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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>
Bryan Schumaker59e6b9c2012-02-24 14:14:50 -050017#include <linux/key.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/keyctl.h>
19#include <linux/fs.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080020#include <linux/capability.h>
Davi Arnaut0cb409d2006-03-24 03:18:43 -080021#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/err.h>
David Howells38bbca62008-04-29 01:01:19 -070023#include <linux/vmalloc.h>
David Howells70a5bb72008-04-29 01:01:26 -070024#include <linux/security.h>
Kent Overstreeta27bb332013-05-07 16:19:08 -070025#include <linux/uio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <asm/uaccess.h>
27#include "internal.h"
28
Davi Arnaut0cb409d2006-03-24 03:18:43 -080029static int key_get_type_from_user(char *type,
30 const char __user *_type,
31 unsigned len)
32{
33 int ret;
34
35 ret = strncpy_from_user(type, _type, len);
Davi Arnaut0cb409d2006-03-24 03:18:43 -080036 if (ret < 0)
Dan Carpenter4303ef12010-06-11 17:30:05 +010037 return ret;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080038 if (ret == 0 || ret >= len)
39 return -EINVAL;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080040 if (type[0] == '.')
41 return -EPERM;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080042 type[len - 1] = '\0';
Davi Arnaut0cb409d2006-03-24 03:18:43 -080043 return 0;
44}
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046/*
David Howells973c9f42011-01-20 16:38:33 +000047 * Extract the description of a new key from userspace and either add it as a
48 * new key to the specified keyring or update a matching key in that keyring.
49 *
David Howellscf7f6012012-09-13 13:06:29 +010050 * If the description is NULL or an empty string, the key type is asked to
51 * generate one from the payload.
52 *
David Howells973c9f42011-01-20 16:38:33 +000053 * The keyring must be writable so that we can attach the key to it.
54 *
55 * If successful, the new key's serial number is returned, otherwise an error
56 * code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +010058SYSCALL_DEFINE5(add_key, const char __user *, _type,
59 const char __user *, _description,
60 const void __user *, _payload,
61 size_t, plen,
62 key_serial_t, ringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -070063{
David Howells664cceb2005-09-28 17:03:15 +010064 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 char type[32], *description;
66 void *payload;
Davi Arnaut0cb409d2006-03-24 03:18:43 -080067 long ret;
David Howells38bbca62008-04-29 01:01:19 -070068 bool vm;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -070071 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 goto error;
73
74 /* draw all the data into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -080075 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 if (ret < 0)
77 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
David Howellscf7f6012012-09-13 13:06:29 +010079 description = NULL;
80 if (_description) {
81 description = strndup_user(_description, PAGE_SIZE);
82 if (IS_ERR(description)) {
83 ret = PTR_ERR(description);
84 goto error;
85 }
86 if (!*description) {
87 kfree(description);
88 description = NULL;
89 }
Davi Arnaut0cb409d2006-03-24 03:18:43 -080090 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
92 /* pull the payload in if one was supplied */
93 payload = NULL;
94
David Howells38bbca62008-04-29 01:01:19 -070095 vm = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 if (_payload) {
97 ret = -ENOMEM;
Andrew Morton4f1c28d2012-05-31 16:26:02 -070098 payload = kmalloc(plen, GFP_KERNEL | __GFP_NOWARN);
David Howells38bbca62008-04-29 01:01:19 -070099 if (!payload) {
100 if (plen <= PAGE_SIZE)
101 goto error2;
102 vm = true;
103 payload = vmalloc(plen);
104 if (!payload)
105 goto error2;
106 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
108 ret = -EFAULT;
109 if (copy_from_user(payload, _payload, plen) != 0)
110 goto error3;
111 }
112
113 /* find the target keyring (which must be writable) */
David Howells55931222009-09-02 09:13:45 +0100114 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100115 if (IS_ERR(keyring_ref)) {
116 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 goto error3;
118 }
119
120 /* create or update the requested key and add it to the target
121 * keyring */
David Howells664cceb2005-09-28 17:03:15 +0100122 key_ref = key_create_or_update(keyring_ref, type, description,
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700123 payload, plen, KEY_PERM_UNDEF,
124 KEY_ALLOC_IN_QUOTA);
David Howells664cceb2005-09-28 17:03:15 +0100125 if (!IS_ERR(key_ref)) {
126 ret = key_ref_to_ptr(key_ref)->serial;
127 key_ref_put(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 }
129 else {
David Howells664cceb2005-09-28 17:03:15 +0100130 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 }
132
David Howells664cceb2005-09-28 17:03:15 +0100133 key_ref_put(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 error3:
David Howells38bbca62008-04-29 01:01:19 -0700135 if (!vm)
136 kfree(payload);
137 else
138 vfree(payload);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 error2:
140 kfree(description);
141 error:
142 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000143}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145/*
David Howells973c9f42011-01-20 16:38:33 +0000146 * Search the process keyrings and keyring trees linked from those for a
147 * matching key. Keyrings must have appropriate Search permission to be
148 * searched.
149 *
150 * If a key is found, it will be attached to the destination keyring if there's
151 * one specified and the serial number of the key will be returned.
152 *
153 * If no key is found, /sbin/request-key will be invoked if _callout_info is
154 * non-NULL in an attempt to create a key. The _callout_info string will be
155 * passed to /sbin/request-key to aid with completing the request. If the
156 * _callout_info string is "" then it will be changed to "-".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +0100158SYSCALL_DEFINE4(request_key, const char __user *, _type,
159 const char __user *, _description,
160 const char __user *, _callout_info,
161 key_serial_t, destringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162{
163 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100164 struct key *key;
165 key_ref_t dest_ref;
David Howells4a38e122008-04-29 01:01:24 -0700166 size_t callout_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 char type[32], *description, *callout_info;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800168 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170 /* pull the type into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800171 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 if (ret < 0)
173 goto error;
David Howells1260f802005-08-04 11:50:01 +0100174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 /* pull the description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800176 description = strndup_user(_description, PAGE_SIZE);
177 if (IS_ERR(description)) {
178 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800180 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182 /* pull the callout info into kernel space */
183 callout_info = NULL;
David Howells4a38e122008-04-29 01:01:24 -0700184 callout_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 if (_callout_info) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800186 callout_info = strndup_user(_callout_info, PAGE_SIZE);
187 if (IS_ERR(callout_info)) {
188 ret = PTR_ERR(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 goto error2;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800190 }
David Howells4a38e122008-04-29 01:01:24 -0700191 callout_len = strlen(callout_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 }
193
194 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100195 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100197 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
198 KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100199 if (IS_ERR(dest_ref)) {
200 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 goto error3;
202 }
203 }
204
205 /* find the key type */
206 ktype = key_type_lookup(type);
207 if (IS_ERR(ktype)) {
208 ret = PTR_ERR(ktype);
209 goto error4;
210 }
211
212 /* do the search */
David Howells4a38e122008-04-29 01:01:24 -0700213 key = request_key_and_link(ktype, description, callout_info,
214 callout_len, NULL, key_ref_to_ptr(dest_ref),
David Howells7e047ef2006-06-26 00:24:50 -0700215 KEY_ALLOC_IN_QUOTA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 if (IS_ERR(key)) {
217 ret = PTR_ERR(key);
218 goto error5;
219 }
220
David Howells4aab1e82011-03-11 17:57:33 +0000221 /* wait for the key to finish being constructed */
222 ret = wait_for_key_construction(key, 1);
223 if (ret < 0)
224 goto error6;
225
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 ret = key->serial;
227
David Howells4aab1e82011-03-11 17:57:33 +0000228error6:
David Howells3e301482005-06-23 22:00:56 -0700229 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700230error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700232error4:
David Howells664cceb2005-09-28 17:03:15 +0100233 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700234error3:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 kfree(callout_info);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700236error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700238error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000240}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242/*
David Howells973c9f42011-01-20 16:38:33 +0000243 * Get the ID of the specified process keyring.
244 *
245 * The requested keyring must have search permission to be found.
