return keyctl_join_session_keyring((const char __user
*) arg2
);
1645 return keyctl_update_key((key_serial_t
) arg2
,
1646 (const void __user
*) arg3
,
1650 return keyctl_revoke_key((key_serial_t
) arg2
);
1652 case KEYCTL_DESCRIBE
:
1653 return keyctl_describe_key((key_serial_t
) arg2
,
1654 (char __user
*) arg3
,
1658 return keyctl_keyring_clear((key_serial_t
) arg2
);
1661 return keyctl_keyring_link((key_serial_t
) arg2
,
1662 (key_serial_t
) arg3
);
1665 return keyctl_keyring_unlink((key_serial_t
) arg2
,
1666 (key_serial_t
) arg3
);
1669 return keyctl_keyring_search((key_serial_t
) arg2
,
1670 (const char __user
*) arg3
,
1671 (const char __user
*) arg4
,
1672 (key_serial_t
) arg5
);
1675 return keyctl_read_key((key_serial_t
) arg2
,
1676 (char __user
*) arg3
,
1680 return keyctl_chown_key((key_serial_t
) arg2
,
1684 case KEYCTL_SETPERM
:
1685 return keyctl_setperm_key((key_serial_t
) arg2
,
1688 case KEYCTL_INSTANTIATE
:
1689 return keyctl_instantiate_key((key_serial_t
) arg2
,
1690 (const void __user
*) arg3
,
1692 (key_serial_t
) arg5
);
1695 return keyctl_negate_key((key_serial_t
) arg2
,
1697 (key_serial_t
) arg4
);
1699 case KEYCTL_SET_REQKEY_KEYRING
:
1700 return keyctl_set_reqkey_keyring(arg2
);
1702 case KEYCTL_SET_TIMEOUT
:
1703 return keyctl_set_timeout((key_serial_t
) arg2
,
1706 case KEYCTL_ASSUME_AUTHORITY
:
1707 return keyctl_assume_authority((key_serial_t
) arg2
);
1709 case KEYCTL_GET_SECURITY
:
1710 return keyctl_get_security((key_serial_t
) arg2
,
1711 (char __user
*) arg3
,
1714 case KEYCTL_SESSION_TO_PARENT
:
1715 return keyctl_session_to_parent();
1718 return keyctl_reject_key((key_serial_t
) arg2
,
1721 (key_serial_t
) arg5
);
1723 case KEYCTL_INSTANTIATE_IOV
:
1724 return keyctl_instantiate_key_iov(
1725 (key_serial_t
) arg2
,
1726 (const struct iovec __user
*) arg3
,
1728 (key_serial_t
) arg5
);
1730 case KEYCTL_INVALIDATE
:
1731 return keyctl_invalidate_key((key_serial_t
) arg2
);
1733 case KEYCTL_GET_PERSISTENT
:
1734 return keyctl_get_persistent((uid_t
)arg2
, (key_serial_t
)arg3
);
1736 case KEYCTL_DH_COMPUTE
:
1737 return keyctl_dh_compute((struct keyctl_dh_params __user
*) arg2
,
1738 (char __user
*) arg3
, (size_t) arg4
,
1739 (struct keyctl_kdf_params __user
*) arg5
);
1741 case KEYCTL_RESTRICT_KEYRING
:
1742 return keyctl_restrict_keyring((key_serial_t
) arg2
,
1743 (const char __user
*) arg3
,
1744 (const char __user
*) arg4
);
1746 case KEYCTL_PKEY_QUERY
:
1749 return keyctl_pkey_query((key_serial_t
)arg2
,
1750 (const char __user
*)arg4
,
1751 (struct keyctl_pkey_query __user
*)arg5
);
1753 case KEYCTL_PKEY_ENCRYPT
:
1754 case KEYCTL_PKEY_DECRYPT
:
1755 case KEYCTL_PKEY_SIGN
:
1756 return keyctl_pkey_e_d_s(
1758 (const struct keyctl_pkey_params __user
*)arg2
,
1759 (const char __user
*)arg3
,
1760 (const void __user
*)arg4
,
1761 (void __user
*)arg5
);
1763 case KEYCTL_PKEY_VERIFY
:
1764 return keyctl_pkey_verify(
1765 (const struct keyctl_pkey_params __user
*)arg2
,
1766 (const char __user
*)arg3
,
1767 (const void __user
*)arg4
,
1768 (const void __user
*)arg5
);