Commit | Line | Data |
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1da177e4 LT |
1 | /* process_keys.c: management of a process's keyrings |
2 | * | |
8589b4e0 | 3 | * Copyright (C) 2004-5 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 LT |
25 | |
26 | /* the root user's tracking struct */ | |
27 | struct key_user root_key_user = { | |
28 | .usage = ATOMIC_INIT(3), | |
29 | .consq = LIST_HEAD_INIT(root_key_user.consq), | |
6cfd76a2 | 30 | .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock), |
1da177e4 LT |
31 | .nkeys = ATOMIC_INIT(2), |
32 | .nikeys = ATOMIC_INIT(2), | |
33 | .uid = 0, | |
34 | }; | |
35 | ||
36 | /* the root user's UID keyring */ | |
37 | struct key root_user_keyring = { | |
38 | .usage = ATOMIC_INIT(1), | |
39 | .serial = 2, | |
40 | .type = &key_type_keyring, | |
41 | .user = &root_key_user, | |
1da177e4 | 42 | .sem = __RWSEM_INITIALIZER(root_user_keyring.sem), |
29db9190 | 43 | .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, |
76d8aeab | 44 | .flags = 1 << KEY_FLAG_INSTANTIATED, |
1da177e4 LT |
45 | .description = "_uid.0", |
46 | #ifdef KEY_DEBUGGING | |
47 | .magic = KEY_DEBUG_MAGIC, | |
48 | #endif | |
49 | }; | |
50 | ||
51 | /* the root user's default session keyring */ | |
52 | struct key root_session_keyring = { | |
53 | .usage = ATOMIC_INIT(1), | |
54 | .serial = 1, | |
55 | .type = &key_type_keyring, | |
56 | .user = &root_key_user, | |
1da177e4 | 57 | .sem = __RWSEM_INITIALIZER(root_session_keyring.sem), |
29db9190 | 58 | .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, |
76d8aeab | 59 | .flags = 1 << KEY_FLAG_INSTANTIATED, |
1da177e4 LT |
60 | .description = "_uid_ses.0", |
61 | #ifdef KEY_DEBUGGING | |
62 | .magic = KEY_DEBUG_MAGIC, | |
63 | #endif | |
64 | }; | |
65 | ||
66 | /*****************************************************************************/ | |
67 | /* | |
68 | * allocate the keyrings to be associated with a UID | |
69 | */ | |
d720024e ML |
70 | int alloc_uid_keyring(struct user_struct *user, |
71 | struct task_struct *ctx) | |
1da177e4 LT |
72 | { |
73 | struct key *uid_keyring, *session_keyring; | |
74 | char buf[20]; | |
75 | int ret; | |
76 | ||
77 | /* concoct a default session keyring */ | |
78 | sprintf(buf, "_uid_ses.%u", user->uid); | |
79 | ||
7e047ef5 DH |
80 | session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx, |
81 | KEY_ALLOC_IN_QUOTA, NULL); | |
1da177e4 LT |
82 | if (IS_ERR(session_keyring)) { |
83 | ret = PTR_ERR(session_keyring); | |
84 | goto error; | |
85 | } | |
86 | ||
87 | /* and a UID specific keyring, pointed to by the default session | |
88 | * keyring */ | |
89 | sprintf(buf, "_uid.%u", user->uid); | |
90 | ||
7e047ef5 DH |
91 | uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx, |
92 | KEY_ALLOC_IN_QUOTA, session_keyring); | |
1da177e4 LT |
93 | if (IS_ERR(uid_keyring)) { |
94 | key_put(session_keyring); | |
95 | ret = PTR_ERR(uid_keyring); | |
96 | goto error; | |
97 | } | |
98 | ||
99 | /* install the keyrings */ | |
100 | user->uid_keyring = uid_keyring; | |
101 | user->session_keyring = session_keyring; | |
102 | ret = 0; | |
103 | ||
664cceb0 | 104 | error: |
1da177e4 LT |
105 | return ret; |
106 | ||
107 | } /* end alloc_uid_keyring() */ | |
108 | ||
