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 | */ |
69664cf1 | 43 | static int install_user_keyrings(struct task_struct *tsk) |
1da177e4 | 44 | { |
69664cf1 | 45 | struct user_struct *user = tsk->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, | |
70 | tsk, KEY_ALLOC_IN_QUOTA, | |
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, | |
86 | tsk, KEY_ALLOC_IN_QUOTA, NULL); | |
87 | if (IS_ERR(session_keyring)) { | |
88 | ret = PTR_ERR(session_keyring); | |
89 | goto error_release; | |
90 | } | |
91 | ||
92 | /* we install a link from the user session keyring to | |
93 | * the user keyring */ | |
94 | ret = key_link(session_keyring, uid_keyring); | |
95 | if (ret < 0) | |
96 | goto error_release_both; | |
97 | } | |
98 | ||
99 | /* install the keyrings */ | |
100 | user->uid_keyring = uid_keyring; | |
101 | user->session_keyring = session_keyring; | |
1da177e4 LT |
102 | } |
103 | ||
69664cf1 DH |
104 | mutex_unlock(&key_user_keyring_mutex); |
105 | kleave(" = 0"); | |
106 | return 0; | |
1da177e4 | 107 | |
69664cf1 DH |
108 | error_release_both: |
109 | key_put(session_keyring); | |
110 | error_release: | |
111 | key_put(uid_keyring); | |
664cceb0 | 112 | error: |
69664cf1 DH |
113 | mutex_unlock(&key_user_keyring_mutex); |
114 | kleave(" = %d", ret); | |
1da177e4 | 115 | return ret; |
69664cf1 | 116 | } |
1da177e4 LT |
117 | |
118 | /*****************************************************************************/ | |
119 | /* | |
120 | * deal with the UID changing | |
121 | */ | |
122 | void switch_uid_keyring(struct user_struct *new_user) | |
123 | { | |
124 | #if 0 /* do nothing for now */ | |
125 | struct key *old; | |
126 | ||
127 | /* switch to the new user's session keyring if we were running under | |
128 | * root's default session keyring */ | |
129 | if (new_user->uid != 0 && | |
130 | current->session_keyring == &root_session_keyring | |
131 | ) { | |
132 | atomic_inc(&new_user->session_keyring->usage); | |
133 | ||
134 | task_lock(current); | |
135 | old = current->session_keyring; | |
136 | current->session_keyring = new_user->session_keyring; | |
137 | task_unlock(current); | |
138 | ||
139 | key_put(old); | |
140 | } | |
141 | #endif | |
142 | ||
143 | } /* end switch_uid_keyring() */ | |
144 | ||
145 | /*****************************************************************************/ | |
146 | /* | |
147 | * install a fresh thread keyring, discarding the old one | |
148 | */ | |
149 | int install_thread_keyring(struct task_struct *tsk) | |
150 | { | |
151 | struct key *keyring, *old; | |
152 | char buf[20]; | |
153 | int ret; | |
154 | ||
155 | sprintf(buf, "_tid.%u", tsk->pid); | |
156 | ||
7e047ef5 DH |
157 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, |
158 | KEY_ALLOC_QUOTA_OVERRUN, NULL); | |
1da177e4 LT |
159 | if (IS_ERR(keyring)) { |
160 | ret = PTR_ERR(keyring); | |
161 | goto error; | |
162 | } | |
163 | ||
164 | task_lock(tsk); | |
165 | old = tsk->thread_keyring; | |
166 | tsk->thread_keyring = keyring; | |
167 | task_unlock(tsk); | |
168 | ||
169 | ret = 0; | |
170 | ||
171 | key_put(old); | |
664cceb0 | 172 | error: |
1da177e4 LT |
173 | return ret; |
174 | ||
175 | } /* end install_thread_keyring() */ | |
176 | ||
177 | /*****************************************************************************/ | |
178 | /* | |
179 | * make sure a process keyring is installed | |
