blob: 18f29de88fda22196a49e28b43175ed1935fff5b [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <asm/uaccess.h>
26#include "internal.h"
27
Davi Arnaut0cb409d2006-03-24 03:18:43 -080028static int key_get_type_from_user(char *type,
29 const char __user *_type,
30 unsigned len)
31{
32 int ret;
33
34 ret = strncpy_from_user(type, _type, len);
Davi Arnaut0cb409d2006-03-24 03:18:43 -080035 if (ret < 0)
Dan Carpenter4303ef12010-06-11 17:30:05 +010036 return ret;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080037 if (ret == 0 || ret >= len)
38 return -EINVAL;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080039 if (type[0] == '.')
40 return -EPERM;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080041 type[len - 1] = '\0';
Davi Arnaut0cb409d2006-03-24 03:18:43 -080042 return 0;
43}
44
Linus Torvalds1da177e2005-04-16 15:20:36 -070045/*
David Howells973c9f42011-01-20 16:38:33 +000046 * Extract the description of a new key from userspace and either add it as a
47 * new key to the specified keyring or update a matching key in that keyring.
48 *
49 * The keyring must be writable so that we can attach the key to it.
50 *
51 * If successful, the new key's serial number is returned, otherwise an error
52 * code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +010054SYSCALL_DEFINE5(add_key, const char __user *, _type,
55 const char __user *, _description,
56 const void __user *, _payload,
57 size_t, plen,
58 key_serial_t, ringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
David Howells664cceb2005-09-28 17:03:15 +010060 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 char type[32], *description;
62 void *payload;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080063 long ret;
David Howells38bbca62008-04-29 01:01:19 -070064 bool vm;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -070067 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 goto error;
69
70 /* draw all the data into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -080071 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 if (ret < 0)
73 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Davi Arnaut0cb409d2006-03-24 03:18:43 -080075 description = strndup_user(_description, PAGE_SIZE);
76 if (IS_ERR(description)) {
77 ret = PTR_ERR(description);
David Howells3e301482005-06-23 22:00:56 -070078 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080079 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81 /* pull the payload in if one was supplied */
82 payload = NULL;
83
David Howells38bbca62008-04-29 01:01:19 -070084 vm = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 if (_payload) {
86 ret = -ENOMEM;
Andrew Morton4f1c28d2012-05-31 16:26:02 -070087 payload = kmalloc(plen, GFP_KERNEL | __GFP_NOWARN);
David Howells38bbca62008-04-29 01:01:19 -070088 if (!payload) {
89 if (plen <= PAGE_SIZE)
90 goto error2;
91 vm = true;
92 payload = vmalloc(plen);
93 if (!payload)
94 goto error2;
95 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97 ret = -EFAULT;
98 if (copy_from_user(payload, _payload, plen) != 0)
99 goto error3;
100 }
101
102 /* find the target keyring (which must be writable) */
David Howells55931222009-09-02 09:13:45 +0100103 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100104 if (IS_ERR(keyring_ref)) {
105 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 goto error3;
107 }
108
109 /* create or update the requested key and add it to the target
110 * keyring */
David Howells664cceb2005-09-28 17:03:15 +0100111 key_ref = key_create_or_update(keyring_ref, type, description,
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700112 payload, plen, KEY_PERM_UNDEF,
113 KEY_ALLOC_IN_QUOTA);
David Howells664cceb2005-09-28 17:03:15 +0100114 if (!IS_ERR(key_ref)) {
115 ret = key_ref_to_ptr(key_ref)->serial;
116 key_ref_put(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 }
118 else {
David Howells664cceb2005-09-28 17:03:15 +0100119 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 }
121
David Howells664cceb2005-09-28 17:03:15 +0100122 key_ref_put(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 error3:
David Howells38bbca62008-04-29 01:01:19 -0700124 if (!vm)
125 kfree(payload);
126 else
127 vfree(payload);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 error2:
129 kfree(description);
130 error:
131 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000132}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134/*
David Howells973c9f42011-01-20 16:38:33 +0000135 * Search the process keyrings and keyring trees linked from those for a
136 * matching key. Keyrings must have appropriate Search permission to be
137 * searched.
138 *
139 * If a key is found, it will be attached to the destination keyring if there's
140 * one specified and the serial number of the key will be returned.
141 *
142 * If no key is found, /sbin/request-key will be invoked if _callout_info is
143 * non-NULL in an attempt to create a key. The _callout_info string will be
144 * passed to /sbin/request-key to aid with completing the request. If the
145 * _callout_info string is "" then it will be changed to "-".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +0100147SYSCALL_DEFINE4(request_key, const char __user *, _type,
148 const char __user *, _description,
149 const char __user *, _callout_info,
150 key_serial_t, destringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151{
152 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100153 struct key *key;
154 key_ref_t dest_ref;
David Howells4a38e122008-04-29 01:01:24 -0700155 size_t callout_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 char type[32], *description, *callout_info;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800157 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
159 /* pull the type into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800160 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 if (ret < 0)
162 goto error;
David Howells1260f802005-08-04 11:50:01 +0100163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 /* pull the description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800165 description = strndup_user(_description, PAGE_SIZE);
166 if (IS_ERR(description)) {
167 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800169 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
171 /* pull the callout info into kernel space */
172 callout_info = NULL;
David Howells4a38e122008-04-29 01:01:24 -0700173 callout_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 if (_callout_info) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800175 callout_info = strndup_user(_callout_info, PAGE_SIZE);
176 if (IS_ERR(callout_info)) {
177 ret = PTR_ERR(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 goto error2;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800179 }
David Howells4a38e122008-04-29 01:01:24 -0700180 callout_len = strlen(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 }
182
183 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100184 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100186 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
187 KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100188 if (IS_ERR(dest_ref)) {
189 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 goto error3;
191 }
192 }
193
194 /* find the key type */
195 ktype = key_type_lookup(type);
196 if (IS_ERR(ktype)) {
197 ret = PTR_ERR(ktype);
198 goto error4;
199 }
200
201 /* do the search */
David Howells4a38e122008-04-29 01:01:24 -0700202 key = request_key_and_link(ktype, description, callout_info,
203 callout_len, NULL, key_ref_to_ptr(dest_ref),
David Howells7e047ef2006-06-26 00:24:50 -0700204 KEY_ALLOC_IN_QUOTA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 if (IS_ERR(key)) {
206 ret = PTR_ERR(key);
207 goto error5;
208 }
209
David Howells4aab1e82011-03-11 17:57:33 +0000210 /* wait for the key to finish being constructed */
211 ret = wait_for_key_construction(key, 1);
212 if (ret < 0)
213 goto error6;
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 ret = key->serial;
216
David Howells4aab1e82011-03-11 17:57:33 +0000217error6:
David Howells3e301482005-06-23 22:00:56 -0700218 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700219error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700221error4:
David Howells664cceb2005-09-28 17:03:15 +0100222 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700223error3:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 kfree(callout_info);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700225error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700227error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000229}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231/*
David Howells973c9f42011-01-20 16:38:33 +0000232 * Get the ID of the specified process keyring.
233 *
234 * The requested keyring must have search permission to be found.
235 *
236 * If successful, the ID of the requested keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 */
238long keyctl_get_keyring_ID(key_serial_t id, int create)
239{
David Howells664cceb2005-09-28 17:03:15 +0100240 key_ref_t key_ref;
David Howells55931222009-09-02 09:13:45 +0100241 unsigned long lflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 long ret;
243
David Howells55931222009-09-02 09:13:45 +0100244 lflags = create ? KEY_LOOKUP_CREATE : 0;
245 key_ref = lookup_user_key(id, lflags, KEY_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100246 if (IS_ERR(key_ref)) {
247 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 goto error;
249 }
250
David Howells664cceb2005-09-28 17:03:15 +0100251 ret = key_ref_to_ptr(key_ref)->serial;
252 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700253error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 return ret;
David Howells973c9f42011-01-20 16:38:33 +0000255}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257/*
David Howells973c9f42011-01-20 16:38:33 +0000258 * Join a (named) session keyring.
