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 | ||
1da177e4 LT |
192 | if (!tsk->signal->process_keyring) { |
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 */ |
1a26feb9 | 203 | spin_lock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
204 | if (!tsk->signal->process_keyring) { |
205 | tsk->signal->process_keyring = keyring; | |
206 | keyring = NULL; | |
207 | } | |
1a26feb9 | 208 | spin_unlock_irq(&tsk->sighand->siglock); |
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 DH |
237 | flags = KEY_ALLOC_QUOTA_OVERRUN; |
238 | if (tsk->signal->session_keyring) | |
239 | flags = KEY_ALLOC_IN_QUOTA; | |
240 | ||
b6dff3ec | 241 | keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk, |
7e047ef5 | 242 | 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 */ | |
1a26feb9 DH |
251 | spin_lock_irq(&tsk->sighand->siglock); |
252 | old = tsk->signal->session_keyring; | |
8589b4e0 | 253 | rcu_assign_pointer(tsk->signal->session_keyring, keyring); |
1a26feb9 | 254 | spin_unlock_irq(&tsk->sighand->siglock); |
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 | ||
267 | /*****************************************************************************/ | |
268 | /* | |
269 | * copy the keys in a thread group for fork without CLONE_THREAD | |
270 | */ | |
271 | int copy_thread_group_keys(struct task_struct *tsk) | |
272 | { | |
1da177e4 LT |
273 | key_check(current->thread_group->session_keyring); |
274 | key_check(current->thread_group->process_keyring); | |
275 | ||
276 | /* no process keyring yet */ | |
277 | tsk->signal->process_keyring = NULL; | |
278 | ||
279 | /* same session keyring */ | |
8589b4e0 | 280 | rcu_read_lock(); |
1da177e4 | 281 | tsk->signal->session_keyring = |
8589b4e0 DH |
282 | key_get(rcu_dereference(current->signal->session_keyring)); |
283 | rcu_read_unlock(); | |
1da177e4 LT |
284 | |
285 | return 0; | |
286 | ||
287 | } /* end copy_thread_group_keys() */ | |
288 | ||
289 | /*****************************************************************************/ | |
290 | /* | |
291 | * copy the keys for fork | |
292 | */ | |
293 | int copy_keys(unsigned long clone_flags, struct task_struct *tsk) | |
294 | { | |
b6dff3ec DH |
295 | key_check(tsk->cred->thread_keyring); |
296 | key_check(tsk->cred->request_key_auth); | |
1da177e4 LT |
297 | |
298 | /* no thread keyring yet */ | |
b6dff3ec | 299 | tsk->cred->thread_keyring = NULL; |
b5f545c8 DH |
300 | |
301 | /* copy the request_key() authorisation for this thread */ | |
b6dff3ec | 302 | key_get(tsk->cred->request_key_auth); |
b5f545c8 | 303 | |
1da177e4 LT |
304 | return 0; |
305 | ||
306 | } /* end copy_keys() */ | |
307 | ||
308 | /*****************************************************************************/ | |
309 | /* | |
310 | * dispose of thread group keys upon thread group destruction | |
311 | */ | |
312 | void exit_thread_group_keys(struct signal_struct *tg) | |
313 | { | |
314 | key_put(tg->session_keyring); | |
315 | key_put(tg->process_keyring); | |
316 | ||
317 | } /* end exit_thread_group_keys() */ | |
318 | ||
319 | /*****************************************************************************/ | |
320 | /* | |
b5f545c8 | 321 | * dispose of per-thread keys upon thread exit |
1da177e4 LT |
322 | */ |
323 | void exit_keys(struct task_struct *tsk) | |
324 | { | |
b6dff3ec DH |
325 | key_put(tsk->cred->thread_keyring); |
326 | key_put(tsk->cred->request_key_auth); | |
1da177e4 LT |
327 | |
328 | } /* end exit_keys() */ | |
329 | ||