180 | */ | |
3e30148c | 181 | int install_process_keyring(struct task_struct *tsk) |
1da177e4 | 182 | { |
1da177e4 LT |
183 | struct key *keyring; |
184 | char buf[20]; | |
185 | int ret; | |
186 | ||
1a26feb9 DH |
187 | might_sleep(); |
188 | ||
1da177e4 LT |
189 | if (!tsk->signal->process_keyring) { |
190 | sprintf(buf, "_pid.%u", tsk->tgid); | |
191 | ||
7e047ef5 DH |
192 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, |
193 | KEY_ALLOC_QUOTA_OVERRUN, NULL); | |
1da177e4 LT |
194 | if (IS_ERR(keyring)) { |
195 | ret = PTR_ERR(keyring); | |
196 | goto error; | |
197 | } | |
198 | ||
8589b4e0 | 199 | /* attach keyring */ |
1a26feb9 | 200 | spin_lock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
201 | if (!tsk->signal->process_keyring) { |
202 | tsk->signal->process_keyring = keyring; | |
203 | keyring = NULL; | |
204 | } | |
1a26feb9 | 205 | spin_unlock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
206 | |
207 | key_put(keyring); | |
208 | } | |
209 | ||
210 | ret = 0; | |
664cceb0 | 211 | error: |
1da177e4 LT |
212 | return ret; |
213 | ||
214 | } /* end install_process_keyring() */ | |
215 | ||
216 | /*****************************************************************************/ | |
217 | /* | |
218 | * install a session keyring, discarding the old one | |
219 | * - if a keyring is not supplied, an empty one is invented | |
220 | */ | |
221 | static int install_session_keyring(struct task_struct *tsk, | |
222 | struct key *keyring) | |
223 | { | |
7e047ef5 | 224 | unsigned long flags; |
1da177e4 LT |
225 | struct key *old; |
226 | char buf[20]; | |
1a26feb9 DH |
227 | |
228 | might_sleep(); | |
1da177e4 LT |
229 | |
230 | /* create an empty session keyring */ | |
231 | if (!keyring) { | |
232 | sprintf(buf, "_ses.%u", tsk->tgid); | |
233 | ||
7e047ef5 DH |
234 | flags = KEY_ALLOC_QUOTA_OVERRUN; |
235 | if (tsk->signal->session_keyring) | |
236 | flags = KEY_ALLOC_IN_QUOTA; | |
237 | ||
238 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, | |
239 | flags, NULL); | |
1a26feb9 DH |
240 | if (IS_ERR(keyring)) |
241 | return PTR_ERR(keyring); | |
1da177e4 LT |
242 | } |
243 | else { | |
244 | atomic_inc(&keyring->usage); | |
245 | } | |
246 | ||
247 | /* install the keyring */ | |
1a26feb9 DH |
248 | spin_lock_irq(&tsk->sighand->siglock); |
249 | old = tsk->signal->session_keyring; | |
8589b4e0 | 250 | rcu_assign_pointer(tsk->signal->session_keyring, keyring); |
1a26feb9 | 251 | spin_unlock_irq(&tsk->sighand->siglock); |
1da177e4 | 252 | |
1a26feb9 DH |
253 | /* we're using RCU on the pointer, but there's no point synchronising |
254 | * on it if it didn't previously point to anything */ | |
255 | if (old) { | |
256 | synchronize_rcu(); | |
257 | key_put(old); | |
258 | } | |
1da177e4 | 259 | |
1a26feb9 | 260 | return 0; |
1da177e4 LT |
261 | |
262 | } /* end install_session_keyring() */ | |
263 | ||
264 | /*****************************************************************************/ | |
265 | /* | |
266 | * copy the keys in a thread group for fork without CLONE_THREAD | |
267 | */ | |
268 | int copy_thread_group_keys(struct task_struct *tsk) | |
269 | { | |
1da177e4 LT |
270 | key_check(current->thread_group->session_keyring); |
271 | key_check(current->thread_group->process_keyring); | |
272 | ||
273 | /* no process keyring yet */ | |
274 | tsk->signal->process_keyring = NULL; | |
275 | ||