246 *
247 * If successful, the ID of the requested keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 */
249long keyctl_get_keyring_ID(key_serial_t id, int create)
250{
David Howells664cceb2005-09-28 17:03:15 +0100251 key_ref_t key_ref;
David Howells55931222009-09-02 09:13:45 +0100252 unsigned long lflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 long ret;
254
David Howells55931222009-09-02 09:13:45 +0100255 lflags = create ? KEY_LOOKUP_CREATE : 0;
256 key_ref = lookup_user_key(id, lflags, KEY_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100257 if (IS_ERR(key_ref)) {
258 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 goto error;
260 }
261
David Howells664cceb2005-09-28 17:03:15 +0100262 ret = key_ref_to_ptr(key_ref)->serial;
263 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700264error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 return ret;
David Howells973c9f42011-01-20 16:38:33 +0000266}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268/*
David Howells973c9f42011-01-20 16:38:33 +0000269 * Join a (named) session keyring.
270 *
271 * Create and join an anonymous session keyring or join a named session
272 * keyring, creating it if necessary. A named session keyring must have Search
273 * permission for it to be joined. Session keyrings without this permit will
274 * be skipped over.
275 *
276 * If successful, the ID of the joined session keyring will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 */
278long keyctl_join_session_keyring(const char __user *_name)
279{
280 char *name;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800281 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283 /* fetch the name from userspace */
284 name = NULL;
285 if (_name) {
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800286 name = strndup_user(_name, PAGE_SIZE);
287 if (IS_ERR(name)) {
288 ret = PTR_ERR(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800290 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 }
292
293 /* join the session */
294 ret = join_session_keyring(name);
Vegard Nossum0d54ee12009-01-17 17:45:45 +0100295 kfree(name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700297error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000299}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301/*
David Howells973c9f42011-01-20 16:38:33 +0000302 * Update a key's data payload from the given data.
303 *
304 * The key must grant the caller Write permission and the key type must support
305 * updating for this to work. A negative key can be positively instantiated
306 * with this call.
307 *
308 * If successful, 0 will be returned. If the key type does not support
309 * updating, then -EOPNOTSUPP will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 */
311long keyctl_update_key(key_serial_t id,
312 const void __user *_payload,
313 size_t plen)
314{
David Howells664cceb2005-09-28 17:03:15 +0100315 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 void *payload;
317 long ret;
318
319 ret = -EINVAL;
320 if (plen > PAGE_SIZE)
321 goto error;
322
323 /* pull the payload in if one was supplied */
324 payload = NULL;
325 if (_payload) {
326 ret = -ENOMEM;
327 payload = kmalloc(plen, GFP_KERNEL);
328 if (!payload)
329 goto error;
330
331 ret = -EFAULT;
332 if (copy_from_user(payload, _payload, plen) != 0)
333 goto error2;
334 }
335
336 /* find the target key (which must be writable) */
David Howells55931222009-09-02 09:13:45 +0100337 key_ref = lookup_user_key(id, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100338 if (IS_ERR(key_ref)) {
339 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 goto error2;
341 }
342
343 /* update the key */
David Howells664cceb2005-09-28 17:03:15 +0100344 ret = key_update(key_ref, payload, plen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
David Howells664cceb2005-09-28 17:03:15 +0100346 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700347error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 kfree(payload);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700349error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000351}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353/*
David Howells973c9f42011-01-20 16:38:33 +0000354 * Revoke a key.
355 *
356 * The key must be grant the caller Write or Setattr permission for this to
357 * work. The key type should give up its quota claim when revoked. The key
358 * and any links to the key will be automatically garbage collected after a
359 * certain amount of time (/proc/sys/kernel/keys/gc_delay).
360 *
361 * If successful, 0 is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 */
363long keyctl_revoke_key(key_serial_t id)
364{
David Howells664cceb2005-09-28 17:03:15 +0100365 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 long ret;
367
David Howells55931222009-09-02 09:13:45 +0100368 key_ref = lookup_user_key(id, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100369 if (IS_ERR(key_ref)) {
370 ret = PTR_ERR(key_ref);
David Howells0c2c9a32009-09-02 09:13:50 +0100371 if (ret != -EACCES)
372 goto error;
373 key_ref = lookup_user_key(id, 0, KEY_SETATTR);
374 if (IS_ERR(key_ref)) {
375 ret = PTR_ERR(key_ref);
376 goto error;
377 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 }
379
David Howells664cceb2005-09-28 17:03:15 +0100380 key_revoke(key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 ret = 0;
382
David Howells664cceb2005-09-28 17:03:15 +0100383 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700384error:
David Howells1260f802005-08-04 11:50:01 +0100385 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000386}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388/*
David Howellsfd758152012-05-11 10:56:56 +0100389 * Invalidate a key.
390 *
391 * The key must be grant the caller Invalidate permission for this to work.
392 * The key and any links to the key will be automatically garbage collected
393 * immediately.
394 *
395 * If successful, 0 is returned.
396 */
397long keyctl_invalidate_key(key_serial_t id)
398{
399 key_ref_t key_ref;
400 long ret;
401
402 kenter("%d", id);
403
404 key_ref = lookup_user_key(id, 0, KEY_SEARCH);
405 if (IS_ERR(key_ref)) {
406 ret = PTR_ERR(key_ref);
407 goto error;
408 }
409
410 key_invalidate(key_ref_to_ptr(key_ref));
411 ret = 0;
412
413 key_ref_put(key_ref);
414error:
415 kleave(" = %ld", ret);
416 return ret;
417}
418
419/*
David Howells973c9f42011-01-20 16:38:33 +0000420 * Clear the specified keyring, creating an empty process keyring if one of the
421 * special keyring IDs is used.
422 *
423 * The keyring must grant the caller Write permission for this to work. If
424 * successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 */
426long keyctl_keyring_clear(key_serial_t ringid)
427{
David Howells664cceb2005-09-28 17:03:15 +0100428 key_ref_t keyring_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 long ret;
430
David Howells55931222009-09-02 09:13:45 +0100431 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100432 if (IS_ERR(keyring_ref)) {
433 ret = PTR_ERR(keyring_ref);
David Howells700920e2012-01-18 15:31:45 +0000434
435 /* Root is permitted to invalidate certain special keyrings */
436 if (capable(CAP_SYS_ADMIN)) {
437 keyring_ref = lookup_user_key(ringid, 0, 0);
438 if (IS_ERR(keyring_ref))
439 goto error;
440 if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR,
441 &key_ref_to_ptr(keyring_ref)->flags))
442 goto clear;
443 goto error_put;
444 }
445
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 goto error;
447 }
448
David Howells700920e2012-01-18 15:31:45 +0000449clear:
David Howells664cceb2005-09-28 17:03:15 +0100450 ret = keyring_clear(key_ref_to_ptr(keyring_ref));
David Howells700920e2012-01-18 15:31:45 +0000451error_put:
David Howells664cceb2005-09-28 17:03:15 +0100452 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700453error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000455}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457/*
David Howells973c9f42011-01-20 16:38:33 +0000458 * Create a link from a keyring to a key if there's no matching key in the
459 * keyring, otherwise replace the link to the matching key with a link to the
460 * new key.
461 *
462 * The key must grant the caller Link permission and the the keyring must grant
463 * the caller Write permission. Furthermore, if an additional link is created,
464 * the keyring's quota will be extended.
465 *
466 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 */
468long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
469{
David Howells664cceb2005-09-28 17:03:15 +0100470 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 long ret;
472
David Howells55931222009-09-02 09:13:45 +0100473 keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100474 if (IS_ERR(keyring_ref)) {
475 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 goto error;
477 }
478
David Howells55931222009-09-02 09:13:45 +0100479 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK);
David Howells664cceb2005-09-28 17:03:15 +0100480 if (IS_ERR(key_ref)) {
481 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 goto error2;
483 }
484
David Howells664cceb2005-09-28 17:03:15 +0100485 ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486
David Howells664cceb2005-09-28 17:03:15 +0100487 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700488error2:
David Howells664cceb2005-09-28 17:03:15 +0100489 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700490error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000492}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494/*
David Howells973c9f42011-01-20 16:38:33 +0000495 * Unlink a key from a keyring.
496 *
497 * The keyring must grant the caller Write permission for this to work; the key
498 * itself need not grant the caller anything. If the last link to a key is
499 * removed then that key will be scheduled for destruction.