330 | /*****************************************************************************/ | |
331 | /* | |
332 | * deal with execve() | |
333 | */ | |
334 | int exec_keys(struct task_struct *tsk) | |
335 | { | |
1da177e4 LT |
336 | struct key *old; |
337 | ||
338 | /* newly exec'd tasks don't get a thread keyring */ | |
339 | task_lock(tsk); | |
b6dff3ec DH |
340 | old = tsk->cred->thread_keyring; |
341 | tsk->cred->thread_keyring = NULL; | |
1da177e4 LT |
342 | task_unlock(tsk); |
343 | ||
344 | key_put(old); | |
345 | ||
346 | /* discard the process keyring from a newly exec'd task */ | |
1a26feb9 | 347 | spin_lock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
348 | old = tsk->signal->process_keyring; |
349 | tsk->signal->process_keyring = NULL; | |
1a26feb9 | 350 | spin_unlock_irq(&tsk->sighand->siglock); |
1da177e4 LT |
351 | |
352 | key_put(old); | |
353 | ||
354 | return 0; | |
355 | ||
356 | } /* end exec_keys() */ | |
357 | ||
358 | /*****************************************************************************/ | |
359 | /* | |
360 | * deal with SUID programs | |
361 | * - we might want to make this invent a new session keyring | |
362 | */ | |
363 | int suid_keys(struct task_struct *tsk) | |
364 | { | |
365 | return 0; | |
366 | ||
367 | } /* end suid_keys() */ | |
368 | ||
369 | /*****************************************************************************/ | |
370 | /* | |
371 | * the filesystem user ID changed | |
372 | */ | |
373 | void key_fsuid_changed(struct task_struct *tsk) | |
374 | { | |
375 | /* update the ownership of the thread keyring */ | |
b6dff3ec DH |
376 | BUG_ON(!tsk->cred); |
377 | if (tsk->cred->thread_keyring) { | |
378 | down_write(&tsk->cred->thread_keyring->sem); | |
379 | tsk->cred->thread_keyring->uid = tsk->cred->fsuid; | |
380 | up_write(&tsk->cred->thread_keyring->sem); | |
1da177e4 LT |
381 | } |
382 | ||
383 | } /* end key_fsuid_changed() */ | |
384 | ||
385 | /*****************************************************************************/ | |
386 | /* | |
387 | * the filesystem group ID changed | |
388 | */ | |
389 | void key_fsgid_changed(struct task_struct *tsk) | |
390 | { | |
391 | /* update the ownership of the thread keyring */ | |
b6dff3ec DH |
392 | BUG_ON(!tsk->cred); |
393 | if (tsk->cred->thread_keyring) { | |
394 | down_write(&tsk->cred->thread_keyring->sem); | |
395 | tsk->cred->thread_keyring->gid = tsk->cred->fsgid; | |
396 | up_write(&tsk->cred->thread_keyring->sem); | |
1da177e4 LT |
397 | } |
398 | ||
399 | } /* end key_fsgid_changed() */ | |
400 | ||
401 | /*****************************************************************************/ | |
402 | /* | |
403 | * search the process keyrings for the first matching key | |
404 | * - we use the supplied match function to see if the description (or other | |
405 | * feature of interest) matches | |
406 | * - we return -EAGAIN if we didn't find any matching key | |
407 | * - we return -ENOKEY if we found only negative matching keys | |
408 | */ | |
664cceb0 DH |
409 | key_ref_t search_process_keyrings(struct key_type *type, |
410 | const void *description, | |
411 | key_match_func_t match, | |
412 | struct task_struct *context) | |
1da177e4 | 413 | { |
3e30148c | 414 | struct request_key_auth *rka; |
c69e8d9c | 415 | struct cred *cred; |
b5f545c8 | 416 | key_ref_t key_ref, ret, err; |
1da177e4 | 417 | |
04c567d9 DH |
418 | might_sleep(); |
419 | ||
c69e8d9c DH |
420 | cred = get_task_cred(context); |
421 | ||
1da177e4 LT |
422 | /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were |
