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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>
17#include <linux/keyctl.h>
18#include <linux/fs.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080019#include <linux/capability.h>
Davi Arnaut0cb409d2006-03-24 03:18:43 -080020#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/err.h>
David Howells38bbca62008-04-29 01:01:19 -070022#include <linux/vmalloc.h>
David Howells70a5bb72008-04-29 01:01:26 -070023#include <linux/security.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/uaccess.h>
25#include "internal.h"
26
Davi Arnaut0cb409d2006-03-24 03:18:43 -080027static int key_get_type_from_user(char *type,
28 const char __user *_type,
29 unsigned len)
30{
31 int ret;
32
33 ret = strncpy_from_user(type, _type, len);
Davi Arnaut0cb409d2006-03-24 03:18:43 -080034 if (ret < 0)
Dan Carpenter4303ef12010-06-11 17:30:05 +010035 return ret;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080036 if (ret == 0 || ret >= len)
37 return -EINVAL;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080038 if (type[0] == '.')
39 return -EPERM;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080040 type[len - 1] = '\0';
Davi Arnaut0cb409d2006-03-24 03:18:43 -080041 return 0;
42}
43
Linus Torvalds1da177e2005-04-16 15:20:36 -070044/*
David Howells973c9f42011-01-20 16:38:33 +000045 * Extract the description of a new key from userspace and either add it as a
46 * new key to the specified keyring or update a matching key in that keyring.
47 *
48 * The keyring must be writable so that we can attach the key to it.
49 *
50 * If successful, the new key's serial number is returned, otherwise an error
51 * code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +010053SYSCALL_DEFINE5(add_key, const char __user *, _type,
54 const char __user *, _description,
55 const void __user *, _payload,
56 size_t, plen,
57 key_serial_t, ringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058{
David Howells664cceb2005-09-28 17:03:15 +010059 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 char type[32], *description;
61 void *payload;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080062 long ret;
David Howells38bbca62008-04-29 01:01:19 -070063 bool vm;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -070066 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 goto error;
68
69 /* draw all the data into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -080070 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 if (ret < 0)
72 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Davi Arnaut0cb409d2006-03-24 03:18:43 -080074 description = strndup_user(_description, PAGE_SIZE);
75 if (IS_ERR(description)) {
76 ret = PTR_ERR(description);
David Howells3e301482005-06-23 22:00:56 -070077 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080078 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80 /* pull the payload in if one was supplied */
81 payload = NULL;
82
David Howells38bbca62008-04-29 01:01:19 -070083 vm = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 if (_payload) {
85 ret = -ENOMEM;
86 payload = kmalloc(plen, GFP_KERNEL);
David Howells38bbca62008-04-29 01:01:19 -070087 if (!payload) {
88 if (plen <= PAGE_SIZE)
89 goto error2;
90 vm = true;
91 payload = vmalloc(plen);
92 if (!payload)
93 goto error2;
94 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96 ret = -EFAULT;
97 if (copy_from_user(payload, _payload, plen) != 0)
98 goto error3;
99 }
100
101 /* find the target keyring (which must be writable) */
David Howells55931222009-09-02 09:13:45 +0100102 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100103 if (IS_ERR(keyring_ref)) {
104 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 goto error3;
106 }
107
108 /* create or update the requested key and add it to the target
109 * keyring */
David Howells664cceb2005-09-28 17:03:15 +0100110 key_ref = key_create_or_update(keyring_ref, type, description,
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700111 payload, plen, KEY_PERM_UNDEF,
112 KEY_ALLOC_IN_QUOTA);
David Howells664cceb2005-09-28 17:03:15 +0100113 if (!IS_ERR(key_ref)) {
114 ret = key_ref_to_ptr(key_ref)->serial;
115 key_ref_put(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 }
117 else {
David Howells664cceb2005-09-28 17:03:15 +0100118 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 }
120
David Howells664cceb2005-09-28 17:03:15 +0100121 key_ref_put(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 error3:
David Howells38bbca62008-04-29 01:01:19 -0700123 if (!vm)
124 kfree(payload);
125 else
126 vfree(payload);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 error2:
128 kfree(description);
129 error:
130 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000131}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133/*
David Howells973c9f42011-01-20 16:38:33 +0000134 * Search the process keyrings and keyring trees linked from those for a
135 * matching key. Keyrings must have appropriate Search permission to be
136 * searched.
137 *
138 * If a key is found, it will be attached to the destination keyring if there's
139 * one specified and the serial number of the key will be returned.
140 *
141 * If no key is found, /sbin/request-key will be invoked if _callout_info is
142 * non-NULL in an attempt to create a key. The _callout_info string will be
143 * passed to /sbin/request-key to aid with completing the request. If the
144 * _callout_info string is "" then it will be changed to "-".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +0100146SYSCALL_DEFINE4(request_key, const char __user *, _type,
147 const char __user *, _description,
148 const char __user *, _callout_info,
149 key_serial_t, destringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150{
151 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100152 struct key *key;
153 key_ref_t dest_ref;
David Howells4a38e122008-04-29 01:01:24 -0700154 size_t callout_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 char type[32], *description, *callout_info;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800156 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158 /* pull the type into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800159 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 if (ret < 0)
161 goto error;
David Howells1260f802005-08-04 11:50:01 +0100162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 /* pull the description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800164 description = strndup_user(_description, PAGE_SIZE);
165 if (IS_ERR(description)) {
166 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800168 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170 /* pull the callout info into kernel space */
171 callout_info = NULL;
David Howells4a38e122008-04-29 01:01:24 -0700172 callout_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 if (_callout_info) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800174 callout_info = strndup_user(_callout_info, PAGE_SIZE);
175 if (IS_ERR(callout_info)) {
176 ret = PTR_ERR(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 goto error2;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800178 }
David Howells4a38e122008-04-29 01:01:24 -0700179 callout_len = strlen(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 }
181
182 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100183 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100185 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
186 KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100187 if (IS_ERR(dest_ref)) {
188 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 goto error3;
190 }
191 }
192
193 /* find the key type */
194 ktype = key_type_lookup(type);
195 if (IS_ERR(ktype)) {
196 ret = PTR_ERR(ktype);
197 goto error4;
198 }
199
200 /* do the search */
David Howells4a38e122008-04-29 01:01:24 -0700201 key = request_key_and_link(ktype, description, callout_info,
202 callout_len, NULL, key_ref_to_ptr(dest_ref),
David Howells7e047ef2006-06-26 00:24:50 -0700203 KEY_ALLOC_IN_QUOTA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 if (IS_ERR(key)) {
205 ret = PTR_ERR(key);
206 goto error5;
207 }
208
David Howells4aab1e82011-03-11 17:57:33 +0000209 /* wait for the key to finish being constructed */
210 ret = wait_for_key_construction(key, 1);
211 if (ret < 0)
212 goto error6;
213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 ret = key->serial;
215
David Howells4aab1e82011-03-11 17:57:33 +0000216error6:
David Howells3e301482005-06-23 22:00:56 -0700217 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700218error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700220error4:
David Howells664cceb2005-09-28 17:03:15 +0100221 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700222error3:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 kfree(callout_info);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700224error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700226error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000228}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230/*
David Howells973c9f42011-01-20 16:38:33 +0000231 * Get the ID of the specified process keyring.
232 *
233 * The requested keyring must have search permission to be found.
