1/* Userspace key control operations
2 *
3 * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
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.
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/sched.h>
15#include <linux/slab.h>
16#include <linux/syscalls.h>
17#include <linux/key.h>
18#include <linux/keyctl.h>
19#include <linux/fs.h>
20#include <linux/capability.h>
21#include <linux/string.h>
22#include <linux/err.h>
23#include <linux/vmalloc.h>
24#include <linux/security.h>
25#include <linux/uio.h>
26#include <asm/uaccess.h>
27#include "internal.h"
28
29#define KEY_MAX_DESC_SIZE 4096
30
31static int key_get_type_from_user(char *type,
32				  const char __user *_type,
33				  unsigned len)
34{
35	int ret;
36
37	ret = strncpy_from_user(type, _type, len);
38	if (ret < 0)
39		return ret;
40	if (ret == 0 || ret >= len)
41		return -EINVAL;
42	if (type[0] == '.')
43		return -EPERM;
44	type[len - 1] = '\0';
45	return 0;
46}
47
48/*
49 * Extract the description of a new key from userspace and either add it as a
50 * new key to the specified keyring or update a matching key in that keyring.
51 *
52 * If the description is NULL or an empty string, the key type is asked to
53 * generate one from the payload.
54 *
55 * The keyring must be writable so that we can attach the key to it.
56 *
57 * If successful, the new key's serial number is returned, otherwise an error
58 * code is returned.
59 */
60SYSCALL_DEFINE5(add_key, const char __user *, _type,
61		const char __user *, _description,
62		const void __user *, _payload,
63		size_t, plen,
64		key_serial_t, ringid)
65{
66	key_ref_t keyring_ref, key_ref;
67	char type[32], *description;
68	void *payload;
69	long ret;
70	bool vm;
71
72	ret = -EINVAL;
73	if (plen > 1024 * 1024 - 1)
74		goto error;
75
76	/* draw all the data into kernel space */
77	ret = key_get_type_from_user(type, _type, sizeof(type));
78	if (ret < 0)
79		goto error;
80
81	description = NULL;
82	if (_description) {
83		description = strndup_user(_description, KEY_MAX_DESC_SIZE);
84		if (IS_ERR(description)) {
85			ret = PTR_ERR(description);
86			goto error;
87		}
88		if (!*description) {
89			kfree(description);
90			description = NULL;
91		} else if ((description[0] == '.') &&
92			   (strncmp(type, "keyring", 7) == 0)) {
93			ret = -EPERM;
94			goto error2;
95		}
96	}
97
98	/* pull the payload in if one was supplied */
99	payload = NULL;
100
101	vm = false;
102	if (_payload) {
103		ret = -ENOMEM;
104		payload = kmalloc(plen, GFP_KERNEL | __GFP_NOWARN);
105		if (!payload) {
106			if (plen <= PAGE_SIZE)
107				goto error2;
108			vm = true;
109			payload = vmalloc(plen);
110			if (!payload)
111				goto error2;
112		}
113
114		ret = -EFAULT;
115		if (copy_from_user(payload, _payload, plen) != 0)
116			goto error3;
117	}
118
119	/* find the target keyring (which must be writable) */
120	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
121	if (IS_ERR(keyring_ref)) {
122		ret = PTR_ERR(keyring_ref);
123		goto error3;
124	}
125
126	/* create or update the requested key and add it to the target
127	 * keyring */
128	key_ref = key_create_or_update(keyring_ref, type, description,
129				       payload, plen, KEY_PERM_UNDEF,
130				       KEY_ALLOC_IN_QUOTA);
131	if (!IS_ERR(key_ref)) {
132		ret = key_ref_to_ptr(key_ref)->serial;
133		key_ref_put(key_ref);
134	}
135	else {
136		ret = PTR_ERR(key_ref);
137	}
138
139	key_ref_put(keyring_ref);
140 error3:
141	if (!vm)
142		kfree(payload);
143	else
144		vfree(payload);
145 error2:
146	kfree(description);
147 error:
148	return ret;
149}
150
151/*
152 * Search the process keyrings and keyring trees linked from those for a
153 * matching key.  Keyrings must have appropriate Search permission to be
154 * searched.
155 *
156 * If a key is found, it will be attached to the destination keyring if there's
157 * one specified and the serial number of the key will be returned.
158 *
159 * If no key is found, /sbin/request-key will be invoked if _callout_info is
160 * non-NULL in an attempt to create a key.  The _callout_info string will be
161 * passed to /sbin/request-key to aid with completing the request.  If the
162 * _callout_info string is "" then it will be changed to "-".
163 */
164SYSCALL_DEFINE4(request_key, const char __user *, _type,
165		const char __user *, _description,
166		const char __user *, _callout_info,
167		key_serial_t, destringid)
168{
169	struct key_type *ktype;
170	struct key *key;
171	key_ref_t dest_ref;
172	size_t callout_len;
173	char type[32], *description, *callout_info;
174	long ret;
175
176	/* pull the type into kernel space */
177	ret = key_get_type_from_user(type, _type, sizeof(type));
178	if (ret < 0)
179		goto error;
180
181	/* pull the description into kernel space */
182	description = strndup_user(_description, KEY_MAX_DESC_SIZE);
183	if (IS_ERR(description)) {
184		ret = PTR_ERR(description);
185		goto error;
186	}
187
188	/* pull the callout info into kernel space */
189	callout_info = NULL;
190	callout_len = 0;
191	if (_callout_info) {
192		callout_info = strndup_user(_callout_info, PAGE_SIZE);
193		if (IS_ERR(callout_info)) {
194			ret = PTR_ERR(callout_info);
195			goto error2;
196		}
197		callout_len = strlen(callout_info);
198	}
199
200	/* get the destination keyring if specified */
201	dest_ref = NULL;
202	if (destringid) {
203		dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
204					   KEY_NEED_WRITE);
205		if (IS_ERR(dest_ref)) {
206			ret = PTR_ERR(dest_ref);
207			goto error3;
208		}
209	}
210
211	/* find the key type */
212	ktype = key_type_lookup(type);
213	if (IS_ERR(ktype)) {
214		ret = PTR_ERR(ktype);
215		goto error4;
216	}
217
218	/* do the search */
219	key = request_key_and_link(ktype, description, callout_info,
220				   callout_len, NULL, key_ref_to_ptr(dest_ref),
221				   KEY_ALLOC_IN_QUOTA);
222	if (IS_ERR(key)) {
223		ret = PTR_ERR(key);
224		goto error5;
225	}
226
227	/* wait for the key to finish being constructed */
228	ret = wait_for_key_construction(key, 1);
229	if (ret < 0)
230		goto error6;
231
232	ret = key->serial;
233
234error6:
235 	key_put(key);
236error5:
237	key_type_put(ktype);
238error4:
239	key_ref_put(dest_ref);
240error3:
241	kfree(callout_info);
242error2:
243	kfree(description);
244error:
245	return ret;
246}
247
248/*
249 * Get the ID of the specified process keyring.