259 *
260 * Create and join an anonymous session keyring or join a named session
261 * keyring, creating it if necessary. A named session keyring must have Search
262 * permission for it to be joined. Session keyrings without this permit will
263 * be skipped over.
264 *
265 * If successful, the ID of the joined session keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 */
267long keyctl_join_session_keyring(const char __user *_name)
268{
269 char *name;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800270 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
272 /* fetch the name from userspace */
273 name = NULL;
274 if (_name) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800275 name = strndup_user(_name, PAGE_SIZE);
276 if (IS_ERR(name)) {
277 ret = PTR_ERR(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800279 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 }
281
282 /* join the session */
283 ret = join_session_keyring(name);
Vegard Nossum0d54ee12009-01-17 17:45:45 +0100284 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700286error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000288}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290/*
David Howells973c9f42011-01-20 16:38:33 +0000291 * Update a key's data payload from the given data.
292 *
293 * The key must grant the caller Write permission and the key type must support
294 * updating for this to work. A negative key can be positively instantiated
295 * with this call.
296 *
297 * If successful, 0 will be returned. If the key type does not support
298 * updating, then -EOPNOTSUPP will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 */
300long keyctl_update_key(key_serial_t id,
301 const void __user *_payload,
302 size_t plen)
303{
David Howells664cceb2005-09-28 17:03:15 +0100304 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 void *payload;
306 long ret;
307
308 ret = -EINVAL;
309 if (plen > PAGE_SIZE)
310 goto error;
311
312 /* pull the payload in if one was supplied */
313 payload = NULL;
314 if (_payload) {
315 ret = -ENOMEM;
316 payload = kmalloc(plen, GFP_KERNEL);
317 if (!payload)
318 goto error;
319
320 ret = -EFAULT;
321 if (copy_from_user(payload, _payload, plen) != 0)
322 goto error2;
323 }
324
325 /* find the target key (which must be writable) */
David Howells55931222009-09-02 09:13:45 +0100326 key_ref = lookup_user_key(id, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100327 if (IS_ERR(key_ref)) {
328 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 goto error2;
330 }
331
332 /* update the key */
David Howells664cceb2005-09-28 17:03:15 +0100333 ret = key_update(key_ref, payload, plen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
David Howells664cceb2005-09-28 17:03:15 +0100335 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700336error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 kfree(payload);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700338error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000340}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342/*
David Howells973c9f42011-01-20 16:38:33 +0000343 * Revoke a key.
344 *
345 * The key must be grant the caller Write or Setattr permission for this to
346 * work. The key type should give up its quota claim when revoked. The key
347 * and any links to the key will be automatically garbage collected after a
348 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
349 *
350 * If successful, 0 is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 */
352long keyctl_revoke_key(key_serial_t id)
353{
David Howells664cceb2005-09-28 17:03:15 +0100354 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 long ret;
356
David Howells55931222009-09-02 09:13:45 +0100357 key_ref = lookup_user_key(id, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100358 if (IS_ERR(key_ref)) {
359 ret = PTR_ERR(key_ref);
David Howells0c2c9a32009-09-02 09:13:50 +0100360 if (ret != -EACCES)
361 goto error;
362 key_ref = lookup_user_key(id, 0, KEY_SETATTR);
363 if (IS_ERR(key_ref)) {
364 ret = PTR_ERR(key_ref);
365 goto error;
366 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 }
368
David Howells664cceb2005-09-28 17:03:15 +0100369 key_revoke(key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 ret = 0;
371
David Howells664cceb2005-09-28 17:03:15 +0100372 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700373error:
David Howells1260f802005-08-04 11:50:01 +0100374 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000375}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377/*
David Howellsfd758152012-05-11 10:56:56 +0100378 * Invalidate a key.
379 *
380 * The key must be grant the caller Invalidate permission for this to work.
381 * The key and any links to the key will be automatically garbage collected
382 * immediately.
383 *
384 * If successful, 0 is returned.
385 */
386long keyctl_invalidate_key(key_serial_t id)
387{
388 key_ref_t key_ref;
389 long ret;
390
391 kenter("%d", id);
392
393 key_ref = lookup_user_key(id, 0, KEY_SEARCH);
394 if (IS_ERR(key_ref)) {
395 ret = PTR_ERR(key_ref);
396 goto error;
397 }
398
399 key_invalidate(key_ref_to_ptr(key_ref));
400 ret = 0;
401
402 key_ref_put(key_ref);
403error:
404 kleave(" = %ld", ret);
405 return ret;
406}
407
408/*
David Howells973c9f42011-01-20 16:38:33 +0000409 * Clear the specified keyring, creating an empty process keyring if one of the
410 * special keyring IDs is used.
411 *
412 * The keyring must grant the caller Write permission for this to work. If
413 * successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 */
415long keyctl_keyring_clear(key_serial_t ringid)
416{
David Howells664cceb2005-09-28 17:03:15 +0100417 key_ref_t keyring_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 long ret;
419
David Howells55931222009-09-02 09:13:45 +0100420 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100421 if (IS_ERR(keyring_ref)) {
422 ret = PTR_ERR(keyring_ref);
David Howells700920e2012-01-18 15:31:45 +0000423
424 /* Root is permitted to invalidate certain special keyrings */
425 if (capable(CAP_SYS_ADMIN)) {
426 keyring_ref = lookup_user_key(ringid, 0, 0);
427 if (IS_ERR(keyring_ref))
428 goto error;
429 if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR,
430 &key_ref_to_ptr(keyring_ref)->flags))
431 goto clear;
432 goto error_put;
433 }
434
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 goto error;
436 }
437
David Howells700920e2012-01-18 15:31:45 +0000438clear:
David Howells664cceb2005-09-28 17:03:15 +0100439 ret = keyring_clear(key_ref_to_ptr(keyring_ref));
David Howells700920e2012-01-18 15:31:45 +0000440error_put:
David Howells664cceb2005-09-28 17:03:15 +0100441 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700442error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000444}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446/*
David Howells973c9f42011-01-20 16:38:33 +0000447 * Create a link from a keyring to a key if there's no matching key in the
448 * keyring, otherwise replace the link to the matching key with a link to the
449 * new key.
450 *
451 * The key must grant the caller Link permission and the the keyring must grant
452 * the caller Write permission. Furthermore, if an additional link is created,
453 * the keyring's quota will be extended.
454 *
455 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 */
457long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
458{
David Howells664cceb2005-09-28 17:03:15 +0100459 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 long ret;
461
David Howells55931222009-09-02 09:13:45 +0100462 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100463 if (IS_ERR(keyring_ref)) {
464 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 goto error;
466 }
467
David Howells55931222009-09-02 09:13:45 +0100468 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK);
David Howells664cceb2005-09-28 17:03:15 +0100469 if (IS_ERR(key_ref)) {
470 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 goto error2;
472 }
473
David Howells664cceb2005-09-28 17:03:15 +0100474 ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475
David Howells664cceb2005-09-28 17:03:15 +0100476 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700477error2:
David Howells664cceb2005-09-28 17:03:15 +0100478 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700479error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000481}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483/*
David Howells973c9f42011-01-20 16:38:33 +0000484 * Unlink a key from a keyring.