500 *
501 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 */
503long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
504{
David Howells664cceb2005-09-28 17:03:15 +0100505 key_ref_t keyring_ref, key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 long ret;
507
David Howells55931222009-09-02 09:13:45 +0100508 keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100509 if (IS_ERR(keyring_ref)) {
510 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 goto error;
512 }
513
David Howells55931222009-09-02 09:13:45 +0100514 key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0);
David Howells664cceb2005-09-28 17:03:15 +0100515 if (IS_ERR(key_ref)) {
516 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 goto error2;
518 }
519
David Howells664cceb2005-09-28 17:03:15 +0100520 ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521
David Howells664cceb2005-09-28 17:03:15 +0100522 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700523error2:
David Howells664cceb2005-09-28 17:03:15 +0100524 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700525error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000527}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529/*
David Howells973c9f42011-01-20 16:38:33 +0000530 * Return a description of a key to userspace.
531 *
532 * The key must grant the caller View permission for this to work.
533 *
534 * If there's a buffer, we place up to buflen bytes of data into it formatted
535 * in the following way:
536 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 * type;uid;gid;perm;description<NUL>
David Howells973c9f42011-01-20 16:38:33 +0000538 *
539 * If successful, we return the amount of description available, irrespective
540 * of how much we may have copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 */
542long keyctl_describe_key(key_serial_t keyid,
543 char __user *buffer,
544 size_t buflen)
545{
David Howells3e301482005-06-23 22:00:56 -0700546 struct key *key, *instkey;
David Howells664cceb2005-09-28 17:03:15 +0100547 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 char *tmpbuf;
549 long ret;
550
David Howells55931222009-09-02 09:13:45 +0100551 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
David Howells664cceb2005-09-28 17:03:15 +0100552 if (IS_ERR(key_ref)) {
David Howells3e301482005-06-23 22:00:56 -0700553 /* viewing a key under construction is permitted if we have the
554 * authorisation token handy */
David Howells664cceb2005-09-28 17:03:15 +0100555 if (PTR_ERR(key_ref) == -EACCES) {
David Howells3e301482005-06-23 22:00:56 -0700556 instkey = key_get_instantiation_authkey(keyid);
557 if (!IS_ERR(instkey)) {
558 key_put(instkey);
David Howells8bbf49762008-11-14 10:39:14 +1100559 key_ref = lookup_user_key(keyid,
David Howells55931222009-09-02 09:13:45 +0100560 KEY_LOOKUP_PARTIAL,
561 0);
David Howells664cceb2005-09-28 17:03:15 +0100562 if (!IS_ERR(key_ref))
David Howells3e301482005-06-23 22:00:56 -0700563 goto okay;
564 }
565 }
566
David Howells664cceb2005-09-28 17:03:15 +0100567 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 goto error;
569 }
570
David Howells3e301482005-06-23 22:00:56 -0700571okay:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 /* calculate how much description we're going to return */
573 ret = -ENOMEM;
574 tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
575 if (!tmpbuf)
576 goto error2;
577
David Howells664cceb2005-09-28 17:03:15 +0100578 key = key_ref_to_ptr(key_ref);
579
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 ret = snprintf(tmpbuf, PAGE_SIZE - 1,
David Howells664cceb2005-09-28 17:03:15 +0100581 "%s;%d;%d;%08x;%s",
David Howells94fd8402010-06-28 14:05:04 +0100582 key->type->name,
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800583 from_kuid_munged(current_user_ns(), key->uid),
584 from_kgid_munged(current_user_ns(), key->gid),
David Howells94fd8402010-06-28 14:05:04 +0100585 key->perm,
586 key->description ?: "");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588 /* include a NUL char at the end of the data */
589 if (ret > PAGE_SIZE - 1)
590 ret = PAGE_SIZE - 1;
591 tmpbuf[ret] = 0;
592 ret++;
593
594 /* consider returning the data */
595 if (buffer && buflen > 0) {
596 if (buflen > ret)
597 buflen = ret;
598
599 if (copy_to_user(buffer, tmpbuf, buflen) != 0)
600 ret = -EFAULT;
601 }
602
603 kfree(tmpbuf);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700604error2:
David Howells664cceb2005-09-28 17:03:15 +0100605 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700606error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000608}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610/*
David Howells973c9f42011-01-20 16:38:33 +0000611 * Search the specified keyring and any keyrings it links to for a matching
612 * key. Only keyrings that grant the caller Search permission will be searched
613 * (this includes the starting keyring). Only keys with Search permission can
614 * be found.
615 *
616 * If successful, the found key will be linked to the destination keyring if
617 * supplied and the key has Link permission, and the found key ID will be
618 * returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 */
620long keyctl_keyring_search(key_serial_t ringid,
621 const char __user *_type,
622 const char __user *_description,
623 key_serial_t destringid)
624{
625 struct key_type *ktype;
David Howells664cceb2005-09-28 17:03:15 +0100626 key_ref_t keyring_ref, key_ref, dest_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 char type[32], *description;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800628 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630 /* pull the type and description into kernel space */
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800631 ret = key_get_type_from_user(type, _type, sizeof(type));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 if (ret < 0)
633 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800635 description = strndup_user(_description, PAGE_SIZE);
636 if (IS_ERR(description)) {
637 ret = PTR_ERR(description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 goto error;
Davi Arnaut0cb409d2006-03-24 03:18:43 -0800639 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640
641 /* get the keyring at which to begin the search */
David Howells55931222009-09-02 09:13:45 +0100642 keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH);
David Howells664cceb2005-09-28 17:03:15 +0100643 if (IS_ERR(keyring_ref)) {
644 ret = PTR_ERR(keyring_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 goto error2;
646 }
647
648 /* get the destination keyring if specified */
David Howells664cceb2005-09-28 17:03:15 +0100649 dest_ref = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 if (destringid) {
David Howells55931222009-09-02 09:13:45 +0100651 dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE,
652 KEY_WRITE);
David Howells664cceb2005-09-28 17:03:15 +0100653 if (IS_ERR(dest_ref)) {
654 ret = PTR_ERR(dest_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 goto error3;
656 }
657 }
658
659 /* find the key type */
660 ktype = key_type_lookup(type);
661 if (IS_ERR(ktype)) {
662 ret = PTR_ERR(ktype);
663 goto error4;
664 }
665
666 /* do the search */
David Howells664cceb2005-09-28 17:03:15 +0100667 key_ref = keyring_search(keyring_ref, ktype, description);
668 if (IS_ERR(key_ref)) {
669 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
671 /* treat lack or presence of a negative key the same */
672 if (ret == -EAGAIN)
673 ret = -ENOKEY;
674 goto error5;
675 }
676
677 /* link the resulting key to the destination keyring if we can */
David Howells664cceb2005-09-28 17:03:15 +0100678 if (dest_ref) {
David Howells29db9192005-10-30 15:02:44 -0800679 ret = key_permission(key_ref, KEY_LINK);
680 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 goto error6;
682
David Howells664cceb2005-09-28 17:03:15 +0100683 ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 if (ret < 0)
685 goto error6;
686 }
687
David Howells664cceb2005-09-28 17:03:15 +0100688 ret = key_ref_to_ptr(key_ref)->serial;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700690error6:
David Howells664cceb2005-09-28 17:03:15 +0100691 key_ref_put(key_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700692error5:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 key_type_put(ktype);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700694error4:
David Howells664cceb2005-09-28 17:03:15 +0100695 key_ref_put(dest_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700696error3:
David Howells664cceb2005-09-28 17:03:15 +0100697 key_ref_put(keyring_ref);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700698error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 kfree(description);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700700error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000702}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704/*
David Howells973c9f42011-01-20 16:38:33 +0000705 * Read a key's payload.
706 *
707 * The key must either grant the caller Read permission, or it must grant the
708 * caller Search permission when searched for from the process keyrings.
