blob: ed73c6c1c326c02bf0f4f80923e4792f292ec2fd [file] [log] [blame]
David Howells973c9f42011-01-20 16:38:33 +00001/* Userspace key control operations
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
David Howells3e301482005-06-23 22:00:56 -07003 * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * 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>
Bryan Schumaker59e6b9c2012-02-24 14:14:50 -050017#include <linux/key.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/keyctl.h>
19#include <linux/fs.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080020#include <linux/capability.h>
Davi Arnaut0cb409d2006-03-24 03:18:43 -080021#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/err.h>
David Howells38bbca62008-04-29 01:01:19 -070023#include <linux/vmalloc.h>
David Howells70a5bb72008-04-29 01:01:26 -070024#include <linux/security.h>
Kent Overstreeta27bb332013-05-07 16:19:08 -070025#include <linux/uio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <asm/uaccess.h>
27#include "internal.h"
28
David Howellsaa9d4432014-12-01 22:52:45 +000029#define KEY_MAX_DESC_SIZE 4096
30
Davi Arnaut0cb409d2006-03-24 03:18:43 -080031static 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);
Davi Arnaut0cb409d2006-03-24 03:18:43 -080038 if (ret < 0)
Dan Carpenter4303ef12010-06-11 17:30:05 +010039 return ret;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080040 if (ret == 0 || ret >= len)
41 return -EINVAL;
David Howells54e2c2c2014-09-16 17:29:03 +010042 if (type[0] == '.')
43 return -EPERM;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080044 type[len - 1] = '\0';
Davi Arnaut0cb409d2006-03-24 03:18:43 -080045 return 0;
46}
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048/*
David Howells973c9f42011-01-20 16:38:33 +000049 * 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 *
David Howellscf7f6012012-09-13 13:06:29 +010052 * If the description is NULL or an empty string, the key type is asked to
53 * generate one from the payload.
54 *
David Howells973c9f42011-01-20 16:38:33 +000055 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +010060SYSCALL_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)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065{
David Howells664cceb2005-09-28 17:03:15 +010066 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 char type[32], *description;
68 void *payload;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080069 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
71 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -070072 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 goto error;
74
75 /* draw all the data into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -080076 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 if (ret < 0)
78 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
David Howellscf7f6012012-09-13 13:06:29 +010080 description = NULL;
81 if (_description) {
David Howellsaa9d4432014-12-01 22:52:45 +000082 description = strndup_user(_description, KEY_MAX_DESC_SIZE);
David Howellscf7f6012012-09-13 13:06:29 +010083 if (IS_ERR(description)) {
84 ret = PTR_ERR(description);
85 goto error;
86 }
87 if (!*description) {
88 kfree(description);
89 description = NULL;
Mimi Zohara4e3b8d2014-05-22 14:02:23 -040090 } else if ((description[0] == '.') &&
91 (strncmp(type, "keyring", 7) == 0)) {
92 ret = -EPERM;
93 goto error2;
David Howellscf7f6012012-09-13 13:06:29 +010094 }
Davi Arnaut0cb409d2006-03-24 03:18:43 -080095 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97 /* pull the payload in if one was supplied */
98 payload = NULL;
99
100 if (_payload) {
101 ret = -ENOMEM;
Andrew Morton4f1c28d2012-05-31 16:26:02 -0700102 payload = kmalloc(plen, GFP_KERNEL | __GFP_NOWARN);
David Howells38bbca62008-04-29 01:01:19 -0700103 if (!payload) {
104 if (plen <= PAGE_SIZE)
105 goto error2;
David Howells38bbca62008-04-29 01:01:19 -0700106 payload = vmalloc(plen);
107 if (!payload)
108 goto error2;
109 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
111 ret = -EFAULT;
112 if (copy_from_user(payload, _payload, plen) != 0)
113 goto error3;
114 }
115
116 /* find the target keyring (which must be writable) */
David Howellsf5895942014-03-14 17:44:49 +0000117 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100118 if (IS_ERR(keyring_ref)) {
119 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 goto error3;
121 }
122
123 /* create or update the requested key and add it to the target
124 * keyring */
David Howells664cceb2005-09-28 17:03:15 +0100125 key_ref = key_create_or_update(keyring_ref, type, description,
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700126 payload, plen, KEY_PERM_UNDEF,
127 KEY_ALLOC_IN_QUOTA);
David Howells664cceb2005-09-28 17:03:15 +0100128 if (!IS_ERR(key_ref)) {
129 ret = key_ref_to_ptr(key_ref)->serial;
130 key_ref_put(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 }
132 else {
David Howells664cceb2005-09-28 17:03:15 +0100133 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 }
135
David Howells664cceb2005-09-28 17:03:15 +0100136 key_ref_put(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 error3:
Geliang Tangd0e0eba2015-10-21 14:04:46 +0100138 kvfree(payload);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 error2:
140 kfree(description);
141 error:
142 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000143}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145/*
David Howells973c9f42011-01-20 16:38:33 +0000146 * Search the process keyrings and keyring trees linked from those for a
147 * matching key. Keyrings must have appropriate Search permission to be
148 * searched.
149 *
150 * If a key is found, it will be attached to the destination keyring if there's
151 * one specified and the serial number of the key will be returned.
152 *
153 * If no key is found, /sbin/request-key will be invoked if _callout_info is
154 * non-NULL in an attempt to create a key. The _callout_info string will be
155 * passed to /sbin/request-key to aid with completing the request. If the
156 * _callout_info string is "" then it will be changed to "-".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +0100158SYSCALL_DEFINE4(request_key, const char __user *, _type,
159 const char __user *, _description,
160 const char __user *, _callout_info,
161 key_serial_t, destringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162{
163 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100164 struct key *key;
165 key_ref_t dest_ref;
David Howells4a38e122008-04-29 01:01:24 -0700166 size_t callout_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 char type[32], *description, *callout_info;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800168 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170 /* pull the type into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800171 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 if (ret < 0)
173 goto error;
David Howells1260f802005-08-04 11:50:01 +0100174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 /* pull the description into kernel space */
David Howellsaa9d4432014-12-01 22:52:45 +0000176 description = strndup_user(_description, KEY_MAX_DESC_SIZE);
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800177 if (IS_ERR(description)) {
178 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800180 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182 /* pull the callout info into kernel space */
183 callout_info = NULL;
David Howells4a38e122008-04-29 01:01:24 -0700184 callout_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 if (_callout_info) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800186 callout_info = strndup_user(_callout_info, PAGE_SIZE);
187 if (IS_ERR(callout_info)) {
188 ret = PTR_ERR(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 goto error2;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800190 }
David Howells4a38e122008-04-29 01:01:24 -0700191 callout_len = strlen(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 }
193
194 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100195 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100197 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
David Howellsf5895942014-03-14 17:44:49 +0000198 KEY_NEED_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100199 if (IS_ERR(dest_ref)) {
200 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 goto error3;
202 }
203 }
204
205 /* find the key type */
206 ktype = key_type_lookup(type);
207 if (IS_ERR(ktype)) {
208 ret = PTR_ERR(ktype);
209 goto error4;
210 }
211
212 /* do the search */
David Howells4a38e122008-04-29 01:01:24 -0700213 key = request_key_and_link(ktype, description, callout_info,
214 callout_len, NULL, key_ref_to_ptr(dest_ref),
David Howells7e047ef2006-06-26 00:24:50 -0700215 KEY_ALLOC_IN_QUOTA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 if (IS_ERR(key)) {
217 ret = PTR_ERR(key);
218 goto error5;
219 }
220
David Howells4aab1e82011-03-11 17:57:33 +0000221 /* wait for the key to finish being constructed */
222 ret = wait_for_key_construction(key, 1);
223 if (ret < 0)
224 goto error6;
225
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 ret = key->serial;
227
David Howells4aab1e82011-03-11 17:57:33 +0000228error6:
David Howells3e301482005-06-23 22:00:56 -0700229 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700230error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700232error4:
David Howells664cceb2005-09-28 17:03:15 +0100233 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700234error3:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 kfree(callout_info);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700236error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700238error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000240}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242/*
David Howells973c9f42011-01-20 16:38:33 +0000243 * Get the ID of the specified process keyring.
244 *
245 * The requested keyring must have search permission to be found.