250 *
251 * The requested keyring must have search permission to be found.
252 *
253 * If successful, the ID of the requested keyring will be returned.
254 */
255long keyctl_get_keyring_ID(key_serial_t id, int create)
256{
257	key_ref_t key_ref;
258	unsigned long lflags;
259	long ret;
260
261	lflags = create ? KEY_LOOKUP_CREATE : 0;
262	key_ref = lookup_user_key(id, lflags, KEY_NEED_SEARCH);
263	if (IS_ERR(key_ref)) {
264		ret = PTR_ERR(key_ref);
265		goto error;
266	}
267
268	ret = key_ref_to_ptr(key_ref)->serial;
269	key_ref_put(key_ref);
270error:
271	return ret;
272}
273
274/*
275 * Join a (named) session keyring.
276 *
277 * Create and join an anonymous session keyring or join a named session
278 * keyring, creating it if necessary.  A named session keyring must have Search
279 * permission for it to be joined.  Session keyrings without this permit will
280 * be skipped over.
281 *
282 * If successful, the ID of the joined session keyring will be returned.
283 */
284long keyctl_join_session_keyring(const char __user *_name)
285{
286	char *name;
287	long ret;
288
289	/* fetch the name from userspace */
290	name = NULL;
291	if (_name) {
292		name = strndup_user(_name, KEY_MAX_DESC_SIZE);
293		if (IS_ERR(name)) {
294			ret = PTR_ERR(name);
295			goto error;
296		}
297	}
298
299	/* join the session */
300	ret = join_session_keyring(name);
301	kfree(name);
302
303error:
304	return ret;
305}
306
307/*
308 * Update a key's data payload from the given data.
309 *
310 * The key must grant the caller Write permission and the key type must support
311 * updating for this to work.  A negative key can be positively instantiated
312 * with this call.
313 *
314 * If successful, 0 will be returned.  If the key type does not support
315 * updating, then -EOPNOTSUPP will be returned.
316 */
317long keyctl_update_key(key_serial_t id,
318		       const void __user *_payload,
319		       size_t plen)
320{
321	key_ref_t key_ref;
322	void *payload;
323	long ret;
324
325	ret = -EINVAL;
326	if (plen > PAGE_SIZE)
327		goto error;
328
329	/* pull the payload in if one was supplied */
330	payload = NULL;
331	if (_payload) {
332		ret = -ENOMEM;
333		payload = kmalloc(plen, GFP_KERNEL);
334		if (!payload)
335			goto error;
336
337		ret = -EFAULT;
338		if (copy_from_user(payload, _payload, plen) != 0)
339			goto error2;
340	}
341
342	/* find the target key (which must be writable) */
343	key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE);
344	if (IS_ERR(key_ref)) {
345		ret = PTR_ERR(key_ref);
346		goto error2;
347	}
348
349	/* update the key */
350	ret = key_update(key_ref, payload, plen);
351
352	key_ref_put(key_ref);
353error2:
354	kfree(payload);
355error:
356	return ret;
357}
358
359/*
360 * Revoke a key.
361 *
362 * The key must be grant the caller Write or Setattr permission for this to
363 * work.  The key type should give up its quota claim when revoked.  The key
364 * and any links to the key will be automatically garbage collected after a
365 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
366 *
367 * If successful, 0 is returned.
368 */
369long keyctl_revoke_key(key_serial_t id)
370{
371	key_ref_t key_ref;
372	long ret;
373
374	key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE);
375	if (IS_ERR(key_ref)) {
376		ret = PTR_ERR(key_ref);
377		if (ret != -EACCES)
378			goto error;
379		key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR);
380		if (IS_ERR(key_ref)) {
381			ret = PTR_ERR(key_ref);
382			goto error;
383		}
384	}
385
386	key_revoke(key_ref_to_ptr(key_ref));
387	ret = 0;
388
389	key_ref_put(key_ref);
390error:
391	return ret;
392}
393
394/*
395 * Invalidate a key.
396 *
397 * The key must be grant the caller Invalidate permission for this to work.
398 * The key and any links to the key will be automatically garbage collected
399 * immediately.
400 *
401 * If successful, 0 is returned.
402 */
403long keyctl_invalidate_key(key_serial_t id)
404{
405	key_ref_t key_ref;
406	long ret;
407
408	kenter("%d", id);
409
410	key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
411	if (IS_ERR(key_ref)) {
412		ret = PTR_ERR(key_ref);
413
414		/* Root is permitted to invalidate certain special keys */
415		if (capable(CAP_SYS_ADMIN)) {
416			key_ref = lookup_user_key(id, 0, 0);
417			if (IS_ERR(key_ref))
418				goto error;
419			if (test_bit(KEY_FLAG_ROOT_CAN_INVAL,
420				     &key_ref_to_ptr(key_ref)->flags))
421				goto invalidate;
422			goto error_put;
423		}
424
425		goto error;
426	}
427
428invalidate:
429	key_invalidate(key_ref_to_ptr(key_ref));
430	ret = 0;
431error_put:
432	key_ref_put(key_ref);
433error:
434	kleave(" = %ld", ret);
435	return ret;
436}
437
438/*
439 * Clear the specified keyring, creating an empty process keyring if one of the
440 * special keyring IDs is used.
441 *
442 * The keyring must grant the caller Write permission for this to work.  If
443 * successful, 0 will be returned.