109 | /*****************************************************************************/ | |
110 | /* | |
111 | * deal with the UID changing | |
112 | */ | |
113 | void switch_uid_keyring(struct user_struct *new_user) | |
114 | { | |
115 | #if 0 /* do nothing for now */ | |
116 | struct key *old; | |
117 | ||
118 | /* switch to the new user's session keyring if we were running under | |
119 | * root's default session keyring */ | |
120 | if (new_user->uid != 0 && | |
121 | current->session_keyring == &root_session_keyring | |
122 | ) { | |
123 | atomic_inc(&new_user->session_keyring->usage); | |
124 | ||
125 | task_lock(current); | |
126 | old = current->session_keyring; | |
127 | current->session_keyring = new_user->session_keyring; | |
128 | task_unlock(current); | |
129 | ||
130 | key_put(old); | |
131 | } | |
132 | #endif | |
133 | ||
134 | } /* end switch_uid_keyring() */ | |
135 | ||
136 | /*****************************************************************************/ | |
137 | /* | |
138 | * install a fresh thread keyring, discarding the old one | |
139 | */ | |
140 | int install_thread_keyring(struct task_struct *tsk) | |
141 | { | |
142 | struct key *keyring, *old; | |
143 | char buf[20]; | |
144 | int ret; | |
145 | ||
146 | sprintf(buf, "_tid.%u", tsk->pid); | |
147 | ||
7e047ef5 DH |
148 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, |
149 | KEY_ALLOC_QUOTA_OVERRUN, NULL); | |
1da177e4 LT |
150 | if (IS_ERR(keyring)) { |
151 | ret = PTR_ERR(keyring); | |
152 | goto error; | |
153 | } | |
154 | ||
155 | task_lock(tsk); | |
156 | old = tsk->thread_keyring; | |
157 | tsk->thread_keyring = keyring; | |
158 | task_unlock(tsk); | |
159 | ||
160 | ret = 0; | |
161 | ||
162 | key_put(old); | |
664cceb0 | 163 | error: |
1da177e4 LT |
164 | return ret; |
165 | ||
166 | } /* end install_thread_keyring() */ | |
167 | ||
168 | /*****************************************************************************/ | |
169 | /* | |
170 | * make sure a process keyring is installed | |
171 | */ | |
3e30148c | 172 | int install_process_keyring(struct task_struct *tsk) |
1da177e4 | 173 | { |
1da177e4 LT |
174 | struct key *keyring; |
175 | char buf[20]; | |
176 | int ret; | |
177 | ||
1a26feb9 DH |
178 | might_sleep(); |
179 | ||
1da177e4 LT |
180 | if (!tsk->signal->process_keyring) { |
181 | sprintf(buf, "_pid.%u", tsk->tgid); | |
182 | ||
7e047ef5 DH |
183 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, |
184 | KEY_ALLOC_QUOTA_OVERRUN, NULL); | |
1da177e4 LT |
185 | if (IS_ERR(keyring)) { |
186 | ret = PTR_ERR(keyring); | |
187 | goto error; | |
188 | } | |
189 | ||
8589b4e0 | 190 | /* attach keyring */ |
1a26feb9 | 191 | spin_lock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
192 | if (!tsk->signal->process_keyring) { |
193 | tsk->signal->process_keyring = keyring; | |
194 | keyring = NULL; | |
195 | } | |
1a26feb9 | 196 | spin_unlock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
197 | |
198 | key_put(keyring); | |
199 | } | |
200 | ||
201 | ret = 0; | |
664cceb0 | 202 | error: |
1da177e4 LT |
203 | return ret; |
204 | ||
205 | } /* end install_process_keyring() */ | |
206 | ||
207 | /*****************************************************************************/ | |
208 | /* | |
209 | * install a session keyring, discarding the old one | |
