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76181c13 | 1 | /* Basic authentication token and access key management |
1da177e4 | 2 | * |
69664cf1 | 3 | * Copyright (C) 2004-2008 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> | |
a7807a32 | 14 | #include <linux/poison.h> |
1da177e4 LT |
15 | #include <linux/sched.h> |
16 | #include <linux/slab.h> | |
29db9190 | 17 | #include <linux/security.h> |
1da177e4 | 18 | #include <linux/workqueue.h> |
e51f6d34 | 19 | #include <linux/random.h> |
1da177e4 | 20 | #include <linux/err.h> |
1d1e9756 | 21 | #include <linux/user_namespace.h> |
1da177e4 LT |
22 | #include "internal.h" |
23 | ||
e18b890b | 24 | static struct kmem_cache *key_jar; |
1da177e4 LT |
25 | struct rb_root key_serial_tree; /* tree of keys indexed by serial */ |
26 | DEFINE_SPINLOCK(key_serial_lock); | |
27 | ||
28 | struct rb_root key_user_tree; /* tree of quota records indexed by UID */ | |
29 | DEFINE_SPINLOCK(key_user_lock); | |
30 | ||
0b77f5bf DH |
31 | unsigned int key_quota_root_maxkeys = 200; /* root's key count quota */ |
32 | unsigned int key_quota_root_maxbytes = 20000; /* root's key space quota */ | |
33 | unsigned int key_quota_maxkeys = 200; /* general key count quota */ | |
34 | unsigned int key_quota_maxbytes = 20000; /* general key space quota */ | |
35 | ||
1da177e4 LT |
36 | static LIST_HEAD(key_types_list); |
37 | static DECLARE_RWSEM(key_types_sem); | |
38 | ||
65f27f38 DH |
39 | static void key_cleanup(struct work_struct *work); |
40 | static DECLARE_WORK(key_cleanup_task, key_cleanup); | |
1da177e4 | 41 | |
973c9f4f | 42 | /* We serialise key instantiation and link */ |
76181c13 | 43 | DEFINE_MUTEX(key_construction_mutex); |
1da177e4 | 44 | |
973c9f4f | 45 | /* Any key who's type gets unegistered will be re-typed to this */ |
1ae8f407 | 46 | static struct key_type key_type_dead = { |
1da177e4 LT |
47 | .name = "dead", |
48 | }; | |
49 | ||
50 | #ifdef KEY_DEBUGGING | |
51 | void __key_check(const struct key *key) | |
52 | { | |
53 | printk("__key_check: key %p {%08x} should be {%08x}\n", | |
54 | key, key->magic, KEY_DEBUG_MAGIC); | |
55 | BUG(); | |
56 | } | |
57 | #endif | |
58 | ||
1da177e4 | 59 | /* |
973c9f4f DH |
60 | * Get the key quota record for a user, allocating a new record if one doesn't |
61 | * already exist. | |
1da177e4 | 62 | */ |
1d1e9756 | 63 | struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns) |
1da177e4 LT |
64 | { |
65 | struct key_user *candidate = NULL, *user; | |
66 | struct rb_node *parent = NULL; | |
67 | struct rb_node **p; | |
68 | ||
973c9f4f | 69 | try_again: |
1da177e4 LT |
70 | p = &key_user_tree.rb_node; |
71 | spin_lock(&key_user_lock); | |
72 | ||
73 | /* search the tree for a user record with a matching UID */ | |
74 | while (*p) { | |
75 | parent = *p; | |
76 | user = rb_entry(parent, struct key_user, node); | |
77 | ||
78 | if (uid < user->uid) | |
79 | p = &(*p)->rb_left; | |
80 | else if (uid > user->uid) | |
81 | p = &(*p)->rb_right; | |
1d1e9756 SH |
82 | else if (user_ns < user->user_ns) |
83 | p = &(*p)->rb_left; | |
84 | else if (user_ns > user->user_ns) | |
85 | p = &(*p)->rb_right; | |
1da177e4 LT |
86 | else |
87 | goto found; | |
88 | } | |
89 | ||
90 | /* if we get here, we failed to find a match in the tree */ | |
91 | if (!candidate) { | |
92 | /* allocate a candidate user record if we don't already have | |
93 | * one */ | |
94 | spin_unlock(&key_user_lock); | |
95 | ||
96 | user = NULL; | |
97 | candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); | |
98 | if (unlikely(!candidate)) | |
99 | goto out; | |
100 | ||
101 | /* the allocation may have scheduled, so we need to repeat the | |
102 | * search lest someone else added the record whilst we were | |
103 | * asleep */ | |
104 | goto try_again; | |
105 | } | |
106 | ||
107 | /* if we get here, then the user record still hadn't appeared on the | |
108 | * second pass - so we use the candidate record */ | |
109 | atomic_set(&candidate->usage, 1); | |
110 | atomic_set(&candidate->nkeys, 0); | |
111 | atomic_set(&candidate->nikeys, 0); | |
112 | candidate->uid = uid; | |
1d1e9756 | 113 | candidate->user_ns = get_user_ns(user_ns); |
1da177e4 LT |
114 | candidate->qnkeys = 0; |
115 | candidate->qnbytes = 0; | |
116 | spin_lock_init(&candidate->lock); | |
76181c13 | 117 | mutex_init(&candidate->cons_lock); |
1da177e4 LT |
118 | |
119 | rb_link_node(&candidate->node, parent, p); | |
120 | rb_insert_color(&candidate->node, &key_user_tree); | |
121 | spin_unlock(&key_user_lock); | |