444 */
445long keyctl_keyring_clear(key_serial_t ringid)
446{
447	key_ref_t keyring_ref;
448	long ret;
449
450	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
451	if (IS_ERR(keyring_ref)) {
452		ret = PTR_ERR(keyring_ref);
453
454		/* Root is permitted to invalidate certain special keyrings */
455		if (capable(CAP_SYS_ADMIN)) {
456			keyring_ref = lookup_user_key(ringid, 0, 0);
457			if (IS_ERR(keyring_ref))
458				goto error;
459			if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR,
460				     &key_ref_to_ptr(keyring_ref)->flags))
461				goto clear;
462			goto error_put;
463		}
464
465		goto error;
466	}
467
468clear:
469	ret = keyring_clear(key_ref_to_ptr(keyring_ref));
470error_put:
471	key_ref_put(keyring_ref);
472error:
473	return ret;
474}
475
476/*
477 * Create a link from a keyring to a key if there's no matching key in the
478 * keyring, otherwise replace the link to the matching key with a link to the
479 * new key.
480 *
481 * The key must grant the caller Link permission and the the keyring must grant
482 * the caller Write permission.  Furthermore, if an additional link is created,
483 * the keyring's quota will be extended.
484 *
485 * If successful, 0 will be returned.
486 */
487long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
488{
489	key_ref_t keyring_ref, key_ref;
490	long ret;
491
492	keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
493	if (IS_ERR(keyring_ref)) {
494		ret = PTR_ERR(keyring_ref);
495		goto error;
496	}
497
498	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK);
499	if (IS_ERR(key_ref)) {
500		ret = PTR_ERR(key_ref);
501		goto error2;
502	}
503
504	ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
505
506	key_ref_put(key_ref);
507error2:
508	key_ref_put(keyring_ref);
509error:
510	return ret;
511}
512
513/*
514 * Unlink a key from a keyring.
515 *
516 * The keyring must grant the caller Write permission for this to work; the key
517 * itself need not grant the caller anything.  If the last link to a key is
518 * removed then that key will be scheduled for destruction.
519 *
520 * If successful, 0 will be returned.
521 */
522long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
523{
524	key_ref_t keyring_ref, key_ref;
525	long ret;
526
527	keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_WRITE);
528	if (IS_ERR(keyring_ref)) {
529		ret = PTR_ERR(keyring_ref);
530		goto error;
531	}
532
533	key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
534	if (IS_ERR(key_ref)) {
535		ret = PTR_ERR(key_ref);
536		goto error2;
537	}
538
539	ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
540
541	key_ref_put(key_ref);
542error2:
543	key_ref_put(keyring_ref);
544error:
545	return ret;
546}
547
548/*
549 * Return a description of a key to userspace.
550 *
551 * The key must grant the caller View permission for this to work.
552 *
553 * If there's a buffer, we place up to buflen bytes of data into it formatted
554 * in the following way:
555 *
556 *	type;uid;gid;perm;description<NUL>
557 *
558 * If successful, we return the amount of description available, irrespective
559 * of how much we may have copied into the buffer.
560 */
561long keyctl_describe_key(key_serial_t keyid,
562			 char __user *buffer,
563			 size_t buflen)
564{
565	struct key *key, *instkey;
566	key_ref_t key_ref;
567	char *infobuf;
568	long ret;
569	int desclen, infolen;
570
571	key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW);
572	if (IS_ERR(key_ref)) {
573		/* viewing a key under construction is permitted if we have the
574		 * authorisation token handy */
575		if (PTR_ERR(key_ref) == -EACCES) {
576			instkey = key_get_instantiation_authkey(keyid);
577			if (!IS_ERR(instkey)) {
578				key_put(instkey);
579				key_ref = lookup_user_key(keyid,
580							  KEY_LOOKUP_PARTIAL,
581							  0);
582				if (!IS_ERR(key_ref))
583					goto okay;
584			}
585		}
586
587		ret = PTR_ERR(key_ref);
588		goto error;
589	}
590
591okay:
592	key = key_ref_to_ptr(key_ref);
593	desclen = strlen(key->description);
594
595	/* calculate how much information we're going to return */
596	ret = -ENOMEM;
597	infobuf = kasprintf(GFP_KERNEL,
598			    "%s;%d;%d;%08x;",
599			    key->type->name,
600			    from_kuid_munged(current_user_ns(), key->uid),
601			    from_kgid_munged(current_user_ns(), key->gid),
602			    key->perm);
603	if (!infobuf)
604		goto error2;
605	infolen = strlen(infobuf);
606	ret = infolen + desclen + 1;
607
608	/* consider returning the data */
609	if (buffer && buflen >= ret) {
610		if (copy_to_user(buffer, infobuf, infolen) != 0 ||
611		    copy_to_user(buffer + infolen, key->description,
612				 desclen + 1) != 0)
613			ret = -EFAULT;
614	}
615
616	kfree(infobuf);
617error2:
618	key_ref_put(key_ref);
619error:
620	return ret;
621}
622
623/*
624 * Search the specified keyring and any keyrings it links to for a matching
625 * key.  Only keyrings that grant the caller Search permission will be searched
626 * (this includes the starting keyring).  Only keys with Search permission can
627 * be found.
628 *
629 * If successful, the found key will be linked to the destination keyring if
630 * supplied and the key has Link permission, and the found key ID will be
631 * returned.
632 */
633long keyctl_keyring_search(key_serial_t ringid,
634			   const char __user *_type,
635			   const char __user *_description,
636			   key_serial_t destringid)
637{
638	struct key_type *ktype;
639	key_ref_t keyring_ref, key_ref, dest_ref;
640	char type[32], *description;
641	long ret;
642
643	/* pull the type and description into kernel space */
644	ret = key_get_type_from_user(type, _type, sizeof(type));
645	if (ret < 0)
646		goto error;
647
648	description = strndup_user(_description, KEY_MAX_DESC_SIZE);
649	if (IS_ERR(description)) {
650		ret = PTR_ERR(description);
651		goto error;
652	}
653
654	/* get the keyring at which to begin the search */
655	keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_SEARCH);
656	if (IS_ERR(keyring_ref)) {
657		ret = PTR_ERR(keyring_ref);
658		goto error2;
659	}
660
661	/* get the destination keyring if specified */
662	dest_ref = NULL;
663	if (destringid) {
664		dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
665					   KEY_NEED_WRITE);
666		if (IS_ERR(dest_ref)) {
667			ret = PTR_ERR(dest_ref);
668			goto error3;
669		}
670	}
671
672	/* find the key type */
673	ktype = key_type_lookup(type);
674	if (IS_ERR(ktype)) {
675		ret = PTR_ERR(ktype);
676		goto error4;
677	}
678
679	/* do the search */
680	key_ref = keyring_search(keyring_ref, ktype, description);
681	if (IS_ERR(key_ref)) {
682		ret = PTR_ERR(key_ref);
683
684		/* treat lack or presence of a negative key the same */
685		if (ret == -EAGAIN)
686			ret = -ENOKEY;
687		goto error5;
688	}
689
690	/* link the resulting key to the destination keyring if we can */
691	if (dest_ref) {
692		ret = key_permission(key_ref, KEY_NEED_LINK);
693		if (ret < 0)
694			goto error6;
695
696		ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref));
697		if (ret < 0)
698			goto error6;
699	}
700
701	ret = key_ref_to_ptr(key_ref)->serial;
702
703error6:
704	key_ref_put(key_ref);
705error5:
706	key_type_put(ktype);
707error4:
708	key_ref_put(dest_ref);
709error3:
710	key_ref_put(keyring_ref);
711error2:
712	kfree(description);
713error:
714	return ret;
715}
716
717/*
718 * Read a key's payload.