276 | /* same session keyring */ | |
8589b4e0 | 277 | rcu_read_lock(); |
1da177e4 | 278 | tsk->signal->session_keyring = |
8589b4e0 DH |
279 | key_get(rcu_dereference(current->signal->session_keyring)); |
280 | rcu_read_unlock(); | |
1da177e4 LT |
281 | |
282 | return 0; | |
283 | ||
284 | } /* end copy_thread_group_keys() */ | |
285 | ||
286 | /*****************************************************************************/ | |
287 | /* | |
288 | * copy the keys for fork | |
289 | */ | |
290 | int copy_keys(unsigned long clone_flags, struct task_struct *tsk) | |
291 | { | |
292 | key_check(tsk->thread_keyring); | |
b5f545c8 | 293 | key_check(tsk->request_key_auth); |
1da177e4 LT |
294 | |
295 | /* no thread keyring yet */ | |
296 | tsk->thread_keyring = NULL; | |
b5f545c8 DH |
297 | |
298 | /* copy the request_key() authorisation for this thread */ | |
299 | key_get(tsk->request_key_auth); | |
300 | ||
1da177e4 LT |
301 | return 0; |
302 | ||
303 | } /* end copy_keys() */ | |
304 | ||
305 | /*****************************************************************************/ | |
306 | /* | |
307 | * dispose of thread group keys upon thread group destruction | |
308 | */ | |
309 | void exit_thread_group_keys(struct signal_struct *tg) | |
310 | { | |
311 | key_put(tg->session_keyring); | |
312 | key_put(tg->process_keyring); | |
313 | ||
314 | } /* end exit_thread_group_keys() */ | |
315 | ||
316 | /*****************************************************************************/ | |
317 | /* | |
b5f545c8 | 318 | * dispose of per-thread keys upon thread exit |
1da177e4 LT |
319 | */ |
320 | void exit_keys(struct task_struct *tsk) | |
321 | { | |
322 | key_put(tsk->thread_keyring); | |
b5f545c8 | 323 | key_put(tsk->request_key_auth); |
1da177e4 LT |
324 | |
325 | } /* end exit_keys() */ | |
326 | ||
327 | /*****************************************************************************/ | |
328 | /* | |
329 | * deal with execve() | |
330 | */ | |
331 | int exec_keys(struct task_struct *tsk) | |
332 | { | |
1da177e4 LT |
333 | struct key *old; |
334 | ||
335 | /* newly exec'd tasks don't get a thread keyring */ | |
336 | task_lock(tsk); | |
337 | old = tsk->thread_keyring; | |
338 | tsk->thread_keyring = NULL; | |
339 | task_unlock(tsk); | |
340 | ||
341 | key_put(old); | |
342 | ||
343 | /* discard the process keyring from a newly exec'd task */ | |
1a26feb9 | 344 | spin_lock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
345 | old = tsk->signal->process_keyring; |
346 | tsk->signal->process_keyring = NULL; | |
1a26feb9 | 347 | spin_unlock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
348 | |
349 | key_put(old); | |
350 | ||
351 | return 0; | |
352 | ||
353 | } /* end exec_keys() */ | |
354 | ||
355 | /*****************************************************************************/ | |
356 | /* | |
357 | * deal with SUID programs | |
358 | * - we might want to make this invent a new session keyring | |
359 | */ | |
360 | int suid_keys(struct task_struct *tsk) | |
361 | { | |
362 | return 0; | |
363 | ||
364 | } /* end suid_keys() */ | |
365 | ||
366 | /*****************************************************************************/ | |
367 | /* | |
368 | * the filesystem user ID changed | |
369 | */ | |
370 | void key_fsuid_changed(struct task_struct *tsk) | |
371 | { | |
372 | /* update the ownership of the thread keyring */ | |