485 *
486 * The keyring must grant the caller Write permission for this to work; the key
487 * itself need not grant the caller anything. If the last link to a key is
488 * removed then that key will be scheduled for destruction.
489 *
490 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 */
492long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
493{
David Howells664cceb2005-09-28 17:03:15 +0100494 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 long ret;
496
David Howells55931222009-09-02 09:13:45 +0100497 keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100498 if (IS_ERR(keyring_ref)) {
499 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 goto error;
501 }
502
David Howells55931222009-09-02 09:13:45 +0100503 key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
David Howells664cceb2005-09-28 17:03:15 +0100504 if (IS_ERR(key_ref)) {
505 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 goto error2;
507 }
508
David Howells664cceb2005-09-28 17:03:15 +0100509 ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
David Howells664cceb2005-09-28 17:03:15 +0100511 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700512error2:
David Howells664cceb2005-09-28 17:03:15 +0100513 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700514error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000516}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518/*
David Howells973c9f42011-01-20 16:38:33 +0000519 * Return a description of a key to userspace.
520 *
521 * The key must grant the caller View permission for this to work.
522 *
523 * If there's a buffer, we place up to buflen bytes of data into it formatted
524 * in the following way:
525 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 * type;uid;gid;perm;description<NUL>
David Howells973c9f42011-01-20 16:38:33 +0000527 *
528 * If successful, we return the amount of description available, irrespective
529 * of how much we may have copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 */
531long keyctl_describe_key(key_serial_t keyid,
532 char __user *buffer,
533 size_t buflen)
534{
David Howells3e301482005-06-23 22:00:56 -0700535 struct key *key, *instkey;
David Howells664cceb2005-09-28 17:03:15 +0100536 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 char *tmpbuf;
538 long ret;
539
David Howells55931222009-09-02 09:13:45 +0100540 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
David Howells664cceb2005-09-28 17:03:15 +0100541 if (IS_ERR(key_ref)) {
David Howells3e301482005-06-23 22:00:56 -0700542 /* viewing a key under construction is permitted if we have the
543 * authorisation token handy */
David Howells664cceb2005-09-28 17:03:15 +0100544 if (PTR_ERR(key_ref) == -EACCES) {
David Howells3e301482005-06-23 22:00:56 -0700545 instkey = key_get_instantiation_authkey(keyid);
546 if (!IS_ERR(instkey)) {
547 key_put(instkey);
David Howells8bbf49762008-11-14 10:39:14 +1100548 key_ref = lookup_user_key(keyid,
David Howells55931222009-09-02 09:13:45 +0100549 KEY_LOOKUP_PARTIAL,
550 0);
David Howells664cceb2005-09-28 17:03:15 +0100551 if (!IS_ERR(key_ref))
David Howells3e301482005-06-23 22:00:56 -0700552 goto okay;
553 }
554 }
555
David Howells664cceb2005-09-28 17:03:15 +0100556 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 goto error;
558 }
559
David Howells3e301482005-06-23 22:00:56 -0700560okay:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 /* calculate how much description we're going to return */
562 ret = -ENOMEM;
563 tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
564 if (!tmpbuf)
565 goto error2;
566
David Howells664cceb2005-09-28 17:03:15 +0100567 key = key_ref_to_ptr(key_ref);
568
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 ret = snprintf(tmpbuf, PAGE_SIZE - 1,
David Howells664cceb2005-09-28 17:03:15 +0100570 "%s;%d;%d;%08x;%s",
David Howells94fd8402010-06-28 14:05:04 +0100571 key->type->name,
572 key->uid,
573 key->gid,
574 key->perm,
575 key->description ?: "");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576
577 /* include a NUL char at the end of the data */
578 if (ret > PAGE_SIZE - 1)
579 ret = PAGE_SIZE - 1;
580 tmpbuf[ret] = 0;
581 ret++;
582
583 /* consider returning the data */
584 if (buffer && buflen > 0) {
585 if (buflen > ret)
586 buflen = ret;
587
588 if (copy_to_user(buffer, tmpbuf, buflen) != 0)
589 ret = -EFAULT;
590 }
591
592 kfree(tmpbuf);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700593error2:
David Howells664cceb2005-09-28 17:03:15 +0100594 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700595error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000597}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599/*
David Howells973c9f42011-01-20 16:38:33 +0000600 * Search the specified keyring and any keyrings it links to for a matching
601 * key. Only keyrings that grant the caller Search permission will be searched
602 * (this includes the starting keyring). Only keys with Search permission can
603 * be found.
604 *
605 * If successful, the found key will be linked to the destination keyring if
606 * supplied and the key has Link permission, and the found key ID will be
607 * returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 */
609long keyctl_keyring_search(key_serial_t ringid,
610 const char __user *_type,
611 const char __user *_description,
612 key_serial_t destringid)
613{
614 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100615 key_ref_t keyring_ref, key_ref, dest_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 char type[32], *description;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800617 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
619 /* pull the type and description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800620 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 if (ret < 0)
622 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800624 description = strndup_user(_description, PAGE_SIZE);
625 if (IS_ERR(description)) {
626 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800628 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630 /* get the keyring at which to begin the search */
David Howells55931222009-09-02 09:13:45 +0100631 keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100632 if (IS_ERR(keyring_ref)) {
633 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 goto error2;
635 }
636
637 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100638 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100640 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
641 KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100642 if (IS_ERR(dest_ref)) {
643 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 goto error3;
645 }
646 }
647
648 /* find the key type */
649 ktype = key_type_lookup(type);
650 if (IS_ERR(ktype)) {
651 ret = PTR_ERR(ktype);
652 goto error4;
653 }
654
655 /* do the search */
David Howells664cceb2005-09-28 17:03:15 +0100656 key_ref = keyring_search(keyring_ref, ktype, description);
657 if (IS_ERR(key_ref)) {
658 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
660 /* treat lack or presence of a negative key the same */
661 if (ret == -EAGAIN)
662 ret = -ENOKEY;
663 goto error5;
664 }
665
666 /* link the resulting key to the destination keyring if we can */
David Howells664cceb2005-09-28 17:03:15 +0100667 if (dest_ref) {
David Howells29db9192005-10-30 15:02:44 -0800668 ret = key_permission(key_ref, KEY_LINK);
669 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 goto error6;
671
David Howells664cceb2005-09-28 17:03:15 +0100672 ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 if (ret < 0)
674 goto error6;
675 }
676
David Howells664cceb2005-09-28 17:03:15 +0100677 ret = key_ref_to_ptr(key_ref)->serial;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700679error6:
David Howells664cceb2005-09-28 17:03:15 +0100680 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700681error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700683error4:
David Howells664cceb2005-09-28 17:03:15 +0100684 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700685error3:
David Howells664cceb2005-09-28 17:03:15 +0100686 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700687error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700689error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000691}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693/*
David Howells973c9f42011-01-20 16:38:33 +0000694 * Read a key's payload.
695 *
696 * The key must either grant the caller Read permission, or it must grant the
697 * caller Search permission when searched for from the process keyrings.