719 *
720 * The key must either grant the caller Read permission, or it must grant the
721 * caller Search permission when searched for from the process keyrings.
722 *
723 * If successful, we place up to buflen bytes of data into the buffer, if one
724 * is provided, and return the amount of data that is available in the key,
725 * irrespective of how much we copied into the buffer.
726 */
727long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
728{
729	struct key *key;
730	key_ref_t key_ref;
731	long ret;
732
733	/* find the key first */
734	key_ref = lookup_user_key(keyid, 0, 0);
735	if (IS_ERR(key_ref)) {
736		ret = -ENOKEY;
737		goto error;
738	}
739
740	key = key_ref_to_ptr(key_ref);
741
742	/* see if we can read it directly */
743	ret = key_permission(key_ref, KEY_NEED_READ);
744	if (ret == 0)
745		goto can_read_key;
746	if (ret != -EACCES)
747		goto error;
748
749	/* we can't; see if it's searchable from this process's keyrings
750	 * - we automatically take account of the fact that it may be
751	 *   dangling off an instantiation key
752	 */
753	if (!is_key_possessed(key_ref)) {
754		ret = -EACCES;
755		goto error2;
756	}
757
758	/* the key is probably readable - now try to read it */
759can_read_key:
760	ret = -EOPNOTSUPP;
761	if (key->type->read) {
762		/* Read the data with the semaphore held (since we might sleep)
763		 * to protect against the key being updated or revoked.
764		 */
765		down_read(&key->sem);
766		ret = key_validate(key);
767		if (ret == 0)
768			ret = key->type->read(key, buffer, buflen);
769		up_read(&key->sem);
770	}
771
772error2:
773	key_put(key);
774error:
775	return ret;
776}
777
778/*
779 * Change the ownership of a key
780 *
781 * The key must grant the caller Setattr permission for this to work, though
782 * the key need not be fully instantiated yet.  For the UID to be changed, or
783 * for the GID to be changed to a group the caller is not a member of, the
784 * caller must have sysadmin capability.  If either uid or gid is -1 then that
785 * attribute is not changed.
786 *
787 * If the UID is to be changed, the new user must have sufficient quota to
788 * accept the key.  The quota deduction will be removed from the old user to
789 * the new user should the attribute be changed.
790 *
791 * If successful, 0 will be returned.
792 */
793long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group)
794{
795	struct key_user *newowner, *zapowner = NULL;
796	struct key *key;
797	key_ref_t key_ref;
798	long ret;
799	kuid_t uid;
800	kgid_t gid;
801
802	uid = make_kuid(current_user_ns(), user);
803	gid = make_kgid(current_user_ns(), group);
804	ret = -EINVAL;
805	if ((user != (uid_t) -1) && !uid_valid(uid))
806		goto error;
807	if ((group != (gid_t) -1) && !gid_valid(gid))
808		goto error;
809
810	ret = 0;
811	if (user == (uid_t) -1 && group == (gid_t) -1)
812		goto error;
813
814	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
815				  KEY_NEED_SETATTR);
816	if (IS_ERR(key_ref)) {
817		ret = PTR_ERR(key_ref);
818		goto error;
819	}
820
821	key = key_ref_to_ptr(key_ref);
822
823	/* make the changes with the locks held to prevent chown/chown races */
824	ret = -EACCES;
825	down_write(&key->sem);
826
827	if (!capable(CAP_SYS_ADMIN)) {
828		/* only the sysadmin can chown a key to some other UID */
829		if (user != (uid_t) -1 && !uid_eq(key->uid, uid))
830			goto error_put;
831
832		/* only the sysadmin can set the key's GID to a group other
833		 * than one of those that the current process subscribes to */
834		if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid))
835			goto error_put;
836	}
837
838	/* change the UID */
839	if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) {
840		ret = -ENOMEM;
841		newowner = key_user_lookup(uid);
842		if (!newowner)
843			goto error_put;
844
845		/* transfer the quota burden to the new user */
846		if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
847			unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ?
848				key_quota_root_maxkeys : key_quota_maxkeys;
849			unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ?
850				key_quota_root_maxbytes : key_quota_maxbytes;
851
852			spin_lock(&newowner->lock);
853			if (newowner->qnkeys + 1 >= maxkeys ||
854			    newowner->qnbytes + key->quotalen >= maxbytes ||
855			    newowner->qnbytes + key->quotalen <
856			    newowner->qnbytes)
857				goto quota_overrun;
858
859			newowner->qnkeys++;
860			newowner->qnbytes += key->quotalen;
861			spin_unlock(&newowner->lock);
862
863			spin_lock(&key->user->lock);
864			key->user->qnkeys--;
865			key->user->qnbytes -= key->quotalen;
866			spin_unlock(&key->user->lock);
867		}
868
869		atomic_dec(&key->user->nkeys);
870		atomic_inc(&newowner->nkeys);
871
872		if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
873			atomic_dec(&key->user->nikeys);
874			atomic_inc(&newowner->nikeys);
875		}
876
877		zapowner = key->user;
878		key->user = newowner;
879		key->uid = uid;
880	}
881
882	/* change the GID */
883	if (group != (gid_t) -1)
884		key->gid = gid;
885
886	ret = 0;
887
888error_put:
889	up_write(&key->sem);
890	key_put(key);
891	if (zapowner)
892		key_user_put(zapowner);
893error:
894	return ret;
895
896quota_overrun:
897	spin_unlock(&newowner->lock);
898	zapowner = newowner;
899	ret = -EDQUOT;
900	goto error_put;
901}
902
903/*
904 * Change the permission mask on a key.