373 | if (tsk->thread_keyring) { | |
374 | down_write(&tsk->thread_keyring->sem); | |
1da177e4 | 375 | tsk->thread_keyring->uid = tsk->fsuid; |
1da177e4 LT |
376 | up_write(&tsk->thread_keyring->sem); |
377 | } | |
378 | ||
379 | } /* end key_fsuid_changed() */ | |
380 | ||
381 | /*****************************************************************************/ | |
382 | /* | |
383 | * the filesystem group ID changed | |
384 | */ | |
385 | void key_fsgid_changed(struct task_struct *tsk) | |
386 | { | |
387 | /* update the ownership of the thread keyring */ | |
388 | if (tsk->thread_keyring) { | |
389 | down_write(&tsk->thread_keyring->sem); | |
1da177e4 | 390 | tsk->thread_keyring->gid = tsk->fsgid; |
1da177e4 LT |
391 | up_write(&tsk->thread_keyring->sem); |
392 | } | |
393 | ||
394 | } /* end key_fsgid_changed() */ | |
395 | ||
396 | /*****************************************************************************/ | |
397 | /* | |
398 | * search the process keyrings for the first matching key | |
399 | * - we use the supplied match function to see if the description (or other | |
400 | * feature of interest) matches | |
401 | * - we return -EAGAIN if we didn't find any matching key | |
402 | * - we return -ENOKEY if we found only negative matching keys | |
403 | */ | |
664cceb0 DH |
404 | key_ref_t search_process_keyrings(struct key_type *type, |
405 | const void *description, | |
406 | key_match_func_t match, | |
407 | struct task_struct *context) | |
1da177e4 | 408 | { |
3e30148c | 409 | struct request_key_auth *rka; |
b5f545c8 | 410 | key_ref_t key_ref, ret, err; |
1da177e4 | 411 | |
04c567d9 DH |
412 | might_sleep(); |
413 | ||
1da177e4 LT |
414 | /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were |
415 | * searchable, but we failed to find a key or we found a negative key; | |
416 | * otherwise we want to return a sample error (probably -EACCES) if | |
417 | * none of the keyrings were searchable | |
418 | * | |
419 | * in terms of priority: success > -ENOKEY > -EAGAIN > other error | |
420 | */ | |
664cceb0 | 421 | key_ref = NULL; |
1da177e4 LT |
422 | ret = NULL; |
423 | err = ERR_PTR(-EAGAIN); | |
424 | ||
425 | /* search the thread keyring first */ | |
3e30148c | 426 | if (context->thread_keyring) { |
664cceb0 DH |
427 | key_ref = keyring_search_aux( |
428 | make_key_ref(context->thread_keyring, 1), | |
429 | context, type, description, match); | |
430 | if (!IS_ERR(key_ref)) | |
1da177e4 LT |
431 | goto found; |
432 | ||
664cceb0 | 433 | switch (PTR_ERR(key_ref)) { |
1da177e4 LT |
434 | case -EAGAIN: /* no key */ |
435 | if (ret) | |
436 | break; | |
437 | case -ENOKEY: /* negative key */ | |
664cceb0 | 438 | ret = key_ref; |
1da177e4 LT |
439 | break; |
440 | default: | |
664cceb0 | 441 | err = key_ref; |
1da177e4 LT |
442 | break; |
443 | } | |
444 | } | |
445 | ||
446 | /* search the process keyring second */ | |
3e30148c | 447 | if (context->signal->process_keyring) { |
664cceb0 DH |
448 | key_ref = keyring_search_aux( |
449 | make_key_ref(context->signal->process_keyring, 1), | |
450 | context, type, description, match); | |
451 | if (!IS_ERR(key_ref)) | |
1da177e4 LT |
452 | goto found; |
453 | ||
664cceb0 | 454 | switch (PTR_ERR(key_ref)) { |
1da177e4 LT |
455 | case -EAGAIN: /* no key */ |
456 | if (ret) | |
457 | break; | |
458 | case -ENOKEY: /* negative key */ | |
664cceb0 | 459 | ret = key_ref; |
1da177e4 LT |