698 *
699 * If successful, we place up to buflen bytes of data into the buffer, if one
700 * is provided, and return the amount of data that is available in the key,
701 * irrespective of how much we copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 */
703long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
704{
David Howells664cceb2005-09-28 17:03:15 +0100705 struct key *key;
706 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 long ret;
708
709 /* find the key first */
David Howells55931222009-09-02 09:13:45 +0100710 key_ref = lookup_user_key(keyid, 0, 0);
David Howells664cceb2005-09-28 17:03:15 +0100711 if (IS_ERR(key_ref)) {
712 ret = -ENOKEY;
713 goto error;
714 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715
David Howells664cceb2005-09-28 17:03:15 +0100716 key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717
David Howells664cceb2005-09-28 17:03:15 +0100718 /* see if we can read it directly */
David Howells29db9192005-10-30 15:02:44 -0800719 ret = key_permission(key_ref, KEY_READ);
720 if (ret == 0)
David Howells664cceb2005-09-28 17:03:15 +0100721 goto can_read_key;
David Howells29db9192005-10-30 15:02:44 -0800722 if (ret != -EACCES)
723 goto error;
David Howells664cceb2005-09-28 17:03:15 +0100724
725 /* we can't; see if it's searchable from this process's keyrings
726 * - we automatically take account of the fact that it may be
727 * dangling off an instantiation key
728 */
729 if (!is_key_possessed(key_ref)) {
730 ret = -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 goto error2;
732 }
733
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 /* the key is probably readable - now try to read it */
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700735can_read_key:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 ret = key_validate(key);
737 if (ret == 0) {
738 ret = -EOPNOTSUPP;
739 if (key->type->read) {
740 /* read the data with the semaphore held (since we
741 * might sleep) */
742 down_read(&key->sem);
743 ret = key->type->read(key, buffer, buflen);
744 up_read(&key->sem);
745 }
746 }
747
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700748error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700750error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000752}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754/*
David Howells973c9f42011-01-20 16:38:33 +0000755 * Change the ownership of a key
756 *
757 * The key must grant the caller Setattr permission for this to work, though
758 * the key need not be fully instantiated yet. For the UID to be changed, or
759 * for the GID to be changed to a group the caller is not a member of, the
760 * caller must have sysadmin capability. If either uid or gid is -1 then that
761 * attribute is not changed.
762 *
763 * If the UID is to be changed, the new user must have sufficient quota to
764 * accept the key. The quota deduction will be removed from the old user to
765 * the new user should the attribute be changed.
766 *
767 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 */
769long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
770{
Fredrik Tolf58016492006-06-26 00:24:51 -0700771 struct key_user *newowner, *zapowner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100773 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 long ret;
775
776 ret = 0;
777 if (uid == (uid_t) -1 && gid == (gid_t) -1)
778 goto error;
779
David Howells55931222009-09-02 09:13:45 +0100780 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
781 KEY_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100782 if (IS_ERR(key_ref)) {
783 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 goto error;
785 }
786
David Howells664cceb2005-09-28 17:03:15 +0100787 key = key_ref_to_ptr(key_ref);
788
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 /* make the changes with the locks held to prevent chown/chown races */
790 ret = -EACCES;
791 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792
793 if (!capable(CAP_SYS_ADMIN)) {
794 /* only the sysadmin can chown a key to some other UID */
795 if (uid != (uid_t) -1 && key->uid != uid)
Fredrik Tolf58016492006-06-26 00:24:51 -0700796 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797
798 /* only the sysadmin can set the key's GID to a group other
799 * than one of those that the current process subscribes to */
800 if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid))
Fredrik Tolf58016492006-06-26 00:24:51 -0700801 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 }
803
Fredrik Tolf58016492006-06-26 00:24:51 -0700804 /* change the UID */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 if (uid != (uid_t) -1 && uid != key->uid) {
Fredrik Tolf58016492006-06-26 00:24:51 -0700806 ret = -ENOMEM;
Serge E. Hallyn1d1e9752009-02-26 18:27:38 -0600807 newowner = key_user_lookup(uid, current_user_ns());
Fredrik Tolf58016492006-06-26 00:24:51 -0700808 if (!newowner)
809 goto error_put;
810
811 /* transfer the quota burden to the new user */
812 if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
David Howells0b77f5b2008-04-29 01:01:32 -0700813 unsigned maxkeys = (uid == 0) ?
814 key_quota_root_maxkeys : key_quota_maxkeys;
815 unsigned maxbytes = (uid == 0) ?
816 key_quota_root_maxbytes : key_quota_maxbytes;
817
Fredrik Tolf58016492006-06-26 00:24:51 -0700818 spin_lock(&newowner->lock);
David Howells0b77f5b2008-04-29 01:01:32 -0700819 if (newowner->qnkeys + 1 >= maxkeys ||
820 newowner->qnbytes + key->quotalen >= maxbytes ||
821 newowner->qnbytes + key->quotalen <
822 newowner->qnbytes)
Fredrik Tolf58016492006-06-26 00:24:51 -0700823 goto quota_overrun;
824
825 newowner->qnkeys++;
826 newowner->qnbytes += key->quotalen;
827 spin_unlock(&newowner->lock);
828
829 spin_lock(&key->user->lock);
830 key->user->qnkeys--;
831 key->user->qnbytes -= key->quotalen;
832 spin_unlock(&key->user->lock);
833 }
834
835 atomic_dec(&key->user->nkeys);
836 atomic_inc(&newowner->nkeys);
837
838 if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
839 atomic_dec(&key->user->nikeys);
840 atomic_inc(&newowner->nikeys);
841 }
842
843 zapowner = key->user;
844 key->user = newowner;
845 key->uid = uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 }
847
848 /* change the GID */
849 if (gid != (gid_t) -1)
850 key->gid = gid;
851
852 ret = 0;
853
Fredrik Tolf58016492006-06-26 00:24:51 -0700854error_put:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 up_write(&key->sem);
856 key_put(key);
Fredrik Tolf58016492006-06-26 00:24:51 -0700857 if (zapowner)
858 key_user_put(zapowner);
859error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 return ret;
861
Fredrik Tolf58016492006-06-26 00:24:51 -0700862quota_overrun:
863 spin_unlock(&newowner->lock);
864 zapowner = newowner;
865 ret = -EDQUOT;
866 goto error_put;
David Howellsa8b17ed2011-01-20 16:38:27 +0000867}
Fredrik Tolf58016492006-06-26 00:24:51 -0700868
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869/*
David Howells973c9f42011-01-20 16:38:33 +0000870 * Change the permission mask on a key.
871 *
872 * The key must grant the caller Setattr permission for this to work, though
873 * the key need not be fully instantiated yet. If the caller does not have
874 * sysadmin capability, it may only change the permission on keys that it owns.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 */
876long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
877{
878 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100879 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 long ret;
881
882 ret = -EINVAL;
David Howells664cceb2005-09-28 17:03:15 +0100883 if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 goto error;
885
David Howells55931222009-09-02 09:13:45 +0100886 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
887 KEY_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100888 if (IS_ERR(key_ref)) {
889 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 goto error;
891 }
892
David Howells664cceb2005-09-28 17:03:15 +0100893 key = key_ref_to_ptr(key_ref);
894
David Howells76d8aea2005-06-23 22:00:49 -0700895 /* make the changes with the locks held to prevent chown/chmod races */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 ret = -EACCES;
897 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
David Howells76d8aea2005-06-23 22:00:49 -0700899 /* if we're not the sysadmin, we can only change a key that we own */
David Howells47d804b2008-11-14 10:39:11 +1100900 if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) {
David Howells76d8aea2005-06-23 22:00:49 -0700901 key->perm = perm;
902 ret = 0;
903 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 up_write(&key->sem);
906 key_put(key);
David Howells76d8aea2005-06-23 22:00:49 -0700907error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000909}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
David Howells8bbf49762008-11-14 10:39:14 +1100911/*
David Howells973c9f42011-01-20 16:38:33 +0000912 * Get the destination keyring for instantiation and check that the caller has
913 * Write permission on it.