246 *
247 * If successful, the ID of the requested keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 */
249long keyctl_get_keyring_ID(key_serial_t id, int create)
250{
David Howells664cceb2005-09-28 17:03:15 +0100251 key_ref_t key_ref;
David Howells55931222009-09-02 09:13:45 +0100252 unsigned long lflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 long ret;
254
David Howells55931222009-09-02 09:13:45 +0100255 lflags = create ? KEY_LOOKUP_CREATE : 0;
David Howellsf5895942014-03-14 17:44:49 +0000256 key_ref = lookup_user_key(id, lflags, KEY_NEED_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100257 if (IS_ERR(key_ref)) {
258 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 goto error;
260 }
261
David Howells664cceb2005-09-28 17:03:15 +0100262 ret = key_ref_to_ptr(key_ref)->serial;
263 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700264error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 return ret;
David Howells973c9f42011-01-20 16:38:33 +0000266}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268/*
David Howells973c9f42011-01-20 16:38:33 +0000269 * Join a (named) session keyring.
270 *
271 * Create and join an anonymous session keyring or join a named session
272 * keyring, creating it if necessary. A named session keyring must have Search
273 * permission for it to be joined. Session keyrings without this permit will
274 * be skipped over.
275 *
276 * If successful, the ID of the joined session keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 */
278long keyctl_join_session_keyring(const char __user *_name)
279{
280 char *name;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800281 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283 /* fetch the name from userspace */
284 name = NULL;
285 if (_name) {
David Howellsaa9d4432014-12-01 22:52:45 +0000286 name = strndup_user(_name, KEY_MAX_DESC_SIZE);
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800287 if (IS_ERR(name)) {
288 ret = PTR_ERR(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800290 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 }
292
293 /* join the session */
294 ret = join_session_keyring(name);
Vegard Nossum0d54ee12009-01-17 17:45:45 +0100295 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700297error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000299}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301/*
David Howells973c9f42011-01-20 16:38:33 +0000302 * Update a key's data payload from the given data.
303 *
304 * The key must grant the caller Write permission and the key type must support
305 * updating for this to work. A negative key can be positively instantiated
306 * with this call.
307 *
308 * If successful, 0 will be returned. If the key type does not support
309 * updating, then -EOPNOTSUPP will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 */
311long keyctl_update_key(key_serial_t id,
312 const void __user *_payload,
313 size_t plen)
314{
David Howells664cceb2005-09-28 17:03:15 +0100315 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 void *payload;
317 long ret;
318
319 ret = -EINVAL;
320 if (plen > PAGE_SIZE)
321 goto error;
322
323 /* pull the payload in if one was supplied */
324 payload = NULL;
325 if (_payload) {
326 ret = -ENOMEM;
327 payload = kmalloc(plen, GFP_KERNEL);
328 if (!payload)
329 goto error;
330
331 ret = -EFAULT;
332 if (copy_from_user(payload, _payload, plen) != 0)
333 goto error2;
334 }
335
336 /* find the target key (which must be writable) */
David Howellsf5895942014-03-14 17:44:49 +0000337 key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100338 if (IS_ERR(key_ref)) {
339 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 goto error2;
341 }
342
343 /* update the key */
David Howells664cceb2005-09-28 17:03:15 +0100344 ret = key_update(key_ref, payload, plen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
David Howells664cceb2005-09-28 17:03:15 +0100346 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700347error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 kfree(payload);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700349error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000351}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353/*
David Howells973c9f42011-01-20 16:38:33 +0000354 * Revoke a key.
355 *
356 * The key must be grant the caller Write or Setattr permission for this to
357 * work. The key type should give up its quota claim when revoked. The key
358 * and any links to the key will be automatically garbage collected after a
359 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
360 *
Mimi Zohard3600bc2015-11-10 08:34:46 -0500361 * Keys with KEY_FLAG_KEEP set should not be revoked.
362 *
David Howells973c9f42011-01-20 16:38:33 +0000363 * If successful, 0 is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 */
365long keyctl_revoke_key(key_serial_t id)
366{
David Howells664cceb2005-09-28 17:03:15 +0100367 key_ref_t key_ref;
Mimi Zohard3600bc2015-11-10 08:34:46 -0500368 struct key *key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 long ret;
370
David Howellsf5895942014-03-14 17:44:49 +0000371 key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100372 if (IS_ERR(key_ref)) {
373 ret = PTR_ERR(key_ref);
David Howells0c2c9a32009-09-02 09:13:50 +0100374 if (ret != -EACCES)
375 goto error;
David Howellsf5895942014-03-14 17:44:49 +0000376 key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR);
David Howells0c2c9a32009-09-02 09:13:50 +0100377 if (IS_ERR(key_ref)) {
378 ret = PTR_ERR(key_ref);
379 goto error;
380 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 }
382
Mimi Zohard3600bc2015-11-10 08:34:46 -0500383 key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 ret = 0;
Mimi Zohard3600bc2015-11-10 08:34:46 -0500385 if (test_bit(KEY_FLAG_KEEP, &key->flags))
Mimi Zohar1d6d1672016-01-07 07:46:36 -0500386 ret = -EPERM;
387 else
Mimi Zohard3600bc2015-11-10 08:34:46 -0500388 key_revoke(key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
David Howells664cceb2005-09-28 17:03:15 +0100390 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700391error:
David Howells1260f802005-08-04 11:50:01 +0100392 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000393}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395/*
David Howellsfd758152012-05-11 10:56:56 +0100396 * Invalidate a key.
397 *
398 * The key must be grant the caller Invalidate permission for this to work.
399 * The key and any links to the key will be automatically garbage collected
400 * immediately.
401 *
Mimi Zohard3600bc2015-11-10 08:34:46 -0500402 * Keys with KEY_FLAG_KEEP set should not be invalidated.
403 *
David Howellsfd758152012-05-11 10:56:56 +0100404 * If successful, 0 is returned.
405 */
406long keyctl_invalidate_key(key_serial_t id)
407{
408 key_ref_t key_ref;
Mimi Zohard3600bc2015-11-10 08:34:46 -0500409 struct key *key;
David Howellsfd758152012-05-11 10:56:56 +0100410 long ret;
411
412 kenter("%d", id);
413
David Howellsf5895942014-03-14 17:44:49 +0000414 key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH);
David Howellsfd758152012-05-11 10:56:56 +0100415 if (IS_ERR(key_ref)) {
416 ret = PTR_ERR(key_ref);
David Howells0c7774a2014-07-17 20:45:08 +0100417
418 /* Root is permitted to invalidate certain special keys */
419 if (capable(CAP_SYS_ADMIN)) {
420 key_ref = lookup_user_key(id, 0, 0);
421 if (IS_ERR(key_ref))
422 goto error;
423 if (test_bit(KEY_FLAG_ROOT_CAN_INVAL,
424 &key_ref_to_ptr(key_ref)->flags))
425 goto invalidate;
426 goto error_put;
427 }
428
David Howellsfd758152012-05-11 10:56:56 +0100429 goto error;
430 }
431
David Howells0c7774a2014-07-17 20:45:08 +0100432invalidate:
Mimi Zohard3600bc2015-11-10 08:34:46 -0500433 key = key_ref_to_ptr(key_ref);
David Howellsfd758152012-05-11 10:56:56 +0100434 ret = 0;
Mimi Zohard3600bc2015-11-10 08:34:46 -0500435 if (test_bit(KEY_FLAG_KEEP, &key->flags))
436 ret = -EPERM;
Mimi Zohar1d6d1672016-01-07 07:46:36 -0500437 else
Mimi Zohard3600bc2015-11-10 08:34:46 -0500438 key_invalidate(key);
David Howells0c7774a2014-07-17 20:45:08 +0100439error_put:
David Howellsfd758152012-05-11 10:56:56 +0100440 key_ref_put(key_ref);
441error:
442 kleave(" = %ld", ret);
443 return ret;
444}
445
446/*
David Howells973c9f42011-01-20 16:38:33 +0000447 * Clear the specified keyring, creating an empty process keyring if one of the
448 * special keyring IDs is used.