234 *
235 * If successful, the ID of the requested keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 */
237long keyctl_get_keyring_ID(key_serial_t id, int create)
238{
David Howells664cceb2005-09-28 17:03:15 +0100239 key_ref_t key_ref;
David Howells55931222009-09-02 09:13:45 +0100240 unsigned long lflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 long ret;
242
David Howells55931222009-09-02 09:13:45 +0100243 lflags = create ? KEY_LOOKUP_CREATE : 0;
244 key_ref = lookup_user_key(id, lflags, KEY_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100245 if (IS_ERR(key_ref)) {
246 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 goto error;
248 }
249
David Howells664cceb2005-09-28 17:03:15 +0100250 ret = key_ref_to_ptr(key_ref)->serial;
251 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700252error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 return ret;
David Howells973c9f42011-01-20 16:38:33 +0000254}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256/*
David Howells973c9f42011-01-20 16:38:33 +0000257 * Join a (named) session keyring.
258 *
259 * Create and join an anonymous session keyring or join a named session
260 * keyring, creating it if necessary. A named session keyring must have Search
261 * permission for it to be joined. Session keyrings without this permit will
262 * be skipped over.
263 *
264 * If successful, the ID of the joined session keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 */
266long keyctl_join_session_keyring(const char __user *_name)
267{
268 char *name;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800269 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
271 /* fetch the name from userspace */
272 name = NULL;
273 if (_name) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800274 name = strndup_user(_name, PAGE_SIZE);
275 if (IS_ERR(name)) {
276 ret = PTR_ERR(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800278 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 }
280
281 /* join the session */
282 ret = join_session_keyring(name);
Vegard Nossum0d54ee12009-01-17 17:45:45 +0100283 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700285error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000287}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289/*
David Howells973c9f42011-01-20 16:38:33 +0000290 * Update a key's data payload from the given data.
291 *
292 * The key must grant the caller Write permission and the key type must support
293 * updating for this to work. A negative key can be positively instantiated
294 * with this call.
295 *
296 * If successful, 0 will be returned. If the key type does not support
297 * updating, then -EOPNOTSUPP will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 */
299long keyctl_update_key(key_serial_t id,
300 const void __user *_payload,
301 size_t plen)
302{
David Howells664cceb2005-09-28 17:03:15 +0100303 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 void *payload;
305 long ret;
306
307 ret = -EINVAL;
308 if (plen > PAGE_SIZE)
309 goto error;
310
311 /* pull the payload in if one was supplied */
312 payload = NULL;
313 if (_payload) {
314 ret = -ENOMEM;
315 payload = kmalloc(plen, GFP_KERNEL);
316 if (!payload)
317 goto error;
318
319 ret = -EFAULT;
320 if (copy_from_user(payload, _payload, plen) != 0)
321 goto error2;
322 }
323
324 /* find the target key (which must be writable) */
David Howells55931222009-09-02 09:13:45 +0100325 key_ref = lookup_user_key(id, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100326 if (IS_ERR(key_ref)) {
327 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 goto error2;
329 }
330
331 /* update the key */
David Howells664cceb2005-09-28 17:03:15 +0100332 ret = key_update(key_ref, payload, plen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333
David Howells664cceb2005-09-28 17:03:15 +0100334 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700335error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 kfree(payload);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700337error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000339}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341/*
David Howells973c9f42011-01-20 16:38:33 +0000342 * Revoke a key.
343 *
344 * The key must be grant the caller Write or Setattr permission for this to
345 * work. The key type should give up its quota claim when revoked. The key
346 * and any links to the key will be automatically garbage collected after a
347 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
348 *
349 * If successful, 0 is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 */
351long keyctl_revoke_key(key_serial_t id)
352{
David Howells664cceb2005-09-28 17:03:15 +0100353 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 long ret;
355
David Howells55931222009-09-02 09:13:45 +0100356 key_ref = lookup_user_key(id, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100357 if (IS_ERR(key_ref)) {
358 ret = PTR_ERR(key_ref);
David Howells0c2c9a32009-09-02 09:13:50 +0100359 if (ret != -EACCES)
360 goto error;
361 key_ref = lookup_user_key(id, 0, KEY_SETATTR);
362 if (IS_ERR(key_ref)) {
363 ret = PTR_ERR(key_ref);
364 goto error;
365 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 }
367
David Howells664cceb2005-09-28 17:03:15 +0100368 key_revoke(key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 ret = 0;
370
David Howells664cceb2005-09-28 17:03:15 +0100371 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700372error:
David Howells1260f802005-08-04 11:50:01 +0100373 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000374}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376/*
David Howells973c9f42011-01-20 16:38:33 +0000377 * Clear the specified keyring, creating an empty process keyring if one of the
378 * special keyring IDs is used.
379 *
380 * The keyring must grant the caller Write permission for this to work. If
381 * successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 */
383long keyctl_keyring_clear(key_serial_t ringid)
384{
David Howells664cceb2005-09-28 17:03:15 +0100385 key_ref_t keyring_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 long ret;
387
David Howells55931222009-09-02 09:13:45 +0100388 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100389 if (IS_ERR(keyring_ref)) {
390 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 goto error;
392 }
393
David Howells664cceb2005-09-28 17:03:15 +0100394 ret = keyring_clear(key_ref_to_ptr(keyring_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
David Howells664cceb2005-09-28 17:03:15 +0100396 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700397error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000399}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401/*
David Howells973c9f42011-01-20 16:38:33 +0000402 * Create a link from a keyring to a key if there's no matching key in the
403 * keyring, otherwise replace the link to the matching key with a link to the
404 * new key.
405 *
406 * The key must grant the caller Link permission and the the keyring must grant
407 * the caller Write permission. Furthermore, if an additional link is created,
408 * the keyring's quota will be extended.
409 *
410 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 */
412long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
413{
David Howells664cceb2005-09-28 17:03:15 +0100414 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 long ret;
416
David Howells55931222009-09-02 09:13:45 +0100417 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100418 if (IS_ERR(keyring_ref)) {
419 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 goto error;
421 }
422
David Howells55931222009-09-02 09:13:45 +0100423 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK);
David Howells664cceb2005-09-28 17:03:15 +0100424 if (IS_ERR(key_ref)) {
425 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 goto error2;
427 }
428
David Howells664cceb2005-09-28 17:03:15 +0100429 ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430
David Howells664cceb2005-09-28 17:03:15 +0100431 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700432error2:
David Howells664cceb2005-09-28 17:03:15 +0100433 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700434error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000436}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438/*
David Howells973c9f42011-01-20 16:38:33 +0000439 * Unlink a key from a keyring.
440 *
441 * The keyring must grant the caller Write permission for this to work; the key
442 * itself need not grant the caller anything. If the last link to a key is
443 * removed then that key will be scheduled for destruction.
444 *
445 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 */
447long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
448{
David Howells664cceb2005-09-28 17:03:15 +0100449 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 long ret;
451
David Howells55931222009-09-02 09:13:45 +0100452 keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100453 if (IS_ERR(keyring_ref)) {
454 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 goto error;
456 }
457
David Howells55931222009-09-02 09:13:45 +0100458 key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
David Howells664cceb2005-09-28 17:03:15 +0100459 if (IS_ERR(key_ref)) {
460 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 goto error2;
462 }
463
David Howells664cceb2005-09-28 17:03:15 +0100464 ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
David Howells664cceb2005-09-28 17:03:15 +0100466 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700467error2:
David Howells664cceb2005-09-28 17:03:15 +0100468 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700469error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000471}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473/*
David Howells973c9f42011-01-20 16:38:33 +0000474 * Return a description of a key to userspace.
475 *
476 * The key must grant the caller View permission for this to work.