709 *
710 * If successful, we place up to buflen bytes of data into the buffer, if one
711 * is provided, and return the amount of data that is available in the key,
712 * irrespective of how much we copied into the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 */
714long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
715{
David Howells664cceb2005-09-28 17:03:15 +0100716 struct key *key;
717 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 long ret;
719
720 /* find the key first */
David Howells55931222009-09-02 09:13:45 +0100721 key_ref = lookup_user_key(keyid, 0, 0);
David Howells664cceb2005-09-28 17:03:15 +0100722 if (IS_ERR(key_ref)) {
723 ret = -ENOKEY;
724 goto error;
725 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726
David Howells664cceb2005-09-28 17:03:15 +0100727 key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728
David Howells664cceb2005-09-28 17:03:15 +0100729 /* see if we can read it directly */
David Howells29db9192005-10-30 15:02:44 -0800730 ret = key_permission(key_ref, KEY_READ);
731 if (ret == 0)
David Howells664cceb2005-09-28 17:03:15 +0100732 goto can_read_key;
David Howells29db9192005-10-30 15:02:44 -0800733 if (ret != -EACCES)
734 goto error;
David Howells664cceb2005-09-28 17:03:15 +0100735
736 /* we can't; see if it's searchable from this process's keyrings
737 * - we automatically take account of the fact that it may be
738 * dangling off an instantiation key
739 */
740 if (!is_key_possessed(key_ref)) {
741 ret = -EACCES;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 goto error2;
743 }
744
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 /* the key is probably readable - now try to read it */
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700746can_read_key:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 ret = key_validate(key);
748 if (ret == 0) {
749 ret = -EOPNOTSUPP;
750 if (key->type->read) {
751 /* read the data with the semaphore held (since we
752 * might sleep) */
753 down_read(&key->sem);
754 ret = key->type->read(key, buffer, buflen);
755 up_read(&key->sem);
756 }
757 }
758
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700759error2:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 key_put(key);
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700761error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000763}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765/*
David Howells973c9f42011-01-20 16:38:33 +0000766 * Change the ownership of a key
767 *
768 * The key must grant the caller Setattr permission for this to work, though
769 * the key need not be fully instantiated yet. For the UID to be changed, or
770 * for the GID to be changed to a group the caller is not a member of, the
771 * caller must have sysadmin capability. If either uid or gid is -1 then that
772 * attribute is not changed.
773 *
774 * If the UID is to be changed, the new user must have sufficient quota to
775 * accept the key. The quota deduction will be removed from the old user to
776 * the new user should the attribute be changed.
777 *
778 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800780long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781{
Fredrik Tolf58016492006-06-26 00:24:51 -0700782 struct key_user *newowner, *zapowner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100784 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 long ret;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800786 kuid_t uid;
787 kgid_t gid;
788
789 uid = make_kuid(current_user_ns(), user);
790 gid = make_kgid(current_user_ns(), group);
791 ret = -EINVAL;
792 if ((user != (uid_t) -1) && !uid_valid(uid))
793 goto error;
794 if ((group != (gid_t) -1) && !gid_valid(gid))
795 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796
797 ret = 0;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800798 if (user == (uid_t) -1 && group == (gid_t) -1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 goto error;
800
David Howells55931222009-09-02 09:13:45 +0100801 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
802 KEY_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100803 if (IS_ERR(key_ref)) {
804 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 goto error;
806 }
807
David Howells664cceb2005-09-28 17:03:15 +0100808 key = key_ref_to_ptr(key_ref);
809
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 /* make the changes with the locks held to prevent chown/chown races */
811 ret = -EACCES;
812 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813
814 if (!capable(CAP_SYS_ADMIN)) {
815 /* only the sysadmin can chown a key to some other UID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800816 if (user != (uid_t) -1 && !uid_eq(key->uid, uid))
Fredrik Tolf58016492006-06-26 00:24:51 -0700817 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818
819 /* only the sysadmin can set the key's GID to a group other
820 * than one of those that the current process subscribes to */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800821 if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid))
Fredrik Tolf58016492006-06-26 00:24:51 -0700822 goto error_put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 }
824
Fredrik Tolf58016492006-06-26 00:24:51 -0700825 /* change the UID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800826 if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) {
Fredrik Tolf58016492006-06-26 00:24:51 -0700827 ret = -ENOMEM;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800828 newowner = key_user_lookup(uid);
Fredrik Tolf58016492006-06-26 00:24:51 -0700829 if (!newowner)
830 goto error_put;
831
832 /* transfer the quota burden to the new user */
833 if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800834 unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ?
David Howells0b77f5b2008-04-29 01:01:32 -0700835 key_quota_root_maxkeys : key_quota_maxkeys;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800836 unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ?
David Howells0b77f5b2008-04-29 01:01:32 -0700837 key_quota_root_maxbytes : key_quota_maxbytes;
838
Fredrik Tolf58016492006-06-26 00:24:51 -0700839 spin_lock(&newowner->lock);
David Howells0b77f5b2008-04-29 01:01:32 -0700840 if (newowner->qnkeys + 1 >= maxkeys ||
841 newowner->qnbytes + key->quotalen >= maxbytes ||
842 newowner->qnbytes + key->quotalen <
843 newowner->qnbytes)
Fredrik Tolf58016492006-06-26 00:24:51 -0700844 goto quota_overrun;
845
846 newowner->qnkeys++;
847 newowner->qnbytes += key->quotalen;
848 spin_unlock(&newowner->lock);
849
850 spin_lock(&key->user->lock);
851 key->user->qnkeys--;
852 key->user->qnbytes -= key->quotalen;
853 spin_unlock(&key->user->lock);
854 }
855
856 atomic_dec(&key->user->nkeys);
857 atomic_inc(&newowner->nkeys);
858
859 if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
860 atomic_dec(&key->user->nikeys);
861 atomic_inc(&newowner->nikeys);
862 }
863
864 zapowner = key->user;
865 key->user = newowner;
866 key->uid = uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 }
868
869 /* change the GID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800870 if (group != (gid_t) -1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 key->gid = gid;
872
873 ret = 0;
874
Fredrik Tolf58016492006-06-26 00:24:51 -0700875error_put:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 up_write(&key->sem);
877 key_put(key);
Fredrik Tolf58016492006-06-26 00:24:51 -0700878 if (zapowner)
879 key_user_put(zapowner);
880error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 return ret;
882
Fredrik Tolf58016492006-06-26 00:24:51 -0700883quota_overrun:
884 spin_unlock(&newowner->lock);
885 zapowner = newowner;
886 ret = -EDQUOT;
887 goto error_put;
David Howellsa8b17ed2011-01-20 16:38:27 +0000888}
Fredrik Tolf58016492006-06-26 00:24:51 -0700889
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890/*
David Howells973c9f42011-01-20 16:38:33 +0000891 * Change the permission mask on a key.
892 *
893 * The key must grant the caller Setattr permission for this to work, though
894 * the key need not be fully instantiated yet. If the caller does not have
895 * sysadmin capability, it may only change the permission on keys that it owns.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 */
897long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
898{
899 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100900 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 long ret;
902
903 ret = -EINVAL;
David Howells664cceb2005-09-28 17:03:15 +0100904 if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 goto error;
906
David Howells55931222009-09-02 09:13:45 +0100907 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
908 KEY_SETATTR);
David Howells664cceb2005-09-28 17:03:15 +0100909 if (IS_ERR(key_ref)) {
910 ret = PTR_ERR(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 goto error;
912 }
913
David Howells664cceb2005-09-28 17:03:15 +0100914 key = key_ref_to_ptr(key_ref);
915
David Howells76d8aea2005-06-23 22:00:49 -0700916 /* make the changes with the locks held to prevent chown/chmod races */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 ret = -EACCES;
918 down_write(&key->sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919
David Howells76d8aea2005-06-23 22:00:49 -0700920 /* if we're not the sysadmin, we can only change a key that we own */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800921 if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) {
David Howells76d8aea2005-06-23 22:00:49 -0700922 key->perm = perm;
923 ret = 0;
924 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 up_write(&key->sem);
927 key_put(key);
David Howells76d8aea2005-06-23 22:00:49 -0700928error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000930}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931
David Howells8bbf49762008-11-14 10:39:14 +1100932/*
David Howells973c9f42011-01-20 16:38:33 +0000933 * Get the destination keyring for instantiation and check that the caller has
934 * Write permission on it.