423 | * searchable, but we failed to find a key or we found a negative key; | |
424 | * otherwise we want to return a sample error (probably -EACCES) if | |
425 | * none of the keyrings were searchable | |
426 | * | |
427 | * in terms of priority: success > -ENOKEY > -EAGAIN > other error | |
428 | */ | |
664cceb0 | 429 | key_ref = NULL; |
1da177e4 LT |
430 | ret = NULL; |
431 | err = ERR_PTR(-EAGAIN); | |
432 | ||
433 | /* search the thread keyring first */ | |
c69e8d9c | 434 | if (cred->thread_keyring) { |
664cceb0 | 435 | key_ref = keyring_search_aux( |
c69e8d9c | 436 | make_key_ref(cred->thread_keyring, 1), |
664cceb0 DH |
437 | context, type, description, match); |
438 | if (!IS_ERR(key_ref)) | |
1da177e4 LT |
439 | goto found; |
440 | ||
664cceb0 | 441 | switch (PTR_ERR(key_ref)) { |
1da177e4 LT |
442 | case -EAGAIN: /* no key */ |
443 | if (ret) | |
444 | break; | |
445 | case -ENOKEY: /* negative key */ | |
664cceb0 | 446 | ret = key_ref; |
1da177e4 LT |
447 | break; |
448 | default: | |
664cceb0 | 449 | err = key_ref; |
1da177e4 LT |
450 | break; |
451 | } | |
452 | } | |
453 | ||
454 | /* search the process keyring second */ | |
3e30148c | 455 | if (context->signal->process_keyring) { |
664cceb0 DH |
456 | key_ref = keyring_search_aux( |
457 | make_key_ref(context->signal->process_keyring, 1), | |
458 | context, type, description, match); | |
459 | if (!IS_ERR(key_ref)) | |
1da177e4 LT |
460 | goto found; |
461 | ||
664cceb0 | 462 | switch (PTR_ERR(key_ref)) { |
1da177e4 LT |
463 | case -EAGAIN: /* no key */ |
464 | if (ret) | |
465 | break; | |
466 | case -ENOKEY: /* negative key */ | |
664cceb0 | 467 | ret = key_ref; |
1da177e4 LT |
468 | break; |
469 | default: | |
664cceb0 | 470 | err = key_ref; |
1da177e4 LT |
471 | break; |
472 | } | |
473 | } | |
474 | ||
3e30148c DH |
475 | /* search the session keyring */ |
476 | if (context->signal->session_keyring) { | |
8589b4e0 | 477 | rcu_read_lock(); |
664cceb0 DH |
478 | key_ref = keyring_search_aux( |
479 | make_key_ref(rcu_dereference( | |
480 | context->signal->session_keyring), | |
481 | 1), | |
3e30148c | 482 | context, type, description, match); |
8589b4e0 | 483 | rcu_read_unlock(); |
3e30148c | 484 | |
664cceb0 | 485 | if (!IS_ERR(key_ref)) |
3e30148c DH |
486 | goto found; |
487 | ||
664cceb0 | 488 | switch (PTR_ERR(key_ref)) { |
3e30148c DH |
489 | case -EAGAIN: /* no key */ |
490 | if (ret) | |
491 | break; | |
492 | case -ENOKEY: /* negative key */ | |
664cceb0 | 493 | ret = key_ref; |
3e30148c DH |
494 | break; |
495 | default: | |
664cceb0 | 496 | err = key_ref; |
3e30148c DH |
497 | break; |
498 | } | |
b5f545c8 DH |
499 | } |
500 | /* or search the user-session keyring */ | |
c69e8d9c | 501 | else if (cred->user->session_keyring) { |
b5f545c8 | 502 | key_ref = keyring_search_aux( |
c69e8d9c | 503 | make_key_ref(cred->user->session_keyring, 1), |
b5f545c8 | 504 | context, type, description, match); |
664cceb0 | 505 | if (!IS_ERR(key_ref)) |
3e30148c DH |
506 | goto found; |
507 | ||
664cceb0 | 508 | switch (PTR_ERR(key_ref)) { |
3e30148c DH |
509 | case -EAGAIN: /* no key */ |
510 | if (ret) | |
511 | break; | |
512 | case -ENOKEY: /* negative key */ | |
664cceb0 | 513 | ret = key_ref; |
3e30148c DH |
514 | break; |
515 | default: | |
664cceb0 | 516 | err = key_ref; |
3e30148c DH |
517 | break; |
518 | } | |
8589b4e0 | 519 | } |
b5f545c8 DH |
520 | |
521 | /* if this process has an instantiation authorisation key, then we also | |