477 *
478 * If there's a buffer, we place up to buflen bytes of data into it formatted
479 * in the following way:
480 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 * type;uid;gid;perm;description<NUL>
David Howells973c9f42011-01-20 16:38:33 +0000482 *
483 * If successful, we return the amount of description available, irrespective
484 * of how much we may have copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 */
486long keyctl_describe_key(key_serial_t keyid,
487 char __user *buffer,
488 size_t buflen)
489{
David Howells3e301482005-06-23 22:00:56 -0700490 struct key *key, *instkey;
David Howells664cceb2005-09-28 17:03:15 +0100491 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 char *tmpbuf;
493 long ret;
494
David Howells55931222009-09-02 09:13:45 +0100495 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
David Howells664cceb2005-09-28 17:03:15 +0100496 if (IS_ERR(key_ref)) {
David Howells3e301482005-06-23 22:00:56 -0700497 /* viewing a key under construction is permitted if we have the
498 * authorisation token handy */
David Howells664cceb2005-09-28 17:03:15 +0100499 if (PTR_ERR(key_ref) == -EACCES) {
David Howells3e301482005-06-23 22:00:56 -0700500 instkey = key_get_instantiation_authkey(keyid);
501 if (!IS_ERR(instkey)) {
502 key_put(instkey);
David Howells8bbf49762008-11-14 10:39:14 +1100503 key_ref = lookup_user_key(keyid,
David Howells55931222009-09-02 09:13:45 +0100504 KEY_LOOKUP_PARTIAL,
505 0);
David Howells664cceb2005-09-28 17:03:15 +0100506 if (!IS_ERR(key_ref))
David Howells3e301482005-06-23 22:00:56 -0700507 goto okay;
508 }
509 }
510
David Howells664cceb2005-09-28 17:03:15 +0100511 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 goto error;
513 }
514
David Howells3e301482005-06-23 22:00:56 -0700515okay:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 /* calculate how much description we're going to return */
517 ret = -ENOMEM;
518 tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
519 if (!tmpbuf)
520 goto error2;
521
David Howells664cceb2005-09-28 17:03:15 +0100522 key = key_ref_to_ptr(key_ref);
523
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 ret = snprintf(tmpbuf, PAGE_SIZE - 1,
David Howells664cceb2005-09-28 17:03:15 +0100525 "%s;%d;%d;%08x;%s",
David Howells94fd8402010-06-28 14:05:04 +0100526 key->type->name,
527 key->uid,
528 key->gid,
529 key->perm,
530 key->description ?: "");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531
532 /* include a NUL char at the end of the data */
533 if (ret > PAGE_SIZE - 1)
534 ret = PAGE_SIZE - 1;
535 tmpbuf[ret] = 0;
536 ret++;
537
538 /* consider returning the data */
539 if (buffer && buflen > 0) {
540 if (buflen > ret)
541 buflen = ret;
542
543 if (copy_to_user(buffer, tmpbuf, buflen) != 0)
544 ret = -EFAULT;
545 }
546
547 kfree(tmpbuf);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700548error2:
David Howells664cceb2005-09-28 17:03:15 +0100549 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700550error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000552}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554/*
David Howells973c9f42011-01-20 16:38:33 +0000555 * Search the specified keyring and any keyrings it links to for a matching
556 * key. Only keyrings that grant the caller Search permission will be searched
557 * (this includes the starting keyring). Only keys with Search permission can
558 * be found.
559 *
560 * If successful, the found key will be linked to the destination keyring if
561 * supplied and the key has Link permission, and the found key ID will be
562 * returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 */
564long keyctl_keyring_search(key_serial_t ringid,
565 const char __user *_type,
566 const char __user *_description,
567 key_serial_t destringid)
568{
569 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100570 key_ref_t keyring_ref, key_ref, dest_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 char type[32], *description;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800572 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
574 /* pull the type and description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800575 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 if (ret < 0)
577 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800579 description = strndup_user(_description, PAGE_SIZE);
580 if (IS_ERR(description)) {
581 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800583 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
585 /* get the keyring at which to begin the search */
David Howells55931222009-09-02 09:13:45 +0100586 keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100587 if (IS_ERR(keyring_ref)) {
588 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 goto error2;
590 }
591
592 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100593 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100595 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
596 KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100597 if (IS_ERR(dest_ref)) {
598 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 goto error3;
600 }
601 }
602
603 /* find the key type */
604 ktype = key_type_lookup(type);
605 if (IS_ERR(ktype)) {
606 ret = PTR_ERR(ktype);
607 goto error4;
608 }
609
610 /* do the search */
David Howells664cceb2005-09-28 17:03:15 +0100611 key_ref = keyring_search(keyring_ref, ktype, description);
612 if (IS_ERR(key_ref)) {
613 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614
615 /* treat lack or presence of a negative key the same */
616 if (ret == -EAGAIN)
617 ret = -ENOKEY;
618 goto error5;
619 }
620
621 /* link the resulting key to the destination keyring if we can */
David Howells664cceb2005-09-28 17:03:15 +0100622 if (dest_ref) {
David Howells29db9192005-10-30 15:02:44 -0800623 ret = key_permission(key_ref, KEY_LINK);
624 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 goto error6;
626
David Howells664cceb2005-09-28 17:03:15 +0100627 ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 if (ret < 0)
629 goto error6;
630 }
631
David Howells664cceb2005-09-28 17:03:15 +0100632 ret = key_ref_to_ptr(key_ref)->serial;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700634error6:
David Howells664cceb2005-09-28 17:03:15 +0100635 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700636error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700638error4:
David Howells664cceb2005-09-28 17:03:15 +0100639 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700640error3:
David Howells664cceb2005-09-28 17:03:15 +0100641 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700642error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700644error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000646}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648/*
David Howells973c9f42011-01-20 16:38:33 +0000649 * Read a key's payload.
650 *
651 * The key must either grant the caller Read permission, or it must grant the
652 * caller Search permission when searched for from the process keyrings.
653 *
654 * If successful, we place up to buflen bytes of data into the buffer, if one
655 * is provided, and return the amount of data that is available in the key,
656 * irrespective of how much we copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 */
658long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
659{
David Howells664cceb2005-09-28 17:03:15 +0100660 struct key *key;
661 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 long ret;
663
664 /* find the key first */
David Howells55931222009-09-02 09:13:45 +0100665 key_ref = lookup_user_key(keyid, 0, 0);
David Howells664cceb2005-09-28 17:03:15 +0100666 if (IS_ERR(key_ref)) {
667 ret = -ENOKEY;
668 goto error;
669 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
David Howells664cceb2005-09-28 17:03:15 +0100671 key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672
David Howells664cceb2005-09-28 17:03:15 +0100673 /* see if we can read it directly */
David Howells29db9192005-10-30 15:02:44 -0800674 ret = key_permission(key_ref, KEY_READ);
675 if (ret == 0)
David Howells664cceb2005-09-28 17:03:15 +0100676 goto can_read_key;
David Howells29db9192005-10-30 15:02:44 -0800677 if (ret != -EACCES)
678 goto error;
David Howells664cceb2005-09-28 17:03:15 +0100679
680 /* we can't; see if it's searchable from this process's keyrings
681 * - we automatically take account of the fact that it may be
682 * dangling off an instantiation key
683 */
684 if (!is_key_possessed(key_ref)) {
685 ret = -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 goto error2;
687 }
688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 /* the key is probably readable - now try to read it */
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700690can_read_key:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 ret = key_validate(key);
692 if (ret == 0) {
693 ret = -EOPNOTSUPP;
694 if (key->type->read) {
695 /* read the data with the semaphore held (since we
696 * might sleep) */
697 down_read(&key->sem);
698 ret = key->type->read(key, buffer, buflen);
699 up_read(&key->sem);
700 }
701 }
702
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700703error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700705error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000707}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709/*
David Howells973c9f42011-01-20 16:38:33 +0000710 * Change the ownership of a key
711 *
712 * The key must grant the caller Setattr permission for this to work, though
713 * the key need not be fully instantiated yet. For the UID to be changed, or
714 * for the GID to be changed to a group the caller is not a member of, the
715 * caller must have sysadmin capability. If either uid or gid is -1 then that
716 * attribute is not changed.
