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 const unsigned char keyrings_capabilities
[2] = {
30 [0] = (KEYCTL_CAPS0_CAPABILITIES
|
31 (IS_ENABLED(CONFIG_PERSISTENT_KEYRINGS
) ? KEYCTL_CAPS0_PERSISTENT_KEYRINGS
: 0) |
32 (IS_ENABLED(CONFIG_KEY_DH_OPERATIONS
) ? KEYCTL_CAPS0_DIFFIE_HELLMAN
: 0) |
33 (IS_ENABLED(CONFIG_ASYMMETRIC_KEY_TYPE
) ? KEYCTL_CAPS0_PUBLIC_KEY
: 0) |
34 (IS_ENABLED(CONFIG_BIG_KEYS
) ? KEYCTL_CAPS0_BIG_KEY
: 0) |
35 KEYCTL_CAPS0_INVALIDATE
|
36 KEYCTL_CAPS0_RESTRICT_KEYRING
|
39 [1] = (KEYCTL_CAPS1_NS_KEYRING_NAME
|
40 KEYCTL_CAPS1_NS_KEY_TAG
),
43 static int key_get_type_from_user(char *type
,
44 const char __user
*_type
,
49 ret
= strncpy_from_user(type
, _type
, len
);
52 if (ret
== 0 || ret
>= len
)
61 * Extract the description of a new key from userspace and either add it as a
62 * new key to the specified keyring or update a matching key in that keyring.
64 * If the description is NULL or an empty string, the key type is asked to
65 * generate one from the payload.
67 * The keyring must be writable so that we can attach the key to it.
69 * If successful, the new key's serial number is returned, otherwise an error
72 SYSCALL_DEFINE5(add_key
, const char __user
*, _type
,
73 const char __user
*, _description
,
74 const void __user
*, _payload
,
78 key_ref_t keyring_ref
, key_ref
;
79 char type
[32], *description
;
84 if (plen
> 1024 * 1024 - 1)
87 /* draw all the data into kernel space */
88 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
94 description
= strndup_user(_description
, KEY_MAX_DESC_SIZE
);
95 if (IS_ERR(description
)) {
96 ret
= PTR_ERR(description
);
102 } else if ((description
[0] == '.') &&
103 (strncmp(type
, "keyring", 7) == 0)) {
109 /* pull the payload in if one was supplied */
114 payload
= kvmalloc(plen
, GFP_KERNEL
);
119 if (copy_from_user(payload
, _payload
, plen
) != 0)
123 /* find the target keyring (which must be writable) */
124 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
125 if (IS_ERR(keyring_ref
)) {
126 ret
= PTR_ERR(keyring_ref
);
130 /* create or update the requested key and add it to the target
132 key_ref
= key_create_or_update(keyring_ref
, type
, description
,
133 payload
, plen
, KEY_PERM_UNDEF
,
135 if (!IS_ERR(key_ref
)) {
136 ret
= key_ref_to_ptr(key_ref
)->serial
;
137 key_ref_put(key_ref
);
140 ret
= PTR_ERR(key_ref
);
143 key_ref_put(keyring_ref
);
146 memzero_explicit(payload
, plen
);
156 * Search the process keyrings and keyring trees linked from those for a
157 * matching key. Keyrings must have appropriate Search permission to be
160 * If a key is found, it will be attached to the destination keyring if there's
161 * one specified and the serial number of the key will be returned.
163 * If no key is found, /sbin/request-key will be invoked if _callout_info is
164 * non-NULL in an attempt to create a key. The _callout_info string will be
165 * passed to /sbin/request-key to aid with completing the request. If the
166 * _callout_info string is "" then it will be changed to "-".
168 SYSCALL_DEFINE4(request_key
, const char __user
*, _type
,
169 const char __user
*, _description
,
170 const char __user
*, _callout_info
,
171 key_serial_t
, destringid
)
173 struct key_type
*ktype
;
177 char type
[32], *description
, *callout_info
;
180 /* pull the type into kernel space */
181 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
185 /* pull the description into kernel space */
186 description
= strndup_user(_description
, KEY_MAX_DESC_SIZE
);
187 if (IS_ERR(description
)) {
188 ret
= PTR_ERR(description
);
192 /* pull the callout info into kernel space */
196 callout_info
= strndup_user(_callout_info
, PAGE_SIZE
);
197 if (IS_ERR(callout_info
)) {
198 ret
= PTR_ERR(callout_info
);
201 callout_len
= strlen(callout_info
);
204 /* get the destination keyring if specified */
207 dest_ref
= lookup_user_key(destringid
, KEY_LOOKUP_CREATE
,
209 if (IS_ERR(dest_ref
)) {
210 ret
= PTR_ERR(dest_ref
);
215 /* find the key type */
216 ktype
= key_type_lookup(type
);
218 ret
= PTR_ERR(ktype
);
223 key
= request_key_and_link(ktype
, description
, NULL
, callout_info
,
224 callout_len
, NULL
, key_ref_to_ptr(dest_ref
),
231 /* wait for the key to finish being constructed */
232 ret
= wait_for_key_construction(key
, 1);
243 key_ref_put(dest_ref
);
253 * Get the ID of the specified process keyring.
255 * The requested keyring must have search permission to be found.
257 * If successful, the ID of the requested keyring will be returned.
259 long keyctl_get_keyring_ID(key_serial_t id
, int create
)
262 unsigned long lflags
;
265 lflags
= create
? KEY_LOOKUP_CREATE
: 0;
266 key_ref
= lookup_user_key(id
, lflags
, KEY_NEED_SEARCH
);
267 if (IS_ERR(key_ref
)) {
268 ret
= PTR_ERR(key_ref
);
272 ret
= key_ref_to_ptr(key_ref
)->serial
;
273 key_ref_put(key_ref
);
279 * Join a (named) session keyring.
281 * Create and join an anonymous session keyring or join a named session
282 * keyring, creating it if necessary. A named session keyring must have Search
283 * permission for it to be joined. Session keyrings without this permit will
284 * be skipped over. It is not permitted for userspace to create or join
285 * keyrings whose name begin with a dot.