210 | * - if a keyring is not supplied, an empty one is invented | |
211 | */ | |
212 | static int install_session_keyring(struct task_struct *tsk, | |
213 | struct key *keyring) | |
214 | { | |
7e047ef5 | 215 | unsigned long flags; |
1da177e4 LT |
216 | struct key *old; |
217 | char buf[20]; | |
1a26feb9 DH |
218 | |
219 | might_sleep(); | |
1da177e4 LT |
220 | |
221 | /* create an empty session keyring */ | |
222 | if (!keyring) { | |
223 | sprintf(buf, "_ses.%u", tsk->tgid); | |
224 | ||
7e047ef5 DH |
225 | flags = KEY_ALLOC_QUOTA_OVERRUN; |
226 | if (tsk->signal->session_keyring) | |
227 | flags = KEY_ALLOC_IN_QUOTA; | |
228 | ||
229 | keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, | |
230 | flags, NULL); | |
1a26feb9 DH |
231 | if (IS_ERR(keyring)) |
232 | return PTR_ERR(keyring); | |
1da177e4 LT |
233 | } |
234 | else { | |
235 | atomic_inc(&keyring->usage); | |
236 | } | |
237 | ||
238 | /* install the keyring */ | |
1a26feb9 DH |
239 | spin_lock_irq(&tsk->sighand->siglock); |
240 | old = tsk->signal->session_keyring; | |
8589b4e0 | 241 | rcu_assign_pointer(tsk->signal->session_keyring, keyring); |
1a26feb9 | 242 | spin_unlock_irq(&tsk->sighand->siglock); |
1da177e4 | 243 | |
1a26feb9 DH |
244 | /* we're using RCU on the pointer, but there's no point synchronising |
245 | * on it if it didn't previously point to anything */ | |
246 | if (old) { | |
247 | synchronize_rcu(); | |
248 | key_put(old); | |
249 | } | |
1da177e4 | 250 | |
1a26feb9 | 251 | return 0; |
1da177e4 LT |
252 | |
253 | } /* end install_session_keyring() */ | |
254 | ||
255 | /*****************************************************************************/ | |
256 | /* | |
257 | * copy the keys in a thread group for fork without CLONE_THREAD | |
258 | */ | |
259 | int copy_thread_group_keys(struct task_struct *tsk) | |
260 | { | |
1da177e4 LT |
261 | key_check(current->thread_group->session_keyring); |
262 | key_check(current->thread_group->process_keyring); | |
263 | ||
264 | /* no process keyring yet */ | |
265 | tsk->signal->process_keyring = NULL; | |
266 | ||
267 | /* same session keyring */ | |
8589b4e0 | 268 | rcu_read_lock(); |
1da177e4 | 269 | tsk->signal->session_keyring = |
8589b4e0 DH |
270 | key_get(rcu_dereference(current->signal->session_keyring)); |
271 | rcu_read_unlock(); | |
1da177e4 LT |
272 | |
273 | return 0; | |
274 | ||
275 | } /* end copy_thread_group_keys() */ | |
276 | ||
277 | /*****************************************************************************/ | |
278 | /* | |
279 | * copy the keys for fork | |
280 | */ | |
281 | int copy_keys(unsigned long clone_flags, struct task_struct *tsk) | |
282 | { | |
283 | key_check(tsk->thread_keyring); | |
b5f545c8 | 284 | key_check(tsk->request_key_auth); |
1da177e4 LT |
285 | |
286 | /* no thread keyring yet */ | |
287 | tsk->thread_keyring = NULL; | |
b5f545c8 DH |
288 | |
289 | /* copy the request_key() authorisation for this thread */ | |
290 | key_get(tsk->request_key_auth); | |
291 | ||
1da177e4 LT |
292 | return 0; |
293 | ||
294 | } /* end copy_keys() */ | |
295 | ||
296 | /*****************************************************************************/ | |
297 | /* | |
298 | * dispose of thread group keys upon thread group destruction | |