460 | break; |
461 | default: | |
664cceb0 | 462 | err = key_ref; |
1da177e4 LT |
463 | break; |
464 | } | |
465 | } | |
466 | ||
3e30148c DH |
467 | /* search the session keyring */ |
468 | if (context->signal->session_keyring) { | |
8589b4e0 | 469 | rcu_read_lock(); |
664cceb0 DH |
470 | key_ref = keyring_search_aux( |
471 | make_key_ref(rcu_dereference( | |
472 | context->signal->session_keyring), | |
473 | 1), | |
3e30148c | 474 | context, type, description, match); |
8589b4e0 | 475 | rcu_read_unlock(); |
3e30148c | 476 | |
664cceb0 | 477 | if (!IS_ERR(key_ref)) |
3e30148c DH |
478 | goto found; |
479 | ||
664cceb0 | 480 | switch (PTR_ERR(key_ref)) { |
3e30148c DH |
481 | case -EAGAIN: /* no key */ |
482 | if (ret) | |
483 | break; | |
484 | case -ENOKEY: /* negative key */ | |
664cceb0 | 485 | ret = key_ref; |
3e30148c DH |
486 | break; |
487 | default: | |
664cceb0 | 488 | err = key_ref; |
3e30148c DH |
489 | break; |
490 | } | |
b5f545c8 DH |
491 | } |
492 | /* or search the user-session keyring */ | |
69664cf1 | 493 | else if (context->user->session_keyring) { |
b5f545c8 DH |
494 | key_ref = keyring_search_aux( |
495 | make_key_ref(context->user->session_keyring, 1), | |
496 | context, type, description, match); | |
664cceb0 | 497 | if (!IS_ERR(key_ref)) |
3e30148c DH |
498 | goto found; |
499 | ||
664cceb0 | 500 | switch (PTR_ERR(key_ref)) { |
3e30148c DH |
501 | case -EAGAIN: /* no key */ |
502 | if (ret) | |
503 | break; | |
504 | case -ENOKEY: /* negative key */ | |
664cceb0 | 505 | ret = key_ref; |
3e30148c DH |
506 | break; |
507 | default: | |
664cceb0 | 508 | err = key_ref; |
3e30148c DH |
509 | break; |
510 | } | |
8589b4e0 | 511 | } |
b5f545c8 DH |
512 | |
513 | /* if this process has an instantiation authorisation key, then we also | |
514 | * search the keyrings of the process mentioned there | |
515 | * - we don't permit access to request_key auth keys via this method | |
516 | */ | |
517 | if (context->request_key_auth && | |
518 | context == current && | |
04c567d9 | 519 | type != &key_type_request_key_auth |
b5f545c8 | 520 | ) { |
04c567d9 DH |
521 | /* defend against the auth key being revoked */ |
522 | down_read(&context->request_key_auth->sem); | |
b5f545c8 | 523 | |
04c567d9 DH |
524 | if (key_validate(context->request_key_auth) == 0) { |
525 | rka = context->request_key_auth->payload.data; | |
b5f545c8 | 526 | |
04c567d9 DH |
527 | key_ref = search_process_keyrings(type, description, |
528 | match, rka->context); | |
1da177e4 | 529 | |
04c567d9 DH |
530 | up_read(&context->request_key_auth->sem); |
531 | ||
532 | if (!IS_ERR(key_ref)) | |
533 | goto found; | |
534 | ||
535 | switch (PTR_ERR(key_ref)) { | |
536 | case -EAGAIN: /* no key */ | |
537 | if (ret) | |
538 | break; | |
539 | case -ENOKEY: /* negative key */ | |
540 | ret = key_ref; | |
3e30148c | 541 | break; |
04c567d9 DH |
542 | default: |
543 | err = key_ref; | |
544 | break; | |
545 | } | |
546 | } else { | |
547 | up_read(&context->request_key_auth->sem); | |
3e30148c | 548 | } |
1da177e4 LT |
549 | } |
550 | ||
551 | /* no key - decide on the error we're going to go for */ | |
664cceb0 | 552 | key_ref = ret ? ret : err; |
1da177e4 | 553 | |
3e30148c | 554 | found: |
664cceb0 | 555 | return key_ref; |
1da177e4 | 556 | |
1da177e4 LT |
557 | } /* end search_process_keyrings() */ |
558 | ||
664cceb0 DH |