287 * If successful, the ID of the joined session keyring will be returned.
289 long keyctl_join_session_keyring(const char __user
*_name
)
294 /* fetch the name from userspace */
297 name
= strndup_user(_name
, KEY_MAX_DESC_SIZE
);
308 /* join the session */
309 ret
= join_session_keyring(name
);
317 * Update a key's data payload from the given data.
319 * The key must grant the caller Write permission and the key type must support
320 * updating for this to work. A negative key can be positively instantiated
323 * If successful, 0 will be returned. If the key type does not support
324 * updating, then -EOPNOTSUPP will be returned.
326 long keyctl_update_key(key_serial_t id
,
327 const void __user
*_payload
,
335 if (plen
> PAGE_SIZE
)
338 /* pull the payload in if one was supplied */
342 payload
= kvmalloc(plen
, GFP_KERNEL
);
347 if (copy_from_user(payload
, _payload
, plen
) != 0)
351 /* find the target key (which must be writable) */
352 key_ref
= lookup_user_key(id
, 0, KEY_NEED_WRITE
);
353 if (IS_ERR(key_ref
)) {
354 ret
= PTR_ERR(key_ref
);
359 ret
= key_update(key_ref
, payload
, plen
);
361 key_ref_put(key_ref
);
363 __kvzfree(payload
, plen
);
371 * The key must be grant the caller Write or Setattr permission for this to
372 * work. The key type should give up its quota claim when revoked. The key
373 * and any links to the key will be automatically garbage collected after a
374 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
376 * Keys with KEY_FLAG_KEEP set should not be revoked.
378 * If successful, 0 is returned.
380 long keyctl_revoke_key(key_serial_t id
)
386 key_ref
= lookup_user_key(id
, 0, KEY_NEED_WRITE
);
387 if (IS_ERR(key_ref
)) {
388 ret
= PTR_ERR(key_ref
);
391 key_ref
= lookup_user_key(id
, 0, KEY_NEED_SETATTR
);
392 if (IS_ERR(key_ref
)) {
393 ret
= PTR_ERR(key_ref
);
398 key
= key_ref_to_ptr(key_ref
);
400 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
405 key_ref_put(key_ref
);
413 * The key must be grant the caller Invalidate permission for this to work.
414 * The key and any links to the key will be automatically garbage collected
417 * Keys with KEY_FLAG_KEEP set should not be invalidated.
419 * If successful, 0 is returned.
421 long keyctl_invalidate_key(key_serial_t id
)
429 key_ref
= lookup_user_key(id
, 0, KEY_NEED_SEARCH
);
430 if (IS_ERR(key_ref
)) {
431 ret
= PTR_ERR(key_ref
);
433 /* Root is permitted to invalidate certain special keys */
434 if (capable(CAP_SYS_ADMIN
)) {
435 key_ref
= lookup_user_key(id
, 0, 0);
438 if (test_bit(KEY_FLAG_ROOT_CAN_INVAL
,
439 &key_ref_to_ptr(key_ref
)->flags
))
448 key
= key_ref_to_ptr(key_ref
);
450 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
455 key_ref_put(key_ref
);
457 kleave(" = %ld", ret
);
462 * Clear the specified keyring, creating an empty process keyring if one of the
463 * special keyring IDs is used.
465 * The keyring must grant the caller Write permission and not have
466 * KEY_FLAG_KEEP set for this to work. If successful, 0 will be returned.
468 long keyctl_keyring_clear(key_serial_t ringid
)
470 key_ref_t keyring_ref
;
474 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
475 if (IS_ERR(keyring_ref
)) {
476 ret
= PTR_ERR(keyring_ref
);
478 /* Root is permitted to invalidate certain special keyrings */
479 if (capable(CAP_SYS_ADMIN
)) {
480 keyring_ref
= lookup_user_key(ringid
, 0, 0);
481 if (IS_ERR(keyring_ref
))
483 if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR
,
484 &key_ref_to_ptr(keyring_ref
)->flags
))
493 keyring
= key_ref_to_ptr(keyring_ref
);
494 if (test_bit(KEY_FLAG_KEEP
, &keyring
->flags
))
497 ret
= keyring_clear(keyring
);
499 key_ref_put(keyring_ref
);
505 * Create a link from a keyring to a key if there's no matching key in the
506 * keyring, otherwise replace the link to the matching key with a link to the
509 * The key must grant the caller Link permission and the the keyring must grant
510 * the caller Write permission. Furthermore, if an additional link is created,
511 * the keyring's quota will be extended.
513 * If successful, 0 will be returned.
515 long keyctl_keyring_link(key_serial_t id
, key_serial_t ringid
)
517 key_ref_t keyring_ref
, key_ref
;
520 keyring_ref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
521 if (IS_ERR(keyring_ref
)) {
522 ret
= PTR_ERR(keyring_ref
);
526 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
, KEY_NEED_LINK
);
527 if (IS_ERR(key_ref
)) {
528 ret
= PTR_ERR(key_ref
);
532 ret
= key_link(key_ref_to_ptr(keyring_ref
), key_ref_to_ptr(key_ref
));
534 key_ref_put(key_ref
);
536 key_ref_put(keyring_ref
);
542 * Unlink a key from a keyring.
544 * The keyring must grant the caller Write permission for this to work; the key
545 * itself need not grant the caller anything. If the last link to a key is
546 * removed then that key will be scheduled for destruction.
548 * Keys or keyrings with KEY_FLAG_KEEP set should not be unlinked.
550 * If successful, 0 will be returned.