299 | */ | |
300 | void exit_thread_group_keys(struct signal_struct *tg) | |
301 | { | |
302 | key_put(tg->session_keyring); | |
303 | key_put(tg->process_keyring); | |
304 | ||
305 | } /* end exit_thread_group_keys() */ | |
306 | ||
307 | /*****************************************************************************/ | |
308 | /* | |
b5f545c8 | 309 | * dispose of per-thread keys upon thread exit |
1da177e4 LT |
310 | */ |
311 | void exit_keys(struct task_struct *tsk) | |
312 | { | |
313 | key_put(tsk->thread_keyring); | |
b5f545c8 | 314 | key_put(tsk->request_key_auth); |
1da177e4 LT |
315 | |
316 | } /* end exit_keys() */ | |
317 | ||
318 | /*****************************************************************************/ | |
319 | /* | |
320 | * deal with execve() | |
321 | */ | |
322 | int exec_keys(struct task_struct *tsk) | |
323 | { | |
1da177e4 LT |
324 | struct key *old; |
325 | ||
326 | /* newly exec'd tasks don't get a thread keyring */ | |
327 | task_lock(tsk); | |
328 | old = tsk->thread_keyring; | |
329 | tsk->thread_keyring = NULL; | |
330 | task_unlock(tsk); | |
331 | ||
332 | key_put(old); | |
333 | ||
334 | /* discard the process keyring from a newly exec'd task */ | |
1a26feb9 | 335 | spin_lock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
336 | old = tsk->signal->process_keyring; |
337 | tsk->signal->process_keyring = NULL; | |
1a26feb9 | 338 | spin_unlock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
339 | |
340 | key_put(old); | |
341 | ||
342 | return 0; | |
343 | ||
344 | } /* end exec_keys() */ | |
345 | ||
346 | /*****************************************************************************/ | |
347 | /* | |
348 | * deal with SUID programs | |
349 | * - we might want to make this invent a new session keyring | |
350 | */ | |
351 | int suid_keys(struct task_struct *tsk) | |
352 | { | |
353 | return 0; | |
354 | ||
355 | } /* end suid_keys() */ | |
356 | ||
357 | /*****************************************************************************/ | |
358 | /* | |
359 | * the filesystem user ID changed | |
360 | */ | |
361 | void key_fsuid_changed(struct task_struct *tsk) | |
362 | { | |
363 | /* update the ownership of the thread keyring */ | |
364 | if (tsk->thread_keyring) { | |
365 | down_write(&tsk->thread_keyring->sem); | |
1da177e4 | 366 | tsk->thread_keyring->uid = tsk->fsuid; |
1da177e4 LT |
367 | up_write(&tsk->thread_keyring->sem); |
368 | } | |
369 | ||
370 | } /* end key_fsuid_changed() */ | |
371 | ||
372 | /*****************************************************************************/ | |
373 | /* | |
374 | * the filesystem group ID changed | |
375 | */ | |
376 | void key_fsgid_changed(struct task_struct *tsk) | |
377 | { | |
378 | /* update the ownership of the thread keyring */ | |
379 | if (tsk->thread_keyring) { | |
380 | down_write(&tsk->thread_keyring->sem); | |
1da177e4 | 381 | tsk->thread_keyring->gid = tsk->fsgid; |
1da177e4 LT |
382 | up_write(&tsk->thread_keyring->sem); |
383 | } | |
384 | ||
385 | } /* end key_fsgid_changed() */ | |
386 | ||
387 | /*****************************************************************************/ | |
388 | /* | |
389 | * search the process keyrings for the first matching key | |