559 | /*****************************************************************************/ |
560 | /* | |
561 | * see if the key we're looking at is the target key | |
562 | */ | |
563 | static int lookup_user_key_possessed(const struct key *key, const void *target) | |
564 | { | |
565 | return key == target; | |
566 | ||
567 | } /* end lookup_user_key_possessed() */ | |
568 | ||
1da177e4 LT |
569 | /*****************************************************************************/ |
570 | /* | |
571 | * lookup a key given a key ID from userspace with a given permissions mask | |
572 | * - don't create special keyrings unless so requested | |
573 | * - partially constructed keys aren't found unless requested | |
574 | */ | |
664cceb0 DH |
575 | key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, |
576 | int create, int partial, key_perm_t perm) | |
1da177e4 | 577 | { |
664cceb0 | 578 | key_ref_t key_ref, skey_ref; |
1da177e4 LT |
579 | struct key *key; |
580 | int ret; | |
581 | ||
3e30148c DH |
582 | if (!context) |
583 | context = current; | |
584 | ||
664cceb0 | 585 | key_ref = ERR_PTR(-ENOKEY); |
1da177e4 LT |
586 | |
587 | switch (id) { | |
588 | case KEY_SPEC_THREAD_KEYRING: | |
3e30148c | 589 | if (!context->thread_keyring) { |
1da177e4 LT |
590 | if (!create) |
591 | goto error; | |
592 | ||
3e30148c | 593 | ret = install_thread_keyring(context); |
1da177e4 LT |
594 | if (ret < 0) { |
595 | key = ERR_PTR(ret); | |
596 | goto error; | |
597 | } | |
598 | } | |
599 | ||
3e30148c | 600 | key = context->thread_keyring; |
1da177e4 | 601 | atomic_inc(&key->usage); |
664cceb0 | 602 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
603 | break; |
604 | ||
605 | case KEY_SPEC_PROCESS_KEYRING: | |
3e30148c | 606 | if (!context->signal->process_keyring) { |
1da177e4 LT |
607 | if (!create) |
608 | goto error; | |
609 | ||
3e30148c | 610 | ret = install_process_keyring(context); |
1da177e4 LT |
611 | if (ret < 0) { |
612 | key = ERR_PTR(ret); | |
613 | goto error; | |
614 | } | |
615 | } | |
616 | ||
3e30148c | 617 | key = context->signal->process_keyring; |
1da177e4 | 618 | atomic_inc(&key->usage); |
664cceb0 | 619 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
620 | break; |
621 | ||
622 | case KEY_SPEC_SESSION_KEYRING: | |
3e30148c | 623 | if (!context->signal->session_keyring) { |
1da177e4 LT |
624 | /* always install a session keyring upon access if one |
625 | * doesn't exist yet */ | |
69664cf1 DH |
626 | ret = install_user_keyrings(context); |
627 | if (ret < 0) | |
628 | goto error; | |
1da177e4 | 629 | ret = install_session_keyring( |
664cceb0 | 630 | context, context->user->session_keyring); |
1da177e4 LT |
631 | if (ret < 0) |
632 | goto error; | |
633 | } | |
634 | ||
3e30148c DH |
635 | rcu_read_lock(); |
636 | key = rcu_dereference(context->signal->session_keyring); | |
1da177e4 | 637 | atomic_inc(&key->usage); |
3e30148c | 638 | rcu_read_unlock(); |
664cceb0 | 639 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
640 | break; |
641 | ||
642 | case KEY_SPEC_USER_KEYRING: | |
69664cf1 DH |
643 | if (!context->user->uid_keyring) { |
644 | ret = install_user_keyrings(context); | |
645 | if (ret < 0) | |
646 | goto error; | |
647 | } | |
648 | ||
3e30148c | 649 | key = context->user->uid_keyring; |
1da177e4 | 650 | atomic_inc(&key->usage); |
664cceb0 | 651 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
652 | break; |
653 | ||