David Howells8bbf49762008-11-14 10:39:14 +1100935 */
936static long get_instantiation_keyring(key_serial_t ringid,
937 struct request_key_auth *rka,
938 struct key **_dest_keyring)
939{
940 key_ref_t dkref;
941
David Howellseca1bf52008-12-29 00:41:51 +0000942 *_dest_keyring = NULL;
943
David Howells8bbf49762008-11-14 10:39:14 +1100944 /* just return a NULL pointer if we weren't asked to make a link */
David Howellseca1bf52008-12-29 00:41:51 +0000945 if (ringid == 0)
David Howells8bbf49762008-11-14 10:39:14 +1100946 return 0;
David Howells8bbf49762008-11-14 10:39:14 +1100947
948 /* if a specific keyring is nominated by ID, then use that */
949 if (ringid > 0) {
David Howells55931222009-09-02 09:13:45 +0100950 dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE);
David Howells8bbf49762008-11-14 10:39:14 +1100951 if (IS_ERR(dkref))
952 return PTR_ERR(dkref);
953 *_dest_keyring = key_ref_to_ptr(dkref);
954 return 0;
955 }
956
957 if (ringid == KEY_SPEC_REQKEY_AUTH_KEY)
958 return -EINVAL;
959
960 /* otherwise specify the destination keyring recorded in the
961 * authorisation key (any KEY_SPEC_*_KEYRING) */
962 if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) {
David Howells21279cf2009-10-15 10:14:35 +0100963 *_dest_keyring = key_get(rka->dest_keyring);
David Howells8bbf49762008-11-14 10:39:14 +1100964 return 0;
965 }
966
967 return -ENOKEY;
968}
969
David Howellsd84f4f92008-11-14 10:39:23 +1100970/*
David Howells973c9f42011-01-20 16:38:33 +0000971 * Change the request_key authorisation key on the current process.
David Howellsd84f4f92008-11-14 10:39:23 +1100972 */
973static int keyctl_change_reqkey_auth(struct key *key)
974{
975 struct cred *new;
976
977 new = prepare_creds();
978 if (!new)
979 return -ENOMEM;
980
981 key_put(new->request_key_auth);
982 new->request_key_auth = key_get(key);
983
984 return commit_creds(new);
985}
986
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987/*
David Howellsee009e4a02011-03-07 15:06:20 +0000988 * Copy the iovec data from userspace
989 */
990static long copy_from_user_iovec(void *buffer, const struct iovec *iov,
991 unsigned ioc)
992{
993 for (; ioc > 0; ioc--) {
994 if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0)
995 return -EFAULT;
996 buffer += iov->iov_len;
997 iov++;
998 }
999 return 0;
1000}
1001
1002/*
David Howells973c9f42011-01-20 16:38:33 +00001003 * Instantiate a key with the specified payload and link the key into the
1004 * destination keyring if one is given.
1005 *
1006 * The caller must have the appropriate instantiation permit set for this to
1007 * work (see keyctl_assume_authority). No other permissions are required.
1008 *
1009 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 */
David Howellsee009e4a02011-03-07 15:06:20 +00001011long keyctl_instantiate_key_common(key_serial_t id,
1012 const struct iovec *payload_iov,
1013 unsigned ioc,
1014 size_t plen,
1015 key_serial_t ringid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016{
David Howellsd84f4f92008-11-14 10:39:23 +11001017 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -07001018 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +11001019 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 void *payload;
1021 long ret;
David Howells38bbca62008-04-29 01:01:19 -07001022 bool vm = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023
David Howellsd84f4f92008-11-14 10:39:23 +11001024 kenter("%d,,%zu,%d", id, plen, ringid);
1025
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 ret = -EINVAL;
David Howells38bbca62008-04-29 01:01:19 -07001027 if (plen > 1024 * 1024 - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 goto error;
1029
David Howellsb5f545c2006-01-08 01:02:47 -08001030 /* the appropriate instantiation authorisation key must have been
1031 * assumed before calling this */
1032 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +11001033 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -08001034 if (!instkey)
1035 goto error;
1036
1037 rka = instkey->payload.data;
1038 if (rka->target_key->serial != id)
1039 goto error;
1040
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 /* pull the payload in if one was supplied */
1042 payload = NULL;
1043
David Howellsee009e4a02011-03-07 15:06:20 +00001044 if (payload_iov) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045 ret = -ENOMEM;
1046 payload = kmalloc(plen, GFP_KERNEL);
David Howells38bbca62008-04-29 01:01:19 -07001047 if (!payload) {
1048 if (plen <= PAGE_SIZE)
1049 goto error;
1050 vm = true;
1051 payload = vmalloc(plen);
1052 if (!payload)
1053 goto error;
1054 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055
David Howellsee009e4a02011-03-07 15:06:20 +00001056 ret = copy_from_user_iovec(payload, payload_iov, ioc);
1057 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 goto error2;
1059 }
1060
David Howells3e301482005-06-23 22:00:56 -07001061 /* find the destination keyring amongst those belonging to the
1062 * requesting task */
David Howells8bbf49762008-11-14 10:39:14 +11001063 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1064 if (ret < 0)
1065 goto error2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066
1067 /* instantiate the key and link it into a keyring */
David Howells3e301482005-06-23 22:00:56 -07001068 ret = key_instantiate_and_link(rka->target_key, payload, plen,
David Howells8bbf49762008-11-14 10:39:14 +11001069 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070
David Howells8bbf49762008-11-14 10:39:14 +11001071 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001072
1073 /* discard the assumed authority if it's just been disabled by
1074 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001075 if (ret == 0)
1076 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001077
1078error2:
David Howells38bbca62008-04-29 01:01:19 -07001079 if (!vm)
1080 kfree(payload);
1081 else
1082 vfree(payload);
David Howellsb5f545c2006-01-08 01:02:47 -08001083error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001085}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087/*
David Howellsee009e4a02011-03-07 15:06:20 +00001088 * Instantiate a key with the specified payload and link the key into the
1089 * 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 * If successful, 0 will be returned.
1095 */
1096long keyctl_instantiate_key(key_serial_t id,
1097 const void __user *_payload,
1098 size_t plen,
1099 key_serial_t ringid)
1100{
1101 if (_payload && plen) {
1102 struct iovec iov[1] = {
1103 [0].iov_base = (void __user *)_payload,
1104 [0].iov_len = plen
1105 };
1106
1107 return keyctl_instantiate_key_common(id, iov, 1, plen, ringid);
1108 }
1109
1110 return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
1111}
1112
1113/*
1114 * Instantiate a key with the specified multipart payload and link the key into
1115 * the destination keyring if one is given.
1116 *
1117 * The caller must have the appropriate instantiation permit set for this to
1118 * work (see keyctl_assume_authority). No other permissions are required.
1119 *
1120 * If successful, 0 will be returned.
1121 */
1122long keyctl_instantiate_key_iov(key_serial_t id,
1123 const struct iovec __user *_payload_iov,
1124 unsigned ioc,
1125 key_serial_t ringid)
1126{
1127 struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
1128 long ret;
1129
David Howells423b97882012-05-21 12:32:13 +01001130 if (!_payload_iov || !ioc)
David Howellsee009e4a02011-03-07 15:06:20 +00001131 goto no_payload;
1132
1133 ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
Christopher Yeohac34ebb2012-05-31 16:26:42 -07001134 ARRAY_SIZE(iovstack), iovstack, &iov);
David Howellsee009e4a02011-03-07 15:06:20 +00001135 if (ret < 0)
Alan Coxa84a9212012-09-28 12:20:02 +01001136 goto err;
David Howellsee009e4a02011-03-07 15:06:20 +00001137 if (ret == 0)
1138 goto no_payload_free;
1139
1140 ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
Alan Coxa84a9212012-09-28 12:20:02 +01001141err:
David Howellsee009e4a02011-03-07 15:06:20 +00001142 if (iov != iovstack)
1143 kfree(iov);
1144 return ret;
1145
1146no_payload_free:
1147 if (iov != iovstack)
1148 kfree(iov);
1149no_payload:
1150 return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
1151}
1152
1153/*
David Howells973c9f42011-01-20 16:38:33 +00001154 * Negatively instantiate the key with the given timeout (in seconds) and link
1155 * the key into the destination keyring if one is given.