905 *
906 * The key must grant the caller Setattr permission for this to work, though
907 * the key need not be fully instantiated yet.  If the caller does not have
908 * sysadmin capability, it may only change the permission on keys that it owns.
909 */
910long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
911{
912	struct key *key;
913	key_ref_t key_ref;
914	long ret;
915
916	ret = -EINVAL;
917	if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
918		goto error;
919
920	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
921				  KEY_NEED_SETATTR);
922	if (IS_ERR(key_ref)) {
923		ret = PTR_ERR(key_ref);
924		goto error;
925	}
926
927	key = key_ref_to_ptr(key_ref);
928
929	/* make the changes with the locks held to prevent chown/chmod races */
930	ret = -EACCES;
931	down_write(&key->sem);
932
933	/* if we're not the sysadmin, we can only change a key that we own */
934	if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) {
935		key->perm = perm;
936		ret = 0;
937	}
938
939	up_write(&key->sem);
940	key_put(key);
941error:
942	return ret;
943}
944
945/*
946 * Get the destination keyring for instantiation and check that the caller has
947 * Write permission on it.
948 */
949static long get_instantiation_keyring(key_serial_t ringid,
950				      struct request_key_auth *rka,
951				      struct key **_dest_keyring)
952{
953	key_ref_t dkref;
954
955	*_dest_keyring = NULL;
956
957	/* just return a NULL pointer if we weren't asked to make a link */
958	if (ringid == 0)
959		return 0;
960
961	/* if a specific keyring is nominated by ID, then use that */
962	if (ringid > 0) {
963		dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
964		if (IS_ERR(dkref))
965			return PTR_ERR(dkref);
966		*_dest_keyring = key_ref_to_ptr(dkref);
967		return 0;
968	}
969
970	if (ringid == KEY_SPEC_REQKEY_AUTH_KEY)
971		return -EINVAL;
972
973	/* otherwise specify the destination keyring recorded in the
974	 * authorisation key (any KEY_SPEC_*_KEYRING) */
975	if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) {
976		*_dest_keyring = key_get(rka->dest_keyring);
977		return 0;
978	}
979
980	return -ENOKEY;
981}
982
983/*
984 * Change the request_key authorisation key on the current process.
985 */
986static int keyctl_change_reqkey_auth(struct key *key)
987{
988	struct cred *new;
989
990	new = prepare_creds();
991	if (!new)
992		return -ENOMEM;
993
994	key_put(new->request_key_auth);
995	new->request_key_auth = key_get(key);
996
997	return commit_creds(new);
998}
999
1000/*
1001 * Instantiate a key with the specified payload and link the key into the
1002 * destination keyring if one is given.
1003 *
1004 * The caller must have the appropriate instantiation permit set for this to
1005 * work (see keyctl_assume_authority).  No other permissions are required.
1006 *
1007 * If successful, 0 will be returned.
1008 */
1009long keyctl_instantiate_key_common(key_serial_t id,
1010				   struct iov_iter *from,
1011				   key_serial_t ringid)
1012{
1013	const struct cred *cred = current_cred();
1014	struct request_key_auth *rka;
1015	struct key *instkey, *dest_keyring;
1016	size_t plen = from ? iov_iter_count(from) : 0;
1017	void *payload;
1018	long ret;
1019
1020	kenter("%d,,%zu,%d", id, plen, ringid);
1021
1022	if (!plen)
1023		from = NULL;
1024
1025	ret = -EINVAL;
1026	if (plen > 1024 * 1024 - 1)
1027		goto error;
1028
1029	/* the appropriate instantiation authorisation key must have been
1030	 * assumed before calling this */
1031	ret = -EPERM;
1032	instkey = cred->request_key_auth;
1033	if (!instkey)
1034		goto error;
1035
1036	rka = instkey->payload.data;
1037	if (rka->target_key->serial != id)
1038		goto error;
1039
1040	/* pull the payload in if one was supplied */
1041	payload = NULL;
1042
1043	if (from) {
1044		ret = -ENOMEM;
1045		payload = kmalloc(plen, GFP_KERNEL);
1046		if (!payload) {
1047			if (plen <= PAGE_SIZE)
1048				goto error;
1049			payload = vmalloc(plen);
1050			if (!payload)
1051				goto error;
1052		}
1053
1054		ret = -EFAULT;
1055		if (copy_from_iter(payload, plen, from) != plen)
1056			goto error2;
1057	}
1058
1059	/* find the destination keyring amongst those belonging to the
1060	 * requesting task */
1061	ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1062	if (ret < 0)
1063		goto error2;
1064
1065	/* instantiate the key and link it into a keyring */
1066	ret = key_instantiate_and_link(rka->target_key, payload, plen,
1067				       dest_keyring, instkey);
1068
1069	key_put(dest_keyring);
1070
1071	/* discard the assumed authority if it's just been disabled by
1072	 * instantiation of the key */
1073	if (ret == 0)
1074		keyctl_change_reqkey_auth(NULL);
1075
1076error2:
1077	kvfree(payload);
1078error:
1079	return ret;
1080}
1081
1082/*
1083 * Instantiate a key with the specified payload and link the key into the
1084 * destination keyring if one is given.
1085 *
1086 * The caller must have the appropriate instantiation permit set for this to
1087 * work (see keyctl_assume_authority).  No other permissions are required.
1088 *
1089 * If successful, 0 will be returned.
1090 */
1091long keyctl_instantiate_key(key_serial_t id,
1092			    const void __user *_payload,
1093			    size_t plen,
1094			    key_serial_t ringid)
1095{
1096	if (_payload && plen) {
1097		struct iovec iov;
1098		struct iov_iter from;
1099		int ret;
1100
1101		ret = import_single_range(WRITE, (void __user *)_payload, plen,
1102					  &iov, &from);
1103		if (unlikely(ret))
1104			return ret;
1105
1106		return keyctl_instantiate_key_common(id, &from, ringid);
1107	}
1108
1109	return keyctl_instantiate_key_common(id, NULL, ringid);
1110}
1111
1112/*
1113 * Instantiate a key with the specified multipart payload and link the key into
1114 * the destination keyring if one is given.