David Howells8bbf49762008-11-14 10:39:14 +1100914 */
915static long get_instantiation_keyring(key_serial_t ringid,
916 struct request_key_auth *rka,
917 struct key **_dest_keyring)
918{
919 key_ref_t dkref;
920
David Howellseca1bf52008-12-29 00:41:51 +0000921 *_dest_keyring = NULL;
922
David Howells8bbf49762008-11-14 10:39:14 +1100923 /* just return a NULL pointer if we weren't asked to make a link */
David Howellseca1bf52008-12-29 00:41:51 +0000924 if (ringid == 0)
David Howells8bbf49762008-11-14 10:39:14 +1100925 return 0;
David Howells8bbf49762008-11-14 10:39:14 +1100926
927 /* if a specific keyring is nominated by ID, then use that */
928 if (ringid > 0) {
David Howells55931222009-09-02 09:13:45 +0100929 dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells8bbf49762008-11-14 10:39:14 +1100930 if (IS_ERR(dkref))
931 return PTR_ERR(dkref);
932 *_dest_keyring = key_ref_to_ptr(dkref);
933 return 0;
934 }
935
936 if (ringid == KEY_SPEC_REQKEY_AUTH_KEY)
937 return -EINVAL;
938
939 /* otherwise specify the destination keyring recorded in the
940 * authorisation key (any KEY_SPEC_*_KEYRING) */
941 if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) {
David Howells21279cf2009-10-15 10:14:35 +0100942 *_dest_keyring = key_get(rka->dest_keyring);
David Howells8bbf49762008-11-14 10:39:14 +1100943 return 0;
944 }
945
946 return -ENOKEY;
947}
948
David Howellsd84f4f92008-11-14 10:39:23 +1100949/*
David Howells973c9f42011-01-20 16:38:33 +0000950 * Change the request_key authorisation key on the current process.
David Howellsd84f4f92008-11-14 10:39:23 +1100951 */
952static int keyctl_change_reqkey_auth(struct key *key)
953{
954 struct cred *new;
955
956 new = prepare_creds();
957 if (!new)
958 return -ENOMEM;
959
960 key_put(new->request_key_auth);
961 new->request_key_auth = key_get(key);
962
963 return commit_creds(new);
964}
965
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966/*
David Howellsee009e4a02011-03-07 15:06:20 +0000967 * Copy the iovec data from userspace
968 */
969static long copy_from_user_iovec(void *buffer, const struct iovec *iov,
970 unsigned ioc)
971{
972 for (; ioc > 0; ioc--) {
973 if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0)
974 return -EFAULT;
975 buffer += iov->iov_len;
976 iov++;
977 }
978 return 0;
979}
980
981/*
David Howells973c9f42011-01-20 16:38:33 +0000982 * Instantiate a key with the specified payload and link the key into the
983 * destination keyring if one is given.
984 *
985 * The caller must have the appropriate instantiation permit set for this to
986 * work (see keyctl_assume_authority). No other permissions are required.
987 *
988 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 */
David Howellsee009e4a02011-03-07 15:06:20 +0000990long keyctl_instantiate_key_common(key_serial_t id,
991 const struct iovec *payload_iov,
992 unsigned ioc,
993 size_t plen,
994 key_serial_t ringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995{
David Howellsd84f4f92008-11-14 10:39:23 +1100996 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -0700997 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +1100998 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999 void *payload;
1000 long ret;
David Howells38bbca62008-04-29 01:01:19 -07001001 bool vm = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002
David Howellsd84f4f92008-11-14 10:39:23 +11001003 kenter("%d,,%zu,%d", id, plen, ringid);
1004
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -07001006 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 goto error;
1008
David Howellsb5f545c2006-01-08 01:02:47 -08001009 /* the appropriate instantiation authorisation key must have been
1010 * assumed before calling this */
1011 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +11001012 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -08001013 if (!instkey)
1014 goto error;
1015
1016 rka = instkey->payload.data;
1017 if (rka->target_key->serial != id)
1018 goto error;
1019
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 /* pull the payload in if one was supplied */
1021 payload = NULL;
1022
David Howellsee009e4a02011-03-07 15:06:20 +00001023 if (payload_iov) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 ret = -ENOMEM;
1025 payload = kmalloc(plen, GFP_KERNEL);
David Howells38bbca62008-04-29 01:01:19 -07001026 if (!payload) {
1027 if (plen <= PAGE_SIZE)
1028 goto error;
1029 vm = true;
1030 payload = vmalloc(plen);
1031 if (!payload)
1032 goto error;
1033 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034
David Howellsee009e4a02011-03-07 15:06:20 +00001035 ret = copy_from_user_iovec(payload, payload_iov, ioc);
1036 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 goto error2;
1038 }
1039
David Howells3e301482005-06-23 22:00:56 -07001040 /* find the destination keyring amongst those belonging to the
1041 * requesting task */
David Howells8bbf49762008-11-14 10:39:14 +11001042 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1043 if (ret < 0)
1044 goto error2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045
1046 /* instantiate the key and link it into a keyring */
David Howells3e301482005-06-23 22:00:56 -07001047 ret = key_instantiate_and_link(rka->target_key, payload, plen,
David Howells8bbf49762008-11-14 10:39:14 +11001048 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049
David Howells8bbf49762008-11-14 10:39:14 +11001050 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001051
1052 /* discard the assumed authority if it's just been disabled by
1053 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001054 if (ret == 0)
1055 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001056
1057error2:
David Howells38bbca62008-04-29 01:01:19 -07001058 if (!vm)
1059 kfree(payload);
1060 else
1061 vfree(payload);
David Howellsb5f545c2006-01-08 01:02:47 -08001062error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001064}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066/*
David Howellsee009e4a02011-03-07 15:06:20 +00001067 * Instantiate a key with the specified payload and link the key into the
1068 * destination keyring if one is given.
1069 *
1070 * The caller must have the appropriate instantiation permit set for this to
1071 * work (see keyctl_assume_authority). No other permissions are required.
1072 *
1073 * If successful, 0 will be returned.
1074 */
1075long keyctl_instantiate_key(key_serial_t id,
1076 const void __user *_payload,
1077 size_t plen,
1078 key_serial_t ringid)
1079{
1080 if (_payload && plen) {
1081 struct iovec iov[1] = {
1082 [0].iov_base = (void __user *)_payload,
1083 [0].iov_len = plen
1084 };
1085
1086 return keyctl_instantiate_key_common(id, iov, 1, plen, ringid);
1087 }
1088
1089 return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
1090}
1091
1092/*
1093 * Instantiate a key with the specified multipart payload and link the key into
1094 * the destination keyring if one is given.
1095 *
1096 * The caller must have the appropriate instantiation permit set for this to
1097 * work (see keyctl_assume_authority). No other permissions are required.
1098 *
1099 * If successful, 0 will be returned.
1100 */
1101long keyctl_instantiate_key_iov(key_serial_t id,
1102 const struct iovec __user *_payload_iov,
1103 unsigned ioc,
1104 key_serial_t ringid)
1105{
1106 struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
1107 long ret;
1108
1109 if (_payload_iov == 0 || ioc == 0)
1110 goto no_payload;
1111
1112 ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
Christopher Yeohfcf63402011-10-31 17:06:39 -07001113 ARRAY_SIZE(iovstack), iovstack, &iov, 1);
David Howellsee009e4a02011-03-07 15:06:20 +00001114 if (ret < 0)
1115 return ret;
1116 if (ret == 0)
1117 goto no_payload_free;
1118
1119 ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
1120
1121 if (iov != iovstack)
1122 kfree(iov);
1123 return ret;
1124
1125no_payload_free:
1126 if (iov != iovstack)
1127 kfree(iov);
1128no_payload:
1129 return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
1130}
1131
1132/*
David Howells973c9f42011-01-20 16:38:33 +00001133 * Negatively instantiate the key with the given timeout (in seconds) and link
1134 * the key into the destination keyring if one is given.