717 *
718 * If the UID is to be changed, the new user must have sufficient quota to
719 * accept the key. The quota deduction will be removed from the old user to
720 * the new user should the attribute be changed.
721 *
722 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 */
724long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
725{
Fredrik Tolf58016492006-06-26 00:24:51 -0700726 struct key_user *newowner, *zapowner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100728 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 long ret;
730
731 ret = 0;
732 if (uid == (uid_t) -1 && gid == (gid_t) -1)
733 goto error;
734
David Howells55931222009-09-02 09:13:45 +0100735 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
736 KEY_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100737 if (IS_ERR(key_ref)) {
738 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 goto error;
740 }
741
David Howells664cceb2005-09-28 17:03:15 +0100742 key = key_ref_to_ptr(key_ref);
743
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 /* make the changes with the locks held to prevent chown/chown races */
745 ret = -EACCES;
746 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747
748 if (!capable(CAP_SYS_ADMIN)) {
749 /* only the sysadmin can chown a key to some other UID */
750 if (uid != (uid_t) -1 && key->uid != uid)
Fredrik Tolf58016492006-06-26 00:24:51 -0700751 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752
753 /* only the sysadmin can set the key's GID to a group other
754 * than one of those that the current process subscribes to */
755 if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid))
Fredrik Tolf58016492006-06-26 00:24:51 -0700756 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 }
758
Fredrik Tolf58016492006-06-26 00:24:51 -0700759 /* change the UID */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 if (uid != (uid_t) -1 && uid != key->uid) {
Fredrik Tolf58016492006-06-26 00:24:51 -0700761 ret = -ENOMEM;
Serge E. Hallyn1d1e9752009-02-26 18:27:38 -0600762 newowner = key_user_lookup(uid, current_user_ns());
Fredrik Tolf58016492006-06-26 00:24:51 -0700763 if (!newowner)
764 goto error_put;
765
766 /* transfer the quota burden to the new user */
767 if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
David Howells0b77f5b2008-04-29 01:01:32 -0700768 unsigned maxkeys = (uid == 0) ?
769 key_quota_root_maxkeys : key_quota_maxkeys;
770 unsigned maxbytes = (uid == 0) ?
771 key_quota_root_maxbytes : key_quota_maxbytes;
772
Fredrik Tolf58016492006-06-26 00:24:51 -0700773 spin_lock(&newowner->lock);
David Howells0b77f5b2008-04-29 01:01:32 -0700774 if (newowner->qnkeys + 1 >= maxkeys ||
775 newowner->qnbytes + key->quotalen >= maxbytes ||
776 newowner->qnbytes + key->quotalen <
777 newowner->qnbytes)
Fredrik Tolf58016492006-06-26 00:24:51 -0700778 goto quota_overrun;
779
780 newowner->qnkeys++;
781 newowner->qnbytes += key->quotalen;
782 spin_unlock(&newowner->lock);
783
784 spin_lock(&key->user->lock);
785 key->user->qnkeys--;
786 key->user->qnbytes -= key->quotalen;
787 spin_unlock(&key->user->lock);
788 }
789
790 atomic_dec(&key->user->nkeys);
791 atomic_inc(&newowner->nkeys);
792
793 if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
794 atomic_dec(&key->user->nikeys);
795 atomic_inc(&newowner->nikeys);
796 }
797
798 zapowner = key->user;
799 key->user = newowner;
800 key->uid = uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 }
802
803 /* change the GID */
804 if (gid != (gid_t) -1)
805 key->gid = gid;
806
807 ret = 0;
808
Fredrik Tolf58016492006-06-26 00:24:51 -0700809error_put:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 up_write(&key->sem);
811 key_put(key);
Fredrik Tolf58016492006-06-26 00:24:51 -0700812 if (zapowner)
813 key_user_put(zapowner);
814error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 return ret;
816
Fredrik Tolf58016492006-06-26 00:24:51 -0700817quota_overrun:
818 spin_unlock(&newowner->lock);
819 zapowner = newowner;
820 ret = -EDQUOT;
821 goto error_put;
David Howellsa8b17ed2011-01-20 16:38:27 +0000822}
Fredrik Tolf58016492006-06-26 00:24:51 -0700823
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824/*
David Howells973c9f42011-01-20 16:38:33 +0000825 * Change the permission mask on a key.
826 *
827 * The key must grant the caller Setattr permission for this to work, though
828 * the key need not be fully instantiated yet. If the caller does not have
829 * sysadmin capability, it may only change the permission on keys that it owns.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 */
831long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
832{
833 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100834 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 long ret;
836
837 ret = -EINVAL;
David Howells664cceb2005-09-28 17:03:15 +0100838 if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 goto error;
840
David Howells55931222009-09-02 09:13:45 +0100841 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
842 KEY_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100843 if (IS_ERR(key_ref)) {
844 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 goto error;
846 }
847
David Howells664cceb2005-09-28 17:03:15 +0100848 key = key_ref_to_ptr(key_ref);
849
David Howells76d8aea2005-06-23 22:00:49 -0700850 /* make the changes with the locks held to prevent chown/chmod races */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 ret = -EACCES;
852 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853
David Howells76d8aea2005-06-23 22:00:49 -0700854 /* if we're not the sysadmin, we can only change a key that we own */
David Howells47d804b2008-11-14 10:39:11 +1100855 if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) {
David Howells76d8aea2005-06-23 22:00:49 -0700856 key->perm = perm;
857 ret = 0;
858 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 up_write(&key->sem);
861 key_put(key);
David Howells76d8aea2005-06-23 22:00:49 -0700862error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000864}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865
David Howells8bbf49762008-11-14 10:39:14 +1100866/*
David Howells973c9f42011-01-20 16:38:33 +0000867 * Get the destination keyring for instantiation and check that the caller has
868 * Write permission on it.
David Howells8bbf49762008-11-14 10:39:14 +1100869 */
870static long get_instantiation_keyring(key_serial_t ringid,
871 struct request_key_auth *rka,
872 struct key **_dest_keyring)
873{
874 key_ref_t dkref;
875
David Howellseca1bf52008-12-29 00:41:51 +0000876 *_dest_keyring = NULL;
877
David Howells8bbf49762008-11-14 10:39:14 +1100878 /* just return a NULL pointer if we weren't asked to make a link */
David Howellseca1bf52008-12-29 00:41:51 +0000879 if (ringid == 0)
David Howells8bbf49762008-11-14 10:39:14 +1100880 return 0;
David Howells8bbf49762008-11-14 10:39:14 +1100881
882 /* if a specific keyring is nominated by ID, then use that */
883 if (ringid > 0) {
David Howells55931222009-09-02 09:13:45 +0100884 dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells8bbf49762008-11-14 10:39:14 +1100885 if (IS_ERR(dkref))
886 return PTR_ERR(dkref);
887 *_dest_keyring = key_ref_to_ptr(dkref);
888 return 0;
889 }
890
891 if (ringid == KEY_SPEC_REQKEY_AUTH_KEY)
892 return -EINVAL;
893
894 /* otherwise specify the destination keyring recorded in the
895 * authorisation key (any KEY_SPEC_*_KEYRING) */
896 if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) {
David Howells21279cf2009-10-15 10:14:35 +0100897 *_dest_keyring = key_get(rka->dest_keyring);
David Howells8bbf49762008-11-14 10:39:14 +1100898 return 0;
899 }
900
901 return -ENOKEY;
902}
903
David Howellsd84f4f92008-11-14 10:39:23 +1100904/*
David Howells973c9f42011-01-20 16:38:33 +0000905 * Change the request_key authorisation key on the current process.