522 | * search the keyrings of the process mentioned there | |
523 | * - we don't permit access to request_key auth keys via this method | |
524 | */ | |
c69e8d9c | 525 | if (cred->request_key_auth && |
b5f545c8 | 526 | context == current && |
04c567d9 | 527 | type != &key_type_request_key_auth |
b5f545c8 | 528 | ) { |
04c567d9 | 529 | /* defend against the auth key being revoked */ |
c69e8d9c | 530 | down_read(&cred->request_key_auth->sem); |
b5f545c8 | 531 | |
c69e8d9c DH |
532 | if (key_validate(cred->request_key_auth) == 0) { |
533 | rka = cred->request_key_auth->payload.data; | |
b5f545c8 | 534 | |
04c567d9 DH |
535 | key_ref = search_process_keyrings(type, description, |
536 | match, rka->context); | |
1da177e4 | 537 | |
c69e8d9c | 538 | up_read(&cred->request_key_auth->sem); |
04c567d9 DH |
539 | |
540 | if (!IS_ERR(key_ref)) | |
541 | goto found; | |
542 | ||
543 | switch (PTR_ERR(key_ref)) { | |
544 | case -EAGAIN: /* no key */ | |
545 | if (ret) | |
546 | break; | |
547 | case -ENOKEY: /* negative key */ | |
548 | ret = key_ref; | |
3e30148c | 549 | break; |
04c567d9 DH |
550 | default: |
551 | err = key_ref; | |
552 | break; | |
553 | } | |
554 | } else { | |
c69e8d9c | 555 | up_read(&cred->request_key_auth->sem); |
3e30148c | 556 | } |
1da177e4 LT |
557 | } |
558 | ||
559 | /* no key - decide on the error we're going to go for */ | |
664cceb0 | 560 | key_ref = ret ? ret : err; |
1da177e4 | 561 | |
3e30148c | 562 | found: |
c69e8d9c | 563 | put_cred(cred); |
664cceb0 | 564 | return key_ref; |
1da177e4 | 565 | |
1da177e4 LT |
566 | } /* end search_process_keyrings() */ |
567 | ||
664cceb0 DH |
568 | /*****************************************************************************/ |
569 | /* | |
570 | * see if the key we're looking at is the target key | |
571 | */ | |
572 | static int lookup_user_key_possessed(const struct key *key, const void *target) | |
573 | { | |
574 | return key == target; | |
575 | ||
576 | } /* end lookup_user_key_possessed() */ | |
577 | ||
1da177e4 LT |
578 | /*****************************************************************************/ |
579 | /* | |
580 | * lookup a key given a key ID from userspace with a given permissions mask | |
581 | * - don't create special keyrings unless so requested | |
582 | * - partially constructed keys aren't found unless requested | |
583 | */ | |
8bbf4976 DH |
584 | key_ref_t lookup_user_key(key_serial_t id, int create, int partial, |
585 | key_perm_t perm) | |
1da177e4 | 586 | { |
8bbf4976 DH |
587 | struct request_key_auth *rka; |
588 | struct task_struct *t = current; | |
86a264ab | 589 | struct cred *cred = current_cred(); |
1da177e4 | 590 | struct key *key; |
b6dff3ec | 591 | key_ref_t key_ref, skey_ref; |
1da177e4 LT |
592 | int ret; |
593 | ||
664cceb0 | 594 | key_ref = ERR_PTR(-ENOKEY); |
1da177e4 LT |
595 | |
596 | switch (id) { | |
597 | case KEY_SPEC_THREAD_KEYRING: | |
b6dff3ec | 598 | if (!cred->thread_keyring) { |
1da177e4 LT |
599 | if (!create) |
600 | goto error; | |
601 | ||
8bbf4976 | 602 | ret = install_thread_keyring(); |
1da177e4 LT |
603 | if (ret < 0) { |
604 | key = ERR_PTR(ret); | |
605 | goto error; | |
606 | } | |
607 | } | |
608 | ||
b6dff3ec | 609 | key = cred->thread_keyring; |
1da177e4 | 610 | atomic_inc(&key->usage); |
664cceb0 | 611 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
612 | break; |
613 | ||
614 | case KEY_SPEC_PROCESS_KEYRING: | |
8bbf4976 | 615 | if (!t->signal->process_keyring) { |
1da177e4 LT |
616 | if (!create) |
617 | goto error; | |
618 | ||