1135 *
1136 * The caller must have the appropriate instantiation permit set for this to
1137 * work (see keyctl_assume_authority). No other permissions are required.
1138 *
1139 * The key and any links to the key will be automatically garbage collected
1140 * after the timeout expires.
1141 *
1142 * Negative keys are used to rate limit repeated request_key() calls by causing
1143 * them to return -ENOKEY until the negative key expires.
1144 *
1145 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146 */
1147long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
1148{
David Howellsfdd1b942011-03-07 15:06:09 +00001149 return keyctl_reject_key(id, timeout, ENOKEY, ringid);
1150}
1151
1152/*
1153 * Negatively instantiate the key with the given timeout (in seconds) and error
1154 * code and link the key into the destination keyring if one is given.
1155 *
1156 * The caller must have the appropriate instantiation permit set for this to
1157 * work (see keyctl_assume_authority). No other permissions are required.
1158 *
1159 * The key and any links to the key will be automatically garbage collected
1160 * after the timeout expires.
1161 *
1162 * Negative keys are used to rate limit repeated request_key() calls by causing
1163 * them to return the specified error code until the negative key expires.
1164 *
1165 * If successful, 0 will be returned.
1166 */
1167long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error,
1168 key_serial_t ringid)
1169{
David Howellsd84f4f92008-11-14 10:39:23 +11001170 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -07001171 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +11001172 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 long ret;
1174
David Howellsfdd1b942011-03-07 15:06:09 +00001175 kenter("%d,%u,%u,%d", id, timeout, error, ringid);
1176
1177 /* must be a valid error code and mustn't be a kernel special */
1178 if (error <= 0 ||
1179 error >= MAX_ERRNO ||
1180 error == ERESTARTSYS ||
1181 error == ERESTARTNOINTR ||
1182 error == ERESTARTNOHAND ||
1183 error == ERESTART_RESTARTBLOCK)
1184 return -EINVAL;
David Howellsd84f4f92008-11-14 10:39:23 +11001185
David Howellsb5f545c2006-01-08 01:02:47 -08001186 /* the appropriate instantiation authorisation key must have been
1187 * assumed before calling this */
1188 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +11001189 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -08001190 if (!instkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192
David Howells3e301482005-06-23 22:00:56 -07001193 rka = instkey->payload.data;
David Howellsb5f545c2006-01-08 01:02:47 -08001194 if (rka->target_key->serial != id)
1195 goto error;
David Howells3e301482005-06-23 22:00:56 -07001196
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 /* find the destination keyring if present (which must also be
1198 * writable) */
David Howells8bbf49762008-11-14 10:39:14 +11001199 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1200 if (ret < 0)
1201 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202
1203 /* instantiate the key and link it into a keyring */
David Howellsfdd1b942011-03-07 15:06:09 +00001204 ret = key_reject_and_link(rka->target_key, timeout, error,
David Howells8bbf49762008-11-14 10:39:14 +11001205 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206
David Howells8bbf49762008-11-14 10:39:14 +11001207 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001208
1209 /* discard the assumed authority if it's just been disabled by
1210 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001211 if (ret == 0)
1212 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001213
1214error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001216}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218/*
David Howells973c9f42011-01-20 16:38:33 +00001219 * Read or set the default keyring in which request_key() will cache keys and
1220 * return the old setting.
1221 *
1222 * If a process keyring is specified then this will be created if it doesn't
1223 * yet exist. The old setting will be returned if successful.
David Howells3e301482005-06-23 22:00:56 -07001224 */
1225long keyctl_set_reqkey_keyring(int reqkey_defl)
1226{
David Howellsd84f4f92008-11-14 10:39:23 +11001227 struct cred *new;
1228 int ret, old_setting;
1229
1230 old_setting = current_cred_xxx(jit_keyring);
1231
1232 if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
1233 return old_setting;
1234
1235 new = prepare_creds();
1236 if (!new)
1237 return -ENOMEM;
David Howells3e301482005-06-23 22:00:56 -07001238
1239 switch (reqkey_defl) {
1240 case KEY_REQKEY_DEFL_THREAD_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001241 ret = install_thread_keyring_to_cred(new);
David Howells3e301482005-06-23 22:00:56 -07001242 if (ret < 0)
David Howellsd84f4f92008-11-14 10:39:23 +11001243 goto error;
David Howells3e301482005-06-23 22:00:56 -07001244 goto set;
1245
1246 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001247 ret = install_process_keyring_to_cred(new);
1248 if (ret < 0) {
1249 if (ret != -EEXIST)
1250 goto error;
1251 ret = 0;
1252 }
1253 goto set;
David Howells3e301482005-06-23 22:00:56 -07001254
1255 case KEY_REQKEY_DEFL_DEFAULT:
1256 case KEY_REQKEY_DEFL_SESSION_KEYRING:
1257 case KEY_REQKEY_DEFL_USER_KEYRING:
1258 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001259 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
1260 goto set;
David Howells3e301482005-06-23 22:00:56 -07001261
1262 case KEY_REQKEY_DEFL_NO_CHANGE:
David Howells3e301482005-06-23 22:00:56 -07001263 case KEY_REQKEY_DEFL_GROUP_KEYRING:
1264 default:
David Howellsd84f4f92008-11-14 10:39:23 +11001265 ret = -EINVAL;
1266 goto error;
David Howells3e301482005-06-23 22:00:56 -07001267 }
1268
David Howellsd84f4f92008-11-14 10:39:23 +11001269set:
1270 new->jit_keyring = reqkey_defl;
1271 commit_creds(new);
1272 return old_setting;
1273error:
1274 abort_creds(new);
Dan Carpenter4303ef12010-06-11 17:30:05 +01001275 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001276}
David Howellsd84f4f92008-11-14 10:39:23 +11001277
David Howells3e301482005-06-23 22:00:56 -07001278/*
David Howells973c9f42011-01-20 16:38:33 +00001279 * Set or clear the timeout on a key.
1280 *
1281 * Either the key must grant the caller Setattr permission or else the caller
1282 * must hold an instantiation authorisation token for the key.
1283 *
1284 * The timeout is either 0 to clear the timeout, or a number of seconds from
1285 * the current time. The key and any links to the key will be automatically
1286 * garbage collected after the timeout expires.
1287 *
1288 * If successful, 0 is returned.
David Howells017679c2006-01-08 01:02:43 -08001289 */
1290long keyctl_set_timeout(key_serial_t id, unsigned timeout)
1291{
David Howells91562352010-06-11 17:31:05 +01001292 struct key *key, *instkey;
David Howells017679c2006-01-08 01:02:43 -08001293 key_ref_t key_ref;
David Howells017679c2006-01-08 01:02:43 -08001294 long ret;
1295
David Howells55931222009-09-02 09:13:45 +01001296 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
1297 KEY_SETATTR);
David Howells017679c2006-01-08 01:02:43 -08001298 if (IS_ERR(key_ref)) {
David Howells91562352010-06-11 17:31:05 +01001299 /* setting the timeout on a key under construction is permitted
1300 * if we have the authorisation token handy */
1301 if (PTR_ERR(key_ref) == -EACCES) {
1302 instkey = key_get_instantiation_authkey(id);
1303 if (!IS_ERR(instkey)) {
1304 key_put(instkey);
1305 key_ref = lookup_user_key(id,
1306 KEY_LOOKUP_PARTIAL,
1307 0);
1308 if (!IS_ERR(key_ref))
1309 goto okay;
1310 }
1311 }
1312
David Howells017679c2006-01-08 01:02:43 -08001313 ret = PTR_ERR(key_ref);
1314 goto error;
1315 }
1316
David Howells91562352010-06-11 17:31:05 +01001317okay:
David Howells017679c2006-01-08 01:02:43 -08001318 key = key_ref_to_ptr(key_ref);
Bryan Schumaker59e6b9c2012-02-24 14:14:50 -05001319 key_set_timeout(key, timeout);
David Howells017679c2006-01-08 01:02:43 -08001320 key_put(key);
1321
1322 ret = 0;
1323error:
1324 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001325}
David Howells017679c2006-01-08 01:02:43 -08001326
David Howells017679c2006-01-08 01:02:43 -08001327/*
David Howells973c9f42011-01-20 16:38:33 +00001328 * Assume (or clear) the authority to instantiate the specified key.
