Commit | Line | Data |
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69664cf1 | 1 | /* Management of a process's keyrings |
1da177e4 | 2 | * |
69664cf1 | 3 | * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
4 | * Written by David Howells (dhowells@redhat.com) |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/keyctl.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/err.h> | |
bb003079 | 19 | #include <linux/mutex.h> |
1da177e4 LT |
20 | #include <asm/uaccess.h> |
21 | #include "internal.h" | |
22 | ||
23 | /* session keyring create vs join semaphore */ | |
bb003079 | 24 | static DEFINE_MUTEX(key_session_mutex); |
1da177e4 | 25 | |
69664cf1 DH |
26 | /* user keyring creation semaphore */ |
27 | static DEFINE_MUTEX(key_user_keyring_mutex); | |
28 | ||
1da177e4 LT |
29 | /* the root user's tracking struct */ |
30 | struct key_user root_key_user = { | |
31 | .usage = ATOMIC_INIT(3), | |
76181c13 | 32 | .cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock), |
6cfd76a2 | 33 | .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock), |
1da177e4 LT |
34 | .nkeys = ATOMIC_INIT(2), |
35 | .nikeys = ATOMIC_INIT(2), | |
36 | .uid = 0, | |
37 | }; | |
38 | ||
1da177e4 LT |
39 | /*****************************************************************************/ |
40 | /* | |
69664cf1 | 41 | * install user and user session keyrings for a particular UID |
1da177e4 | 42 | */ |
8bbf4976 | 43 | int install_user_keyrings(void) |
1da177e4 | 44 | { |
b6dff3ec | 45 | struct user_struct *user = current->cred->user; |
1da177e4 LT |
46 | struct key *uid_keyring, *session_keyring; |
47 | char buf[20]; | |
48 | int ret; | |
49 | ||
69664cf1 | 50 | kenter("%p{%u}", user, user->uid); |
1da177e4 | 51 | |
69664cf1 DH |
52 | if (user->uid_keyring) { |
53 | kleave(" = 0 [exist]"); | |
54 | return 0; | |
1da177e4 LT |
55 | } |
56 | ||
69664cf1 DH |
57 | mutex_lock(&key_user_keyring_mutex); |
58 | ret = 0; | |
1da177e4 | 59 | |
69664cf1 DH |
60 | if (!user->uid_keyring) { |
61 | /* get the UID-specific keyring | |
62 | * - there may be one in existence already as it may have been | |
63 | * pinned by a session, but the user_struct pointing to it | |
64 | * may have been destroyed by setuid */ | |
65 | sprintf(buf, "_uid.%u", user->uid); | |
66 | ||
67 | uid_keyring = find_keyring_by_name(buf, true); | |
68 | if (IS_ERR(uid_keyring)) { | |
69 | uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, | |
8bbf4976 | 70 | current, KEY_ALLOC_IN_QUOTA, |
69664cf1 DH |
71 | NULL); |
72 | if (IS_ERR(uid_keyring)) { | |
73 | ret = PTR_ERR(uid_keyring); | |
74 | goto error; | |
75 | } | |
76 | } | |
77 | ||
78 | /* get a default session keyring (which might also exist | |
79 | * already) */ | |
80 | sprintf(buf, "_uid_ses.%u", user->uid); | |
81 | ||
82 | session_keyring = find_keyring_by_name(buf, true); | |
83 | if (IS_ERR(session_keyring)) { | |
84 | session_keyring = | |
85 | keyring_alloc(buf, user->uid, (gid_t) -1, | |
8bbf4976 DH |
86 | current, KEY_ALLOC_IN_QUOTA, |
87 | NULL); | |
69664cf1 DH |
88 | if (IS_ERR(session_keyring)) { |
89 | ret = PTR_ERR(session_keyring); | |
90 | goto error_release; | |
91 | } | |
92 | ||
93 | /* we install a link from the user session keyring to | |
94 | * the user keyring */ | |
95 | ret = key_link(session_keyring, uid_keyring); | |
96 | if (ret < 0) | |
97 | goto error_release_both; | |
98 | } | |
99 | ||
100 | /* install the keyrings */ | |
101 | user->uid_keyring = uid_keyring; | |
102 | user->session_keyring = session_keyring; | |
1da177e4 LT |
103 | } |
104 | ||