8bbf4976 | 619 | ret = install_process_keyring(); |
1da177e4 LT |
620 | if (ret < 0) { |
621 | key = ERR_PTR(ret); | |
622 | goto error; | |
623 | } | |
624 | } | |
625 | ||
8bbf4976 | 626 | key = t->signal->process_keyring; |
1da177e4 | 627 | atomic_inc(&key->usage); |
664cceb0 | 628 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
629 | break; |
630 | ||
631 | case KEY_SPEC_SESSION_KEYRING: | |
8bbf4976 | 632 | if (!t->signal->session_keyring) { |
1da177e4 LT |
633 | /* always install a session keyring upon access if one |
634 | * doesn't exist yet */ | |
8bbf4976 | 635 | ret = install_user_keyrings(); |
69664cf1 DH |
636 | if (ret < 0) |
637 | goto error; | |
b6dff3ec DH |
638 | ret = install_session_keyring( |
639 | cred->user->session_keyring); | |
1da177e4 LT |
640 | if (ret < 0) |
641 | goto error; | |
642 | } | |
643 | ||
3e30148c | 644 | rcu_read_lock(); |
8bbf4976 | 645 | key = rcu_dereference(t->signal->session_keyring); |
1da177e4 | 646 | atomic_inc(&key->usage); |
3e30148c | 647 | rcu_read_unlock(); |
664cceb0 | 648 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
649 | break; |
650 | ||
651 | case KEY_SPEC_USER_KEYRING: | |
b6dff3ec | 652 | if (!cred->user->uid_keyring) { |
8bbf4976 | 653 | ret = install_user_keyrings(); |
69664cf1 DH |
654 | if (ret < 0) |
655 | goto error; | |
656 | } | |
657 | ||
b6dff3ec | 658 | key = cred->user->uid_keyring; |
1da177e4 | 659 | atomic_inc(&key->usage); |
664cceb0 | 660 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
661 | break; |
662 | ||
663 | case KEY_SPEC_USER_SESSION_KEYRING: | |
b6dff3ec | 664 | if (!cred->user->session_keyring) { |
8bbf4976 | 665 | ret = install_user_keyrings(); |
69664cf1 DH |
666 | if (ret < 0) |
667 | goto error; | |
668 | } | |
669 | ||
b6dff3ec | 670 | key = cred->user->session_keyring; |
1da177e4 | 671 | atomic_inc(&key->usage); |
664cceb0 | 672 | key_ref = make_key_ref(key, 1); |
1da177e4 LT |
673 | break; |
674 | ||
675 | case KEY_SPEC_GROUP_KEYRING: | |
676 | /* group keyrings are not yet supported */ | |
677 | key = ERR_PTR(-EINVAL); | |
678 | goto error; | |
679 | ||
b5f545c8 | 680 | case KEY_SPEC_REQKEY_AUTH_KEY: |
b6dff3ec | 681 | key = cred->request_key_auth; |
b5f545c8 DH |
682 | if (!key) |
683 | goto error; | |
684 | ||
685 | atomic_inc(&key->usage); | |
686 | key_ref = make_key_ref(key, 1); | |
687 | break; | |
688 | ||
8bbf4976 | 689 | case KEY_SPEC_REQUESTOR_KEYRING: |
b6dff3ec | 690 | if (!cred->request_key_auth) |
8bbf4976 DH |
691 | goto error; |
692 | ||
b6dff3ec DH |
693 | down_read(&cred->request_key_auth->sem); |
694 | if (cred->request_key_auth->flags & KEY_FLAG_REVOKED) { | |
8bbf4976 DH |
695 | key_ref = ERR_PTR(-EKEYREVOKED); |
696 | key = NULL; | |
697 | } else { | |
b6dff3ec | 698 | rka = cred->request_key_auth->payload.data; |
8bbf4976 DH |
699 | key = rka->dest_keyring; |
700 | atomic_inc(&key->usage); | |
701 | } | |
b6dff3ec | 702 | up_read(&cred->request_key_auth->sem); |
8bbf4976 DH |
703 | if (!key) |
704 | goto error; | |
705 | key_ref = make_key_ref(key, 1); | |
706 | break; | |
707 | ||
1da177e4 | 708 | default: |
664cceb0 | 709 | key_ref = ERR_PTR(-EINVAL); |
1da177e4 LT |
710 | if (id < 1) |
711 | goto error; | |
712 | ||
713 | key = key_lookup(id); | |
664cceb0 | 714 | if (IS_ERR(key)) { |
e231c2ee | 715 | key_ref = ERR_CAST(key); |
1da177e4 | 716 | goto error; |
664cceb0 DH |
717 | } |
718 | ||
719 | key_ref = make_key_ref(key, 0); | |
720 | ||
721 | /* check to see if we possess the key */ | |