390 | * - we use the supplied match function to see if the description (or other | |
391 | * feature of interest) matches | |
392 | * - we return -EAGAIN if we didn't find any matching key | |
393 | * - we return -ENOKEY if we found only negative matching keys | |
394 | */ | |
664cceb0 DH |
395 | key_ref_t search_process_keyrings(struct key_type *type, |
396 | const void *description, | |
397 | key_match_func_t match, | |
398 | struct task_struct *context) | |
1da177e4 | 399 | { |
3e30148c | 400 | struct request_key_auth *rka; |
b5f545c8 | 401 | key_ref_t key_ref, ret, err; |
1da177e4 | 402 | |
04c567d9 DH |
403 | might_sleep(); |
404 | ||
1da177e4 LT |
405 | /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were |
406 | * searchable, but we failed to find a key or we found a negative key; | |
407 | * otherwise we want to return a sample error (probably -EACCES) if | |
408 | * none of the keyrings were searchable | |
409 | * | |
410 | * in terms of priority: success > -ENOKEY > -EAGAIN > other error | |
411 | */ | |
664cceb0 | 412 | key_ref = NULL; |
1da177e4 LT |
413 | ret = NULL; |
414 | err = ERR_PTR(-EAGAIN); | |
415 | ||
416 | /* search the thread keyring first */ | |
3e30148c | 417 | if (context->thread_keyring) { |
664cceb0 DH |
418 | key_ref = keyring_search_aux( |
419 | make_key_ref(context->thread_keyring, 1), | |
420 | context, type, description, match); | |
421 | if (!IS_ERR(key_ref)) | |
1da177e4 LT |
422 | goto found; |
423 | ||
664cceb0 | 424 | switch (PTR_ERR(key_ref)) { |
1da177e4 LT |
425 | case -EAGAIN: /* no key */ |
426 | if (ret) | |
427 | break; | |
428 | case -ENOKEY: /* negative key */ | |
664cceb0 | 429 | ret = key_ref; |
1da177e4 LT |
430 | break; |
431 | default: | |
664cceb0 | 432 | err = key_ref; |
1da177e4 LT |
433 | break; |
434 | } | |
435 | } | |
436 | ||
437 | /* search the process keyring second */ | |
3e30148c | 438 | if (context->signal->process_keyring) { |
664cceb0 DH |
439 | key_ref = keyring_search_aux( |
440 | make_key_ref(context->signal->process_keyring, 1), | |
441 | context, type, description, match); | |
442 | if (!IS_ERR(key_ref)) | |
1da177e4 LT |
443 | goto found; |
444 | ||
664cceb0 | 445 | switch (PTR_ERR(key_ref)) { |
1da177e4 LT |
446 | case -EAGAIN: /* no key */ |
447 | if (ret) | |
448 | break; | |
449 | case -ENOKEY: /* negative key */ | |
664cceb0 | 450 | ret = key_ref; |
1da177e4 LT |
451 | break; |
452 | default: | |
664cceb0 | 453 | err = key_ref; |
1da177e4 LT |
454 | break; |
455 | } | |
456 | } | |
457 | ||
3e30148c DH |
458 | /* search the session keyring */ |
459 | if (context->signal->session_keyring) { | |
8589b4e0 | 460 | rcu_read_lock(); |
664cceb0 DH |
461 | key_ref = keyring_search_aux( |
462 | make_key_ref(rcu_dereference( | |
463 | context->signal->session_keyring), | |
464 | 1), | |
3e30148c | 465 | context, type, description, match); |
8589b4e0 | 466 | rcu_read_unlock(); |
3e30148c | 467 | |
664cceb0 | 468 | if (!IS_ERR(key_ref)) |
3e30148c DH |
469 | goto found; |
470 | ||
664cceb0 | 471 | switch (PTR_ERR(key_ref)) { |
3e30148c DH |
472 | case -EAGAIN: /* no key */ |
473 | if (ret) | |
474 | break; | |
475 | case -ENOKEY: /* negative key */ | |
664cceb0 | 476 | ret = key_ref; |
3e30148c DH |
477 | break; |
478 | default: | |
664cceb0 | 479 | err = key_ref; |