552 long keyctl_keyring_unlink(key_serial_t id
, key_serial_t ringid
)
554 key_ref_t keyring_ref
, key_ref
;
555 struct key
*keyring
, *key
;
558 keyring_ref
= lookup_user_key(ringid
, 0, KEY_NEED_WRITE
);
559 if (IS_ERR(keyring_ref
)) {
560 ret
= PTR_ERR(keyring_ref
);
564 key_ref
= lookup_user_key(id
, KEY_LOOKUP_FOR_UNLINK
, 0);
565 if (IS_ERR(key_ref
)) {
566 ret
= PTR_ERR(key_ref
);
570 keyring
= key_ref_to_ptr(keyring_ref
);
571 key
= key_ref_to_ptr(key_ref
);
572 if (test_bit(KEY_FLAG_KEEP
, &keyring
->flags
) &&
573 test_bit(KEY_FLAG_KEEP
, &key
->flags
))
576 ret
= key_unlink(keyring
, key
);
578 key_ref_put(key_ref
);
580 key_ref_put(keyring_ref
);
586 * Move a link to a key from one keyring to another, displacing any matching
587 * key from the destination keyring.
589 * The key must grant the caller Link permission and both keyrings must grant
590 * the caller Write permission. There must also be a link in the from keyring
591 * to the key. If both keyrings are the same, nothing is done.
593 * If successful, 0 will be returned.
595 long keyctl_keyring_move(key_serial_t id
, key_serial_t from_ringid
,
596 key_serial_t to_ringid
, unsigned int flags
)
598 key_ref_t key_ref
, from_ref
, to_ref
;
601 if (flags
& ~KEYCTL_MOVE_EXCL
)
604 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
, KEY_NEED_LINK
);
606 return PTR_ERR(key_ref
);
608 from_ref
= lookup_user_key(from_ringid
, 0, KEY_NEED_WRITE
);
609 if (IS_ERR(from_ref
)) {
610 ret
= PTR_ERR(from_ref
);
614 to_ref
= lookup_user_key(to_ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
615 if (IS_ERR(to_ref
)) {
616 ret
= PTR_ERR(to_ref
);
620 ret
= key_move(key_ref_to_ptr(key_ref
), key_ref_to_ptr(from_ref
),
621 key_ref_to_ptr(to_ref
), flags
);
625 key_ref_put(from_ref
);
627 key_ref_put(key_ref
);
632 * Return a description of a key to userspace.
634 * The key must grant the caller View permission for this to work.
636 * If there's a buffer, we place up to buflen bytes of data into it formatted
637 * in the following way:
639 * type;uid;gid;perm;description<NUL>
641 * If successful, we return the amount of description available, irrespective
642 * of how much we may have copied into the buffer.
644 long keyctl_describe_key(key_serial_t keyid
,
648 struct key
*key
, *instkey
;
652 int desclen
, infolen
;
654 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, KEY_NEED_VIEW
);
655 if (IS_ERR(key_ref
)) {
656 /* viewing a key under construction is permitted if we have the
657 * authorisation token handy */
658 if (PTR_ERR(key_ref
) == -EACCES
) {
659 instkey
= key_get_instantiation_authkey(keyid
);
660 if (!IS_ERR(instkey
)) {
662 key_ref
= lookup_user_key(keyid
,
665 if (!IS_ERR(key_ref
))
670 ret
= PTR_ERR(key_ref
);
675 key
= key_ref_to_ptr(key_ref
);
676 desclen
= strlen(key
->description
);
678 /* calculate how much information we're going to return */
680 infobuf
= kasprintf(GFP_KERNEL
,
683 from_kuid_munged(current_user_ns(), key
->uid
),
684 from_kgid_munged(current_user_ns(), key
->gid
),
688 infolen
= strlen(infobuf
);
689 ret
= infolen
+ desclen
+ 1;
691 /* consider returning the data */
692 if (buffer
&& buflen
>= ret
) {
693 if (copy_to_user(buffer
, infobuf
, infolen
) != 0 ||
694 copy_to_user(buffer
+ infolen
, key
->description
,
701 key_ref_put(key_ref
);
707 * Search the specified keyring and any keyrings it links to for a matching
708 * key. Only keyrings that grant the caller Search permission will be searched
709 * (this includes the starting keyring). Only keys with Search permission can
712 * If successful, the found key will be linked to the destination keyring if
713 * supplied and the key has Link permission, and the found key ID will be
716 long keyctl_keyring_search(key_serial_t ringid
,
717 const char __user
*_type
,
718 const char __user
*_description
,
719 key_serial_t destringid
)
721 struct key_type
*ktype
;
722 key_ref_t keyring_ref
, key_ref
, dest_ref
;
723 char type
[32], *description
;
726 /* pull the type and description into kernel space */
727 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
731 description
= strndup_user(_description
, KEY_MAX_DESC_SIZE
);
732 if (IS_ERR(description
)) {
733 ret
= PTR_ERR(description
);
737 /* get the keyring at which to begin the search */
738 keyring_ref
= lookup_user_key(ringid
, 0, KEY_NEED_SEARCH
);
739 if (IS_ERR(keyring_ref
)) {
740 ret
= PTR_ERR(keyring_ref
);
744 /* get the destination keyring if specified */
747 dest_ref
= lookup_user_key(destringid
, KEY_LOOKUP_CREATE
,
749 if (IS_ERR(dest_ref
)) {
750 ret
= PTR_ERR(dest_ref
);
755 /* find the key type */
756 ktype
= key_type_lookup(type
);
758 ret
= PTR_ERR(ktype
);
763 key_ref
= keyring_search(keyring_ref
, ktype
, description
, true);
764 if (IS_ERR(key_ref
)) {
765 ret
= PTR_ERR(key_ref
);
767 /* treat lack or presence of a negative key the same */
773 /* link the resulting key to the destination keyring if we can */
775 ret
= key_permission(key_ref
, KEY_NEED_LINK
);
779 ret
= key_link(key_ref_to_ptr(dest_ref
), key_ref_to_ptr(key_ref
));
784 ret
= key_ref_to_ptr(key_ref
)->serial
;
787 key_ref_put(key_ref
);
791 key_ref_put(dest_ref
);
793 key_ref_put(keyring_ref
);
801 * Call the read method
803 static long __keyctl_read_key(struct key
*key
, char *buffer
, size_t buflen
)
807 down_read(&key
->sem
);
808 ret
= key_validate(key
);
810 ret
= key
->type
->read(key
, buffer
, buflen
);
816 * Read a key's payload.