69664cf1 DH |
105 | mutex_unlock(&key_user_keyring_mutex); |
106 | kleave(" = 0"); | |
107 | return 0; | |
1da177e4 | 108 | |
69664cf1 DH |
109 | error_release_both: |
110 | key_put(session_keyring); | |
111 | error_release: | |
112 | key_put(uid_keyring); | |
664cceb0 | 113 | error: |
69664cf1 DH |
114 | mutex_unlock(&key_user_keyring_mutex); |
115 | kleave(" = %d", ret); | |
1da177e4 | 116 | return ret; |
69664cf1 | 117 | } |
1da177e4 LT |
118 | |
119 | /*****************************************************************************/ | |
120 | /* | |
121 | * deal with the UID changing | |
122 | */ | |
123 | void switch_uid_keyring(struct user_struct *new_user) | |
124 | { | |
125 | #if 0 /* do nothing for now */ | |
126 | struct key *old; | |
127 | ||
128 | /* switch to the new user's session keyring if we were running under | |
129 | * root's default session keyring */ | |
130 | if (new_user->uid != 0 && | |
131 | current->session_keyring == &root_session_keyring | |
132 | ) { | |
133 | atomic_inc(&new_user->session_keyring->usage); | |
134 | ||
135 | task_lock(current); | |
136 | old = current->session_keyring; | |
137 | current->session_keyring = new_user->session_keyring; | |
138 | task_unlock(current); | |
139 | ||
140 | key_put(old); | |
141 | } | |
142 | #endif | |
143 | ||
144 | } /* end switch_uid_keyring() */ | |
145 | ||
146 | /*****************************************************************************/ | |
147 | /* | |
148 | * install a fresh thread keyring, discarding the old one | |
149 | */ | |
8bbf4976 | 150 | int install_thread_keyring(void) |
1da177e4 | 151 | { |
8bbf4976 | 152 | struct task_struct *tsk = current; |
1da177e4 LT |
153 | struct key *keyring, *old; |
154 | char buf[20]; | |
155 | int ret; | |
156 | ||
157 | sprintf(buf, "_tid.%u", tsk->pid); | |
158 | ||
b6dff3ec | 159 | keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, |
7e047ef5 | 160 | KEY_ALLOC_QUOTA_OVERRUN, NULL); |
1da177e4 LT |
161 | if (IS_ERR(keyring)) { |
162 | ret = PTR_ERR(keyring); | |
163 | goto error; | |
164 | } | |
165 | ||
166 | task_lock(tsk); | |
b6dff3ec DH |
167 | old = tsk->cred->thread_keyring; |
168 | tsk->cred->thread_keyring = keyring; | |
1da177e4 LT |
169 | task_unlock(tsk); |
170 | ||
171 | ret = 0; | |
172 | ||
173 | key_put(old); | |
664cceb0 | 174 | error: |
1da177e4 LT |
175 | return ret; |
176 | ||
177 | } /* end install_thread_keyring() */ | |
178 | ||
179 | /*****************************************************************************/ | |
180 | /* | |
181 | * make sure a process keyring is installed | |
182 | */ | |
8bbf4976 | 183 | int install_process_keyring(void) |
1da177e4 | 184 | { |
8bbf4976 | 185 | struct task_struct *tsk = current; |
1da177e4 LT |
186 | struct key *keyring; |
187 | char buf[20]; | |
188 | int ret; | |
189 | ||
1a26feb9 DH |
190 | might_sleep(); |
191 | ||
bb952bb9 | 192 | if (!tsk->cred->tgcred->process_keyring) { |
1da177e4 LT |
193 | sprintf(buf, "_pid.%u", tsk->tgid); |
194 | ||
b6dff3ec | 195 | keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, |
7e047ef5 | 196 | KEY_ALLOC_QUOTA_OVERRUN, NULL); |
1da177e4 LT |
197 | if (IS_ERR(keyring)) { |
198 | ret = PTR_ERR(keyring); | |
199 | goto error; | |
200 | } | |
201 | ||
8589b4e0 | 202 | /* attach keyring */ |
bb952bb9 DH |
203 | spin_lock_irq(&tsk->cred->tgcred->lock); |
204 | if (!tsk->cred->tgcred->process_keyring) { | |
205 | tsk->cred->tgcred->process_keyring = keyring; | |
1da177e4 LT |
206 | keyring = NULL; |
207 | } | |
bb952bb9 | 208 | spin_unlock_irq(&tsk->cred->tgcred->lock); |