3e30148c DH |
480 | break; |
481 | } | |
b5f545c8 DH |
482 | } |
483 | /* or search the user-session keyring */ | |
484 | else { | |
485 | key_ref = keyring_search_aux( | |
486 | make_key_ref(context->user->session_keyring, 1), | |
487 | context, type, description, match); | |
664cceb0 | 488 | if (!IS_ERR(key_ref)) |
3e30148c DH |
489 | goto found; |
490 | ||
664cceb0 | 491 | switch (PTR_ERR(key_ref)) { |
3e30148c DH |
492 | case -EAGAIN: /* no key */ |
493 | if (ret) | |
494 | break; | |
495 | case -ENOKEY: /* negative key */ | |
664cceb0 | 496 | ret = key_ref; |
3e30148c DH |
497 | break; |
498 | default: | |
664cceb0 | 499 | err = key_ref; |
3e30148c DH |
500 | break; |
501 | } | |
8589b4e0 | 502 | } |
b5f545c8 DH |
503 | |
504 | /* if this process has an instantiation authorisation key, then we also | |
505 | * search the keyrings of the process mentioned there | |
506 | * - we don't permit access to request_key auth keys via this method | |
507 | */ | |
508 | if (context->request_key_auth && | |
509 | context == current && | |
04c567d9 | 510 | type != &key_type_request_key_auth |
b5f545c8 | 511 | ) { |
04c567d9 DH |
512 | /* defend against the auth key being revoked */ |
513 | down_read(&context->request_key_auth->sem); | |
b5f545c8 | 514 | |
04c567d9 DH |
515 | if (key_validate(context->request_key_auth) == 0) { |
516 | rka = context->request_key_auth->payload.data; | |
b5f545c8 | 517 | |
04c567d9 DH |
518 | key_ref = search_process_keyrings(type, description, |
519 | match, rka->context); | |
1da177e4 | 520 | |
04c567d9 DH |
521 | up_read(&context->request_key_auth->sem); |
522 | ||
523 | if (!IS_ERR(key_ref)) | |
524 | goto found; | |
525 | ||
526 | switch (PTR_ERR(key_ref)) { | |
527 | case -EAGAIN: /* no key */ | |
528 | if (ret) | |
529 | break; | |
530 | case -ENOKEY: /* negative key */ | |
531 | ret = key_ref; | |
3e30148c | 532 | break; |
04c567d9 DH |
533 | default: |
534 | err = key_ref; | |
535 | break; | |
536 | } | |
537 | } else { | |
538 | up_read(&context->request_key_auth->sem); | |
3e30148c | 539 | } |
1da177e4 LT |
540 | } |
541 | ||
542 | /* no key - decide on the error we're going to go for */ | |
664cceb0 | 543 | key_ref = ret ? ret : err; |
1da177e4 | 544 | |
3e30148c | 545 | found: |
664cceb0 | 546 | return key_ref; |
1da177e4 | 547 | |
1da177e4 LT |
548 | } /* end search_process_keyrings() */ |
549 | ||
664cceb0 DH |
550 | /*****************************************************************************/ |
551 | /* | |
552 | * see if the key we're looking at is the target key | |
553 | */ | |
554 | static int lookup_user_key_possessed(const struct key *key, const void *target) | |
555 | { | |
556 | return key == target; | |
557 | ||
558 | } /* end lookup_user_key_possessed() */ | |
559 | ||
1da177e4 LT |
560 | /*****************************************************************************/ |
561 | /* | |
562 | * lookup a key given a key ID from userspace with a given permissions mask | |
563 | * - don't create special keyrings unless so requested | |
564 | * - partially constructed keys aren't found unless requested | |
565 | */ | |
664cceb0 DH |
566 | key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, |
567 | int create, int partial, key_perm_t perm) | |
1da177e4 | 568 | { |