449 *
Mimi Zohard3600bc2015-11-10 08:34:46 -0500450 * The keyring must grant the caller Write permission and not have
451 * KEY_FLAG_KEEP set for this to work. If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 */
453long keyctl_keyring_clear(key_serial_t ringid)
454{
David Howells664cceb2005-09-28 17:03:15 +0100455 key_ref_t keyring_ref;
Mimi Zohard3600bc2015-11-10 08:34:46 -0500456 struct key *keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 long ret;
458
David Howellsf5895942014-03-14 17:44:49 +0000459 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100460 if (IS_ERR(keyring_ref)) {
461 ret = PTR_ERR(keyring_ref);
David Howells700920e2012-01-18 15:31:45 +0000462
463 /* Root is permitted to invalidate certain special keyrings */
464 if (capable(CAP_SYS_ADMIN)) {
465 keyring_ref = lookup_user_key(ringid, 0, 0);
466 if (IS_ERR(keyring_ref))
467 goto error;
468 if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR,
469 &key_ref_to_ptr(keyring_ref)->flags))
470 goto clear;
471 goto error_put;
472 }
473
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 goto error;
475 }
476
David Howells700920e2012-01-18 15:31:45 +0000477clear:
Mimi Zohard3600bc2015-11-10 08:34:46 -0500478 keyring = key_ref_to_ptr(keyring_ref);
479 if (test_bit(KEY_FLAG_KEEP, &keyring->flags))
480 ret = -EPERM;
481 else
482 ret = keyring_clear(keyring);
David Howells700920e2012-01-18 15:31:45 +0000483error_put:
David Howells664cceb2005-09-28 17:03:15 +0100484 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700485error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000487}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489/*
David Howells973c9f42011-01-20 16:38:33 +0000490 * Create a link from a keyring to a key if there's no matching key in the
491 * keyring, otherwise replace the link to the matching key with a link to the
492 * new key.
493 *
494 * The key must grant the caller Link permission and the the keyring must grant
495 * the caller Write permission. Furthermore, if an additional link is created,
496 * the keyring's quota will be extended.
497 *
498 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 */
500long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
501{
David Howells664cceb2005-09-28 17:03:15 +0100502 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 long ret;
504
David Howellsf5895942014-03-14 17:44:49 +0000505 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100506 if (IS_ERR(keyring_ref)) {
507 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 goto error;
509 }
510
David Howellsf5895942014-03-14 17:44:49 +0000511 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK);
David Howells664cceb2005-09-28 17:03:15 +0100512 if (IS_ERR(key_ref)) {
513 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 goto error2;
515 }
516
David Howells664cceb2005-09-28 17:03:15 +0100517 ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518
David Howells664cceb2005-09-28 17:03:15 +0100519 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700520error2:
David Howells664cceb2005-09-28 17:03:15 +0100521 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700522error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000524}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526/*
David Howells973c9f42011-01-20 16:38:33 +0000527 * Unlink a key from a keyring.
528 *
529 * The keyring must grant the caller Write permission for this to work; the key
530 * itself need not grant the caller anything. If the last link to a key is
531 * removed then that key will be scheduled for destruction.
532 *
Mimi Zohard3600bc2015-11-10 08:34:46 -0500533 * Keys or keyrings with KEY_FLAG_KEEP set should not be unlinked.
534 *
David Howells973c9f42011-01-20 16:38:33 +0000535 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 */
537long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
538{
David Howells664cceb2005-09-28 17:03:15 +0100539 key_ref_t keyring_ref, key_ref;
Mimi Zohard3600bc2015-11-10 08:34:46 -0500540 struct key *keyring, *key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 long ret;
542
David Howellsf5895942014-03-14 17:44:49 +0000543 keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100544 if (IS_ERR(keyring_ref)) {
545 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 goto error;
547 }
548
David Howells55931222009-09-02 09:13:45 +0100549 key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
David Howells664cceb2005-09-28 17:03:15 +0100550 if (IS_ERR(key_ref)) {
551 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 goto error2;
553 }
554
Mimi Zohard3600bc2015-11-10 08:34:46 -0500555 keyring = key_ref_to_ptr(keyring_ref);
556 key = key_ref_to_ptr(key_ref);
557 if (test_bit(KEY_FLAG_KEEP, &keyring->flags) &&
558 test_bit(KEY_FLAG_KEEP, &key->flags))
559 ret = -EPERM;
560 else
561 ret = key_unlink(keyring, key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
David Howells664cceb2005-09-28 17:03:15 +0100563 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700564error2:
David Howells664cceb2005-09-28 17:03:15 +0100565 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700566error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000568}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570/*
David Howells973c9f42011-01-20 16:38:33 +0000571 * Return a description of a key to userspace.
572 *
573 * The key must grant the caller View permission for this to work.
574 *
575 * If there's a buffer, we place up to buflen bytes of data into it formatted
576 * in the following way:
577 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 * type;uid;gid;perm;description<NUL>
David Howells973c9f42011-01-20 16:38:33 +0000579 *
580 * If successful, we return the amount of description available, irrespective
581 * of how much we may have copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 */
583long keyctl_describe_key(key_serial_t keyid,
584 char __user *buffer,
585 size_t buflen)
586{
David Howells3e301482005-06-23 22:00:56 -0700587 struct key *key, *instkey;
David Howells664cceb2005-09-28 17:03:15 +0100588 key_ref_t key_ref;
David Howellsaa9d4432014-12-01 22:52:45 +0000589 char *infobuf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 long ret;
David Howellsaa9d4432014-12-01 22:52:45 +0000591 int desclen, infolen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592
David Howellsf5895942014-03-14 17:44:49 +0000593 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW);
David Howells664cceb2005-09-28 17:03:15 +0100594 if (IS_ERR(key_ref)) {
David Howells3e301482005-06-23 22:00:56 -0700595 /* viewing a key under construction is permitted if we have the
596 * authorisation token handy */
David Howells664cceb2005-09-28 17:03:15 +0100597 if (PTR_ERR(key_ref) == -EACCES) {
David Howells3e301482005-06-23 22:00:56 -0700598 instkey = key_get_instantiation_authkey(keyid);
599 if (!IS_ERR(instkey)) {
600 key_put(instkey);
David Howells8bbf49762008-11-14 10:39:14 +1100601 key_ref = lookup_user_key(keyid,
David Howells55931222009-09-02 09:13:45 +0100602 KEY_LOOKUP_PARTIAL,
603 0);
David Howells664cceb2005-09-28 17:03:15 +0100604 if (!IS_ERR(key_ref))
David Howells3e301482005-06-23 22:00:56 -0700605 goto okay;
606 }
607 }
608
David Howells664cceb2005-09-28 17:03:15 +0100609 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 goto error;
611 }
612
David Howells3e301482005-06-23 22:00:56 -0700613okay:
David Howells664cceb2005-09-28 17:03:15 +0100614 key = key_ref_to_ptr(key_ref);
David Howellsaa9d4432014-12-01 22:52:45 +0000615 desclen = strlen(key->description);
David Howells664cceb2005-09-28 17:03:15 +0100616
David Howellsaa9d4432014-12-01 22:52:45 +0000617 /* calculate how much information we're going to return */
618 ret = -ENOMEM;
619 infobuf = kasprintf(GFP_KERNEL,
620 "%s;%d;%d;%08x;",
621 key->type->name,
622 from_kuid_munged(current_user_ns(), key->uid),
623 from_kgid_munged(current_user_ns(), key->gid),
624 key->perm);
625 if (!infobuf)
626 goto error2;
627 infolen = strlen(infobuf);
628 ret = infolen + desclen + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630 /* consider returning the data */
David Howellsaa9d4432014-12-01 22:52:45 +0000631 if (buffer && buflen >= ret) {
632 if (copy_to_user(buffer, infobuf, infolen) != 0 ||
633 copy_to_user(buffer + infolen, key->description,
634 desclen + 1) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 ret = -EFAULT;
636 }
637
David Howellsaa9d4432014-12-01 22:52:45 +0000638 kfree(infobuf);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700639error2:
David Howells664cceb2005-09-28 17:03:15 +0100640 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700641error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000643}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645/*
David Howells973c9f42011-01-20 16:38:33 +0000646 * Search the specified keyring and any keyrings it links to for a matching
647 * key. Only keyrings that grant the caller Search permission will be searched
648 * (this includes the starting keyring). Only keys with Search permission can
649 * be found.