1da177e4 LT |
209 | |
210 | key_put(keyring); | |
211 | } | |
212 | ||
213 | ret = 0; | |
664cceb0 | 214 | error: |
1da177e4 LT |
215 | return ret; |
216 | ||
217 | } /* end install_process_keyring() */ | |
218 | ||
219 | /*****************************************************************************/ | |
220 | /* | |
221 | * install a session keyring, discarding the old one | |
222 | * - if a keyring is not supplied, an empty one is invented | |
223 | */ | |
8bbf4976 | 224 | static int install_session_keyring(struct key *keyring) |
1da177e4 | 225 | { |
8bbf4976 | 226 | struct task_struct *tsk = current; |
7e047ef5 | 227 | unsigned long flags; |
1da177e4 LT |
228 | struct key *old; |
229 | char buf[20]; | |
1a26feb9 DH |
230 | |
231 | might_sleep(); | |
1da177e4 LT |
232 | |
233 | /* create an empty session keyring */ | |
234 | if (!keyring) { | |
235 | sprintf(buf, "_ses.%u", tsk->tgid); | |
236 | ||
7e047ef5 | 237 | flags = KEY_ALLOC_QUOTA_OVERRUN; |
bb952bb9 | 238 | if (tsk->cred->tgcred->session_keyring) |
7e047ef5 DH |
239 | flags = KEY_ALLOC_IN_QUOTA; |
240 | ||
bb952bb9 DH |
241 | keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, |
242 | tsk, flags, NULL); | |
1a26feb9 DH |
243 | if (IS_ERR(keyring)) |
244 | return PTR_ERR(keyring); | |
1da177e4 LT |
245 | } |
246 | else { | |
247 | atomic_inc(&keyring->usage); | |
248 | } | |
249 | ||
250 | /* install the keyring */ | |
bb952bb9 DH |
251 | spin_lock_irq(&tsk->cred->tgcred->lock); |
252 | old = tsk->cred->tgcred->session_keyring; | |
253 | rcu_assign_pointer(tsk->cred->tgcred->session_keyring, keyring); | |
254 | spin_unlock_irq(&tsk->cred->tgcred->lock); | |
1da177e4 | 255 | |
1a26feb9 DH |
256 | /* we're using RCU on the pointer, but there's no point synchronising |
257 | * on it if it didn't previously point to anything */ | |
258 | if (old) { | |
259 | synchronize_rcu(); | |
260 | key_put(old); | |
261 | } | |
1da177e4 | 262 | |
1a26feb9 | 263 | return 0; |
1da177e4 LT |
264 | |
265 | } /* end install_session_keyring() */ | |
266 | ||
1da177e4 LT |
267 | /*****************************************************************************/ |
268 | /* | |
269 | * copy the keys for fork | |
270 | */ | |
271 | int copy_keys(unsigned long clone_flags, struct task_struct *tsk) | |
272 | { | |
b6dff3ec DH |
273 | key_check(tsk->cred->thread_keyring); |
274 | key_check(tsk->cred->request_key_auth); | |
1da177e4 LT |
275 | |
276 | /* no thread keyring yet */ | |
b6dff3ec | 277 | tsk->cred->thread_keyring = NULL; |
b5f545c8 DH |
278 | |
279 | /* copy the request_key() authorisation for this thread */ | |
b6dff3ec | 280 | key_get(tsk->cred->request_key_auth); |
b5f545c8 | 281 | |
1da177e4 LT |
282 | return 0; |
283 | ||
284 | } /* end copy_keys() */ | |
285 | ||
1da177e4 LT |
286 | /*****************************************************************************/ |
287 | /* | |
b5f545c8 | 288 | * dispose of per-thread keys upon thread exit |
1da177e4 LT |
289 | */ |
290 | void exit_keys(struct task_struct *tsk) | |
291 | { | |
b6dff3ec DH |
292 | key_put(tsk->cred->thread_keyring); |
293 | key_put(tsk->cred->request_key_auth); | |
1da177e4 LT |
294 | |
295 | } /* end exit_keys() */ | |
296 | ||
297 | /*****************************************************************************/ | |
298 | /* | |
299 | * deal with execve() | |
300 | */ | |
301 | int exec_keys(struct task_struct *tsk) | |
302 | { | |
1da177e4 LT |
303 | struct key *old; |
304 | ||
305 | /* newly exec'd tasks don't get a thread keyring */ | |
306 | task_lock(tsk); | |
b6dff3ec DH |