1156 *
1157 * The caller must have the appropriate instantiation permit set for this to
1158 * work (see keyctl_assume_authority). No other permissions are required.
1159 *
1160 * The key and any links to the key will be automatically garbage collected
1161 * after the timeout expires.
1162 *
1163 * Negative keys are used to rate limit repeated request_key() calls by causing
1164 * them to return -ENOKEY until the negative key expires.
1165 *
1166 * If successful, 0 will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 */
1168long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
1169{
David Howellsfdd1b942011-03-07 15:06:09 +00001170 return keyctl_reject_key(id, timeout, ENOKEY, ringid);
1171}
1172
1173/*
1174 * Negatively instantiate the key with the given timeout (in seconds) and error
1175 * code and link the key into the destination keyring if one is given.
1176 *
1177 * The caller must have the appropriate instantiation permit set for this to
1178 * work (see keyctl_assume_authority). No other permissions are required.
1179 *
1180 * The key and any links to the key will be automatically garbage collected
1181 * after the timeout expires.
1182 *
1183 * Negative keys are used to rate limit repeated request_key() calls by causing
1184 * them to return the specified error code until the negative key expires.
1185 *
1186 * If successful, 0 will be returned.
1187 */
1188long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error,
1189 key_serial_t ringid)
1190{
David Howellsd84f4f92008-11-14 10:39:23 +11001191 const struct cred *cred = current_cred();
David Howells3e301482005-06-23 22:00:56 -07001192 struct request_key_auth *rka;
David Howells8bbf49762008-11-14 10:39:14 +11001193 struct key *instkey, *dest_keyring;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 long ret;
1195
David Howellsfdd1b942011-03-07 15:06:09 +00001196 kenter("%d,%u,%u,%d", id, timeout, error, ringid);
1197
1198 /* must be a valid error code and mustn't be a kernel special */
1199 if (error <= 0 ||
1200 error >= MAX_ERRNO ||
1201 error == ERESTARTSYS ||
1202 error == ERESTARTNOINTR ||
1203 error == ERESTARTNOHAND ||
1204 error == ERESTART_RESTARTBLOCK)
1205 return -EINVAL;
David Howellsd84f4f92008-11-14 10:39:23 +11001206
David Howellsb5f545c2006-01-08 01:02:47 -08001207 /* the appropriate instantiation authorisation key must have been
1208 * assumed before calling this */
1209 ret = -EPERM;
David Howellsd84f4f92008-11-14 10:39:23 +11001210 instkey = cred->request_key_auth;
David Howellsb5f545c2006-01-08 01:02:47 -08001211 if (!instkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213
David Howells3e301482005-06-23 22:00:56 -07001214 rka = instkey->payload.data;
David Howellsb5f545c2006-01-08 01:02:47 -08001215 if (rka->target_key->serial != id)
1216 goto error;
David Howells3e301482005-06-23 22:00:56 -07001217
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 /* find the destination keyring if present (which must also be
1219 * writable) */
David Howells8bbf49762008-11-14 10:39:14 +11001220 ret = get_instantiation_keyring(ringid, rka, &dest_keyring);
1221 if (ret < 0)
1222 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001223
1224 /* instantiate the key and link it into a keyring */
David Howellsfdd1b942011-03-07 15:06:09 +00001225 ret = key_reject_and_link(rka->target_key, timeout, error,
David Howells8bbf49762008-11-14 10:39:14 +11001226 dest_keyring, instkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227
David Howells8bbf49762008-11-14 10:39:14 +11001228 key_put(dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -08001229
1230 /* discard the assumed authority if it's just been disabled by
1231 * instantiation of the key */
David Howellsd84f4f92008-11-14 10:39:23 +11001232 if (ret == 0)
1233 keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001234
1235error:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001237}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239/*
David Howells973c9f42011-01-20 16:38:33 +00001240 * Read or set the default keyring in which request_key() will cache keys and
1241 * return the old setting.
1242 *
1243 * If a process keyring is specified then this will be created if it doesn't
1244 * yet exist. The old setting will be returned if successful.
David Howells3e301482005-06-23 22:00:56 -07001245 */
1246long keyctl_set_reqkey_keyring(int reqkey_defl)
1247{
David Howellsd84f4f92008-11-14 10:39:23 +11001248 struct cred *new;
1249 int ret, old_setting;
1250
1251 old_setting = current_cred_xxx(jit_keyring);
1252
1253 if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE)
1254 return old_setting;
1255
1256 new = prepare_creds();
1257 if (!new)
1258 return -ENOMEM;
David Howells3e301482005-06-23 22:00:56 -07001259
1260 switch (reqkey_defl) {
1261 case KEY_REQKEY_DEFL_THREAD_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001262 ret = install_thread_keyring_to_cred(new);
David Howells3e301482005-06-23 22:00:56 -07001263 if (ret < 0)
David Howellsd84f4f92008-11-14 10:39:23 +11001264 goto error;
David Howells3e301482005-06-23 22:00:56 -07001265 goto set;
1266
1267 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001268 ret = install_process_keyring_to_cred(new);
1269 if (ret < 0) {
1270 if (ret != -EEXIST)
1271 goto error;
1272 ret = 0;
1273 }
1274 goto set;
David Howells3e301482005-06-23 22:00:56 -07001275
1276 case KEY_REQKEY_DEFL_DEFAULT:
1277 case KEY_REQKEY_DEFL_SESSION_KEYRING:
1278 case KEY_REQKEY_DEFL_USER_KEYRING:
1279 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
David Howellsd84f4f92008-11-14 10:39:23 +11001280 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
1281 goto set;
David Howells3e301482005-06-23 22:00:56 -07001282
1283 case KEY_REQKEY_DEFL_NO_CHANGE:
David Howells3e301482005-06-23 22:00:56 -07001284 case KEY_REQKEY_DEFL_GROUP_KEYRING:
1285 default:
David Howellsd84f4f92008-11-14 10:39:23 +11001286 ret = -EINVAL;
1287 goto error;
David Howells3e301482005-06-23 22:00:56 -07001288 }
1289
David Howellsd84f4f92008-11-14 10:39:23 +11001290set:
1291 new->jit_keyring = reqkey_defl;
1292 commit_creds(new);
1293 return old_setting;
1294error:
1295 abort_creds(new);
Dan Carpenter4303ef12010-06-11 17:30:05 +01001296 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001297}
David Howellsd84f4f92008-11-14 10:39:23 +11001298
David Howells3e301482005-06-23 22:00:56 -07001299/*
David Howells973c9f42011-01-20 16:38:33 +00001300 * Set or clear the timeout on a key.
1301 *
1302 * Either the key must grant the caller Setattr permission or else the caller
1303 * must hold an instantiation authorisation token for the key.
1304 *
1305 * The timeout is either 0 to clear the timeout, or a number of seconds from
1306 * the current time. The key and any links to the key will be automatically
1307 * garbage collected after the timeout expires.
1308 *
1309 * If successful, 0 is returned.
David Howells017679c2006-01-08 01:02:43 -08001310 */
1311long keyctl_set_timeout(key_serial_t id, unsigned timeout)
1312{
David Howells91562352010-06-11 17:31:05 +01001313 struct key *key, *instkey;
David Howells017679c2006-01-08 01:02:43 -08001314 key_ref_t key_ref;
David Howells017679c2006-01-08 01:02:43 -08001315 long ret;
1316
David Howells55931222009-09-02 09:13:45 +01001317 key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
1318 KEY_SETATTR);
David Howells017679c2006-01-08 01:02:43 -08001319 if (IS_ERR(key_ref)) {
David Howells91562352010-06-11 17:31:05 +01001320 /* setting the timeout on a key under construction is permitted
1321 * if we have the authorisation token handy */
1322 if (PTR_ERR(key_ref) == -EACCES) {
1323 instkey = key_get_instantiation_authkey(id);
1324 if (!IS_ERR(instkey)) {
1325 key_put(instkey);
1326 key_ref = lookup_user_key(id,
1327 KEY_LOOKUP_PARTIAL,
1328 0);
1329 if (!IS_ERR(key_ref))
1330 goto okay;
1331 }
1332 }
1333
David Howells017679c2006-01-08 01:02:43 -08001334 ret = PTR_ERR(key_ref);
1335 goto error;
1336 }
1337
David Howells91562352010-06-11 17:31:05 +01001338okay:
David Howells017679c2006-01-08 01:02:43 -08001339 key = key_ref_to_ptr(key_ref);
Bryan Schumaker59e6b9c2012-02-24 14:14:50 -05001340 key_set_timeout(key, timeout);
David Howells017679c2006-01-08 01:02:43 -08001341 key_put(key);
1342
1343 ret = 0;
1344error:
1345 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001346}
David Howells017679c2006-01-08 01:02:43 -08001347
David Howells017679c2006-01-08 01:02:43 -08001348/*
David Howells973c9f42011-01-20 16:38:33 +00001349 * Assume (or clear) the authority to instantiate the specified key.