650 *
651 * If successful, the found key will be linked to the destination keyring if
652 * supplied and the key has Link permission, and the found key ID will be
653 * returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 */
655long keyctl_keyring_search(key_serial_t ringid,
656 const char __user *_type,
657 const char __user *_description,
658 key_serial_t destringid)
659{
660 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100661 key_ref_t keyring_ref, key_ref, dest_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 char type[32], *description;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800663 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
665 /* pull the type and description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800666 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 if (ret < 0)
668 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
David Howellsaa9d4432014-12-01 22:52:45 +0000670 description = strndup_user(_description, KEY_MAX_DESC_SIZE);
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800671 if (IS_ERR(description)) {
672 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800674 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
676 /* get the keyring at which to begin the search */
David Howellsf5895942014-03-14 17:44:49 +0000677 keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100678 if (IS_ERR(keyring_ref)) {
679 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 goto error2;
681 }
682
683 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100684 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100686 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
David Howellsf5895942014-03-14 17:44:49 +0000687 KEY_NEED_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100688 if (IS_ERR(dest_ref)) {
689 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 goto error3;
691 }
692 }
693
694 /* find the key type */
695 ktype = key_type_lookup(type);
696 if (IS_ERR(ktype)) {
697 ret = PTR_ERR(ktype);
698 goto error4;
699 }
700
701 /* do the search */
David Howells664cceb2005-09-28 17:03:15 +0100702 key_ref = keyring_search(keyring_ref, ktype, description);
703 if (IS_ERR(key_ref)) {
704 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705
706 /* treat lack or presence of a negative key the same */
707 if (ret == -EAGAIN)
708 ret = -ENOKEY;
709 goto error5;
710 }
711
712 /* link the resulting key to the destination keyring if we can */
David Howells664cceb2005-09-28 17:03:15 +0100713 if (dest_ref) {
David Howellsf5895942014-03-14 17:44:49 +0000714 ret = key_permission(key_ref, KEY_NEED_LINK);
David Howells29db9192005-10-30 15:02:44 -0800715 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 goto error6;
717
David Howells664cceb2005-09-28 17:03:15 +0100718 ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 if (ret < 0)
720 goto error6;
721 }
722
David Howells664cceb2005-09-28 17:03:15 +0100723 ret = key_ref_to_ptr(key_ref)->serial;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700725error6:
David Howells664cceb2005-09-28 17:03:15 +0100726 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700727error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700729error4:
David Howells664cceb2005-09-28 17:03:15 +0100730 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700731error3:
David Howells664cceb2005-09-28 17:03:15 +0100732 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700733error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700735error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000737}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739/*
David Howells973c9f42011-01-20 16:38:33 +0000740 * Read a key's payload.
741 *
742 * The key must either grant the caller Read permission, or it must grant the
743 * caller Search permission when searched for from the process keyrings.
744 *
745 * If successful, we place up to buflen bytes of data into the buffer, if one
746 * is provided, and return the amount of data that is available in the key,
747 * irrespective of how much we copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 */
749long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
750{
David Howells664cceb2005-09-28 17:03:15 +0100751 struct key *key;
752 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 long ret;
754
755 /* find the key first */
David Howells55931222009-09-02 09:13:45 +0100756 key_ref = lookup_user_key(keyid, 0, 0);
David Howells664cceb2005-09-28 17:03:15 +0100757 if (IS_ERR(key_ref)) {
758 ret = -ENOKEY;
759 goto error;
760 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761
David Howells664cceb2005-09-28 17:03:15 +0100762 key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763
David Howells664cceb2005-09-28 17:03:15 +0100764 /* see if we can read it directly */
David Howellsf5895942014-03-14 17:44:49 +0000765 ret = key_permission(key_ref, KEY_NEED_READ);
David Howells29db9192005-10-30 15:02:44 -0800766 if (ret == 0)
David Howells664cceb2005-09-28 17:03:15 +0100767 goto can_read_key;
David Howells29db9192005-10-30 15:02:44 -0800768 if (ret != -EACCES)
769 goto error;
David Howells664cceb2005-09-28 17:03:15 +0100770
771 /* we can't; see if it's searchable from this process's keyrings
772 * - we automatically take account of the fact that it may be
773 * dangling off an instantiation key
774 */
775 if (!is_key_possessed(key_ref)) {
776 ret = -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 goto error2;
778 }
779
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 /* the key is probably readable - now try to read it */
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700781can_read_key:
David Howellsb4a1b4f2015-12-18 01:34:26 +0000782 ret = -EOPNOTSUPP;
783 if (key->type->read) {
784 /* Read the data with the semaphore held (since we might sleep)
785 * to protect against the key being updated or revoked.
786 */
787 down_read(&key->sem);
788 ret = key_validate(key);
789 if (ret == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 ret = key->type->read(key, buffer, buflen);
David Howellsb4a1b4f2015-12-18 01:34:26 +0000791 up_read(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 }
793
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700794error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700796error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000798}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800/*
David Howells973c9f42011-01-20 16:38:33 +0000801 * Change the ownership of a key
802 *
803 * The key must grant the caller Setattr permission for this to work, though
804 * the key need not be fully instantiated yet. For the UID to be changed, or
805 * for the GID to be changed to a group the caller is not a member of, the
806 * caller must have sysadmin capability. If either uid or gid is -1 then that
807 * attribute is not changed.
808 *
809 * If the UID is to be changed, the new user must have sufficient quota to
810 * accept the key. The quota deduction will be removed from the old user to
811 * the new user should the attribute be changed.
812 *
813 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800815long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816{
Fredrik Tolf58016492006-06-26 00:24:51 -0700817 struct key_user *newowner, *zapowner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100819 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 long ret;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800821 kuid_t uid;
822 kgid_t gid;
823
824 uid = make_kuid(current_user_ns(), user);
825 gid = make_kgid(current_user_ns(), group);
826 ret = -EINVAL;
827 if ((user != (uid_t) -1) && !uid_valid(uid))
828 goto error;
829 if ((group != (gid_t) -1) && !gid_valid(gid))
830 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831
832 ret = 0;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800833 if (user == (uid_t) -1 && group == (gid_t) -1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 goto error;
835
David Howells55931222009-09-02 09:13:45 +0100836 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
David Howellsf5895942014-03-14 17:44:49 +0000837 KEY_NEED_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100838 if (IS_ERR(key_ref)) {
839 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 goto error;
841 }
842
David Howells664cceb2005-09-28 17:03:15 +0100843 key = key_ref_to_ptr(key_ref);
844
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 /* make the changes with the locks held to prevent chown/chown races */
846 ret = -EACCES;
847 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848
849 if (!capable(CAP_SYS_ADMIN)) {
850 /* only the sysadmin can chown a key to some other UID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800851 if (user != (uid_t) -1 && !uid_eq(key->uid, uid))
Fredrik Tolf58016492006-06-26 00:24:51 -0700852 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853
854 /* only the sysadmin can set the key's GID to a group other
855 * than one of those that the current process subscribes to */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800856 if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid))
Fredrik Tolf58016492006-06-26 00:24:51 -0700857 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 }
859
Fredrik Tolf58016492006-06-26 00:24:51 -0700860 /* change the UID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800861 if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) {
Fredrik Tolf58016492006-06-26 00:24:51 -0700862 ret = -ENOMEM;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800863 newowner = key_user_lookup(uid);
Fredrik Tolf58016492006-06-26 00:24:51 -0700864 if (!newowner)
865 goto error_put;
866
867 /* transfer the quota burden to the new user */
868 if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800869 unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ?
David Howells0b77f5b2008-04-29 01:01:32 -0700870 key_quota_root_maxkeys : key_quota_maxkeys;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800871 unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ?
David Howells0b77f5b2008-04-29 01:01:32 -0700872 key_quota_root_maxbytes : key_quota_maxbytes;
873
Fredrik Tolf58016492006-06-26 00:24:51 -0700874 spin_lock(&newowner->lock);
David Howells0b77f5b2008-04-29 01:01:32 -0700875 if (newowner->qnkeys + 1 >= maxkeys ||
876 newowner->qnbytes + key->quotalen >= maxbytes ||
877 newowner->qnbytes + key->quotalen <
878 newowner->qnbytes)
Fredrik Tolf58016492006-06-26 00:24:51 -0700879 goto quota_overrun;
880
881 newowner->qnkeys++;
882 newowner->qnbytes += key->quotalen;
883 spin_unlock(&newowner->lock);
884
885 spin_lock(&key->user->lock);
886 key->user->qnkeys--;
887 key->user->qnbytes -= key->quotalen;
888 spin_unlock(&key->user->lock);
889 }
890
891 atomic_dec(&key->user->nkeys);
892 atomic_inc(&newowner->nkeys);
893
894 if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
895 atomic_dec(&key->user->nikeys);
896 atomic_inc(&newowner->nikeys);
897 }
898
899 zapowner = key->user;
900 key->user = newowner;
901 key->uid = uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 }
903
904 /* change the GID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800905 if (group != (gid_t) -1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 key->gid = gid;
907
908 ret = 0;
909
Fredrik Tolf58016492006-06-26 00:24:51 -0700910error_put:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 up_write(&key->sem);
912 key_put(key);
Fredrik Tolf58016492006-06-26 00:24:51 -0700913 if (zapowner)
914 key_user_put(zapowner);
915error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 return ret;
917
Fredrik Tolf58016492006-06-26 00:24:51 -0700918quota_overrun:
919 spin_unlock(&newowner->lock);
920 zapowner = newowner;
921 ret = -EDQUOT;
922 goto error_put;
David Howellsa8b17ed2011-01-20 16:38:27 +0000923}
Fredrik Tolf58016492006-06-26 00:24:51 -0700924
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925/*
David Howells973c9f42011-01-20 16:38:33 +0000926 * Change the permission mask on a key.