307 | old = tsk->cred->thread_keyring; |
308 | tsk->cred->thread_keyring = NULL; | |
1da177e4 LT |
309 | task_unlock(tsk); |
310 | ||
311 | key_put(old); | |
312 | ||
313 | /* discard the process keyring from a newly exec'd task */ | |
bb952bb9 DH |
314 | spin_lock_irq(&tsk->cred->tgcred->lock); |
315 | old = tsk->cred->tgcred->process_keyring; | |
316 | tsk->cred->tgcred->process_keyring = NULL; | |
317 | spin_unlock_irq(&tsk->cred->tgcred->lock); | |
1da177e4 LT |
318 | |
319 | key_put(old); | |
320 | ||
321 | return 0; | |
322 | ||
323 | } /* end exec_keys() */ | |
324 | ||
325 | /*****************************************************************************/ | |
326 | /* | |
327 | * deal with SUID programs | |
328 | * - we might want to make this invent a new session keyring | |
329 | */ | |
330 | int suid_keys(struct task_struct *tsk) | |
331 | { | |
332 | return 0; | |
333 | ||
334 | } /* end suid_keys() */ | |
335 | ||
336 | /*****************************************************************************/ | |
337 | /* | |
338 | * the filesystem user ID changed | |
339 | */ | |
340 | void key_fsuid_changed(struct task_struct *tsk) | |
341 | { | |
342 | /* update the ownership of the thread keyring */ | |
b6dff3ec DH |
343 | BUG_ON(!tsk->cred); |
344 | if (tsk->cred->thread_keyring) { | |
345 | down_write(&tsk->cred->thread_keyring->sem); | |
346 | tsk->cred->thread_keyring->uid = tsk->cred->fsuid; | |
347 | up_write(&tsk->cred->thread_keyring->sem); | |
1da177e4 LT |
348 | } |
349 | ||
350 | } /* end key_fsuid_changed() */ | |
351 | ||
352 | /*****************************************************************************/ | |
353 | /* | |
354 | * the filesystem group ID changed | |
355 | */ | |
356 | void key_fsgid_changed(struct task_struct *tsk) | |
357 | { | |
358 | /* update the ownership of the thread keyring */ | |
b6dff3ec DH |
359 | BUG_ON(!tsk->cred); |
360 | if (tsk->cred->thread_keyring) { | |
361 | down_write(&tsk->cred->thread_keyring->sem); | |
362 | tsk->cred->thread_keyring->gid = tsk->cred->fsgid; | |
363 | up_write(&tsk->cred->thread_keyring->sem); | |
1da177e4 LT |
364 | } |
365 | ||
366 | } /* end key_fsgid_changed() */ | |
367 | ||
368 | /*****************************************************************************/ | |
369 | /* | |
370 | * search the process keyrings for the first matching key | |
371 | * - we use the supplied match function to see if the description (or other | |
372 | * feature of interest) matches | |
373 | * - we return -EAGAIN if we didn't find any matching key | |
374 | * - we return -ENOKEY if we found only negative matching keys | |
375 | */ | |
664cceb0 DH |
376 | key_ref_t search_process_keyrings(struct key_type *type, |
377 | const void *description, | |
378 | key_match_func_t match, | |
379 | struct task_struct *context) | |
1da177e4 | 380 | { |
3e30148c | 381 | struct request_key_auth *rka; |
c69e8d9c | 382 | struct cred *cred; |
b5f545c8 | 383 | key_ref_t key_ref, ret, err; |
1da177e4 | 384 | |
04c567d9 DH |
385 | might_sleep(); |
386 | ||
c69e8d9c DH |
387 | cred = get_task_cred(context); |
388 | ||
1da177e4 LT |
389 | /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were |
390 | * searchable, but we failed to find a key or we found a negative key; | |
391 | * otherwise we want to return a sample error (probably -EACCES) if | |
392 | * none of the keyrings were searchable | |
393 | * | |
394 | * in terms of priority: success > -ENOKEY > -EAGAIN > other error | |
395 | */ | |
664cceb0 | 396 | key_ref = NULL; |
1da177e4 LT |
397 | ret = NULL; |