1350 *
1351 * This sets the authoritative token currently in force for key instantiation.
1352 * This must be done for a key to be instantiated. It has the effect of making
1353 * available all the keys from the caller of the request_key() that created a
1354 * key to request_key() calls made by the caller of this function.
1355 *
1356 * The caller must have the instantiation key in their process keyrings with a
1357 * Search permission grant available to the caller.
1358 *
1359 * If the ID given is 0, then the setting will be cleared and 0 returned.
1360 *
1361 * If the ID given has a matching an authorisation key, then that key will be
1362 * set and its ID will be returned. The authorisation key can be read to get
1363 * the callout information passed to request_key().
David Howellsb5f545c2006-01-08 01:02:47 -08001364 */
1365long keyctl_assume_authority(key_serial_t id)
1366{
1367 struct key *authkey;
1368 long ret;
1369
1370 /* special key IDs aren't permitted */
1371 ret = -EINVAL;
1372 if (id < 0)
1373 goto error;
1374
1375 /* we divest ourselves of authority if given an ID of 0 */
1376 if (id == 0) {
David Howellsd84f4f92008-11-14 10:39:23 +11001377 ret = keyctl_change_reqkey_auth(NULL);
David Howellsb5f545c2006-01-08 01:02:47 -08001378 goto error;
1379 }
1380
1381 /* attempt to assume the authority temporarily granted to us whilst we
1382 * instantiate the specified key
1383 * - the authorisation key must be in the current task's keyrings
1384 * somewhere
1385 */
1386 authkey = key_get_instantiation_authkey(id);
1387 if (IS_ERR(authkey)) {
1388 ret = PTR_ERR(authkey);
1389 goto error;
1390 }
1391
David Howellsd84f4f92008-11-14 10:39:23 +11001392 ret = keyctl_change_reqkey_auth(authkey);
1393 if (ret < 0)
1394 goto error;
1395 key_put(authkey);
David Howellsb5f545c2006-01-08 01:02:47 -08001396
David Howellsd84f4f92008-11-14 10:39:23 +11001397 ret = authkey->serial;
David Howellsb5f545c2006-01-08 01:02:47 -08001398error:
1399 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001400}
David Howellsb5f545c2006-01-08 01:02:47 -08001401
David Howells70a5bb72008-04-29 01:01:26 -07001402/*
David Howells973c9f42011-01-20 16:38:33 +00001403 * Get a key's the LSM security label.
1404 *
1405 * The key must grant the caller View permission for this to work.
1406 *
1407 * If there's a buffer, then up to buflen bytes of data will be placed into it.
1408 *
1409 * If successful, the amount of information available will be returned,
1410 * irrespective of how much was copied (including the terminal NUL).
David Howells70a5bb72008-04-29 01:01:26 -07001411 */
1412long keyctl_get_security(key_serial_t keyid,
1413 char __user *buffer,
1414 size_t buflen)
1415{
1416 struct key *key, *instkey;
1417 key_ref_t key_ref;
1418 char *context;
1419 long ret;
1420
David Howells55931222009-09-02 09:13:45 +01001421 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW);
David Howells70a5bb72008-04-29 01:01:26 -07001422 if (IS_ERR(key_ref)) {
1423 if (PTR_ERR(key_ref) != -EACCES)
1424 return PTR_ERR(key_ref);
1425
1426 /* viewing a key under construction is also permitted if we
1427 * have the authorisation token handy */
1428 instkey = key_get_instantiation_authkey(keyid);
1429 if (IS_ERR(instkey))
Roel Kluinfa1cc7b2009-12-15 15:05:12 -08001430 return PTR_ERR(instkey);
David Howells70a5bb72008-04-29 01:01:26 -07001431 key_put(instkey);
1432
David Howells55931222009-09-02 09:13:45 +01001433 key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0);
David Howells70a5bb72008-04-29 01:01:26 -07001434 if (IS_ERR(key_ref))
1435 return PTR_ERR(key_ref);
1436 }
1437
1438 key = key_ref_to_ptr(key_ref);
1439 ret = security_key_getsecurity(key, &context);
1440 if (ret == 0) {
1441 /* if no information was returned, give userspace an empty
1442 * string */
1443 ret = 1;
1444 if (buffer && buflen > 0 &&
1445 copy_to_user(buffer, "", 1) != 0)
1446 ret = -EFAULT;
1447 } else if (ret > 0) {
1448 /* return as much data as there's room for */
1449 if (buffer && buflen > 0) {
1450 if (buflen > ret)
1451 buflen = ret;
1452
1453 if (copy_to_user(buffer, context, buflen) != 0)
1454 ret = -EFAULT;
1455 }
1456
1457 kfree(context);
1458 }
1459
1460 key_ref_put(key_ref);
1461 return ret;
1462}
1463
David Howellsee18d642009-09-02 09:14:21 +01001464/*
David Howells973c9f42011-01-20 16:38:33 +00001465 * Attempt to install the calling process's session keyring on the process's
1466 * parent process.
1467 *
1468 * The keyring must exist and must grant the caller LINK permission, and the
1469 * parent process must be single-threaded and must have the same effective
1470 * ownership as this process and mustn't be SUID/SGID.
1471 *
1472 * The keyring will be emplaced on the parent when it next resumes userspace.
1473 *
1474 * If successful, 0 will be returned.