927 *
928 * The key must grant the caller Setattr permission for this to work, though
929 * the key need not be fully instantiated yet. If the caller does not have
930 * sysadmin capability, it may only change the permission on keys that it owns.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 */
932long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
933{
934 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100935 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 long ret;
937
938 ret = -EINVAL;
David Howells664cceb2005-09-28 17:03:15 +0100939 if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940 goto error;
941
David Howells55931222009-09-02 09:13:45 +0100942 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
David Howellsf5895942014-03-14 17:44:49 +0000943 KEY_NEED_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100944 if (IS_ERR(key_ref)) {
945 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 goto error;
947 }
948
David Howells664cceb2005-09-28 17:03:15 +0100949 key = key_ref_to_ptr(key_ref);
950
David Howells76d8aea2005-06-23 22:00:49 -0700951 /* make the changes with the locks held to prevent chown/chmod races */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 ret = -EACCES;
953 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
David Howells76d8aea2005-06-23 22:00:49 -0700955 /* if we're not the sysadmin, we can only change a key that we own */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800956 if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) {
David Howells76d8aea2005-06-23 22:00:49 -0700957 key->perm = perm;
958 ret = 0;
959 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 up_write(&key->sem);
962 key_put(key);
David Howells76d8aea2005-06-23 22:00:49 -0700963error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000965}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966
David Howells8bbf49762008-11-14 10:39:14 +1100967/*
David Howells973c9f42011-01-20 16:38:33 +0000968 * Get the destination keyring for instantiation and check that the caller has
969 * Write permission on it.
David Howells8bbf49762008-11-14 10:39:14 +1100970 */
971static long get_instantiation_keyring(key_serial_t ringid,
972 struct request_key_auth *rka,
973 struct key **_dest_keyring)
974{
975 key_ref_t dkref;
976
David Howellseca1bf52008-12-29 00:41:51 +0000977 *_dest_keyring = NULL;
978
David Howells8bbf49762008-11-14 10:39:14 +1100979 /* just return a NULL pointer if we weren't asked to make a link */
David Howellseca1bf52008-12-29 00:41:51 +0000980 if (ringid == 0)
David Howells8bbf49762008-11-14 10:39:14 +1100981 return 0;
David Howells8bbf49762008-11-14 10:39:14 +1100982
983 /* if a specific keyring is nominated by ID, then use that */
984 if (ringid > 0) {
David Howellsf5895942014-03-14 17:44:49 +0000985 dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE);
David Howells8bbf49762008-11-14 10:39:14 +1100986 if (IS_ERR(dkref))
987 return PTR_ERR(dkref);
988 *_dest_keyring = key_ref_to_ptr(dkref);
989 return 0;
990 }
991
992 if (ringid == KEY_SPEC_REQKEY_AUTH_KEY)
993 return -EINVAL;
994
995 /* otherwise specify the destination keyring recorded in the
996 * authorisation key (any KEY_SPEC_*_KEYRING) */
997 if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) {
David Howells21279cf2009-10-15 10:14:35 +0100998 *_dest_keyring = key_get(rka->dest_keyring);
David Howells8bbf49762008-11-14 10:39:14 +1100999 return 0;
1000 }
1001
1002 return -ENOKEY;
1003}
1004
David Howellsd84f4f92008-11-14 10:39:23 +11001005/*
David Howells973c9f42011-01-20 16:38:33 +00001006 * Change the request_key authorisation key on the current process.
David Howellsd84f4f92008-11-14 10:39:23 +11001007 */
1008static int keyctl_change_reqkey_auth(struct key *key)
1009{
1010 struct cred *new;
1011
1012 new = prepare_creds();
1013 if (!new)
1014 return -ENOMEM;
1015
1016 key_put(new->request_key_auth);
1017 new->request_key_auth = key_get(key);
1018
1019 return commit_creds(new);
1020}
1021
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022/*
David Howells973c9f42011-01-20 16:38:33 +00001023 * Instantiate a key with the specified payload and link the key into the
1024 * destination keyring if one is given.
1025 *
1026 * The caller must have the appropriate instantiation permit set for this to
1027 * work (see keyctl_assume_authority). No other permissions are required.
1028 *
1029 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 */
David Howellsee009e4a02011-03-07 15:06:20 +00001031long keyctl_instantiate_key_common(key_serial_t id,
Al Virob353a1f2015-03-17 09:59:38 -04001032 struct iov_iter *from,
David Howellsee009e4a02011-03-07 15:06:20 +00001033 key_serial_t ringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034{
David Howellsd84f4f92008-11-14 10:39:23 +11001035 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -07001036 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +11001037 struct key *instkey, *dest_keyring;
Al Virob353a1f2015-03-17 09:59:38 -04001038 size_t plen = from ? iov_iter_count(from) : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 void *payload;
1040 long ret;
1041
David Howellsd84f4f92008-11-14 10:39:23 +11001042 kenter("%d,,%zu,%d", id, plen, ringid);
1043
Al Virob353a1f2015-03-17 09:59:38 -04001044 if (!plen)
1045 from = NULL;
1046
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -07001048 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 goto error;
1050
David Howellsb5f545c2006-01-08 01:02:47 -08001051 /* the appropriate instantiation authorisation key must have been
1052 * assumed before calling this */
1053 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +11001054 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -08001055 if (!instkey)
1056 goto error;
1057
David Howells146aa8b2015-10-21 14:04:48 +01001058 rka = instkey->payload.data[0];
David Howellsb5f545c2006-01-08 01:02:47 -08001059 if (rka->target_key->serial != id)
1060 goto error;
1061
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 /* pull the payload in if one was supplied */
1063 payload = NULL;
1064
Al Virob353a1f2015-03-17 09:59:38 -04001065 if (from) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 ret = -ENOMEM;
1067 payload = kmalloc(plen, GFP_KERNEL);
David Howells38bbca62008-04-29 01:01:19 -07001068 if (!payload) {
1069 if (plen <= PAGE_SIZE)
1070 goto error;
David Howells38bbca62008-04-29 01:01:19 -07001071 payload = vmalloc(plen);
1072 if (!payload)
1073 goto error;
1074 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075
Al Virob353a1f2015-03-17 09:59:38 -04001076 ret = -EFAULT;
1077 if (copy_from_iter(payload, plen, from) != plen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078 goto error2;
1079 }
1080
David Howells3e301482005-06-23 22:00:56 -07001081 /* find the destination keyring amongst those belonging to the
1082 * requesting task */
David Howells8bbf49762008-11-14 10:39:14 +11001083 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1084 if (ret < 0)
1085 goto error2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086
1087 /* instantiate the key and link it into a keyring */
David Howells3e301482005-06-23 22:00:56 -07001088 ret = key_instantiate_and_link(rka->target_key, payload, plen,
David Howells8bbf49762008-11-14 10:39:14 +11001089 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090
David Howells8bbf49762008-11-14 10:39:14 +11001091 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001092
1093 /* discard the assumed authority if it's just been disabled by
1094 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001095 if (ret == 0)
1096 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001097
1098error2:
Al Virob353a1f2015-03-17 09:59:38 -04001099 kvfree(payload);
David Howellsb5f545c2006-01-08 01:02:47 -08001100error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001102}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104/*
David Howellsee009e4a02011-03-07 15:06:20 +00001105 * Instantiate a key with the specified payload and link the key into the
1106 * destination keyring if one is given.
1107 *
1108 * The caller must have the appropriate instantiation permit set for this to
1109 * work (see keyctl_assume_authority). No other permissions are required.
1110 *
1111 * If successful, 0 will be returned.