398 | err = ERR_PTR(-EAGAIN); | |
399 | ||
400 | /* search the thread keyring first */ | |
c69e8d9c | 401 | if (cred->thread_keyring) { |
664cceb0 | 402 | key_ref = keyring_search_aux( |
c69e8d9c | 403 | make_key_ref(cred->thread_keyring, 1), |
664cceb0 DH |
404 | context, type, description, match); |
405 | if (!IS_ERR(key_ref)) | |
1da177e4 LT |
406 | goto found; |
407 | ||
664cceb0 | 408 | switch (PTR_ERR(key_ref)) { |
1da177e4 LT |
409 | case -EAGAIN: /* no key */ |
410 | if (ret) | |
411 | break; | |
412 | case -ENOKEY: /* negative key */ | |
664cceb0 | 413 | ret = key_ref; |
1da177e4 LT |
414 | break; |
415 | default: | |
664cceb0 | 416 | err = key_ref; |
1da177e4 LT |
417 | break; |
418 | } | |
419 | } | |
420 | ||
421 | /* search the process keyring second */ | |
bb952bb9 | 422 | if (cred->tgcred->process_keyring) { |
664cceb0 | 423 | key_ref = keyring_search_aux( |
bb952bb9 | 424 | make_key_ref(cred->tgcred->process_keyring, 1), |
664cceb0 DH |
425 | context, type, description, match); |
426 | if (!IS_ERR(key_ref)) | |
1da177e4 LT |
427 | goto found; |
428 | ||
664cceb0 | 429 | switch (PTR_ERR(key_ref)) { |
1da177e4 LT |
430 | case -EAGAIN: /* no key */ |
431 | if (ret) | |
432 | break; | |
433 | case -ENOKEY: /* negative key */ | |
664cceb0 | 434 | ret = key_ref; |
1da177e4 LT |
435 | break; |
436 | default: | |
664cceb0 | 437 | err = key_ref; |
1da177e4 LT |
438 | break; |
439 | } | |
440 | } | |
441 | ||
3e30148c | 442 | /* search the session keyring */ |
bb952bb9 | 443 | if (cred->tgcred->session_keyring) { |
8589b4e0 | 444 | rcu_read_lock(); |
664cceb0 DH |
445 | key_ref = keyring_search_aux( |
446 | make_key_ref(rcu_dereference( | |
bb952bb9 | 447 | cred->tgcred->session_keyring), |
664cceb0 | 448 | 1), |
3e30148c | 449 | context, type, description, match); |
8589b4e0 | 450 | rcu_read_unlock(); |
3e30148c | 451 | |
664cceb0 | 452 | if (!IS_ERR(key_ref)) |
3e30148c DH |
453 | goto found; |
454 | ||
664cceb0 | 455 | switch (PTR_ERR(key_ref)) { |
3e30148c DH |
456 | case -EAGAIN: /* no key */ |
457 | if (ret) | |
458 | break; | |
459 | case -ENOKEY: /* negative key */ | |
664cceb0 | 460 | ret = key_ref; |
3e30148c DH |
461 | break; |
462 | default: | |
664cceb0 | 463 | err = key_ref; |
3e30148c DH |
464 | break; |
465 | } | |
b5f545c8 DH |
466 | } |
467 | /* or search the user-session keyring */ | |
c69e8d9c | 468 | else if (cred->user->session_keyring) { |
b5f545c8 | 469 | key_ref = keyring_search_aux( |
c69e8d9c | 470 | make_key_ref(cred->user->session_keyring, 1), |
b5f545c8 | 471 | context, type, description, match); |
664cceb0 | 472 | if (!IS_ERR(key_ref)) |
3e30148c DH |
473 | goto found; |
474 | ||
664cceb0 | 475 | switch (PTR_ERR(key_ref)) { |
3e30148c DH |
476 | case -EAGAIN: /* no key */ |
477 | if (ret) | |
478 | break; | |
479 | case -ENOKEY: /* negative key */ | |
664cceb0 | 480 | ret = key_ref; |
3e30148c DH |
481 | break; |
482 | default: | |
664cceb0 | 483 | err = key_ref; |
3e30148c DH |
484 | break; |
485 | } | |
8589b4e0 | 486 | } |
b5f545c8 DH |
487 | |
488 | /* if this process has an instantiation authorisation key, then we also | |
489 | * search the keyrings of the process mentioned there | |
490 | * - we don't permit access to request_key auth keys via this method | |
491 | */ | |
c69e8d9c | 492 | if (cred->request_key_auth && |
b5f545c8 | 493 | context == current && |
04c567d9 | 494 | type != &key_type_request_key_auth |
b5f545c8 | 495 | ) { |
04c567d9 | 496 | /* defend against the auth key being revoked */ |
c69e8d9c | 497 | down_read(&cred->request_key_auth->sem); |