664cceb0 | 569 | key_ref_t key_ref, skey_ref; |
1da177e4 LT |
570 | struct key *key; |
571 | int ret; | |
572 | ||
3e30148c DH |
573 | if (!context) |
574 | context = current; | |
575 | ||
664cceb0 | 576 | key_ref = ERR_PTR(-ENOKEY); |
1da177e4 LT |
577 | |
578 | switch (id) { | |
579 | case KEY_SPEC_THREAD_KEYRING: | |
3e30148c | 580 | if (!context->thread_keyring) { |
1da177e4 LT |
581 | if (!create) |
582 | goto error; | |
583 | ||
3e30148c | 584 | ret = install_thread_keyring(context); |
1da177e4 LT |
585 | if (ret < 0) { |
586 | key = ERR_PTR(ret); | |
587 | goto error; | |
588 | } | |
589 | } | |
590 | ||
3e30148c | 591 | key = context->thread_keyring; |
1da177e4 | 592 | atomic_inc(&key->usage); |
664cceb0 | 593 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
594 | break; |
595 | ||
596 | case KEY_SPEC_PROCESS_KEYRING: | |
3e30148c | 597 | if (!context->signal->process_keyring) { |
1da177e4 LT |
598 | if (!create) |
599 | goto error; | |
600 | ||
3e30148c | 601 | ret = install_process_keyring(context); |
1da177e4 LT |
602 | if (ret < 0) { |
603 | key = ERR_PTR(ret); | |
604 | goto error; | |
605 | } | |
606 | } | |
607 | ||
3e30148c | 608 | key = context->signal->process_keyring; |
1da177e4 | 609 | atomic_inc(&key->usage); |
664cceb0 | 610 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
611 | break; |
612 | ||
613 | case KEY_SPEC_SESSION_KEYRING: | |
3e30148c | 614 | if (!context->signal->session_keyring) { |
1da177e4 LT |
615 | /* always install a session keyring upon access if one |
616 | * doesn't exist yet */ | |
617 | ret = install_session_keyring( | |
664cceb0 | 618 | context, context->user->session_keyring); |
1da177e4 LT |
619 | if (ret < 0) |
620 | goto error; | |
621 | } | |
622 | ||
3e30148c DH |
623 | rcu_read_lock(); |
624 | key = rcu_dereference(context->signal->session_keyring); | |
1da177e4 | 625 | atomic_inc(&key->usage); |
3e30148c | 626 | rcu_read_unlock(); |
664cceb0 | 627 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
628 | break; |
629 | ||
630 | case KEY_SPEC_USER_KEYRING: | |
3e30148c | 631 | key = context->user->uid_keyring; |
1da177e4 | 632 | atomic_inc(&key->usage); |
664cceb0 | 633 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
634 | break; |
635 | ||
636 | case KEY_SPEC_USER_SESSION_KEYRING: | |
3e30148c | 637 | key = context->user->session_keyring; |
1da177e4 | 638 | atomic_inc(&key->usage); |
664cceb0 | 639 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
640 | break; |
641 | ||
642 | case KEY_SPEC_GROUP_KEYRING: | |
643 | /* group keyrings are not yet supported */ | |
644 | key = ERR_PTR(-EINVAL); | |
645 | goto error; | |
646 | ||
b5f545c8 DH |
647 | case KEY_SPEC_REQKEY_AUTH_KEY: |
648 | key = context->request_key_auth; | |
649 | if (!key) | |
650 | goto error; | |
651 | ||
652 | atomic_inc(&key->usage); | |
653 | key_ref = make_key_ref(key, 1); | |
654 | break; | |
655 | ||
1da177e4 | 656 | default: |
664cceb0 | 657 | key_ref = ERR_PTR(-EINVAL); |
1da177e4 LT |
658 | if (id < 1) |
659 | goto error; | |
660 | ||
661 | key = key_lookup(id); | |
664cceb0 DH |
662 | if (IS_ERR(key)) { |
663 | key_ref = ERR_PTR(PTR_ERR(key)); | |
1da177e4 | 664 | goto error; |
664cceb0 DH |
665 | } |
666 | ||
667 | key_ref = make_key_ref(key, 0); | |