818 * The key must either grant the caller Read permission, or it must grant the
819 * caller Search permission when searched for from the process keyrings.
821 * If successful, we place up to buflen bytes of data into the buffer, if one
822 * is provided, and return the amount of data that is available in the key,
823 * irrespective of how much we copied into the buffer.
825 long keyctl_read_key(key_serial_t keyid
, char __user
*buffer
, size_t buflen
)
830 char *key_data
= NULL
;
833 /* find the key first */
834 key_ref
= lookup_user_key(keyid
, 0, 0);
835 if (IS_ERR(key_ref
)) {
840 key
= key_ref_to_ptr(key_ref
);
842 ret
= key_read_state(key
);
844 goto key_put_out
; /* Negatively instantiated */
846 /* see if we can read it directly */
847 ret
= key_permission(key_ref
, KEY_NEED_READ
);
853 /* we can't; see if it's searchable from this process's keyrings
854 * - we automatically take account of the fact that it may be
855 * dangling off an instantiation key
857 if (!is_key_possessed(key_ref
)) {
862 /* the key is probably readable - now try to read it */
864 if (!key
->type
->read
) {
869 if (!buffer
|| !buflen
) {
870 /* Get the key length from the read method */
871 ret
= __keyctl_read_key(key
, NULL
, 0);
876 * Read the data with the semaphore held (since we might sleep)
877 * to protect against the key being updated or revoked.
879 * Allocating a temporary buffer to hold the keys before
880 * transferring them to user buffer to avoid potential
881 * deadlock involving page fault and mmap_sem.
883 * key_data_len = (buflen <= PAGE_SIZE)
884 * ? buflen : actual length of key data
886 * This prevents allocating arbitrary large buffer which can
887 * be much larger than the actual key length. In the latter case,
888 * at least 2 passes of this loop is required.
890 key_data_len
= (buflen
<= PAGE_SIZE
) ? buflen
: 0;
893 key_data
= kvmalloc(key_data_len
, GFP_KERNEL
);
900 ret
= __keyctl_read_key(key
, key_data
, key_data_len
);
903 * Read methods will just return the required length without
904 * any copying if the provided length isn't large enough.
906 if (ret
<= 0 || ret
> buflen
)
910 * The key may change (unlikely) in between 2 consecutive
911 * __keyctl_read_key() calls. In this case, we reallocate
912 * a larger buffer and redo the key read when
913 * key_data_len < ret <= buflen.
915 if (ret
> key_data_len
) {
916 if (unlikely(key_data
))
917 __kvzfree(key_data
, key_data_len
);
919 continue; /* Allocate buffer */
922 if (copy_to_user(buffer
, key_data
, ret
))
926 __kvzfree(key_data
, key_data_len
);
935 * Change the ownership of a key
937 * The key must grant the caller Setattr permission for this to work, though
938 * the key need not be fully instantiated yet. For the UID to be changed, or
939 * for the GID to be changed to a group the caller is not a member of, the
940 * caller must have sysadmin capability. If either uid or gid is -1 then that
941 * attribute is not changed.
943 * If the UID is to be changed, the new user must have sufficient quota to
944 * accept the key. The quota deduction will be removed from the old user to
945 * the new user should the attribute be changed.
947 * If successful, 0 will be returned.
949 long keyctl_chown_key(key_serial_t id
, uid_t user
, gid_t group
)
951 struct key_user
*newowner
, *zapowner
= NULL
;
958 uid
= make_kuid(current_user_ns(), user
);
959 gid
= make_kgid(current_user_ns(), group
);
961 if ((user
!= (uid_t
) -1) && !uid_valid(uid
))
963 if ((group
!= (gid_t
) -1) && !gid_valid(gid
))
967 if (user
== (uid_t
) -1 && group
== (gid_t
) -1)
970 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
972 if (IS_ERR(key_ref
)) {
973 ret
= PTR_ERR(key_ref
);
977 key
= key_ref_to_ptr(key_ref
);
979 /* make the changes with the locks held to prevent chown/chown races */
981 down_write(&key
->sem
);
983 if (!capable(CAP_SYS_ADMIN
)) {
984 /* only the sysadmin can chown a key to some other UID */
985 if (user
!= (uid_t
) -1 && !uid_eq(key
->uid
, uid
))
988 /* only the sysadmin can set the key's GID to a group other
989 * than one of those that the current process subscribes to */
990 if (group
!= (gid_t
) -1 && !gid_eq(gid
, key
->gid
) && !in_group_p(gid
))
995 if (user
!= (uid_t
) -1 && !uid_eq(uid
, key
->uid
)) {
997 newowner
= key_user_lookup(uid
);
1001 /* transfer the quota burden to the new user */
1002 if (test_bit(KEY_FLAG_IN_QUOTA
, &key
->flags
)) {
1003 unsigned maxkeys
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
1004 key_quota_root_maxkeys
: key_quota_maxkeys
;
1005 unsigned maxbytes
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
1006 key_quota_root_maxbytes
: key_quota_maxbytes
;
1008 spin_lock(&newowner
->lock
);
1009 if (newowner
->qnkeys
+ 1 > maxkeys
||
1010 newowner
->qnbytes
+ key
->quotalen
> maxbytes
||
1011 newowner
->qnbytes
+ key
->quotalen
<
1016 newowner
->qnbytes
+= key
->quotalen
;
1017 spin_unlock(&newowner
->lock
);
1019 spin_lock(&key
->user
->lock
);
1020 key
->user
->qnkeys
--;
1021 key
->user
->qnbytes
-= key
->quotalen
;
1022 spin_unlock(&key
->user
->lock
);
1025 atomic_dec(&key
->user
->nkeys
);
1026 atomic_inc(&newowner
->nkeys
);
1028 if (key
->state
!= KEY_IS_UNINSTANTIATED
) {
1029 atomic_dec(&key
->user
->nikeys
);
1030 atomic_inc(&newowner
->nikeys
);
1033 zapowner
= key
->user
;
1034 key
->user
= newowner
;
1038 /* change the GID */
1039 if (group
!= (gid_t
) -1)
1045 up_write(&key
->sem
);
1048 key_user_put(zapowner
);
1053 spin_unlock(&newowner
->lock
);
1054 zapowner
= newowner
;
1060 * Change the permission mask on a key.