b5f545c8 | 498 | |
c69e8d9c DH |
499 | if (key_validate(cred->request_key_auth) == 0) { |
500 | rka = cred->request_key_auth->payload.data; | |
b5f545c8 | 501 | |
04c567d9 DH |
502 | key_ref = search_process_keyrings(type, description, |
503 | match, rka->context); | |
1da177e4 | 504 | |
c69e8d9c | 505 | up_read(&cred->request_key_auth->sem); |
04c567d9 DH |
506 | |
507 | if (!IS_ERR(key_ref)) | |
508 | goto found; | |
509 | ||
510 | switch (PTR_ERR(key_ref)) { | |
511 | case -EAGAIN: /* no key */ | |
512 | if (ret) | |
513 | break; | |
514 | case -ENOKEY: /* negative key */ | |
515 | ret = key_ref; | |
3e30148c | 516 | break; |
04c567d9 DH |
517 | default: |
518 | err = key_ref; | |
519 | break; | |
520 | } | |
521 | } else { | |
c69e8d9c | 522 | up_read(&cred->request_key_auth->sem); |
3e30148c | 523 | } |
1da177e4 LT |
524 | } |
525 | ||
526 | /* no key - decide on the error we're going to go for */ | |
664cceb0 | 527 | key_ref = ret ? ret : err; |
1da177e4 | 528 | |
3e30148c | 529 | found: |
c69e8d9c | 530 | put_cred(cred); |
664cceb0 | 531 | return key_ref; |
1da177e4 | 532 | |
1da177e4 LT |
533 | } /* end search_process_keyrings() */ |
534 | ||
664cceb0 DH |
535 | /*****************************************************************************/ |
536 | /* | |
537 | * see if the key we're looking at is the target key | |
538 | */ | |
539 | static int lookup_user_key_possessed(const struct key *key, const void *target) | |
540 | { | |
541 | return key == target; | |
542 | ||
543 | } /* end lookup_user_key_possessed() */ | |
544 | ||
1da177e4 LT |
545 | /*****************************************************************************/ |
546 | /* | |
547 | * lookup a key given a key ID from userspace with a given permissions mask | |
548 | * - don't create special keyrings unless so requested | |
549 | * - partially constructed keys aren't found unless requested | |
550 | */ | |
8bbf4976 DH |
551 | key_ref_t lookup_user_key(key_serial_t id, int create, int partial, |
552 | key_perm_t perm) | |
1da177e4 | 553 | { |
8bbf4976 DH |
554 | struct request_key_auth *rka; |
555 | struct task_struct *t = current; | |
bb952bb9 | 556 | struct cred *cred; |
1da177e4 | 557 | struct key *key; |
b6dff3ec | 558 | key_ref_t key_ref, skey_ref; |
1da177e4 LT |
559 | int ret; |
560 | ||
bb952bb9 DH |
561 | try_again: |
562 | cred = get_current_cred(); | |
664cceb0 | 563 | key_ref = ERR_PTR(-ENOKEY); |
1da177e4 LT |
564 | |
565 | switch (id) { | |
566 | case KEY_SPEC_THREAD_KEYRING: | |
b6dff3ec | 567 | if (!cred->thread_keyring) { |
1da177e4 LT |
568 | if (!create) |
569 | goto error; | |
570 | ||
8bbf4976 | 571 | ret = install_thread_keyring(); |
1da177e4 LT |
572 | if (ret < 0) { |
573 | key = ERR_PTR(ret); | |
574 | goto error; | |
575 | } | |
bb952bb9 | 576 | goto reget_creds; |
1da177e4 LT |
577 | } |
578 | ||
b6dff3ec | 579 | key = cred->thread_keyring; |
1da177e4 | 580 | atomic_inc(&key->usage); |
664cceb0 | 581 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
582 | break; |
583 | ||
584 | case KEY_SPEC_PROCESS_KEYRING: | |
bb952bb9 | 585 | if (!cred->tgcred->process_keyring) { |
1da177e4 LT |
586 | if (!create) |
587 | goto error; | |
588 | ||
8bbf4976 | 589 | ret = install_process_keyring(); |
1da177e4 LT |
590 | if (ret < 0) { |
591 | key = ERR_PTR(ret); | |
592 | goto error; | |
593 | } | |
bb952bb9 | 594 | goto reget_creds; |
1da177e4 LT |
595 | } |
596 | ||
bb952bb9 | 597 | key = cred->tgcred->process_keyring; |
1da177e4 | 598 | atomic_inc(&key->usage); |