654 | case KEY_SPEC_USER_SESSION_KEYRING: | |
69664cf1 DH |
655 | if (!context->user->session_keyring) { |
656 | ret = install_user_keyrings(context); | |
657 | if (ret < 0) | |
658 | goto error; | |
659 | } | |
660 | ||
3e30148c | 661 | key = context->user->session_keyring; |
1da177e4 | 662 | atomic_inc(&key->usage); |
664cceb0 | 663 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
664 | break; |
665 | ||
666 | case KEY_SPEC_GROUP_KEYRING: | |
667 | /* group keyrings are not yet supported */ | |
668 | key = ERR_PTR(-EINVAL); | |
669 | goto error; | |
670 | ||
b5f545c8 DH |
671 | case KEY_SPEC_REQKEY_AUTH_KEY: |
672 | key = context->request_key_auth; | |
673 | if (!key) | |
674 | goto error; | |
675 | ||
676 | atomic_inc(&key->usage); | |
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 */ |
29db9190 DH |
728 | ret = key_task_permission(key_ref, context, perm); |
729 | if (ret < 0) | |
1da177e4 LT |
730 | goto invalid_key; |
731 | ||
664cceb0 DH |
732 | error: |
733 | return key_ref; | |
1da177e4 | 734 | |
664cceb0 DH |
735 | invalid_key: |
736 | key_ref_put(key_ref); | |
737 | key_ref = ERR_PTR(ret); | |
1da177e4 LT |
738 | goto error; |
739 | ||
740 | } /* end lookup_user_key() */ | |
741 | ||
742 | /*****************************************************************************/ | |
743 | /* | |
744 | * join the named keyring as the session keyring if possible, or attempt to | |
745 | * create a new one of that name if not | |
746 | * - if the name is NULL, an empty anonymous keyring is installed instead | |
747 | * - named session keyring joining is done with a semaphore held | |
748 | */ | |
749 | long join_session_keyring(const char *name) | |
750 | { | |
751 | struct task_struct *tsk = current; | |
1da177e4 LT |
752 | struct key *keyring; |
753 | long ret; | |
754 | ||
755 | /* if no name is provided, install an anonymous keyring */ | |
756 | if (!name) { | |
757 | ret = install_session_keyring(tsk, NULL); | |
758 | if (ret < 0) | |
759 | goto error; | |
760 | ||
3e30148c DH |
761 | rcu_read_lock(); |
762 | ret = rcu_dereference(tsk->signal->session_keyring)->serial; | |
763 | rcu_read_unlock(); | |
1da177e4 LT |
764 | goto error; |
765 | } | |
766 | ||
767 | /* allow the user to join or create a named keyring */ | |
bb003079 | 768 | mutex_lock(&key_session_mutex); |
1da177e4 LT |
769 | |
770 | /* look for an existing keyring of this name */ | |
69664cf1 | 771 | keyring = find_keyring_by_name(name, false); |
1da177e4 LT |
772 | if (PTR_ERR(keyring) == -ENOKEY) { |
773 | /* not found - try and create a new one */ | |
7e047ef5 DH |
774 | keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk, |
775 | KEY_ALLOC_IN_QUOTA, NULL); | |
1da177e4 LT |
776 | if (IS_ERR(keyring)) { |
777 | ret = PTR_ERR(keyring); | |
bcf945d3 | 778 | goto error2; |
1da177e4 LT |
779 | } |
780 | } | |
781 | else if (IS_ERR(keyring)) { | |
782 | ret = PTR_ERR(keyring); | |
783 | goto error2; | |
784 | } | |
785 | ||
786 | /* we've got a keyring - now to install it */ | |
787 | ret = install_session_keyring(tsk, keyring); | |
788 | if (ret < 0) | |
789 | goto error2; | |
790 | ||
791 | ret = keyring->serial; | |
792 | key_put(keyring); | |
793 | ||
664cceb0 | 794 | error2: |
bb003079 | 795 | mutex_unlock(&key_session_mutex); |
664cceb0 | 796 | error: |
1da177e4 LT |
797 | return ret; |
798 | ||
799 | } /* end join_session_keyring() */ |