David Howellsd84f4f92008-11-14 10:39:23 +1100906 */
907static int keyctl_change_reqkey_auth(struct key *key)
908{
909 struct cred *new;
910
911 new = prepare_creds();
912 if (!new)
913 return -ENOMEM;
914
915 key_put(new->request_key_auth);
916 new->request_key_auth = key_get(key);
917
918 return commit_creds(new);
919}
920
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921/*
David Howellsee009e4a02011-03-07 15:06:20 +0000922 * Copy the iovec data from userspace
923 */
924static long copy_from_user_iovec(void *buffer, const struct iovec *iov,
925 unsigned ioc)
926{
927 for (; ioc > 0; ioc--) {
928 if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0)
929 return -EFAULT;
930 buffer += iov->iov_len;
931 iov++;
932 }
933 return 0;
934}
935
936/*
David Howells973c9f42011-01-20 16:38:33 +0000937 * Instantiate a key with the specified payload and link the key into the
938 * destination keyring if one is given.
939 *
940 * The caller must have the appropriate instantiation permit set for this to
941 * work (see keyctl_assume_authority). No other permissions are required.
942 *
943 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 */
David Howellsee009e4a02011-03-07 15:06:20 +0000945long keyctl_instantiate_key_common(key_serial_t id,
946 const struct iovec *payload_iov,
947 unsigned ioc,
948 size_t plen,
949 key_serial_t ringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950{
David Howellsd84f4f92008-11-14 10:39:23 +1100951 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -0700952 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +1100953 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 void *payload;
955 long ret;
David Howells38bbca62008-04-29 01:01:19 -0700956 bool vm = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957
David Howellsd84f4f92008-11-14 10:39:23 +1100958 kenter("%d,,%zu,%d", id, plen, ringid);
959
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -0700961 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 goto error;
963
David Howellsb5f545c2006-01-08 01:02:47 -0800964 /* the appropriate instantiation authorisation key must have been
965 * assumed before calling this */
966 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +1100967 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -0800968 if (!instkey)
969 goto error;
970
971 rka = instkey->payload.data;
972 if (rka->target_key->serial != id)
973 goto error;
974
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 /* pull the payload in if one was supplied */
976 payload = NULL;
977
David Howellsee009e4a02011-03-07 15:06:20 +0000978 if (payload_iov) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 ret = -ENOMEM;
980 payload = kmalloc(plen, GFP_KERNEL);
David Howells38bbca62008-04-29 01:01:19 -0700981 if (!payload) {
982 if (plen <= PAGE_SIZE)
983 goto error;
984 vm = true;
985 payload = vmalloc(plen);
986 if (!payload)
987 goto error;
988 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989
David Howellsee009e4a02011-03-07 15:06:20 +0000990 ret = copy_from_user_iovec(payload, payload_iov, ioc);
991 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 goto error2;
993 }
994
David Howells3e301482005-06-23 22:00:56 -0700995 /* find the destination keyring amongst those belonging to the
996 * requesting task */
David Howells8bbf49762008-11-14 10:39:14 +1100997 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
998 if (ret < 0)
999 goto error2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000
1001 /* instantiate the key and link it into a keyring */
David Howells3e301482005-06-23 22:00:56 -07001002 ret = key_instantiate_and_link(rka->target_key, payload, plen,
David Howells8bbf49762008-11-14 10:39:14 +11001003 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004
David Howells8bbf49762008-11-14 10:39:14 +11001005 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001006
1007 /* discard the assumed authority if it's just been disabled by
1008 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001009 if (ret == 0)
1010 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001011
1012error2:
David Howells38bbca62008-04-29 01:01:19 -07001013 if (!vm)
1014 kfree(payload);
1015 else
1016 vfree(payload);
David Howellsb5f545c2006-01-08 01:02:47 -08001017error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001019}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021/*
David Howellsee009e4a02011-03-07 15:06:20 +00001022 * Instantiate a key with the specified payload and link the key into the
1023 * destination keyring if one is given.
1024 *
1025 * The caller must have the appropriate instantiation permit set for this to
1026 * work (see keyctl_assume_authority). No other permissions are required.
1027 *
1028 * If successful, 0 will be returned.
1029 */
1030long keyctl_instantiate_key(key_serial_t id,
1031 const void __user *_payload,
1032 size_t plen,
1033 key_serial_t ringid)
1034{
1035 if (_payload && plen) {
1036 struct iovec iov[1] = {
1037 [0].iov_base = (void __user *)_payload,
1038 [0].iov_len = plen
1039 };
1040
1041 return keyctl_instantiate_key_common(id, iov, 1, plen, ringid);
1042 }
1043
1044 return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
1045}
1046
1047/*
1048 * Instantiate a key with the specified multipart payload and link the key into
1049 * the destination keyring if one is given.
1050 *
1051 * The caller must have the appropriate instantiation permit set for this to
1052 * work (see keyctl_assume_authority). No other permissions are required.
1053 *
1054 * If successful, 0 will be returned.
1055 */
1056long keyctl_instantiate_key_iov(key_serial_t id,
1057 const struct iovec __user *_payload_iov,
1058 unsigned ioc,
1059 key_serial_t ringid)
1060{
1061 struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
1062 long ret;
1063
1064 if (_payload_iov == 0 || ioc == 0)
1065 goto no_payload;
1066
1067 ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
Christopher Yeohfcf63402011-10-31 17:06:39 -07001068 ARRAY_SIZE(iovstack), iovstack, &iov, 1);
David Howellsee009e4a02011-03-07 15:06:20 +00001069 if (ret < 0)
1070 return ret;
1071 if (ret == 0)
1072 goto no_payload_free;
1073
1074 ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
1075
1076 if (iov != iovstack)
1077 kfree(iov);
1078 return ret;
1079
1080no_payload_free:
1081 if (iov != iovstack)
1082 kfree(iov);
1083no_payload:
1084 return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
1085}
1086
1087/*
David Howells973c9f42011-01-20 16:38:33 +00001088 * Negatively instantiate the key with the given timeout (in seconds) and link
1089 * the key into the destination keyring if one is given.
1090 *
1091 * The caller must have the appropriate instantiation permit set for this to
1092 * work (see keyctl_assume_authority). No other permissions are required.
1093 *
1094 * The key and any links to the key will be automatically garbage collected
1095 * after the timeout expires.
1096 *
1097 * Negative keys are used to rate limit repeated request_key() calls by causing
1098 * them to return -ENOKEY until the negative key expires.
1099 *
1100 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 */
1102long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
1103{
David Howellsfdd1b942011-03-07 15:06:09 +00001104 return keyctl_reject_key(id, timeout, ENOKEY, ringid);
1105}
1106
1107/*
1108 * Negatively instantiate the key with the given timeout (in seconds) and error
1109 * code and link the key into the destination keyring if one is given.