664cceb0 | 599 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
600 | break; |
601 | ||
602 | case KEY_SPEC_SESSION_KEYRING: | |
bb952bb9 | 603 | if (!cred->tgcred->session_keyring) { |
1da177e4 LT |
604 | /* always install a session keyring upon access if one |
605 | * doesn't exist yet */ | |
8bbf4976 | 606 | ret = install_user_keyrings(); |
69664cf1 DH |
607 | if (ret < 0) |
608 | goto error; | |
b6dff3ec DH |
609 | ret = install_session_keyring( |
610 | cred->user->session_keyring); | |
1da177e4 LT |
611 | if (ret < 0) |
612 | goto error; | |
bb952bb9 | 613 | goto reget_creds; |
1da177e4 LT |
614 | } |
615 | ||
3e30148c | 616 | rcu_read_lock(); |
bb952bb9 | 617 | key = rcu_dereference(cred->tgcred->session_keyring); |
1da177e4 | 618 | atomic_inc(&key->usage); |
3e30148c | 619 | rcu_read_unlock(); |
664cceb0 | 620 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
621 | break; |
622 | ||
623 | case KEY_SPEC_USER_KEYRING: | |
b6dff3ec | 624 | if (!cred->user->uid_keyring) { |
8bbf4976 | 625 | ret = install_user_keyrings(); |
69664cf1 DH |
626 | if (ret < 0) |
627 | goto error; | |
628 | } | |
629 | ||
b6dff3ec | 630 | key = cred->user->uid_keyring; |
1da177e4 | 631 | atomic_inc(&key->usage); |
664cceb0 | 632 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
633 | break; |
634 | ||
635 | case KEY_SPEC_USER_SESSION_KEYRING: | |
b6dff3ec | 636 | if (!cred->user->session_keyring) { |
8bbf4976 | 637 | ret = install_user_keyrings(); |
69664cf1 DH |
638 | if (ret < 0) |
639 | goto error; | |
640 | } | |
641 | ||
b6dff3ec | 642 | key = cred->user->session_keyring; |
1da177e4 | 643 | atomic_inc(&key->usage); |
664cceb0 | 644 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
645 | break; |
646 | ||
647 | case KEY_SPEC_GROUP_KEYRING: | |
648 | /* group keyrings are not yet supported */ | |
649 | key = ERR_PTR(-EINVAL); | |
650 | goto error; | |
651 | ||
b5f545c8 | 652 | case KEY_SPEC_REQKEY_AUTH_KEY: |
b6dff3ec | 653 | key = cred->request_key_auth; |
b5f545c8 DH |
654 | if (!key) |
655 | goto error; | |
656 | ||
657 | atomic_inc(&key->usage); | |
658 | key_ref = make_key_ref(key, 1); | |
659 | break; | |
660 | ||
8bbf4976 | 661 | case KEY_SPEC_REQUESTOR_KEYRING: |
b6dff3ec | 662 | if (!cred->request_key_auth) |
8bbf4976 DH |
663 | goto error; |
664 | ||
b6dff3ec DH |
665 | down_read(&cred->request_key_auth->sem); |
666 | if (cred->request_key_auth->flags & KEY_FLAG_REVOKED) { | |
8bbf4976 DH |
667 | key_ref = ERR_PTR(-EKEYREVOKED); |
668 | key = NULL; | |
669 | } else { | |
b6dff3ec | 670 | rka = cred->request_key_auth->payload.data; |
8bbf4976 DH |
671 | key = rka->dest_keyring; |
672 | atomic_inc(&key->usage); | |
673 | } | |
b6dff3ec | 674 | up_read(&cred->request_key_auth->sem); |
8bbf4976 DH |
675 | if (!key) |
676 | goto error; | |
677 | key_ref = make_key_ref(key, 1); | |
678 | break; | |
679 | ||
1da177e4 | 680 | default: |
664cceb0 | 681 | key_ref = ERR_PTR(-EINVAL); |
1da177e4 LT |
682 | if (id < 1) |
683 | goto error; | |
684 | ||
685 | key = key_lookup(id); | |
664cceb0 | 686 | if (IS_ERR(key)) { |
e231c2ee | 687 | key_ref = ERR_CAST(key); |
1da177e4 | 688 | goto error; |
664cceb0 DH |
689 | } |
690 | ||
691 | key_ref = make_key_ref(key, 0); | |
692 | ||
693 | /* check to see if we possess the key */ | |
694 | skey_ref = search_process_keyrings(key->type, key, | |
695 | lookup_user_key_possessed, | |
696 | current); | |
697 | ||
698 | if (!IS_ERR(skey_ref)) { | |
699 | key_put(key); | |
700 | key_ref = skey_ref; | |
701 | } | |
702 | ||
1da177e4 LT |
703 | break; |
704 | } | |
705 | ||
76181c13 DH |