1115 *
1116 * The caller must have the appropriate instantiation permit set for this to
1117 * work (see keyctl_assume_authority).  No other permissions are required.
1118 *
1119 * If successful, 0 will be returned.
1120 */
1121long keyctl_instantiate_key_iov(key_serial_t id,
1122				const struct iovec __user *_payload_iov,
1123				unsigned ioc,
1124				key_serial_t ringid)
1125{
1126	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
1127	struct iov_iter from;
1128	long ret;
1129
1130	if (!_payload_iov)
1131		ioc = 0;
1132
1133	ret = import_iovec(WRITE, _payload_iov, ioc,
1134				    ARRAY_SIZE(iovstack), &iov, &from);
1135	if (ret < 0)
1136		return ret;
1137	ret = keyctl_instantiate_key_common(id, &from, ringid);
1138	kfree(iov);
1139	return ret;
1140}
1141
1142/*
1143 * Negatively instantiate the key with the given timeout (in seconds) and link
1144 * the key into the destination keyring if one is given.
1145 *
1146 * The caller must have the appropriate instantiation permit set for this to
1147 * work (see keyctl_assume_authority).  No other permissions are required.
1148 *
1149 * The key and any links to the key will be automatically garbage collected
1150 * after the timeout expires.
1151 *
1152 * Negative keys are used to rate limit repeated request_key() calls by causing
1153 * them to return -ENOKEY until the negative key expires.
1154 *
1155 * If successful, 0 will be returned.
1156 */
1157long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
1158{
1159	return keyctl_reject_key(id, timeout, ENOKEY, ringid);
1160}
1161
1162/*
1163 * Negatively instantiate the key with the given timeout (in seconds) and error
1164 * code and link the key into the destination keyring if one is given.
1165 *
1166 * The caller must have the appropriate instantiation permit set for this to
1167 * work (see keyctl_assume_authority).  No other permissions are required.
1168 *
1169 * The key and any links to the key will be automatically garbage collected
1170 * after the timeout expires.
1171 *
1172 * Negative keys are used to rate limit repeated request_key() calls by causing
1173 * them to return the specified error code until the negative key expires.
1174 *
1175 * If successful, 0 will be returned.
1176 */
1177long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error,
1178		       key_serial_t ringid)
1179{
1180	const struct cred *cred = current_cred();
1181	struct request_key_auth *rka;
1182	struct key *instkey, *dest_keyring;
1183	long ret;
1184
1185	kenter("%d,%u,%u,%d", id, timeout, error, ringid);
1186
1187	/* must be a valid error code and mustn't be a kernel special */
1188	if (error <= 0 ||
1189	    error >= MAX_ERRNO ||
1190	    error == ERESTARTSYS ||
1191	    error == ERESTARTNOINTR ||
1192	    error == ERESTARTNOHAND ||
1193	    error == ERESTART_RESTARTBLOCK)
1194		return -EINVAL;
1195
1196	/* the appropriate instantiation authorisation key must have been
1197	 * assumed before calling this */
1198	ret = -EPERM;
1199	instkey = cred->request_key_auth;
1200	if (!instkey)
1201		goto error;
1202
1203	rka = instkey->payload.data;
1204	if (rka->target_key->serial != id)
1205		goto error;
1206
1207	/* find the destination keyring if present (which must also be
1208	 * writable) */
1209	ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1210	if (ret < 0)
1211		goto error;
1212
1213	/* instantiate the key and link it into a keyring */
1214	ret = key_reject_and_link(rka->target_key, timeout, error,
1215				  dest_keyring, instkey);
1216
1217	key_put(dest_keyring);
1218
1219	/* discard the assumed authority if it's just been disabled by
1220	 * instantiation of the key */
1221	if (ret == 0)
1222		keyctl_change_reqkey_auth(NULL);
1223
1224error:
1225	return ret;
1226}
1227
1228/*
1229 * Read or set the default keyring in which request_key() will cache keys and
1230 * return the old setting.
1231 *
1232 * If a process keyring is specified then this will be created if it doesn't
1233 * yet exist.  The old setting will be returned if successful.
1234 */
1235long keyctl_set_reqkey_keyring(int reqkey_defl)
1236{
1237	struct cred *new;
1238	int ret, old_setting;
1239
1240	old_setting = current_cred_xxx(jit_keyring);
1241
1242	if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
1243		return old_setting;
1244
1245	new = prepare_creds();
1246	if (!new)
1247		return -ENOMEM;
1248
1249	switch (reqkey_defl) {
1250	case KEY_REQKEY_DEFL_THREAD_KEYRING:
1251		ret = install_thread_keyring_to_cred(new);
1252		if (ret < 0)
1253			goto error;
1254		goto set;
1255
1256	case KEY_REQKEY_DEFL_PROCESS_KEYRING:
1257		ret = install_process_keyring_to_cred(new);
1258		if (ret < 0) {
1259			if (ret != -EEXIST)
1260				goto error;
1261			ret = 0;
1262		}
1263		goto set;
1264
1265	case KEY_REQKEY_DEFL_DEFAULT:
1266	case KEY_REQKEY_DEFL_SESSION_KEYRING:
1267	case KEY_REQKEY_DEFL_USER_KEYRING:
1268	case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
1269	case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
1270		goto set;
1271
1272	case KEY_REQKEY_DEFL_NO_CHANGE:
1273	case KEY_REQKEY_DEFL_GROUP_KEYRING:
1274	default:
1275		ret = -EINVAL;
1276		goto error;
1277	}
1278
1279set:
1280	new->jit_keyring = reqkey_defl;
1281	commit_creds(new);
1282	return old_setting;
1283error:
1284	abort_creds(new);
1285	return ret;
1286}
1287
1288/*
1289 * Set or clear the timeout on a key.
1290 *
1291 * Either the key must grant the caller Setattr permission or else the caller
1292 * must hold an instantiation authorisation token for the key.
1293 *
1294 * The timeout is either 0 to clear the timeout, or a number of seconds from
1295 * the current time.  The key and any links to the key will be automatically
1296 * garbage collected after the timeout expires.
1297 *
1298 * If successful, 0 is returned.