David Howellsee18d642009-09-02 09:14:21 +01001475 */
1476long keyctl_session_to_parent(void)
1477{
1478 struct task_struct *me, *parent;
1479 const struct cred *mycred, *pcred;
Al Viro67d12142012-06-27 11:07:19 +04001480 struct callback_head *newwork, *oldwork;
David Howellsee18d642009-09-02 09:14:21 +01001481 key_ref_t keyring_r;
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001482 struct cred *cred;
David Howellsee18d642009-09-02 09:14:21 +01001483 int ret;
1484
1485 keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
1486 if (IS_ERR(keyring_r))
1487 return PTR_ERR(keyring_r);
1488
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001489 ret = -ENOMEM;
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001490
David Howellsee18d642009-09-02 09:14:21 +01001491 /* our parent is going to need a new cred struct, a new tgcred struct
1492 * and new security data, so we allocate them here to prevent ENOMEM in
1493 * our parent */
David Howellsee18d642009-09-02 09:14:21 +01001494 cred = cred_alloc_blank();
1495 if (!cred)
Al Viro67d12142012-06-27 11:07:19 +04001496 goto error_keyring;
1497 newwork = &cred->rcu;
David Howellsee18d642009-09-02 09:14:21 +01001498
David Howells3a505972012-10-02 19:24:29 +01001499 cred->session_keyring = key_ref_to_ptr(keyring_r);
1500 keyring_r = NULL;
Al Viro67d12142012-06-27 11:07:19 +04001501 init_task_work(newwork, key_change_session_keyring);
David Howellsee18d642009-09-02 09:14:21 +01001502
1503 me = current;
David Howells9d1ac652010-09-10 09:59:46 +01001504 rcu_read_lock();
David Howellsee18d642009-09-02 09:14:21 +01001505 write_lock_irq(&tasklist_lock);
1506
David Howellsee18d642009-09-02 09:14:21 +01001507 ret = -EPERM;
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001508 oldwork = NULL;
1509 parent = me->real_parent;
David Howellsee18d642009-09-02 09:14:21 +01001510
1511 /* the parent mustn't be init and mustn't be a kernel thread */
1512 if (parent->pid <= 1 || !parent->mm)
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001513 goto unlock;
David Howellsee18d642009-09-02 09:14:21 +01001514
1515 /* the parent must be single threaded */
Oleg Nesterovdd98acf2010-05-26 14:43:23 -07001516 if (!thread_group_empty(parent))
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001517 goto unlock;
David Howellsee18d642009-09-02 09:14:21 +01001518
1519 /* the parent and the child must have different session keyrings or
1520 * there's no point */
1521 mycred = current_cred();
1522 pcred = __task_cred(parent);
1523 if (mycred == pcred ||
David Howells3a505972012-10-02 19:24:29 +01001524 mycred->session_keyring == pcred->session_keyring) {
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001525 ret = 0;
1526 goto unlock;
1527 }
David Howellsee18d642009-09-02 09:14:21 +01001528
1529 /* the parent must have the same effective ownership and mustn't be
1530 * SUID/SGID */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -08001531 if (!uid_eq(pcred->uid, mycred->euid) ||
1532 !uid_eq(pcred->euid, mycred->euid) ||
1533 !uid_eq(pcred->suid, mycred->euid) ||
1534 !gid_eq(pcred->gid, mycred->egid) ||
1535 !gid_eq(pcred->egid, mycred->egid) ||
1536 !gid_eq(pcred->sgid, mycred->egid))
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001537 goto unlock;
David Howellsee18d642009-09-02 09:14:21 +01001538
1539 /* the keyrings must have the same UID */
David Howells3a505972012-10-02 19:24:29 +01001540 if ((pcred->session_keyring &&
Linus Torvalds2a74dbb2012-12-16 15:40:50 -08001541 !uid_eq(pcred->session_keyring->uid, mycred->euid)) ||
1542 !uid_eq(mycred->session_keyring->uid, mycred->euid))
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001543 goto unlock;
David Howellsee18d642009-09-02 09:14:21 +01001544
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001545 /* cancel an already pending keyring replacement */
1546 oldwork = task_work_cancel(parent, key_change_session_keyring);
David Howellsee18d642009-09-02 09:14:21 +01001547
1548 /* the replacement session keyring is applied just prior to userspace
1549 * restarting */
Al Viro67d12142012-06-27 11:07:19 +04001550 ret = task_work_add(parent, newwork, true);
Oleg Nesterov413cd3d2012-05-11 10:59:08 +10001551 if (!ret)
1552 newwork = NULL;
1553unlock:
David Howellsee18d642009-09-02 09:14:21 +01001554 write_unlock_irq(&tasklist_lock);
David Howells9d1ac652010-09-10 09:59:46 +01001555 rcu_read_unlock();
Al Viro67d12142012-06-27 11:07:19 +04001556 if (oldwork)
1557 put_cred(container_of(oldwork, struct cred, rcu));
1558 if (newwork)
1559 put_cred(cred);
David Howellsee18d642009-09-02 09:14:21 +01001560 return ret;
1561
1562error_keyring:
1563 key_ref_put(keyring_r);
1564 return ret;
1565}
1566
David Howellsb5f545c2006-01-08 01:02:47 -08001567/*
David Howells973c9f42011-01-20 16:38:33 +00001568 * The key control system call
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569 */
Heiko Carstens938bb9f2009-01-14 14:14:30 +01001570SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3,
1571 unsigned long, arg4, unsigned long, arg5)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572{
1573 switch (option) {
1574 case KEYCTL_GET_KEYRING_ID:
1575 return keyctl_get_keyring_ID((key_serial_t) arg2,
1576 (int) arg3);
1577
1578 case KEYCTL_JOIN_SESSION_KEYRING:
1579 return keyctl_join_session_keyring((const char __user *) arg2);
1580
1581 case KEYCTL_UPDATE:
1582 return keyctl_update_key((key_serial_t) arg2,
1583 (const void __user *) arg3,
1584 (size_t) arg4);
1585
1586 case KEYCTL_REVOKE:
1587 return keyctl_revoke_key((key_serial_t) arg2);
1588
1589 case KEYCTL_DESCRIBE:
1590 return keyctl_describe_key((key_serial_t) arg2,
1591 (char __user *) arg3,
1592 (unsigned) arg4);
1593
1594 case KEYCTL_CLEAR:
1595 return keyctl_keyring_clear((key_serial_t) arg2);
1596
1597 case KEYCTL_LINK:
1598 return keyctl_keyring_link((key_serial_t) arg2,
1599 (key_serial_t) arg3);
1600
1601 case KEYCTL_UNLINK:
1602 return keyctl_keyring_unlink((key_serial_t) arg2,
1603 (key_serial_t) arg3);
1604
1605 case KEYCTL_SEARCH:
1606 return keyctl_keyring_search((key_serial_t) arg2,
1607 (const char __user *) arg3,
1608 (const char __user *) arg4,
1609 (key_serial_t) arg5);
1610
1611 case KEYCTL_READ:
1612 return keyctl_read_key((key_serial_t) arg2,
1613 (char __user *) arg3,
1614 (size_t) arg4);
1615
1616 case KEYCTL_CHOWN:
1617 return keyctl_chown_key((key_serial_t) arg2,
1618 (uid_t) arg3,
1619 (gid_t) arg4);
1620
1621 case KEYCTL_SETPERM:
1622 return keyctl_setperm_key((key_serial_t) arg2,
1623 (key_perm_t) arg3);
1624
1625 case KEYCTL_INSTANTIATE:
1626 return keyctl_instantiate_key((key_serial_t) arg2,
1627 (const void __user *) arg3,
1628 (size_t) arg4,
1629 (key_serial_t) arg5);
1630
1631 case KEYCTL_NEGATE:
1632 return keyctl_negate_key((key_serial_t) arg2,
1633 (unsigned) arg3,
1634 (key_serial_t) arg4);
1635
David Howells3e301482005-06-23 22:00:56 -07001636 case KEYCTL_SET_REQKEY_KEYRING:
1637 return keyctl_set_reqkey_keyring(arg2);
1638
David Howells017679c2006-01-08 01:02:43 -08001639 case KEYCTL_SET_TIMEOUT:
1640 return keyctl_set_timeout((key_serial_t) arg2,
1641 (unsigned) arg3);
1642
David Howellsb5f545c2006-01-08 01:02:47 -08001643 case KEYCTL_ASSUME_AUTHORITY:
1644 return keyctl_assume_authority((key_serial_t) arg2);
1645
David Howells70a5bb72008-04-29 01:01:26 -07001646 case KEYCTL_GET_SECURITY:
1647 return keyctl_get_security((key_serial_t) arg2,
James Morris90bd49a2008-12-29 14:35:35 +11001648 (char __user *) arg3,
David Howells70a5bb72008-04-29 01:01:26 -07001649 (size_t) arg4);
1650
David Howellsee18d642009-09-02 09:14:21 +01001651 case KEYCTL_SESSION_TO_PARENT:
1652 return keyctl_session_to_parent();
1653
David Howellsfdd1b942011-03-07 15:06:09 +00001654 case KEYCTL_REJECT:
1655 return keyctl_reject_key((key_serial_t) arg2,
1656 (unsigned) arg3,
1657 (unsigned) arg4,
1658 (key_serial_t) arg5);
1659
David Howellsee009e4a02011-03-07 15:06:20 +00001660 case KEYCTL_INSTANTIATE_IOV:
1661 return keyctl_instantiate_key_iov(
1662 (key_serial_t) arg2,
1663 (const struct iovec __user *) arg3,
1664 (unsigned) arg4,
1665 (key_serial_t) arg5);
1666
David Howellsfd758152012-05-11 10:56:56 +01001667 case KEYCTL_INVALIDATE:
1668 return keyctl_invalidate_key((key_serial_t) arg2);
1669
David Howellsf36f8c72013-09-24 10:35:19 +01001670 case KEYCTL_GET_PERSISTENT:
1671 return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3);
1672
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 default:
1674 return -EOPNOTSUPP;
1675 }
David Howellsa8b17ed2011-01-20 16:38:27 +00001676}