706 | if (!partial) { |
707 | ret = wait_for_key_construction(key, true); | |
708 | switch (ret) { | |
709 | case -ERESTARTSYS: | |
710 | goto invalid_key; | |
711 | default: | |
712 | if (perm) | |
713 | goto invalid_key; | |
714 | case 0: | |
715 | break; | |
716 | } | |
717 | } else if (perm) { | |
1da177e4 LT |
718 | ret = key_validate(key); |
719 | if (ret < 0) | |
720 | goto invalid_key; | |
721 | } | |
722 | ||
723 | ret = -EIO; | |
76d8aeab | 724 | if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
1da177e4 LT |
725 | goto invalid_key; |
726 | ||
3e30148c | 727 | /* check the permissions */ |
8bbf4976 | 728 | ret = key_task_permission(key_ref, t, perm); |
29db9190 | 729 | if (ret < 0) |
1da177e4 LT |
730 | goto invalid_key; |
731 | ||
664cceb0 | 732 | error: |
bb952bb9 | 733 | put_cred(cred); |
664cceb0 | 734 | return key_ref; |
1da177e4 | 735 | |
664cceb0 DH |
736 | invalid_key: |
737 | key_ref_put(key_ref); | |
738 | key_ref = ERR_PTR(ret); | |
1da177e4 LT |
739 | goto error; |
740 | ||
bb952bb9 DH |
741 | /* if we attempted to install a keyring, then it may have caused new |
742 | * creds to be installed */ | |
743 | reget_creds: | |
744 | put_cred(cred); | |
745 | goto try_again; | |
746 | ||
1da177e4 LT |
747 | } /* end lookup_user_key() */ |
748 | ||
749 | /*****************************************************************************/ | |
750 | /* | |
751 | * join the named keyring as the session keyring if possible, or attempt to | |
752 | * create a new one of that name if not | |
753 | * - if the name is NULL, an empty anonymous keyring is installed instead | |
754 | * - named session keyring joining is done with a semaphore held | |
755 | */ | |
756 | long join_session_keyring(const char *name) | |
757 | { | |
758 | struct task_struct *tsk = current; | |
bb952bb9 | 759 | struct cred *cred = current->cred; |
1da177e4 LT |
760 | struct key *keyring; |
761 | long ret; | |
762 | ||
763 | /* if no name is provided, install an anonymous keyring */ | |
764 | if (!name) { | |
8bbf4976 | 765 | ret = install_session_keyring(NULL); |
1da177e4 LT |
766 | if (ret < 0) |
767 | goto error; | |
768 | ||
3e30148c | 769 | rcu_read_lock(); |
bb952bb9 | 770 | ret = rcu_dereference(cred->tgcred->session_keyring)->serial; |
3e30148c | 771 | rcu_read_unlock(); |
1da177e4 LT |
772 | goto error; |
773 | } | |
774 | ||
775 | /* allow the user to join or create a named keyring */ | |
bb003079 | 776 | mutex_lock(&key_session_mutex); |
1da177e4 LT |
777 | |
778 | /* look for an existing keyring of this name */ | |
69664cf1 | 779 | keyring = find_keyring_by_name(name, false); |
1da177e4 LT |
780 | if (PTR_ERR(keyring) == -ENOKEY) { |
781 | /* not found - try and create a new one */ | |
bb952bb9 | 782 | keyring = keyring_alloc(name, cred->uid, cred->gid, tsk, |
7e047ef5 | 783 | KEY_ALLOC_IN_QUOTA, NULL); |
1da177e4 LT |
784 | if (IS_ERR(keyring)) { |
785 | ret = PTR_ERR(keyring); | |
bcf945d3 | 786 | goto error2; |
1da177e4 LT |
787 | } |
788 | } | |
789 | else if (IS_ERR(keyring)) { | |
790 | ret = PTR_ERR(keyring); | |
791 | goto error2; | |
792 | } | |
793 | ||
794 | /* we've got a keyring - now to install it */ | |
8bbf4976 | 795 | ret = install_session_keyring(keyring); |
1da177e4 LT |
796 | if (ret < 0) |
797 | goto error2; | |
798 | ||
799 | ret = keyring->serial; | |
800 | key_put(keyring); | |
801 | ||
664cceb0 | 802 | error2: |
bb003079 | 803 | mutex_unlock(&key_session_mutex); |
664cceb0 | 804 | error: |
1da177e4 LT |
805 | return ret; |
806 | ||
807 | } /* end join_session_keyring() */ |