1062 * The key must grant the caller Setattr permission for this to work, though
1063 * the key need not be fully instantiated yet. If the caller does not have
1064 * sysadmin capability, it may only change the permission on keys that it owns.
1066 long keyctl_setperm_key(key_serial_t id
, key_perm_t perm
)
1073 if (perm
& ~(KEY_POS_ALL
| KEY_USR_ALL
| KEY_GRP_ALL
| KEY_OTH_ALL
))
1076 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
1078 if (IS_ERR(key_ref
)) {
1079 ret
= PTR_ERR(key_ref
);
1083 key
= key_ref_to_ptr(key_ref
);
1085 /* make the changes with the locks held to prevent chown/chmod races */
1087 down_write(&key
->sem
);
1089 /* if we're not the sysadmin, we can only change a key that we own */
1090 if (capable(CAP_SYS_ADMIN
) || uid_eq(key
->uid
, current_fsuid())) {
1095 up_write(&key
->sem
);
1102 * Get the destination keyring for instantiation and check that the caller has
1103 * Write permission on it.
1105 static long get_instantiation_keyring(key_serial_t ringid
,
1106 struct request_key_auth
*rka
,
1107 struct key
**_dest_keyring
)
1111 *_dest_keyring
= NULL
;
1113 /* just return a NULL pointer if we weren't asked to make a link */
1117 /* if a specific keyring is nominated by ID, then use that */
1119 dkref
= lookup_user_key(ringid
, KEY_LOOKUP_CREATE
, KEY_NEED_WRITE
);
1121 return PTR_ERR(dkref
);
1122 *_dest_keyring
= key_ref_to_ptr(dkref
);
1126 if (ringid
== KEY_SPEC_REQKEY_AUTH_KEY
)
1129 /* otherwise specify the destination keyring recorded in the
1130 * authorisation key (any KEY_SPEC_*_KEYRING) */
1131 if (ringid
>= KEY_SPEC_REQUESTOR_KEYRING
) {
1132 *_dest_keyring
= key_get(rka
->dest_keyring
);
1140 * Change the request_key authorisation key on the current process.
1142 static int keyctl_change_reqkey_auth(struct key
*key
)
1146 new = prepare_creds();
1150 key_put(new->request_key_auth
);
1151 new->request_key_auth
= key_get(key
);
1153 return commit_creds(new);
1157 * Instantiate a key with the specified payload and link the key into the
1158 * destination keyring if one is given.
1160 * The caller must have the appropriate instantiation permit set for this to
1161 * work (see keyctl_assume_authority). No other permissions are required.
1163 * If successful, 0 will be returned.
1165 long keyctl_instantiate_key_common(key_serial_t id
,
1166 struct iov_iter
*from
,
1167 key_serial_t ringid
)
1169 const struct cred
*cred
= current_cred();
1170 struct request_key_auth
*rka
;
1171 struct key
*instkey
, *dest_keyring
;
1172 size_t plen
= from
? iov_iter_count(from
) : 0;
1176 kenter("%d,,%zu,%d", id
, plen
, ringid
);
1182 if (plen
> 1024 * 1024 - 1)
1185 /* the appropriate instantiation authorisation key must have been
1186 * assumed before calling this */
1188 instkey
= cred
->request_key_auth
;
1192 rka
= instkey
->payload
.data
[0];
1193 if (rka
->target_key
->serial
!= id
)
1196 /* pull the payload in if one was supplied */
1201 payload
= kvmalloc(plen
, GFP_KERNEL
);
1206 if (!copy_from_iter_full(payload
, plen
, from
))
1210 /* find the destination keyring amongst those belonging to the
1211 * requesting task */
1212 ret
= get_instantiation_keyring(ringid
, rka
, &dest_keyring
);
1216 /* instantiate the key and link it into a keyring */
1217 ret
= key_instantiate_and_link(rka
->target_key
, payload
, plen
,
1218 dest_keyring
, instkey
);
1220 key_put(dest_keyring
);
1222 /* discard the assumed authority if it's just been disabled by
1223 * instantiation of the key */
1225 keyctl_change_reqkey_auth(NULL
);
1229 memzero_explicit(payload
, plen
);
1237 * Instantiate a key with the specified payload and link the key into the
1238 * destination keyring if one is given.
1240 * The caller must have the appropriate instantiation permit set for this to
1241 * work (see keyctl_assume_authority). No other permissions are required.
1243 * If successful, 0 will be returned.
1245 long keyctl_instantiate_key(key_serial_t id
,
1246 const void __user
*_payload
,
1248 key_serial_t ringid
)
1250 if (_payload
&& plen
) {
1252 struct iov_iter from
;
1255 ret
= import_single_range(WRITE
, (void __user
*)_payload
, plen
,
1260 return keyctl_instantiate_key_common(id
, &from
, ringid
);
1263 return keyctl_instantiate_key_common(id
, NULL
, ringid
);
1267 * Instantiate a key with the specified multipart payload and link the key into
1268 * the destination keyring if one is given.
1270 * The caller must have the appropriate instantiation permit set for this to
1271 * work (see keyctl_assume_authority). No other permissions are required.
1273 * If successful, 0 will be returned.
1275 long keyctl_instantiate_key_iov(key_serial_t id
,
1276 const struct iovec __user
*_payload_iov
,
1278 key_serial_t ringid
)
1280 struct iovec iovstack
[UIO_FASTIOV
], *iov
= iovstack
;
1281 struct iov_iter from
;
1287 ret
= import_iovec(WRITE
, _payload_iov
, ioc
,
1288 ARRAY_SIZE(iovstack
), &iov
, &from
);
1291 ret
= keyctl_instantiate_key_common(id
, &from
, ringid
);
1297 * Negatively instantiate the key with the given timeout (in seconds) and link
1298 * the key into the destination keyring if one is given.