1299 */
1300long keyctl_set_timeout(key_serial_t id, unsigned timeout)
1301{
1302	struct key *key, *instkey;
1303	key_ref_t key_ref;
1304	long ret;
1305
1306	key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
1307				  KEY_NEED_SETATTR);
1308	if (IS_ERR(key_ref)) {
1309		/* setting the timeout on a key under construction is permitted
1310		 * if we have the authorisation token handy */
1311		if (PTR_ERR(key_ref) == -EACCES) {
1312			instkey = key_get_instantiation_authkey(id);
1313			if (!IS_ERR(instkey)) {
1314				key_put(instkey);
1315				key_ref = lookup_user_key(id,
1316							  KEY_LOOKUP_PARTIAL,
1317							  0);
1318				if (!IS_ERR(key_ref))
1319					goto okay;
1320			}
1321		}
1322
1323		ret = PTR_ERR(key_ref);
1324		goto error;
1325	}
1326
1327okay:
1328	key = key_ref_to_ptr(key_ref);
1329	key_set_timeout(key, timeout);
1330	key_put(key);
1331
1332	ret = 0;
1333error:
1334	return ret;
1335}
1336
1337/*
1338 * Assume (or clear) the authority to instantiate the specified key.
1339 *
1340 * This sets the authoritative token currently in force for key instantiation.
1341 * This must be done for a key to be instantiated.  It has the effect of making
1342 * available all the keys from the caller of the request_key() that created a
1343 * key to request_key() calls made by the caller of this function.
1344 *
1345 * The caller must have the instantiation key in their process keyrings with a
1346 * Search permission grant available to the caller.
1347 *
1348 * If the ID given is 0, then the setting will be cleared and 0 returned.
1349 *
1350 * If the ID given has a matching an authorisation key, then that key will be
1351 * set and its ID will be returned.  The authorisation key can be read to get
1352 * the callout information passed to request_key().
1353 */
1354long keyctl_assume_authority(key_serial_t id)
1355{
1356	struct key *authkey;
1357	long ret;
1358
1359	/* special key IDs aren't permitted */
1360	ret = -EINVAL;
1361	if (id < 0)
1362		goto error;
1363
1364	/* we divest ourselves of authority if given an ID of 0 */
1365	if (id == 0) {
1366		ret = keyctl_change_reqkey_auth(NULL);
1367		goto error;
1368	}
1369
1370	/* attempt to assume the authority temporarily granted to us whilst we
1371	 * instantiate the specified key
1372	 * - the authorisation key must be in the current task's keyrings
1373	 *   somewhere
1374	 */
1375	authkey = key_get_instantiation_authkey(id);
1376	if (IS_ERR(authkey)) {
1377		ret = PTR_ERR(authkey);
1378		goto error;
1379	}
1380
1381	ret = keyctl_change_reqkey_auth(authkey);
1382	if (ret < 0)
1383		goto error;
1384	key_put(authkey);
1385
1386	ret = authkey->serial;
1387error:
1388	return ret;
1389}
1390
1391/*
1392 * Get a key's the LSM security label.
1393 *
1394 * The key must grant the caller View permission for this to work.
1395 *
1396 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1397 *
1398 * If successful, the amount of information available will be returned,
1399 * irrespective of how much was copied (including the terminal NUL).
1400 */
1401long keyctl_get_security(key_serial_t keyid,
1402			 char __user *buffer,
1403			 size_t buflen)
1404{
1405	struct key *key, *instkey;
1406	key_ref_t key_ref;
1407	char *context;
1408	long ret;
1409
1410	key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW);
1411	if (IS_ERR(key_ref)) {
1412		if (PTR_ERR(key_ref) != -EACCES)
1413			return PTR_ERR(key_ref);
1414
1415		/* viewing a key under construction is also permitted if we
1416		 * have the authorisation token handy */
1417		instkey = key_get_instantiation_authkey(keyid);
1418		if (IS_ERR(instkey))
1419			return PTR_ERR(instkey);
1420		key_put(instkey);
1421
1422		key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
1423		if (IS_ERR(key_ref))
1424			return PTR_ERR(key_ref);
1425	}
1426
1427	key = key_ref_to_ptr(key_ref);
1428	ret = security_key_getsecurity(key, &context);
1429	if (ret == 0) {
1430		/* if no information was returned, give userspace an empty
1431		 * string */
1432		ret = 1;
1433		if (buffer && buflen > 0 &&
1434		    copy_to_user(buffer, "", 1) != 0)
1435			ret = -EFAULT;
1436	} else if (ret > 0) {
1437		/* return as much data as there's room for */
1438		if (buffer && buflen > 0) {
1439			if (buflen > ret)
1440				buflen = ret;
1441
1442			if (copy_to_user(buffer, context, buflen) != 0)
1443				ret = -EFAULT;
1444		}
1445
1446		kfree(context);
1447	}
1448
1449	key_ref_put(key_ref);
1450	return ret;
1451}
1452
1453/*
1454 * Attempt to install the calling process's session keyring on the process's
1455 * parent process.
1456 *
1457 * The keyring must exist and must grant the caller LINK permission, and the
1458 * parent process must be single-threaded and must have the same effective
1459 * ownership as this process and mustn't be SUID/SGID.
1460 *
1461 * The keyring will be emplaced on the parent when it next resumes userspace.
1462 *
1463 * If successful, 0 will be returned.