1112 */
1113long keyctl_instantiate_key(key_serial_t id,
1114 const void __user *_payload,
1115 size_t plen,
1116 key_serial_t ringid)
1117{
1118 if (_payload && plen) {
Al Virob353a1f2015-03-17 09:59:38 -04001119 struct iovec iov;
1120 struct iov_iter from;
1121 int ret;
David Howellsee009e4a02011-03-07 15:06:20 +00001122
Al Virob353a1f2015-03-17 09:59:38 -04001123 ret = import_single_range(WRITE, (void __user *)_payload, plen,
1124 &iov, &from);
1125 if (unlikely(ret))
1126 return ret;
1127
1128 return keyctl_instantiate_key_common(id, &from, ringid);
David Howellsee009e4a02011-03-07 15:06:20 +00001129 }
1130
Al Virob353a1f2015-03-17 09:59:38 -04001131 return keyctl_instantiate_key_common(id, NULL, ringid);
David Howellsee009e4a02011-03-07 15:06:20 +00001132}
1133
1134/*
1135 * Instantiate a key with the specified multipart payload and link the key into
1136 * the destination keyring if one is given.
1137 *
1138 * The caller must have the appropriate instantiation permit set for this to
1139 * work (see keyctl_assume_authority). No other permissions are required.
1140 *
1141 * If successful, 0 will be returned.
1142 */
1143long keyctl_instantiate_key_iov(key_serial_t id,
1144 const struct iovec __user *_payload_iov,
1145 unsigned ioc,
1146 key_serial_t ringid)
1147{
1148 struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
Al Virob353a1f2015-03-17 09:59:38 -04001149 struct iov_iter from;
David Howellsee009e4a02011-03-07 15:06:20 +00001150 long ret;
1151
Al Virob353a1f2015-03-17 09:59:38 -04001152 if (!_payload_iov)
1153 ioc = 0;
David Howellsee009e4a02011-03-07 15:06:20 +00001154
Al Virob353a1f2015-03-17 09:59:38 -04001155 ret = import_iovec(WRITE, _payload_iov, ioc,
1156 ARRAY_SIZE(iovstack), &iov, &from);
David Howellsee009e4a02011-03-07 15:06:20 +00001157 if (ret < 0)
Al Virob353a1f2015-03-17 09:59:38 -04001158 return ret;
1159 ret = keyctl_instantiate_key_common(id, &from, ringid);
1160 kfree(iov);
David Howellsee009e4a02011-03-07 15:06:20 +00001161 return ret;
David Howellsee009e4a02011-03-07 15:06:20 +00001162}
1163
1164/*
David Howells973c9f42011-01-20 16:38:33 +00001165 * Negatively instantiate the key with the given timeout (in seconds) and link
1166 * the key into the destination keyring if one is given.
1167 *
1168 * The caller must have the appropriate instantiation permit set for this to
1169 * work (see keyctl_assume_authority). No other permissions are required.
1170 *
1171 * The key and any links to the key will be automatically garbage collected
1172 * after the timeout expires.
1173 *
1174 * Negative keys are used to rate limit repeated request_key() calls by causing
1175 * them to return -ENOKEY until the negative key expires.
1176 *
1177 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178 */
1179long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
1180{
David Howellsfdd1b942011-03-07 15:06:09 +00001181 return keyctl_reject_key(id, timeout, ENOKEY, ringid);
1182}
1183
1184/*
1185 * Negatively instantiate the key with the given timeout (in seconds) and error
1186 * code and link the key into the destination keyring if one is given.
1187 *
1188 * The caller must have the appropriate instantiation permit set for this to
1189 * work (see keyctl_assume_authority). No other permissions are required.
1190 *
1191 * The key and any links to the key will be automatically garbage collected
1192 * after the timeout expires.
1193 *
1194 * Negative keys are used to rate limit repeated request_key() calls by causing
1195 * them to return the specified error code until the negative key expires.
1196 *
1197 * If successful, 0 will be returned.
1198 */
1199long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error,
1200 key_serial_t ringid)
1201{
David Howellsd84f4f92008-11-14 10:39:23 +11001202 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -07001203 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +11001204 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 long ret;
1206
David Howellsfdd1b942011-03-07 15:06:09 +00001207 kenter("%d,%u,%u,%d", id, timeout, error, ringid);
1208
1209 /* must be a valid error code and mustn't be a kernel special */
1210 if (error <= 0 ||
1211 error >= MAX_ERRNO ||
1212 error == ERESTARTSYS ||
1213 error == ERESTARTNOINTR ||
1214 error == ERESTARTNOHAND ||
1215 error == ERESTART_RESTARTBLOCK)
1216 return -EINVAL;
David Howellsd84f4f92008-11-14 10:39:23 +11001217
David Howellsb5f545c2006-01-08 01:02:47 -08001218 /* the appropriate instantiation authorisation key must have been
1219 * assumed before calling this */
1220 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +11001221 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -08001222 if (!instkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224
David Howells146aa8b2015-10-21 14:04:48 +01001225 rka = instkey->payload.data[0];
David Howellsb5f545c2006-01-08 01:02:47 -08001226 if (rka->target_key->serial != id)
1227 goto error;
David Howells3e301482005-06-23 22:00:56 -07001228
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 /* find the destination keyring if present (which must also be
1230 * writable) */
David Howells8bbf49762008-11-14 10:39:14 +11001231 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1232 if (ret < 0)
1233 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234
1235 /* instantiate the key and link it into a keyring */
David Howellsfdd1b942011-03-07 15:06:09 +00001236 ret = key_reject_and_link(rka->target_key, timeout, error,
David Howells8bbf49762008-11-14 10:39:14 +11001237 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238
David Howells8bbf49762008-11-14 10:39:14 +11001239 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001240
1241 /* discard the assumed authority if it's just been disabled by
1242 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001243 if (ret == 0)
1244 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001245
1246error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001248}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250/*
David Howells973c9f42011-01-20 16:38:33 +00001251 * Read or set the default keyring in which request_key() will cache keys and
1252 * return the old setting.
1253 *
1254 * If a process keyring is specified then this will be created if it doesn't
1255 * yet exist. The old setting will be returned if successful.
David Howells3e301482005-06-23 22:00:56 -07001256 */
1257long keyctl_set_reqkey_keyring(int reqkey_defl)
1258{
David Howellsd84f4f92008-11-14 10:39:23 +11001259 struct cred *new;
1260 int ret, old_setting;
1261
1262 old_setting = current_cred_xxx(jit_keyring);
1263
1264 if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
1265 return old_setting;
1266
1267 new = prepare_creds();
1268 if (!new)
1269 return -ENOMEM;
David Howells3e301482005-06-23 22:00:56 -07001270
1271 switch (reqkey_defl) {
1272 case KEY_REQKEY_DEFL_THREAD_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001273 ret = install_thread_keyring_to_cred(new);
David Howells3e301482005-06-23 22:00:56 -07001274 if (ret < 0)
David Howellsd84f4f92008-11-14 10:39:23 +11001275 goto error;
David Howells3e301482005-06-23 22:00:56 -07001276 goto set;
1277
1278 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001279 ret = install_process_keyring_to_cred(new);
1280 if (ret < 0) {
1281 if (ret != -EEXIST)
1282 goto error;
1283 ret = 0;
1284 }
1285 goto set;
David Howells3e301482005-06-23 22:00:56 -07001286
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:
David Howellsd84f4f92008-11-14 10:39:23 +11001291 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
1292 goto set;
David Howells3e301482005-06-23 22:00:56 -07001293
1294 case KEY_REQKEY_DEFL_NO_CHANGE:
David Howells3e301482005-06-23 22:00:56 -07001295 case KEY_REQKEY_DEFL_GROUP_KEYRING:
1296 default:
David Howellsd84f4f92008-11-14 10:39:23 +11001297 ret = -EINVAL;
1298 goto error;
David Howells3e301482005-06-23 22:00:56 -07001299 }
1300
David Howellsd84f4f92008-11-14 10:39:23 +11001301set:
1302 new->jit_keyring = reqkey_defl;
1303 commit_creds(new);
1304 return old_setting;
1305error:
1306 abort_creds(new);
Dan Carpenter4303ef12010-06-11 17:30:05 +01001307 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001308}
David Howellsd84f4f92008-11-14 10:39:23 +11001309
David Howells3e301482005-06-23 22:00:56 -07001310/*
David Howells973c9f42011-01-20 16:38:33 +00001311 * Set or clear the timeout on a key.
1312 *
1313 * Either the key must grant the caller Setattr permission or else the caller
1314 * must hold an instantiation authorisation token for the key.
1315 *
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.
1319 *
Mimi Zohard3600bc2015-11-10 08:34:46 -05001320 * Keys with KEY_FLAG_KEEP set should not be timed out.