1110 *
1111 * The caller must have the appropriate instantiation permit set for this to
1112 * work (see keyctl_assume_authority). No other permissions are required.
1113 *
1114 * The key and any links to the key will be automatically garbage collected
1115 * after the timeout expires.
1116 *
1117 * Negative keys are used to rate limit repeated request_key() calls by causing
1118 * them to return the specified error code until the negative key expires.
1119 *
1120 * If successful, 0 will be returned.
1121 */
1122long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error,
1123 key_serial_t ringid)
1124{
David Howellsd84f4f92008-11-14 10:39:23 +11001125 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -07001126 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +11001127 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 long ret;
1129
David Howellsfdd1b942011-03-07 15:06:09 +00001130 kenter("%d,%u,%u,%d", id, timeout, error, ringid);
1131
1132 /* must be a valid error code and mustn't be a kernel special */
1133 if (error <= 0 ||
1134 error >= MAX_ERRNO ||
1135 error == ERESTARTSYS ||
1136 error == ERESTARTNOINTR ||
1137 error == ERESTARTNOHAND ||
1138 error == ERESTART_RESTARTBLOCK)
1139 return -EINVAL;
David Howellsd84f4f92008-11-14 10:39:23 +11001140
David Howellsb5f545c2006-01-08 01:02:47 -08001141 /* the appropriate instantiation authorisation key must have been
1142 * assumed before calling this */
1143 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +11001144 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -08001145 if (!instkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147
David Howells3e301482005-06-23 22:00:56 -07001148 rka = instkey->payload.data;
David Howellsb5f545c2006-01-08 01:02:47 -08001149 if (rka->target_key->serial != id)
1150 goto error;
David Howells3e301482005-06-23 22:00:56 -07001151
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 /* find the destination keyring if present (which must also be
1153 * writable) */
David Howells8bbf49762008-11-14 10:39:14 +11001154 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1155 if (ret < 0)
1156 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157
1158 /* instantiate the key and link it into a keyring */
David Howellsfdd1b942011-03-07 15:06:09 +00001159 ret = key_reject_and_link(rka->target_key, timeout, error,
David Howells8bbf49762008-11-14 10:39:14 +11001160 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161
David Howells8bbf49762008-11-14 10:39:14 +11001162 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001163
1164 /* discard the assumed authority if it's just been disabled by
1165 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001166 if (ret == 0)
1167 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001168
1169error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001171}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173/*
David Howells973c9f42011-01-20 16:38:33 +00001174 * Read or set the default keyring in which request_key() will cache keys and
1175 * return the old setting.
1176 *
1177 * If a process keyring is specified then this will be created if it doesn't
1178 * yet exist. The old setting will be returned if successful.
David Howells3e301482005-06-23 22:00:56 -07001179 */
1180long keyctl_set_reqkey_keyring(int reqkey_defl)
1181{
David Howellsd84f4f92008-11-14 10:39:23 +11001182 struct cred *new;
1183 int ret, old_setting;
1184
1185 old_setting = current_cred_xxx(jit_keyring);
1186
1187 if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
1188 return old_setting;
1189
1190 new = prepare_creds();
1191 if (!new)
1192 return -ENOMEM;
David Howells3e301482005-06-23 22:00:56 -07001193
1194 switch (reqkey_defl) {
1195 case KEY_REQKEY_DEFL_THREAD_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001196 ret = install_thread_keyring_to_cred(new);
David Howells3e301482005-06-23 22:00:56 -07001197 if (ret < 0)
David Howellsd84f4f92008-11-14 10:39:23 +11001198 goto error;
David Howells3e301482005-06-23 22:00:56 -07001199 goto set;
1200
1201 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001202 ret = install_process_keyring_to_cred(new);
1203 if (ret < 0) {
1204 if (ret != -EEXIST)
1205 goto error;
1206 ret = 0;
1207 }
1208 goto set;
David Howells3e301482005-06-23 22:00:56 -07001209
1210 case KEY_REQKEY_DEFL_DEFAULT:
1211 case KEY_REQKEY_DEFL_SESSION_KEYRING:
1212 case KEY_REQKEY_DEFL_USER_KEYRING:
1213 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001214 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
1215 goto set;
David Howells3e301482005-06-23 22:00:56 -07001216
1217 case KEY_REQKEY_DEFL_NO_CHANGE:
David Howells3e301482005-06-23 22:00:56 -07001218 case KEY_REQKEY_DEFL_GROUP_KEYRING:
1219 default:
David Howellsd84f4f92008-11-14 10:39:23 +11001220 ret = -EINVAL;
1221 goto error;
David Howells3e301482005-06-23 22:00:56 -07001222 }
1223
David Howellsd84f4f92008-11-14 10:39:23 +11001224set:
1225 new->jit_keyring = reqkey_defl;
1226 commit_creds(new);
1227 return old_setting;
1228error:
1229 abort_creds(new);
Dan Carpenter4303ef12010-06-11 17:30:05 +01001230 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001231}
David Howellsd84f4f92008-11-14 10:39:23 +11001232
David Howells3e301482005-06-23 22:00:56 -07001233/*
David Howells973c9f42011-01-20 16:38:33 +00001234 * Set or clear the timeout on a key.
1235 *
1236 * Either the key must grant the caller Setattr permission or else the caller
1237 * must hold an instantiation authorisation token for the key.
1238 *
1239 * The timeout is either 0 to clear the timeout, or a number of seconds from
1240 * the current time. The key and any links to the key will be automatically
1241 * garbage collected after the timeout expires.
1242 *
1243 * If successful, 0 is returned.
David Howells017679c2006-01-08 01:02:43 -08001244 */
1245long keyctl_set_timeout(key_serial_t id, unsigned timeout)
1246{
1247 struct timespec now;
David Howells91562352010-06-11 17:31:05 +01001248 struct key *key, *instkey;
David Howells017679c2006-01-08 01:02:43 -08001249 key_ref_t key_ref;
1250 time_t expiry;
1251 long ret;
1252
David Howells55931222009-09-02 09:13:45 +01001253 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
1254 KEY_SETATTR);
David Howells017679c2006-01-08 01:02:43 -08001255 if (IS_ERR(key_ref)) {
David Howells91562352010-06-11 17:31:05 +01001256 /* setting the timeout on a key under construction is permitted
1257 * if we have the authorisation token handy */
1258 if (PTR_ERR(key_ref) == -EACCES) {
1259 instkey = key_get_instantiation_authkey(id);
1260 if (!IS_ERR(instkey)) {
1261 key_put(instkey);
1262 key_ref = lookup_user_key(id,
1263 KEY_LOOKUP_PARTIAL,
1264 0);
1265 if (!IS_ERR(key_ref))
1266 goto okay;
1267 }
1268 }
1269
David Howells017679c2006-01-08 01:02:43 -08001270 ret = PTR_ERR(key_ref);
1271 goto error;
1272 }
1273
David Howells91562352010-06-11 17:31:05 +01001274okay:
David Howells017679c2006-01-08 01:02:43 -08001275 key = key_ref_to_ptr(key_ref);
1276
1277 /* make the changes with the locks held to prevent races */
1278 down_write(&key->sem);
1279
1280 expiry = 0;
1281 if (timeout > 0) {
1282 now = current_kernel_time();
1283 expiry = now.tv_sec + timeout;
1284 }
1285
1286 key->expiry = expiry;
David Howellsc08ef802009-09-14 17:26:13 +01001287 key_schedule_gc(key->expiry + key_gc_delay);
David Howells017679c2006-01-08 01:02:43 -08001288
1289 up_write(&key->sem);
1290 key_put(key);
1291
1292 ret = 0;
1293error:
1294 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001295}
David Howells017679c2006-01-08 01:02:43 -08001296
David Howells017679c2006-01-08 01:02:43 -08001297/*
David Howells973c9f42011-01-20 16:38:33 +00001298 * Assume (or clear) the authority to instantiate the specified key.