668 | ||
669 | /* check to see if we possess the key */ | |
670 | skey_ref = search_process_keyrings(key->type, key, | |
671 | lookup_user_key_possessed, | |
672 | current); | |
673 | ||
674 | if (!IS_ERR(skey_ref)) { | |
675 | key_put(key); | |
676 | key_ref = skey_ref; | |
677 | } | |
678 | ||
1da177e4 LT |
679 | break; |
680 | } | |
681 | ||
3e30148c | 682 | /* check the status */ |
1da177e4 LT |
683 | if (perm) { |
684 | ret = key_validate(key); | |
685 | if (ret < 0) | |
686 | goto invalid_key; | |
687 | } | |
688 | ||
689 | ret = -EIO; | |
76d8aeab | 690 | if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
1da177e4 LT |
691 | goto invalid_key; |
692 | ||
3e30148c | 693 | /* check the permissions */ |
29db9190 DH |
694 | ret = key_task_permission(key_ref, context, perm); |
695 | if (ret < 0) | |
1da177e4 LT |
696 | goto invalid_key; |
697 | ||
664cceb0 DH |
698 | error: |
699 | return key_ref; | |
1da177e4 | 700 | |
664cceb0 DH |
701 | invalid_key: |
702 | key_ref_put(key_ref); | |
703 | key_ref = ERR_PTR(ret); | |
1da177e4 LT |
704 | goto error; |
705 | ||
706 | } /* end lookup_user_key() */ | |
707 | ||
708 | /*****************************************************************************/ | |
709 | /* | |
710 | * join the named keyring as the session keyring if possible, or attempt to | |
711 | * create a new one of that name if not | |
712 | * - if the name is NULL, an empty anonymous keyring is installed instead | |
713 | * - named session keyring joining is done with a semaphore held | |
714 | */ | |
715 | long join_session_keyring(const char *name) | |
716 | { | |
717 | struct task_struct *tsk = current; | |
1da177e4 LT |
718 | struct key *keyring; |
719 | long ret; | |
720 | ||
721 | /* if no name is provided, install an anonymous keyring */ | |
722 | if (!name) { | |
723 | ret = install_session_keyring(tsk, NULL); | |
724 | if (ret < 0) | |
725 | goto error; | |
726 | ||
3e30148c DH |
727 | rcu_read_lock(); |
728 | ret = rcu_dereference(tsk->signal->session_keyring)->serial; | |
729 | rcu_read_unlock(); | |
1da177e4 LT |
730 | goto error; |
731 | } | |
732 | ||
733 | /* allow the user to join or create a named keyring */ | |
bb003079 | 734 | mutex_lock(&key_session_mutex); |
1da177e4 LT |
735 | |
736 | /* look for an existing keyring of this name */ | |
737 | keyring = find_keyring_by_name(name, 0); | |
738 | if (PTR_ERR(keyring) == -ENOKEY) { | |
739 | /* not found - try and create a new one */ | |
7e047ef5 DH |
740 | keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk, |
741 | KEY_ALLOC_IN_QUOTA, NULL); | |
1da177e4 LT |
742 | if (IS_ERR(keyring)) { |
743 | ret = PTR_ERR(keyring); | |
bcf945d3 | 744 | goto error2; |
1da177e4 LT |
745 | } |
746 | } | |
747 | else if (IS_ERR(keyring)) { | |
748 | ret = PTR_ERR(keyring); | |
749 | goto error2; | |
750 | } | |
751 | ||
752 | /* we've got a keyring - now to install it */ | |
753 | ret = install_session_keyring(tsk, keyring); | |
754 | if (ret < 0) | |
755 | goto error2; | |
756 | ||
757 | ret = keyring->serial; | |
758 | key_put(keyring); | |
759 | ||
664cceb0 | 760 | error2: |
bb003079 | 761 | mutex_unlock(&key_session_mutex); |
664cceb0 | 762 | error: |
1da177e4 LT |
763 | return ret; |
764 | ||
765 | } /* end join_session_keyring() */ |