1464 */
1465long keyctl_session_to_parent(void)
1466{
1467	struct task_struct *me, *parent;
1468	const struct cred *mycred, *pcred;
1469	struct callback_head *newwork, *oldwork;
1470	key_ref_t keyring_r;
1471	struct cred *cred;
1472	int ret;
1473
1474	keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_NEED_LINK);
1475	if (IS_ERR(keyring_r))
1476		return PTR_ERR(keyring_r);
1477
1478	ret = -ENOMEM;
1479
1480	/* our parent is going to need a new cred struct, a new tgcred struct
1481	 * and new security data, so we allocate them here to prevent ENOMEM in
1482	 * our parent */
1483	cred = cred_alloc_blank();
1484	if (!cred)
1485		goto error_keyring;
1486	newwork = &cred->rcu;
1487
1488	cred->session_keyring = key_ref_to_ptr(keyring_r);
1489	keyring_r = NULL;
1490	init_task_work(newwork, key_change_session_keyring);
1491
1492	me = current;
1493	rcu_read_lock();
1494	write_lock_irq(&tasklist_lock);
1495
1496	ret = -EPERM;
1497	oldwork = NULL;
1498	parent = me->real_parent;
1499
1500	/* the parent mustn't be init and mustn't be a kernel thread */
1501	if (parent->pid <= 1 || !parent->mm)
1502		goto unlock;
1503
1504	/* the parent must be single threaded */
1505	if (!thread_group_empty(parent))
1506		goto unlock;
1507
1508	/* the parent and the child must have different session keyrings or
1509	 * there's no point */
1510	mycred = current_cred();
1511	pcred = __task_cred(parent);
1512	if (mycred == pcred ||
1513	    mycred->session_keyring == pcred->session_keyring) {
1514		ret = 0;
1515		goto unlock;
1516	}
1517
1518	/* the parent must have the same effective ownership and mustn't be
1519	 * SUID/SGID */
1520	if (!uid_eq(pcred->uid,	 mycred->euid) ||
1521	    !uid_eq(pcred->euid, mycred->euid) ||
1522	    !uid_eq(pcred->suid, mycred->euid) ||
1523	    !gid_eq(pcred->gid,	 mycred->egid) ||
1524	    !gid_eq(pcred->egid, mycred->egid) ||
1525	    !gid_eq(pcred->sgid, mycred->egid))
1526		goto unlock;
1527
1528	/* the keyrings must have the same UID */
1529	if ((pcred->session_keyring &&
1530	     !uid_eq(pcred->session_keyring->uid, mycred->euid)) ||
1531	    !uid_eq(mycred->session_keyring->uid, mycred->euid))
1532		goto unlock;
1533
1534	/* cancel an already pending keyring replacement */
1535	oldwork = task_work_cancel(parent, key_change_session_keyring);
1536
1537	/* the replacement session keyring is applied just prior to userspace
1538	 * restarting */
1539	ret = task_work_add(parent, newwork, true);
1540	if (!ret)
1541		newwork = NULL;
1542unlock:
1543	write_unlock_irq(&tasklist_lock);
1544	rcu_read_unlock();
1545	if (oldwork)
1546		put_cred(container_of(oldwork, struct cred, rcu));
1547	if (newwork)
1548		put_cred(cred);
1549	return ret;
1550
1551error_keyring:
1552	key_ref_put(keyring_r);
1553	return ret;
1554}
1555
1556/*
1557 * The key control system call
1558 */
1559SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
1560		unsigned long, arg4, unsigned long, arg5)
1561{
1562	switch (option) {
1563	case KEYCTL_GET_KEYRING_ID:
1564		return keyctl_get_keyring_ID((key_serial_t) arg2,
1565					     (int) arg3);
1566
1567	case KEYCTL_JOIN_SESSION_KEYRING:
1568		return keyctl_join_session_keyring((const char __user *) arg2);
1569
1570	case KEYCTL_UPDATE:
1571		return keyctl_update_key((key_serial_t) arg2,
1572					 (const void __user *) arg3,
1573					 (size_t) arg4);
1574
1575	case KEYCTL_REVOKE:
1576		return keyctl_revoke_key((key_serial_t) arg2);
1577
1578	case KEYCTL_DESCRIBE:
1579		return keyctl_describe_key((key_serial_t) arg2,
1580					   (char __user *) arg3,
1581					   (unsigned) arg4);
1582
1583	case KEYCTL_CLEAR:
1584		return keyctl_keyring_clear((key_serial_t) arg2);
1585
1586	case KEYCTL_LINK:
1587		return keyctl_keyring_link((key_serial_t) arg2,
1588					   (key_serial_t) arg3);
1589
1590	case KEYCTL_UNLINK:
1591		return keyctl_keyring_unlink((key_serial_t) arg2,
1592					     (key_serial_t) arg3);
1593
1594	case KEYCTL_SEARCH:
1595		return keyctl_keyring_search((key_serial_t) arg2,
1596					     (const char __user *) arg3,
1597					     (const char __user *) arg4,
1598					     (key_serial_t) arg5);
1599
1600	case KEYCTL_READ:
1601		return keyctl_read_key((key_serial_t) arg2,
1602				       (char __user *) arg3,
1603				       (size_t) arg4);
1604
1605	case KEYCTL_CHOWN:
1606		return keyctl_chown_key((key_serial_t) arg2,
1607					(uid_t) arg3,
1608					(gid_t) arg4);
1609
1610	case KEYCTL_SETPERM:
1611		return keyctl_setperm_key((key_serial_t) arg2,
1612					  (key_perm_t) arg3);
1613
1614	case KEYCTL_INSTANTIATE:
1615		return keyctl_instantiate_key((key_serial_t) arg2,
1616					      (const void __user *) arg3,
1617					      (size_t) arg4,
1618					      (key_serial_t) arg5);
1619
1620	case KEYCTL_NEGATE:
1621		return keyctl_negate_key((key_serial_t) arg2,
1622					 (unsigned) arg3,
1623					 (key_serial_t) arg4);
1624
1625	case KEYCTL_SET_REQKEY_KEYRING:
1626		return keyctl_set_reqkey_keyring(arg2);
1627
1628	case KEYCTL_SET_TIMEOUT:
1629		return keyctl_set_timeout((key_serial_t) arg2,
1630					  (unsigned) arg3);
1631
1632	case KEYCTL_ASSUME_AUTHORITY:
1633		return keyctl_assume_authority((key_serial_t) arg2);
1634
1635	case KEYCTL_GET_SECURITY:
1636		return keyctl_get_security((key_serial_t) arg2,
1637					   (char __user *) arg3,
1638					   (size_t) arg4);
1639
1640	case KEYCTL_SESSION_TO_PARENT:
1641		return keyctl_session_to_parent();
1642
1643	case KEYCTL_REJECT:
1644		return keyctl_reject_key((key_serial_t) arg2,
1645					 (unsigned) arg3,
1646					 (unsigned) arg4,
1647					 (key_serial_t) arg5);
1648
1649	case KEYCTL_INSTANTIATE_IOV:
1650		return keyctl_instantiate_key_iov(
1651			(key_serial_t) arg2,
1652			(const struct iovec __user *) arg3,
1653			(unsigned) arg4,
1654			(key_serial_t) arg5);
1655
1656	case KEYCTL_INVALIDATE:
1657		return keyctl_invalidate_key((key_serial_t) arg2);
1658
1659	case KEYCTL_GET_PERSISTENT:
1660		return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3);
1661
1662	default:
1663		return -EOPNOTSUPP;
1664	}
1665}
1666