1299 *
1300 * This sets the authoritative token currently in force for key instantiation.
1301 * This must be done for a key to be instantiated. It has the effect of making
1302 * available all the keys from the caller of the request_key() that created a
1303 * key to request_key() calls made by the caller of this function.
1304 *
1305 * The caller must have the instantiation key in their process keyrings with a
1306 * Search permission grant available to the caller.
1307 *
1308 * If the ID given is 0, then the setting will be cleared and 0 returned.
1309 *
1310 * If the ID given has a matching an authorisation key, then that key will be
1311 * set and its ID will be returned. The authorisation key can be read to get
1312 * the callout information passed to request_key().
David Howellsb5f545c2006-01-08 01:02:47 -08001313 */
1314long keyctl_assume_authority(key_serial_t id)
1315{
1316 struct key *authkey;
1317 long ret;
1318
1319 /* special key IDs aren't permitted */
1320 ret = -EINVAL;
1321 if (id < 0)
1322 goto error;
1323
1324 /* we divest ourselves of authority if given an ID of 0 */
1325 if (id == 0) {
David Howellsd84f4f92008-11-14 10:39:23 +11001326 ret = keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001327 goto error;
1328 }
1329
1330 /* attempt to assume the authority temporarily granted to us whilst we
1331 * instantiate the specified key
1332 * - the authorisation key must be in the current task's keyrings
1333 * somewhere
1334 */
1335 authkey = key_get_instantiation_authkey(id);
1336 if (IS_ERR(authkey)) {
1337 ret = PTR_ERR(authkey);
1338 goto error;
1339 }
1340
David Howellsd84f4f92008-11-14 10:39:23 +11001341 ret = keyctl_change_reqkey_auth(authkey);
1342 if (ret < 0)
1343 goto error;
1344 key_put(authkey);
David Howellsb5f545c2006-01-08 01:02:47 -08001345
David Howellsd84f4f92008-11-14 10:39:23 +11001346 ret = authkey->serial;
David Howellsb5f545c2006-01-08 01:02:47 -08001347error:
1348 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001349}
David Howellsb5f545c2006-01-08 01:02:47 -08001350
David Howells70a5bb72008-04-29 01:01:26 -07001351/*
David Howells973c9f42011-01-20 16:38:33 +00001352 * Get a key's the LSM security label.
1353 *
1354 * The key must grant the caller View permission for this to work.
1355 *
1356 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1357 *
1358 * If successful, the amount of information available will be returned,
1359 * irrespective of how much was copied (including the terminal NUL).
David Howells70a5bb72008-04-29 01:01:26 -07001360 */
1361long keyctl_get_security(key_serial_t keyid,
1362 char __user *buffer,
1363 size_t buflen)
1364{
1365 struct key *key, *instkey;
1366 key_ref_t key_ref;
1367 char *context;
1368 long ret;
1369
David Howells55931222009-09-02 09:13:45 +01001370 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
David Howells70a5bb72008-04-29 01:01:26 -07001371 if (IS_ERR(key_ref)) {
1372 if (PTR_ERR(key_ref) != -EACCES)
1373 return PTR_ERR(key_ref);
1374
1375 /* viewing a key under construction is also permitted if we
1376 * have the authorisation token handy */
1377 instkey = key_get_instantiation_authkey(keyid);
1378 if (IS_ERR(instkey))
Roel Kluinfa1cc7b2009-12-15 15:05:12 -08001379 return PTR_ERR(instkey);
David Howells70a5bb72008-04-29 01:01:26 -07001380 key_put(instkey);
1381
David Howells55931222009-09-02 09:13:45 +01001382 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
David Howells70a5bb72008-04-29 01:01:26 -07001383 if (IS_ERR(key_ref))
1384 return PTR_ERR(key_ref);
1385 }
1386
1387 key = key_ref_to_ptr(key_ref);
1388 ret = security_key_getsecurity(key, &context);
1389 if (ret == 0) {
1390 /* if no information was returned, give userspace an empty
1391 * string */
1392 ret = 1;
1393 if (buffer && buflen > 0 &&
1394 copy_to_user(buffer, "", 1) != 0)
1395 ret = -EFAULT;
1396 } else if (ret > 0) {
1397 /* return as much data as there's room for */
1398 if (buffer && buflen > 0) {
1399 if (buflen > ret)
1400 buflen = ret;
1401
1402 if (copy_to_user(buffer, context, buflen) != 0)
1403 ret = -EFAULT;
1404 }
1405
1406 kfree(context);
1407 }
1408
1409 key_ref_put(key_ref);
1410 return ret;
1411}
1412
David Howellsee18d642009-09-02 09:14:21 +01001413/*
David Howells973c9f42011-01-20 16:38:33 +00001414 * Attempt to install the calling process's session keyring on the process's
1415 * parent process.
1416 *
1417 * The keyring must exist and must grant the caller LINK permission, and the
1418 * parent process must be single-threaded and must have the same effective
1419 * ownership as this process and mustn't be SUID/SGID.
1420 *
1421 * The keyring will be emplaced on the parent when it next resumes userspace.
1422 *
1423 * If successful, 0 will be returned.