1329 *
1330 * This sets the authoritative token currently in force for key instantiation.
1331 * This must be done for a key to be instantiated. It has the effect of making
1332 * available all the keys from the caller of the request_key() that created a
1333 * key to request_key() calls made by the caller of this function.
1334 *
1335 * The caller must have the instantiation key in their process keyrings with a
1336 * Search permission grant available to the caller.
1337 *
1338 * If the ID given is 0, then the setting will be cleared and 0 returned.
1339 *
1340 * If the ID given has a matching an authorisation key, then that key will be
1341 * set and its ID will be returned. The authorisation key can be read to get
1342 * the callout information passed to request_key().
David Howellsb5f545c2006-01-08 01:02:47 -08001343 */
1344long keyctl_assume_authority(key_serial_t id)
1345{
1346 struct key *authkey;
1347 long ret;
1348
1349 /* special key IDs aren't permitted */
1350 ret = -EINVAL;
1351 if (id < 0)
1352 goto error;
1353
1354 /* we divest ourselves of authority if given an ID of 0 */
1355 if (id == 0) {
David Howellsd84f4f92008-11-14 10:39:23 +11001356 ret = keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001357 goto error;
1358 }
1359
1360 /* attempt to assume the authority temporarily granted to us whilst we
1361 * instantiate the specified key
1362 * - the authorisation key must be in the current task's keyrings
1363 * somewhere
1364 */
1365 authkey = key_get_instantiation_authkey(id);
1366 if (IS_ERR(authkey)) {
1367 ret = PTR_ERR(authkey);
1368 goto error;
1369 }
1370
David Howellsd84f4f92008-11-14 10:39:23 +11001371 ret = keyctl_change_reqkey_auth(authkey);
1372 if (ret < 0)
1373 goto error;
1374 key_put(authkey);
David Howellsb5f545c2006-01-08 01:02:47 -08001375
David Howellsd84f4f92008-11-14 10:39:23 +11001376 ret = authkey->serial;
David Howellsb5f545c2006-01-08 01:02:47 -08001377error:
1378 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001379}
David Howellsb5f545c2006-01-08 01:02:47 -08001380
David Howells70a5bb72008-04-29 01:01:26 -07001381/*
David Howells973c9f42011-01-20 16:38:33 +00001382 * Get a key's the LSM security label.
1383 *
1384 * The key must grant the caller View permission for this to work.
1385 *
1386 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1387 *
1388 * If successful, the amount of information available will be returned,
1389 * irrespective of how much was copied (including the terminal NUL).
David Howells70a5bb72008-04-29 01:01:26 -07001390 */
1391long keyctl_get_security(key_serial_t keyid,
1392 char __user *buffer,
1393 size_t buflen)
1394{
1395 struct key *key, *instkey;
1396 key_ref_t key_ref;
1397 char *context;
1398 long ret;
1399
David Howells55931222009-09-02 09:13:45 +01001400 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
David Howells70a5bb72008-04-29 01:01:26 -07001401 if (IS_ERR(key_ref)) {
1402 if (PTR_ERR(key_ref) != -EACCES)
1403 return PTR_ERR(key_ref);
1404
1405 /* viewing a key under construction is also permitted if we
1406 * have the authorisation token handy */
1407 instkey = key_get_instantiation_authkey(keyid);
1408 if (IS_ERR(instkey))
Roel Kluinfa1cc7b2009-12-15 15:05:12 -08001409 return PTR_ERR(instkey);
David Howells70a5bb72008-04-29 01:01:26 -07001410 key_put(instkey);
1411
David Howells55931222009-09-02 09:13:45 +01001412 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
David Howells70a5bb72008-04-29 01:01:26 -07001413 if (IS_ERR(key_ref))
1414 return PTR_ERR(key_ref);
1415 }
1416
1417 key = key_ref_to_ptr(key_ref);
1418 ret = security_key_getsecurity(key, &context);
1419 if (ret == 0) {
1420 /* if no information was returned, give userspace an empty
1421 * string */
1422 ret = 1;
1423 if (buffer && buflen > 0 &&
1424 copy_to_user(buffer, "", 1) != 0)
1425 ret = -EFAULT;
1426 } else if (ret > 0) {
1427 /* return as much data as there's room for */
1428 if (buffer && buflen > 0) {
1429 if (buflen > ret)
1430 buflen = ret;
1431
1432 if (copy_to_user(buffer, context, buflen) != 0)
1433 ret = -EFAULT;
1434 }
1435
1436 kfree(context);
1437 }
1438
1439 key_ref_put(key_ref);
1440 return ret;
1441}
1442
David Howellsee18d642009-09-02 09:14:21 +01001443/*
David Howells973c9f42011-01-20 16:38:33 +00001444 * Attempt to install the calling process's session keyring on the process's
1445 * parent process.
1446 *
1447 * The keyring must exist and must grant the caller LINK permission, and the
1448 * parent process must be single-threaded and must have the same effective
1449 * ownership as this process and mustn't be SUID/SGID.
1450 *
1451 * The keyring will be emplaced on the parent when it next resumes userspace.
1452 *
1453 * If successful, 0 will be returned.