1300 * The caller must have the appropriate instantiation permit set for this to
1301 * work (see keyctl_assume_authority). No other permissions are required.
1303 * The key and any links to the key will be automatically garbage collected
1304 * after the timeout expires.
1306 * Negative keys are used to rate limit repeated request_key() calls by causing
1307 * them to return -ENOKEY until the negative key expires.
1309 * If successful, 0 will be returned.
1311 long keyctl_negate_key(key_serial_t id
, unsigned timeout
, key_serial_t ringid
)
1313 return keyctl_reject_key(id
, timeout
, ENOKEY
, ringid
);
1317 * Negatively instantiate the key with the given timeout (in seconds) and error
1318 * code and link the key into the destination keyring if one is given.
1320 * The caller must have the appropriate instantiation permit set for this to
1321 * work (see keyctl_assume_authority). No other permissions are required.
1323 * The key and any links to the key will be automatically garbage collected
1324 * after the timeout expires.
1326 * Negative keys are used to rate limit repeated request_key() calls by causing
1327 * them to return the specified error code until the negative key expires.
1329 * If successful, 0 will be returned.
1331 long keyctl_reject_key(key_serial_t id
, unsigned timeout
, unsigned error
,
1332 key_serial_t ringid
)
1334 const struct cred
*cred
= current_cred();
1335 struct request_key_auth
*rka
;
1336 struct key
*instkey
, *dest_keyring
;
1339 kenter("%d,%u,%u,%d", id
, timeout
, error
, ringid
);
1341 /* must be a valid error code and mustn't be a kernel special */
1343 error
>= MAX_ERRNO
||
1344 error
== ERESTARTSYS
||
1345 error
== ERESTARTNOINTR
||
1346 error
== ERESTARTNOHAND
||
1347 error
== ERESTART_RESTARTBLOCK
)
1350 /* the appropriate instantiation authorisation key must have been
1351 * assumed before calling this */
1353 instkey
= cred
->request_key_auth
;
1357 rka
= instkey
->payload
.data
[0];
1358 if (rka
->target_key
->serial
!= id
)
1361 /* find the destination keyring if present (which must also be
1363 ret
= get_instantiation_keyring(ringid
, rka
, &dest_keyring
);
1367 /* instantiate the key and link it into a keyring */
1368 ret
= key_reject_and_link(rka
->target_key
, timeout
, error
,
1369 dest_keyring
, instkey
);
1371 key_put(dest_keyring
);
1373 /* discard the assumed authority if it's just been disabled by
1374 * instantiation of the key */
1376 keyctl_change_reqkey_auth(NULL
);
1383 * Read or set the default keyring in which request_key() will cache keys and
1384 * return the old setting.
1386 * If a thread or process keyring is specified then it will be created if it
1387 * doesn't yet exist. The old setting will be returned if successful.
1389 long keyctl_set_reqkey_keyring(int reqkey_defl
)
1392 int ret
, old_setting
;
1394 old_setting
= current_cred_xxx(jit_keyring
);
1396 if (reqkey_defl
== KEY_REQKEY_DEFL_NO_CHANGE
)
1399 new = prepare_creds();
1403 switch (reqkey_defl
) {
1404 case KEY_REQKEY_DEFL_THREAD_KEYRING
:
1405 ret
= install_thread_keyring_to_cred(new);
1410 case KEY_REQKEY_DEFL_PROCESS_KEYRING
:
1411 ret
= install_process_keyring_to_cred(new);
1416 case KEY_REQKEY_DEFL_DEFAULT
:
1417 case KEY_REQKEY_DEFL_SESSION_KEYRING
:
1418 case KEY_REQKEY_DEFL_USER_KEYRING
:
1419 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING
:
1420 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING
:
1423 case KEY_REQKEY_DEFL_NO_CHANGE
:
1424 case KEY_REQKEY_DEFL_GROUP_KEYRING
:
1431 new->jit_keyring
= reqkey_defl
;
1440 * Set or clear the timeout on a key.
1442 * Either the key must grant the caller Setattr permission or else the caller
1443 * must hold an instantiation authorisation token for the key.
1445 * The timeout is either 0 to clear the timeout, or a number of seconds from
1446 * the current time. The key and any links to the key will be automatically
1447 * garbage collected after the timeout expires.
1449 * Keys with KEY_FLAG_KEEP set should not be timed out.
1451 * If successful, 0 is returned.
1453 long keyctl_set_timeout(key_serial_t id
, unsigned timeout
)
1455 struct key
*key
, *instkey
;
1459 key_ref
= lookup_user_key(id
, KEY_LOOKUP_CREATE
| KEY_LOOKUP_PARTIAL
,
1461 if (IS_ERR(key_ref
)) {
1462 /* setting the timeout on a key under construction is permitted
1463 * if we have the authorisation token handy */
1464 if (PTR_ERR(key_ref
) == -EACCES
) {
1465 instkey
= key_get_instantiation_authkey(id
);
1466 if (!IS_ERR(instkey
)) {
1468 key_ref
= lookup_user_key(id
,
1471 if (!IS_ERR(key_ref
))
1476 ret
= PTR_ERR(key_ref
);
1481 key
= key_ref_to_ptr(key_ref
);
1483 if (test_bit(KEY_FLAG_KEEP
, &key
->flags
))
1486 key_set_timeout(key
, timeout
);
1494 * Assume (or clear) the authority to instantiate the specified key.
1496 * This sets the authoritative token currently in force for key instantiation.
1497 * This must be done for a key to be instantiated. It has the effect of making
1498 * available all the keys from the caller of the request_key() that created a
1499 * key to request_key() calls made by the caller of this function.
1501 * The caller must have the instantiation key in their process keyrings with a
1502 * Search permission grant available to the caller.
1504 * If the ID given is 0, then the setting will be cleared and 0 returned.
1506 * If the ID given has a matching an authorisation key, then that key will be
1507 * set and its ID will be returned. The authorisation key can be read to get
1508 * the callout information passed to request_key().