722 | skey_ref = search_process_keyrings(key->type, key, | |
723 | lookup_user_key_possessed, | |
724 | current); | |
725 | ||
726 | if (!IS_ERR(skey_ref)) { | |
727 | key_put(key); | |
728 | key_ref = skey_ref; | |
729 | } | |
730 | ||
1da177e4 LT |
731 | break; |
732 | } | |
733 | ||
76181c13 DH |
734 | if (!partial) { |
735 | ret = wait_for_key_construction(key, true); | |
736 | switch (ret) { | |
737 | case -ERESTARTSYS: | |
738 | goto invalid_key; | |
739 | default: | |
740 | if (perm) | |
741 | goto invalid_key; | |
742 | case 0: | |
743 | break; | |
744 | } | |
745 | } else if (perm) { | |
1da177e4 LT |
746 | ret = key_validate(key); |
747 | if (ret < 0) | |
748 | goto invalid_key; | |
749 | } | |
750 | ||
751 | ret = -EIO; | |
76d8aeab | 752 | if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
1da177e4 LT |
753 | goto invalid_key; |
754 | ||
3e30148c | 755 | /* check the permissions */ |
8bbf4976 | 756 | ret = key_task_permission(key_ref, t, perm); |
29db9190 | 757 | if (ret < 0) |
1da177e4 LT |
758 | goto invalid_key; |
759 | ||
664cceb0 DH |
760 | error: |
761 | return key_ref; | |
1da177e4 | 762 | |
664cceb0 DH |
763 | invalid_key: |
764 | key_ref_put(key_ref); | |
765 | key_ref = ERR_PTR(ret); | |
1da177e4 LT |
766 | goto error; |
767 | ||
768 | } /* end lookup_user_key() */ | |
769 | ||
770 | /*****************************************************************************/ | |
771 | /* | |
772 | * join the named keyring as the session keyring if possible, or attempt to | |
773 | * create a new one of that name if not | |
774 | * - if the name is NULL, an empty anonymous keyring is installed instead | |
775 | * - named session keyring joining is done with a semaphore held | |
776 | */ | |
777 | long join_session_keyring(const char *name) | |
778 | { | |
779 | struct task_struct *tsk = current; | |
1da177e4 LT |
780 | struct key *keyring; |
781 | long ret; | |
782 | ||
783 | /* if no name is provided, install an anonymous keyring */ | |
784 | if (!name) { | |
8bbf4976 | 785 | ret = install_session_keyring(NULL); |
1da177e4 LT |
786 | if (ret < 0) |
787 | goto error; | |
788 | ||
3e30148c DH |
789 | rcu_read_lock(); |
790 | ret = rcu_dereference(tsk->signal->session_keyring)->serial; | |
791 | rcu_read_unlock(); | |
1da177e4 LT |
792 | goto error; |
793 | } | |
794 | ||
795 | /* allow the user to join or create a named keyring */ | |
bb003079 | 796 | mutex_lock(&key_session_mutex); |
1da177e4 LT |
797 | |
798 | /* look for an existing keyring of this name */ | |
69664cf1 | 799 | keyring = find_keyring_by_name(name, false); |
1da177e4 LT |
800 | if (PTR_ERR(keyring) == -ENOKEY) { |
801 | /* not found - try and create a new one */ | |
b6dff3ec | 802 | keyring = keyring_alloc(name, tsk->cred->uid, tsk->cred->gid, tsk, |
7e047ef5 | 803 | KEY_ALLOC_IN_QUOTA, NULL); |
1da177e4 LT |
804 | if (IS_ERR(keyring)) { |
805 | ret = PTR_ERR(keyring); | |
bcf945d3 | 806 | goto error2; |
1da177e4 LT |
807 | } |
808 | } | |
809 | else if (IS_ERR(keyring)) { | |
810 | ret = PTR_ERR(keyring); | |
811 | goto error2; | |
812 | } | |
813 | ||
814 | /* we've got a keyring - now to install it */ | |
8bbf4976 | 815 | ret = install_session_keyring(keyring); |
1da177e4 LT |
816 | if (ret < 0) |
817 | goto error2; | |
818 | ||
819 | ret = keyring->serial; | |
820 | key_put(keyring); | |
821 | ||
664cceb0 | 822 | error2: |
bb003079 | 823 | mutex_unlock(&key_session_mutex); |
664cceb0 | 824 | error: |
1da177e4 LT |
825 | return ret; |
826 | ||
827 | } /* end join_session_keyring() */ |