1321 *
David Howells973c9f42011-01-20 16:38:33 +00001322 * If successful, 0 is returned.
David Howells017679c2006-01-08 01:02:43 -08001323 */
1324long keyctl_set_timeout(key_serial_t id, unsigned timeout)
1325{
David Howells91562352010-06-11 17:31:05 +01001326 struct key *key, *instkey;
David Howells017679c2006-01-08 01:02:43 -08001327 key_ref_t key_ref;
David Howells017679c2006-01-08 01:02:43 -08001328 long ret;
1329
David Howells55931222009-09-02 09:13:45 +01001330 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
David Howellsf5895942014-03-14 17:44:49 +00001331 KEY_NEED_SETATTR);
David Howells017679c2006-01-08 01:02:43 -08001332 if (IS_ERR(key_ref)) {
David Howells91562352010-06-11 17:31:05 +01001333 /* 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)) {
1338 key_put(instkey);
1339 key_ref = lookup_user_key(id,
1340 KEY_LOOKUP_PARTIAL,
1341 0);
1342 if (!IS_ERR(key_ref))
1343 goto okay;
1344 }
1345 }
1346
David Howells017679c2006-01-08 01:02:43 -08001347 ret = PTR_ERR(key_ref);
1348 goto error;
1349 }
1350
David Howells91562352010-06-11 17:31:05 +01001351okay:
David Howells017679c2006-01-08 01:02:43 -08001352 key = key_ref_to_ptr(key_ref);
Mimi Zohar1d6d1672016-01-07 07:46:36 -05001353 ret = 0;
Mimi Zohard3600bc2015-11-10 08:34:46 -05001354 if (test_bit(KEY_FLAG_KEEP, &key->flags))
1355 ret = -EPERM;
Mimi Zohar1d6d1672016-01-07 07:46:36 -05001356 else
Mimi Zohard3600bc2015-11-10 08:34:46 -05001357 key_set_timeout(key, timeout);
David Howells017679c2006-01-08 01:02:43 -08001358 key_put(key);
1359
David Howells017679c2006-01-08 01:02:43 -08001360error:
1361 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001362}
David Howells017679c2006-01-08 01:02:43 -08001363
David Howells017679c2006-01-08 01:02:43 -08001364/*
David Howells973c9f42011-01-20 16:38:33 +00001365 * Assume (or clear) the authority to instantiate the specified key.
1366 *
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.
1371 *
1372 * The caller must have the instantiation key in their process keyrings with a
1373 * Search permission grant available to the caller.
1374 *
1375 * If the ID given is 0, then the setting will be cleared and 0 returned.
1376 *
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().
David Howellsb5f545c2006-01-08 01:02:47 -08001380 */
1381long keyctl_assume_authority(key_serial_t id)
1382{
1383 struct key *authkey;
1384 long ret;
1385
1386 /* special key IDs aren't permitted */
1387 ret = -EINVAL;
1388 if (id < 0)
1389 goto error;
1390
1391 /* we divest ourselves of authority if given an ID of 0 */
1392 if (id == 0) {
David Howellsd84f4f92008-11-14 10:39:23 +11001393 ret = keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001394 goto error;
1395 }
1396
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
1400 * somewhere
1401 */
1402 authkey = key_get_instantiation_authkey(id);
1403 if (IS_ERR(authkey)) {
1404 ret = PTR_ERR(authkey);
1405 goto error;
1406 }
1407
David Howellsd84f4f92008-11-14 10:39:23 +11001408 ret = keyctl_change_reqkey_auth(authkey);
1409 if (ret < 0)
1410 goto error;
1411 key_put(authkey);
David Howellsb5f545c2006-01-08 01:02:47 -08001412
David Howellsd84f4f92008-11-14 10:39:23 +11001413 ret = authkey->serial;
David Howellsb5f545c2006-01-08 01:02:47 -08001414error:
1415 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001416}
David Howellsb5f545c2006-01-08 01:02:47 -08001417
David Howells70a5bb72008-04-29 01:01:26 -07001418/*
David Howells973c9f42011-01-20 16:38:33 +00001419 * Get a key's the LSM security label.
1420 *
1421 * The key must grant the caller View permission for this to work.
1422 *
1423 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1424 *
1425 * If successful, the amount of information available will be returned,
1426 * irrespective of how much was copied (including the terminal NUL).
David Howells70a5bb72008-04-29 01:01:26 -07001427 */
1428long keyctl_get_security(key_serial_t keyid,
1429 char __user *buffer,
1430 size_t buflen)
1431{
1432 struct key *key, *instkey;
1433 key_ref_t key_ref;
1434 char *context;
1435 long ret;
1436
David Howellsf5895942014-03-14 17:44:49 +00001437 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW);
David Howells70a5bb72008-04-29 01:01:26 -07001438 if (IS_ERR(key_ref)) {
1439 if (PTR_ERR(key_ref) != -EACCES)
1440 return PTR_ERR(key_ref);
1441
1442 /* viewing a key under construction is also permitted if we
1443 * have the authorisation token handy */
1444 instkey = key_get_instantiation_authkey(keyid);
1445 if (IS_ERR(instkey))
Roel Kluinfa1cc7b2009-12-15 15:05:12 -08001446 return PTR_ERR(instkey);
David Howells70a5bb72008-04-29 01:01:26 -07001447 key_put(instkey);
1448
David Howells55931222009-09-02 09:13:45 +01001449 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
David Howells70a5bb72008-04-29 01:01:26 -07001450 if (IS_ERR(key_ref))
1451 return PTR_ERR(key_ref);
1452 }
1453
1454 key = key_ref_to_ptr(key_ref);
1455 ret = security_key_getsecurity(key, &context);
1456 if (ret == 0) {
1457 /* if no information was returned, give userspace an empty
1458 * string */
1459 ret = 1;
1460 if (buffer && buflen > 0 &&
1461 copy_to_user(buffer, "", 1) != 0)
1462 ret = -EFAULT;
1463 } else if (ret > 0) {
1464 /* return as much data as there's room for */
1465 if (buffer && buflen > 0) {
1466 if (buflen > ret)
1467 buflen = ret;
1468
1469 if (copy_to_user(buffer, context, buflen) != 0)
1470 ret = -EFAULT;
1471 }
1472
1473 kfree(context);
1474 }
1475
1476 key_ref_put(key_ref);
1477 return ret;
1478}
1479
David Howellsee18d642009-09-02 09:14:21 +01001480/*
David Howells973c9f42011-01-20 16:38:33 +00001481 * Attempt to install the calling process's session keyring on the process's
1482 * parent process.
1483 *
1484 * The keyring must exist and must grant the caller LINK permission, and the
1485 * parent process must be single-threaded and must have the same effective
1486 * ownership as this process and mustn't be SUID/SGID.
1487 *
1488 * The keyring will be emplaced on the parent when it next resumes userspace.
1489 *
1490 * If successful, 0 will be returned.