David Howellsee18d642009-09-02 09:14:21 +01001454 */
1455long keyctl_session_to_parent(void)
1456{
Geert Uytterhoevena00ae4d2009-12-13 20:21:34 +01001457#ifdef TIF_NOTIFY_RESUME
David Howellsee18d642009-09-02 09:14:21 +01001458 struct task_struct *me, *parent;
1459 const struct cred *mycred, *pcred;
1460 struct cred *cred, *oldcred;
1461 key_ref_t keyring_r;
1462 int ret;
1463
1464 keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
1465 if (IS_ERR(keyring_r))
1466 return PTR_ERR(keyring_r);
1467
1468 /* our parent is going to need a new cred struct, a new tgcred struct
1469 * and new security data, so we allocate them here to prevent ENOMEM in
1470 * our parent */
1471 ret = -ENOMEM;
1472 cred = cred_alloc_blank();
1473 if (!cred)
1474 goto error_keyring;
1475
1476 cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
1477 keyring_r = NULL;
1478
1479 me = current;
David Howells9d1ac652010-09-10 09:59:46 +01001480 rcu_read_lock();
David Howellsee18d642009-09-02 09:14:21 +01001481 write_lock_irq(&tasklist_lock);
1482
1483 parent = me->real_parent;
1484 ret = -EPERM;
1485
1486 /* the parent mustn't be init and mustn't be a kernel thread */
1487 if (parent->pid <= 1 || !parent->mm)
1488 goto not_permitted;
1489
1490 /* the parent must be single threaded */
Oleg Nesterovdd98acf2010-05-26 14:43:23 -07001491 if (!thread_group_empty(parent))
David Howellsee18d642009-09-02 09:14:21 +01001492 goto not_permitted;
1493
1494 /* the parent and the child must have different session keyrings or
1495 * there's no point */
1496 mycred = current_cred();
1497 pcred = __task_cred(parent);
1498 if (mycred == pcred ||
1499 mycred->tgcred->session_keyring == pcred->tgcred->session_keyring)
1500 goto already_same;
1501
1502 /* the parent must have the same effective ownership and mustn't be
1503 * SUID/SGID */
Justin P. Mattockc5b60b52010-04-21 00:02:11 -07001504 if (pcred->uid != mycred->euid ||
David Howellsee18d642009-09-02 09:14:21 +01001505 pcred->euid != mycred->euid ||
1506 pcred->suid != mycred->euid ||
Justin P. Mattockc5b60b52010-04-21 00:02:11 -07001507 pcred->gid != mycred->egid ||
David Howellsee18d642009-09-02 09:14:21 +01001508 pcred->egid != mycred->egid ||
1509 pcred->sgid != mycred->egid)
1510 goto not_permitted;
1511
1512 /* the keyrings must have the same UID */
David Howells3d964062010-09-10 09:59:51 +01001513 if ((pcred->tgcred->session_keyring &&
1514 pcred->tgcred->session_keyring->uid != mycred->euid) ||
David Howellsee18d642009-09-02 09:14:21 +01001515 mycred->tgcred->session_keyring->uid != mycred->euid)
1516 goto not_permitted;
1517
David Howellsee18d642009-09-02 09:14:21 +01001518 /* if there's an already pending keyring replacement, then we replace
1519 * that */
1520 oldcred = parent->replacement_session_keyring;
1521
1522 /* the replacement session keyring is applied just prior to userspace
1523 * restarting */
1524 parent->replacement_session_keyring = cred;
1525 cred = NULL;
1526 set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
1527
1528 write_unlock_irq(&tasklist_lock);
David Howells9d1ac652010-09-10 09:59:46 +01001529 rcu_read_unlock();
David Howellsee18d642009-09-02 09:14:21 +01001530 if (oldcred)
1531 put_cred(oldcred);
1532 return 0;
1533
1534already_same:
1535 ret = 0;
1536not_permitted:
Marc Dionne5c843422009-09-14 12:46:23 +01001537 write_unlock_irq(&tasklist_lock);
David Howells9d1ac652010-09-10 09:59:46 +01001538 rcu_read_unlock();
David Howellsee18d642009-09-02 09:14:21 +01001539 put_cred(cred);
1540 return ret;
1541
1542error_keyring:
1543 key_ref_put(keyring_r);
1544 return ret;
Geert Uytterhoevena00ae4d2009-12-13 20:21:34 +01001545
1546#else /* !TIF_NOTIFY_RESUME */
1547 /*
1548 * To be removed when TIF_NOTIFY_RESUME has been implemented on
1549 * m68k/xtensa
1550 */
1551#warning TIF_NOTIFY_RESUME not implemented
1552 return -EOPNOTSUPP;
1553#endif /* !TIF_NOTIFY_RESUME */
David Howellsee18d642009-09-02 09:14:21 +01001554}
1555
David Howellsb5f545c2006-01-08 01:02:47 -08001556/*
David Howells973c9f42011-01-20 16:38:33 +00001557 * The key control system call
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558 */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001559SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
1560 unsigned long, arg4, unsigned long, arg5)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001561{
1562 switch (option) {
1563 case KEYCTL_GET_KEYRING_ID:
1564 return keyctl_get_keyring_ID((key_serial_t) arg2,
1565 (int) arg3);
1566
1567 case KEYCTL_JOIN_SESSION_KEYRING:
1568 return keyctl_join_session_keyring((const char __user *) arg2);
1569
1570 case KEYCTL_UPDATE:
1571 return keyctl_update_key((key_serial_t) arg2,
1572 (const void __user *) arg3,
1573 (size_t) arg4);
1574
1575 case KEYCTL_REVOKE:
1576 return keyctl_revoke_key((key_serial_t) arg2);
1577
1578 case KEYCTL_DESCRIBE:
1579 return keyctl_describe_key((key_serial_t) arg2,
1580 (char __user *) arg3,
1581 (unsigned) arg4);
1582
1583 case KEYCTL_CLEAR:
1584 return keyctl_keyring_clear((key_serial_t) arg2);
1585
1586 case KEYCTL_LINK:
1587 return keyctl_keyring_link((key_serial_t) arg2,
1588 (key_serial_t) arg3);
1589
1590 case KEYCTL_UNLINK:
1591 return keyctl_keyring_unlink((key_serial_t) arg2,
1592 (key_serial_t) arg3);
1593
1594 case KEYCTL_SEARCH:
1595 return keyctl_keyring_search((key_serial_t) arg2,
1596 (const char __user *) arg3,
1597 (const char __user *) arg4,
1598 (key_serial_t) arg5);
1599
1600 case KEYCTL_READ:
1601 return keyctl_read_key((key_serial_t) arg2,
1602 (char __user *) arg3,
1603 (size_t) arg4);
1604
1605 case KEYCTL_CHOWN:
1606 return keyctl_chown_key((key_serial_t) arg2,
1607 (uid_t) arg3,
1608 (gid_t) arg4);
1609
1610 case KEYCTL_SETPERM:
1611 return keyctl_setperm_key((key_serial_t) arg2,
1612 (key_perm_t) arg3);
1613
1614 case KEYCTL_INSTANTIATE:
1615 return keyctl_instantiate_key((key_serial_t) arg2,
1616 (const void __user *) arg3,
1617 (size_t) arg4,
1618 (key_serial_t) arg5);
1619
1620 case KEYCTL_NEGATE:
1621 return keyctl_negate_key((key_serial_t) arg2,
1622 (unsigned) arg3,
1623 (key_serial_t) arg4);
1624
David Howells3e301482005-06-23 22:00:56 -07001625 case KEYCTL_SET_REQKEY_KEYRING:
1626 return keyctl_set_reqkey_keyring(arg2);
1627
David Howells017679c2006-01-08 01:02:43 -08001628 case KEYCTL_SET_TIMEOUT:
1629 return keyctl_set_timeout((key_serial_t) arg2,
1630 (unsigned) arg3);
1631
David Howellsb5f545c2006-01-08 01:02:47 -08001632 case KEYCTL_ASSUME_AUTHORITY:
1633 return keyctl_assume_authority((key_serial_t) arg2);
1634
David Howells70a5bb72008-04-29 01:01:26 -07001635 case KEYCTL_GET_SECURITY:
1636 return keyctl_get_security((key_serial_t) arg2,
James Morris90bd49a2008-12-29 14:35:35 +11001637 (char __user *) arg3,
David Howells70a5bb72008-04-29 01:01:26 -07001638 (size_t) arg4);
1639
David Howellsee18d642009-09-02 09:14:21 +01001640 case KEYCTL_SESSION_TO_PARENT:
1641 return keyctl_session_to_parent();
1642
David Howellsfdd1b942011-03-07 15:06:09 +00001643 case KEYCTL_REJECT:
1644 return keyctl_reject_key((key_serial_t) arg2,
1645 (unsigned) arg3,
1646 (unsigned) arg4,
1647 (key_serial_t) arg5);
1648
David Howellsee009e4a02011-03-07 15:06:20 +00001649 case KEYCTL_INSTANTIATE_IOV:
1650 return keyctl_instantiate_key_iov(
1651 (key_serial_t) arg2,
1652 (const struct iovec __user *) arg3,
1653 (unsigned) arg4,
1654 (key_serial_t) arg5);
1655
David Howellsfd758152012-05-11 10:56:56 +01001656 case KEYCTL_INVALIDATE:
1657 return keyctl_invalidate_key((key_serial_t) arg2);
1658
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659 default:
1660 return -EOPNOTSUPP;
1661 }
David Howellsa8b17ed2011-01-20 16:38:27 +00001662}