David Howellsee18d642009-09-02 09:14:21 +01001424 */
1425long keyctl_session_to_parent(void)
1426{
Geert Uytterhoevena00ae4d2009-12-13 20:21:34 +01001427#ifdef TIF_NOTIFY_RESUME
David Howellsee18d642009-09-02 09:14:21 +01001428 struct task_struct *me, *parent;
1429 const struct cred *mycred, *pcred;
1430 struct cred *cred, *oldcred;
1431 key_ref_t keyring_r;
1432 int ret;
1433
1434 keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
1435 if (IS_ERR(keyring_r))
1436 return PTR_ERR(keyring_r);
1437
1438 /* our parent is going to need a new cred struct, a new tgcred struct
1439 * and new security data, so we allocate them here to prevent ENOMEM in
1440 * our parent */
1441 ret = -ENOMEM;
1442 cred = cred_alloc_blank();
1443 if (!cred)
1444 goto error_keyring;
1445
1446 cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
1447 keyring_r = NULL;
1448
1449 me = current;
David Howells9d1ac652010-09-10 09:59:46 +01001450 rcu_read_lock();
David Howellsee18d642009-09-02 09:14:21 +01001451 write_lock_irq(&tasklist_lock);
1452
1453 parent = me->real_parent;
1454 ret = -EPERM;
1455
1456 /* the parent mustn't be init and mustn't be a kernel thread */
1457 if (parent->pid <= 1 || !parent->mm)
1458 goto not_permitted;
1459
1460 /* the parent must be single threaded */
Oleg Nesterovdd98acf2010-05-26 14:43:23 -07001461 if (!thread_group_empty(parent))
David Howellsee18d642009-09-02 09:14:21 +01001462 goto not_permitted;
1463
1464 /* the parent and the child must have different session keyrings or
1465 * there's no point */
1466 mycred = current_cred();
1467 pcred = __task_cred(parent);
1468 if (mycred == pcred ||
1469 mycred->tgcred->session_keyring == pcred->tgcred->session_keyring)
1470 goto already_same;
1471
1472 /* the parent must have the same effective ownership and mustn't be
1473 * SUID/SGID */
Justin P. Mattockc5b60b52010-04-21 00:02:11 -07001474 if (pcred->uid != mycred->euid ||
David Howellsee18d642009-09-02 09:14:21 +01001475 pcred->euid != mycred->euid ||
1476 pcred->suid != mycred->euid ||
Justin P. Mattockc5b60b52010-04-21 00:02:11 -07001477 pcred->gid != mycred->egid ||
David Howellsee18d642009-09-02 09:14:21 +01001478 pcred->egid != mycred->egid ||
1479 pcred->sgid != mycred->egid)
1480 goto not_permitted;
1481
1482 /* the keyrings must have the same UID */
David Howells3d964062010-09-10 09:59:51 +01001483 if ((pcred->tgcred->session_keyring &&
1484 pcred->tgcred->session_keyring->uid != mycred->euid) ||
David Howellsee18d642009-09-02 09:14:21 +01001485 mycred->tgcred->session_keyring->uid != mycred->euid)
1486 goto not_permitted;
1487
David Howellsee18d642009-09-02 09:14:21 +01001488 /* if there's an already pending keyring replacement, then we replace
1489 * that */
1490 oldcred = parent->replacement_session_keyring;
1491
1492 /* the replacement session keyring is applied just prior to userspace
1493 * restarting */
1494 parent->replacement_session_keyring = cred;
1495 cred = NULL;
1496 set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
1497
1498 write_unlock_irq(&tasklist_lock);
David Howells9d1ac652010-09-10 09:59:46 +01001499 rcu_read_unlock();
David Howellsee18d642009-09-02 09:14:21 +01001500 if (oldcred)
1501 put_cred(oldcred);
1502 return 0;
1503
1504already_same:
1505 ret = 0;
1506not_permitted:
Marc Dionne5c843422009-09-14 12:46:23 +01001507 write_unlock_irq(&tasklist_lock);
David Howells9d1ac652010-09-10 09:59:46 +01001508 rcu_read_unlock();
David Howellsee18d642009-09-02 09:14:21 +01001509 put_cred(cred);
1510 return ret;
1511
1512error_keyring:
1513 key_ref_put(keyring_r);
1514 return ret;
Geert Uytterhoevena00ae4d2009-12-13 20:21:34 +01001515
1516#else /* !TIF_NOTIFY_RESUME */
1517 /*
1518 * To be removed when TIF_NOTIFY_RESUME has been implemented on
1519 * m68k/xtensa
1520 */
1521#warning TIF_NOTIFY_RESUME not implemented
1522 return -EOPNOTSUPP;
1523#endif /* !TIF_NOTIFY_RESUME */
David Howellsee18d642009-09-02 09:14:21 +01001524}
1525
David Howellsb5f545c2006-01-08 01:02:47 -08001526/*
David Howells973c9f42011-01-20 16:38:33 +00001527 * The key control system call
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528 */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001529SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
1530 unsigned long, arg4, unsigned long, arg5)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531{
1532 switch (option) {
1533 case KEYCTL_GET_KEYRING_ID:
1534 return keyctl_get_keyring_ID((key_serial_t) arg2,
1535 (int) arg3);
1536
1537 case KEYCTL_JOIN_SESSION_KEYRING:
1538 return keyctl_join_session_keyring((const char __user *) arg2);
1539
1540 case KEYCTL_UPDATE:
1541 return keyctl_update_key((key_serial_t) arg2,
1542 (const void __user *) arg3,
1543 (size_t) arg4);
1544
1545 case KEYCTL_REVOKE:
1546 return keyctl_revoke_key((key_serial_t) arg2);
1547
1548 case KEYCTL_DESCRIBE:
1549 return keyctl_describe_key((key_serial_t) arg2,
1550 (char __user *) arg3,
1551 (unsigned) arg4);
1552
1553 case KEYCTL_CLEAR:
1554 return keyctl_keyring_clear((key_serial_t) arg2);
1555
1556 case KEYCTL_LINK:
1557 return keyctl_keyring_link((key_serial_t) arg2,
1558 (key_serial_t) arg3);
1559
1560 case KEYCTL_UNLINK:
1561 return keyctl_keyring_unlink((key_serial_t) arg2,
1562 (key_serial_t) arg3);
1563
1564 case KEYCTL_SEARCH:
1565 return keyctl_keyring_search((key_serial_t) arg2,
1566 (const char __user *) arg3,
1567 (const char __user *) arg4,
1568 (key_serial_t) arg5);
1569
1570 case KEYCTL_READ:
1571 return keyctl_read_key((key_serial_t) arg2,
1572 (char __user *) arg3,
1573 (size_t) arg4);
1574
1575 case KEYCTL_CHOWN:
1576 return keyctl_chown_key((key_serial_t) arg2,
1577 (uid_t) arg3,
1578 (gid_t) arg4);
1579
1580 case KEYCTL_SETPERM:
1581 return keyctl_setperm_key((key_serial_t) arg2,
1582 (key_perm_t) arg3);
1583
1584 case KEYCTL_INSTANTIATE:
1585 return keyctl_instantiate_key((key_serial_t) arg2,
1586 (const void __user *) arg3,
1587 (size_t) arg4,
1588 (key_serial_t) arg5);
1589
1590 case KEYCTL_NEGATE:
1591 return keyctl_negate_key((key_serial_t) arg2,
1592 (unsigned) arg3,
1593 (key_serial_t) arg4);
1594
David Howells3e301482005-06-23 22:00:56 -07001595 case KEYCTL_SET_REQKEY_KEYRING:
1596 return keyctl_set_reqkey_keyring(arg2);
1597
David Howells017679c2006-01-08 01:02:43 -08001598 case KEYCTL_SET_TIMEOUT:
1599 return keyctl_set_timeout((key_serial_t) arg2,
1600 (unsigned) arg3);
1601
David Howellsb5f545c2006-01-08 01:02:47 -08001602 case KEYCTL_ASSUME_AUTHORITY:
1603 return keyctl_assume_authority((key_serial_t) arg2);
1604
David Howells70a5bb72008-04-29 01:01:26 -07001605 case KEYCTL_GET_SECURITY:
1606 return keyctl_get_security((key_serial_t) arg2,
James Morris90bd49a2008-12-29 14:35:35 +11001607 (char __user *) arg3,
David Howells70a5bb72008-04-29 01:01:26 -07001608 (size_t) arg4);
1609
David Howellsee18d642009-09-02 09:14:21 +01001610 case KEYCTL_SESSION_TO_PARENT:
1611 return keyctl_session_to_parent();
1612
David Howellsfdd1b942011-03-07 15:06:09 +00001613 case KEYCTL_REJECT:
1614 return keyctl_reject_key((key_serial_t) arg2,
1615 (unsigned) arg3,
1616 (unsigned) arg4,
1617 (key_serial_t) arg5);
1618
David Howellsee009e4a02011-03-07 15:06:20 +00001619 case KEYCTL_INSTANTIATE_IOV:
1620 return keyctl_instantiate_key_iov(
1621 (key_serial_t) arg2,
1622 (const struct iovec __user *) arg3,
1623 (unsigned) arg4,
1624 (key_serial_t) arg5);
1625
Linus Torvalds1da177e2005-04-16 15:20:36 -07001626 default:
1627 return -EOPNOTSUPP;
1628 }
David Howellsa8b17ed2011-01-20 16:38:27 +00001629}