1510 long keyctl_assume_authority(key_serial_t id
)
1512 struct key
*authkey
;
1515 /* special key IDs aren't permitted */
1520 /* we divest ourselves of authority if given an ID of 0 */
1522 ret
= keyctl_change_reqkey_auth(NULL
);
1526 /* attempt to assume the authority temporarily granted to us whilst we
1527 * instantiate the specified key
1528 * - the authorisation key must be in the current task's keyrings
1531 authkey
= key_get_instantiation_authkey(id
);
1532 if (IS_ERR(authkey
)) {
1533 ret
= PTR_ERR(authkey
);
1537 ret
= keyctl_change_reqkey_auth(authkey
);
1539 ret
= authkey
->serial
;
1546 * Get a key's the LSM security label.
1548 * The key must grant the caller View permission for this to work.
1550 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1552 * If successful, the amount of information available will be returned,
1553 * irrespective of how much was copied (including the terminal NUL).
1555 long keyctl_get_security(key_serial_t keyid
,
1556 char __user
*buffer
,
1559 struct key
*key
, *instkey
;
1564 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, KEY_NEED_VIEW
);
1565 if (IS_ERR(key_ref
)) {
1566 if (PTR_ERR(key_ref
) != -EACCES
)
1567 return PTR_ERR(key_ref
);
1569 /* viewing a key under construction is also permitted if we
1570 * have the authorisation token handy */
1571 instkey
= key_get_instantiation_authkey(keyid
);
1572 if (IS_ERR(instkey
))
1573 return PTR_ERR(instkey
);
1576 key_ref
= lookup_user_key(keyid
, KEY_LOOKUP_PARTIAL
, 0);
1577 if (IS_ERR(key_ref
))
1578 return PTR_ERR(key_ref
);
1581 key
= key_ref_to_ptr(key_ref
);
1582 ret
= security_key_getsecurity(key
, &context
);
1584 /* if no information was returned, give userspace an empty
1587 if (buffer
&& buflen
> 0 &&
1588 copy_to_user(buffer
, "", 1) != 0)
1590 } else if (ret
> 0) {
1591 /* return as much data as there's room for */
1592 if (buffer
&& buflen
> 0) {
1596 if (copy_to_user(buffer
, context
, buflen
) != 0)
1603 key_ref_put(key_ref
);
1608 * Attempt to install the calling process's session keyring on the process's
1611 * The keyring must exist and must grant the caller LINK permission, and the
1612 * parent process must be single-threaded and must have the same effective
1613 * ownership as this process and mustn't be SUID/SGID.
1615 * The keyring will be emplaced on the parent when it next resumes userspace.
1617 * If successful, 0 will be returned.
1619 long keyctl_session_to_parent(void)
1621 struct task_struct
*me
, *parent
;
1622 const struct cred
*mycred
, *pcred
;
1623 struct callback_head
*newwork
, *oldwork
;
1624 key_ref_t keyring_r
;
1628 keyring_r
= lookup_user_key(KEY_SPEC_SESSION_KEYRING
, 0, KEY_NEED_LINK
);
1629 if (IS_ERR(keyring_r
))
1630 return PTR_ERR(keyring_r
);
1634 /* our parent is going to need a new cred struct, a new tgcred struct
1635 * and new security data, so we allocate them here to prevent ENOMEM in
1637 cred
= cred_alloc_blank();
1640 newwork
= &cred
->rcu
;
1642 cred
->session_keyring
= key_ref_to_ptr(keyring_r
);
1644 init_task_work(newwork
, key_change_session_keyring
);
1648 write_lock_irq(&tasklist_lock
);
1652 parent
= rcu_dereference_protected(me
->real_parent
,
1653 lockdep_is_held(&tasklist_lock
));
1655 /* the parent mustn't be init and mustn't be a kernel thread */
1656 if (parent
->pid
<= 1 || !parent
->mm
)
1659 /* the parent must be single threaded */
1660 if (!thread_group_empty(parent
))
1663 /* the parent and the child must have different session keyrings or
1664 * there's no point */
1665 mycred
= current_cred();
1666 pcred
= __task_cred(parent
);
1667 if (mycred
== pcred
||
1668 mycred
->session_keyring
== pcred
->session_keyring
) {
1673 /* the parent must have the same effective ownership and mustn't be
1675 if (!uid_eq(pcred
->uid
, mycred
->euid
) ||
1676 !uid_eq(pcred
->euid
, mycred
->euid
) ||
1677 !uid_eq(pcred
->suid
, mycred
->euid
) ||
1678 !gid_eq(pcred
->gid
, mycred
->egid
) ||
1679 !gid_eq(pcred
->egid
, mycred
->egid
) ||
1680 !gid_eq(pcred
->sgid
, mycred
->egid
))
1683 /* the keyrings must have the same UID */
1684 if ((pcred
->session_keyring
&&
1685 !uid_eq(pcred
->session_keyring
->uid
, mycred
->euid
)) ||
1686 !uid_eq(mycred
->session_keyring
->uid
, mycred
->euid
))
1689 /* cancel an already pending keyring replacement */
1690 oldwork
= task_work_cancel(parent
, key_change_session_keyring
);
1692 /* the replacement session keyring is applied just prior to userspace
1694 ret
= task_work_add(parent
, newwork
, true);
1698 write_unlock_irq(&tasklist_lock
);
1701 put_cred(container_of(oldwork
, struct cred
, rcu
));
1707 key_ref_put(keyring_r
);
1712 * Apply a restriction to a given keyring.
1714 * The caller must have Setattr permission to change keyring restrictions.
1716 * The requested type name may be a NULL pointer to reject all attempts
1717 * to link to the keyring. In this case, _restriction must also be NULL.
1718 * Otherwise, both _type and _restriction must be non-NULL.
1720 * Returns 0 if successful.