David Howellsee18d642009-09-02 09:14:21 +01001491 */
1492long keyctl_session_to_parent(void)
1493{
1494 struct task_struct *me, *parent;
1495 const struct cred *mycred, *pcred;
Al Viro67d12142012-06-27 11:07:19 +04001496 struct callback_head *newwork, *oldwork;
David Howellsee18d642009-09-02 09:14:21 +01001497 key_ref_t keyring_r;
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001498 struct cred *cred;
David Howellsee18d642009-09-02 09:14:21 +01001499 int ret;
1500
David Howellsf5895942014-03-14 17:44:49 +00001501 keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_NEED_LINK);
David Howellsee18d642009-09-02 09:14:21 +01001502 if (IS_ERR(keyring_r))
1503 return PTR_ERR(keyring_r);
1504
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001505 ret = -ENOMEM;
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001506
David Howellsee18d642009-09-02 09:14:21 +01001507 /* our parent is going to need a new cred struct, a new tgcred struct
1508 * and new security data, so we allocate them here to prevent ENOMEM in
1509 * our parent */
David Howellsee18d642009-09-02 09:14:21 +01001510 cred = cred_alloc_blank();
1511 if (!cred)
Al Viro67d12142012-06-27 11:07:19 +04001512 goto error_keyring;
1513 newwork = &cred->rcu;
David Howellsee18d642009-09-02 09:14:21 +01001514
David Howells3a505972012-10-02 19:24:29 +01001515 cred->session_keyring = key_ref_to_ptr(keyring_r);
1516 keyring_r = NULL;
Al Viro67d12142012-06-27 11:07:19 +04001517 init_task_work(newwork, key_change_session_keyring);
David Howellsee18d642009-09-02 09:14:21 +01001518
1519 me = current;
David Howells9d1ac652010-09-10 09:59:46 +01001520 rcu_read_lock();
David Howellsee18d642009-09-02 09:14:21 +01001521 write_lock_irq(&tasklist_lock);
1522
David Howellsee18d642009-09-02 09:14:21 +01001523 ret = -EPERM;
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001524 oldwork = NULL;
1525 parent = me->real_parent;
David Howellsee18d642009-09-02 09:14:21 +01001526
1527 /* the parent mustn't be init and mustn't be a kernel thread */
1528 if (parent->pid <= 1 || !parent->mm)
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001529 goto unlock;
David Howellsee18d642009-09-02 09:14:21 +01001530
1531 /* the parent must be single threaded */
Oleg Nesterovdd98acf2010-05-26 14:43:23 -07001532 if (!thread_group_empty(parent))
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001533 goto unlock;
David Howellsee18d642009-09-02 09:14:21 +01001534
1535 /* the parent and the child must have different session keyrings or
1536 * there's no point */
1537 mycred = current_cred();
1538 pcred = __task_cred(parent);
1539 if (mycred == pcred ||
David Howells3a505972012-10-02 19:24:29 +01001540 mycred->session_keyring == pcred->session_keyring) {
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001541 ret = 0;
1542 goto unlock;
1543 }
David Howellsee18d642009-09-02 09:14:21 +01001544
1545 /* the parent must have the same effective ownership and mustn't be
1546 * SUID/SGID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -08001547 if (!uid_eq(pcred->uid, mycred->euid) ||
1548 !uid_eq(pcred->euid, mycred->euid) ||
1549 !uid_eq(pcred->suid, mycred->euid) ||
1550 !gid_eq(pcred->gid, mycred->egid) ||
1551 !gid_eq(pcred->egid, mycred->egid) ||
1552 !gid_eq(pcred->sgid, mycred->egid))
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001553 goto unlock;
David Howellsee18d642009-09-02 09:14:21 +01001554
1555 /* the keyrings must have the same UID */
David Howells3a505972012-10-02 19:24:29 +01001556 if ((pcred->session_keyring &&
Linus Torvalds2a74dbb2012-12-16 15:40:50 -08001557 !uid_eq(pcred->session_keyring->uid, mycred->euid)) ||
1558 !uid_eq(mycred->session_keyring->uid, mycred->euid))
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001559 goto unlock;
David Howellsee18d642009-09-02 09:14:21 +01001560
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001561 /* cancel an already pending keyring replacement */
1562 oldwork = task_work_cancel(parent, key_change_session_keyring);
David Howellsee18d642009-09-02 09:14:21 +01001563
1564 /* the replacement session keyring is applied just prior to userspace
1565 * restarting */
Al Viro67d12142012-06-27 11:07:19 +04001566 ret = task_work_add(parent, newwork, true);
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001567 if (!ret)
1568 newwork = NULL;
1569unlock:
David Howellsee18d642009-09-02 09:14:21 +01001570 write_unlock_irq(&tasklist_lock);
David Howells9d1ac652010-09-10 09:59:46 +01001571 rcu_read_unlock();
Al Viro67d12142012-06-27 11:07:19 +04001572 if (oldwork)
1573 put_cred(container_of(oldwork, struct cred, rcu));
1574 if (newwork)
1575 put_cred(cred);
David Howellsee18d642009-09-02 09:14:21 +01001576 return ret;
1577
1578error_keyring:
1579 key_ref_put(keyring_r);
1580 return ret;
1581}
1582
David Howellsb5f545c2006-01-08 01:02:47 -08001583/*
David Howells973c9f42011-01-20 16:38:33 +00001584 * The key control system call
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585 */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001586SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
1587 unsigned long, arg4, unsigned long, arg5)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588{
1589 switch (option) {
1590 case KEYCTL_GET_KEYRING_ID:
1591 return keyctl_get_keyring_ID((key_serial_t) arg2,
1592 (int) arg3);
1593
1594 case KEYCTL_JOIN_SESSION_KEYRING:
1595 return keyctl_join_session_keyring((const char __user *) arg2);
1596
1597 case KEYCTL_UPDATE:
1598 return keyctl_update_key((key_serial_t) arg2,
1599 (const void __user *) arg3,
1600 (size_t) arg4);
1601
1602 case KEYCTL_REVOKE:
1603 return keyctl_revoke_key((key_serial_t) arg2);
1604
1605 case KEYCTL_DESCRIBE:
1606 return keyctl_describe_key((key_serial_t) arg2,
1607 (char __user *) arg3,
1608 (unsigned) arg4);
1609
1610 case KEYCTL_CLEAR:
1611 return keyctl_keyring_clear((key_serial_t) arg2);
1612
1613 case KEYCTL_LINK:
1614 return keyctl_keyring_link((key_serial_t) arg2,
1615 (key_serial_t) arg3);
1616
1617 case KEYCTL_UNLINK:
1618 return keyctl_keyring_unlink((key_serial_t) arg2,
1619 (key_serial_t) arg3);
1620
1621 case KEYCTL_SEARCH:
1622 return keyctl_keyring_search((key_serial_t) arg2,
1623 (const char __user *) arg3,
1624 (const char __user *) arg4,
1625 (key_serial_t) arg5);
1626
1627 case KEYCTL_READ:
1628 return keyctl_read_key((key_serial_t) arg2,
1629 (char __user *) arg3,
1630 (size_t) arg4);
1631
1632 case KEYCTL_CHOWN:
1633 return keyctl_chown_key((key_serial_t) arg2,
1634 (uid_t) arg3,
1635 (gid_t) arg4);
1636
1637 case KEYCTL_SETPERM:
1638 return keyctl_setperm_key((key_serial_t) arg2,
1639 (key_perm_t) arg3);
1640
1641 case KEYCTL_INSTANTIATE:
1642 return keyctl_instantiate_key((key_serial_t) arg2,
1643 (const void __user *) arg3,
1644 (size_t) arg4,
1645 (key_serial_t) arg5);
1646
1647 case KEYCTL_NEGATE:
1648 return keyctl_negate_key((key_serial_t) arg2,
1649 (unsigned) arg3,
1650 (key_serial_t) arg4);
1651
David Howells3e301482005-06-23 22:00:56 -07001652 case KEYCTL_SET_REQKEY_KEYRING:
1653 return keyctl_set_reqkey_keyring(arg2);
1654
David Howells017679c2006-01-08 01:02:43 -08001655 case KEYCTL_SET_TIMEOUT:
1656 return keyctl_set_timeout((key_serial_t) arg2,
1657 (unsigned) arg3);
1658
David Howellsb5f545c2006-01-08 01:02:47 -08001659 case KEYCTL_ASSUME_AUTHORITY:
1660 return keyctl_assume_authority((key_serial_t) arg2);
1661
David Howells70a5bb72008-04-29 01:01:26 -07001662 case KEYCTL_GET_SECURITY:
1663 return keyctl_get_security((key_serial_t) arg2,
James Morris90bd49a2008-12-29 14:35:35 +11001664 (char __user *) arg3,
David Howells70a5bb72008-04-29 01:01:26 -07001665 (size_t) arg4);
1666
David Howellsee18d642009-09-02 09:14:21 +01001667 case KEYCTL_SESSION_TO_PARENT:
1668 return keyctl_session_to_parent();
1669
David Howellsfdd1b942011-03-07 15:06:09 +00001670 case KEYCTL_REJECT:
1671 return keyctl_reject_key((key_serial_t) arg2,
1672 (unsigned) arg3,
1673 (unsigned) arg4,
1674 (key_serial_t) arg5);
1675
David Howellsee009e4a02011-03-07 15:06:20 +00001676 case KEYCTL_INSTANTIATE_IOV:
1677 return keyctl_instantiate_key_iov(
1678 (key_serial_t) arg2,
1679 (const struct iovec __user *) arg3,
1680 (unsigned) arg4,
1681 (key_serial_t) arg5);
1682
David Howellsfd758152012-05-11 10:56:56 +01001683 case KEYCTL_INVALIDATE:
1684 return keyctl_invalidate_key((key_serial_t) arg2);
1685
David Howellsf36f8c72013-09-24 10:35:19 +01001686 case KEYCTL_GET_PERSISTENT:
1687 return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3);
1688
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689 default:
1690 return -EOPNOTSUPP;
1691 }
David Howellsa8b17ed2011-01-20 16:38:27 +00001692}