1722 long keyctl_restrict_keyring(key_serial_t id
, const char __user
*_type
,
1723 const char __user
*_restriction
)
1727 char *restriction
= NULL
;
1730 key_ref
= lookup_user_key(id
, 0, KEY_NEED_SETATTR
);
1731 if (IS_ERR(key_ref
))
1732 return PTR_ERR(key_ref
);
1739 ret
= key_get_type_from_user(type
, _type
, sizeof(type
));
1743 restriction
= strndup_user(_restriction
, PAGE_SIZE
);
1744 if (IS_ERR(restriction
)) {
1745 ret
= PTR_ERR(restriction
);
1753 ret
= keyring_restrict(key_ref
, _type
? type
: NULL
, restriction
);
1756 key_ref_put(key_ref
);
1761 * Get keyrings subsystem capabilities.
1763 long keyctl_capabilities(unsigned char __user
*_buffer
, size_t buflen
)
1765 size_t size
= buflen
;
1768 if (size
> sizeof(keyrings_capabilities
))
1769 size
= sizeof(keyrings_capabilities
);
1770 if (copy_to_user(_buffer
, keyrings_capabilities
, size
) != 0)
1772 if (size
< buflen
&&
1773 clear_user(_buffer
+ size
, buflen
- size
) != 0)
1777 return sizeof(keyrings_capabilities
);
1781 * The key control system call
1783 SYSCALL_DEFINE5(keyctl
, int, option
, unsigned long, arg2
, unsigned long, arg3
,
1784 unsigned long, arg4
, unsigned long, arg5
)
1787 case KEYCTL_GET_KEYRING_ID
:
1788 return keyctl_get_keyring_ID((key_serial_t
) arg2
,
1791 case KEYCTL_JOIN_SESSION_KEYRING
:
1792 return keyctl_join_session_keyring((const char __user
*) arg2
);
1795 return keyctl_update_key((key_serial_t
) arg2
,
1796 (const void __user
*) arg3
,
1800 return keyctl_revoke_key((key_serial_t
) arg2
);
1802 case KEYCTL_DESCRIBE
:
1803 return keyctl_describe_key((key_serial_t
) arg2
,
1804 (char __user
*) arg3
,
1808 return keyctl_keyring_clear((key_serial_t
) arg2
);
1811 return keyctl_keyring_link((key_serial_t
) arg2
,
1812 (key_serial_t
) arg3
);
1815 return keyctl_keyring_unlink((key_serial_t
) arg2
,
1816 (key_serial_t
) arg3
);
1819 return keyctl_keyring_search((key_serial_t
) arg2
,
1820 (const char __user
*) arg3
,
1821 (const char __user
*) arg4
,
1822 (key_serial_t
) arg5
);
1825 return keyctl_read_key((key_serial_t
) arg2
,
1826 (char __user
*) arg3
,
1830 return keyctl_chown_key((key_serial_t
) arg2
,
1834 case KEYCTL_SETPERM
:
1835 return keyctl_setperm_key((key_serial_t
) arg2
,
1838 case KEYCTL_INSTANTIATE
:
1839 return keyctl_instantiate_key((key_serial_t
) arg2
,
1840 (const void __user
*) arg3
,
1842 (key_serial_t
) arg5
);
1845 return keyctl_negate_key((key_serial_t
) arg2
,
1847 (key_serial_t
) arg4
);
1849 case KEYCTL_SET_REQKEY_KEYRING
:
1850 return keyctl_set_reqkey_keyring(arg2
);
1852 case KEYCTL_SET_TIMEOUT
:
1853 return keyctl_set_timeout((key_serial_t
) arg2
,
1856 case KEYCTL_ASSUME_AUTHORITY
:
1857 return keyctl_assume_authority((key_serial_t
) arg2
);
1859 case KEYCTL_GET_SECURITY
:
1860 return keyctl_get_security((key_serial_t
) arg2
,
1861 (char __user
*) arg3
,
1864 case KEYCTL_SESSION_TO_PARENT
:
1865 return keyctl_session_to_parent();
1868 return keyctl_reject_key((key_serial_t
) arg2
,
1871 (key_serial_t
) arg5
);
1873 case KEYCTL_INSTANTIATE_IOV
:
1874 return keyctl_instantiate_key_iov(
1875 (key_serial_t
) arg2
,
1876 (const struct iovec __user
*) arg3
,
1878 (key_serial_t
) arg5
);
1880 case KEYCTL_INVALIDATE
:
1881 return keyctl_invalidate_key((key_serial_t
) arg2
);
1883 case KEYCTL_GET_PERSISTENT
:
1884 return keyctl_get_persistent((uid_t
)arg2
, (key_serial_t
)arg3
);
1886 case KEYCTL_DH_COMPUTE
:
1887 return keyctl_dh_compute((struct keyctl_dh_params __user
*) arg2
,
1888 (char __user
*) arg3
, (size_t) arg4
,
1889 (struct keyctl_kdf_params __user
*) arg5
);
1891 case KEYCTL_RESTRICT_KEYRING
:
1892 return keyctl_restrict_keyring((key_serial_t
) arg2
,
1893 (const char __user
*) arg3
,
1894 (const char __user
*) arg4
);
1896 case KEYCTL_PKEY_QUERY
:
1899 return keyctl_pkey_query((key_serial_t
)arg2
,
1900 (const char __user
*)arg4
,
1901 (struct keyctl_pkey_query __user
*)arg5
);
1903 case KEYCTL_PKEY_ENCRYPT
:
1904 case KEYCTL_PKEY_DECRYPT
:
1905 case KEYCTL_PKEY_SIGN
:
1906 return keyctl_pkey_e_d_s(
1908 (const struct keyctl_pkey_params __user
*)arg2
,
1909 (const char __user
*)arg3
,
1910 (const void __user
*)arg4
,
1911 (void __user
*)arg5
);
1913 case KEYCTL_PKEY_VERIFY
:
1914 return keyctl_pkey_verify(
1915 (const struct keyctl_pkey_params __user
*)arg2
,
1916 (const char __user
*)arg3
,
1917 (const void __user
*)arg4
,
1918 (const void __user
*)arg5
);
1921 return keyctl_keyring_move((key_serial_t
)arg2
,
1924 (unsigned int)arg5
);
1926 case KEYCTL_CAPABILITIES
:
1927 return keyctl_capabilities((unsigned char __user
*)arg2
, (size_t)arg3
);