122 | user = candidate; | |
123 | goto out; | |
124 | ||
125 | /* okay - we found a user record for this UID */ | |
973c9f4f | 126 | found: |
1da177e4 LT |
127 | atomic_inc(&user->usage); |
128 | spin_unlock(&key_user_lock); | |
a7f988ba | 129 | kfree(candidate); |
973c9f4f | 130 | out: |
1da177e4 | 131 | return user; |
a8b17ed0 | 132 | } |
1da177e4 | 133 | |
1da177e4 | 134 | /* |
973c9f4f | 135 | * Dispose of a user structure |
1da177e4 LT |
136 | */ |
137 | void key_user_put(struct key_user *user) | |
138 | { | |
139 | if (atomic_dec_and_lock(&user->usage, &key_user_lock)) { | |
140 | rb_erase(&user->node, &key_user_tree); | |
141 | spin_unlock(&key_user_lock); | |
1d1e9756 | 142 | put_user_ns(user->user_ns); |
1da177e4 LT |
143 | |
144 | kfree(user); | |
145 | } | |
a8b17ed0 | 146 | } |
1da177e4 | 147 | |
1da177e4 | 148 | /* |
973c9f4f DH |
149 | * Allocate a serial number for a key. These are assigned randomly to avoid |
150 | * security issues through covert channel problems. | |
1da177e4 LT |
151 | */ |
152 | static inline void key_alloc_serial(struct key *key) | |
153 | { | |
154 | struct rb_node *parent, **p; | |
155 | struct key *xkey; | |
156 | ||
e51f6d34 | 157 | /* propose a random serial number and look for a hole for it in the |
1da177e4 | 158 | * serial number tree */ |
e51f6d34 ML |
159 | do { |
160 | get_random_bytes(&key->serial, sizeof(key->serial)); | |
161 | ||
162 | key->serial >>= 1; /* negative numbers are not permitted */ | |
163 | } while (key->serial < 3); | |
164 | ||
165 | spin_lock(&key_serial_lock); | |
1da177e4 | 166 | |
9ad0830f | 167 | attempt_insertion: |
1da177e4 LT |
168 | parent = NULL; |
169 | p = &key_serial_tree.rb_node; | |
170 | ||
171 | while (*p) { | |
172 | parent = *p; | |
173 | xkey = rb_entry(parent, struct key, serial_node); | |
174 | ||
175 | if (key->serial < xkey->serial) | |
176 | p = &(*p)->rb_left; | |
177 | else if (key->serial > xkey->serial) | |
178 | p = &(*p)->rb_right; | |
179 | else | |
180 | goto serial_exists; | |
181 | } | |
9ad0830f DH |
182 | |
183 | /* we've found a suitable hole - arrange for this key to occupy it */ | |
184 | rb_link_node(&key->serial_node, parent, p); | |
185 | rb_insert_color(&key->serial_node, &key_serial_tree); | |
186 | ||
187 | spin_unlock(&key_serial_lock); | |
188 | return; | |
1da177e4 LT |
189 | |
190 | /* we found a key with the proposed serial number - walk the tree from | |
191 | * that point looking for the next unused serial number */ | |
e51f6d34 | 192 | serial_exists: |
1da177e4 | 193 | for (;;) { |
e51f6d34 | 194 | key->serial++; |
9ad0830f DH |
195 | if (key->serial < 3) { |
196 | key->serial = 3; | |
197 | goto attempt_insertion; | |
198 | } | |
1da177e4 LT |
199 | |
200 | parent = rb_next(parent); | |
201 | if (!parent) | |
9ad0830f | 202 | goto attempt_insertion; |
1da177e4 LT |
203 | |
204 | xkey = rb_entry(parent, struct key, serial_node); | |
205 | if (key->serial < xkey->serial) | |
9ad0830f | 206 | goto attempt_insertion; |
1da177e4 | 207 | } |
a8b17ed0 | 208 | } |
1da177e4 | 209 | |
973c9f4f DH |
210 | /** |
211 | * key_alloc - Allocate a key of the specified type. | |
212 | * @type: The type of key to allocate. | |
213 | * @desc: The key description to allow the key to be searched out. | |
214 | * @uid: The owner of the new key. | |
215 | * @gid: The group ID for the new key's group permissions. | |
216 | * @cred: The credentials specifying UID namespace. | |
217 | * @perm: The permissions mask of the new key. | |
218 | * @flags: Flags specifying quota properties. | |
219 | * | |
220 | * Allocate a key of the specified type with the attributes given. The key is | |
221 | * returned in an uninstantiated state and the caller needs to instantiate the | |
222 | * key before returning. | |
223 | * | |
224 | * The user's key count quota is updated to reflect the creation of the key and | |
225 | * the user's key data quota has the default for the key type reserved. The | |
226 | * instantiation function should amend this as necessary. If insufficient | |
227 | * quota is available, -EDQUOT will be returned. | |
228 | * | |
229 | * The LSM security modules can prevent a key being created, in which case | |
230 | * -EACCES will be returned. | |
231 | * | |
232 | * Returns a pointer to the new key if successful and an error code otherwise. | |
233 | * | |
234 | * Note that the caller needs to ensure the key type isn't uninstantiated. | |
235 | * Internally this can be done by locking key_types_sem. Externally, this can | |
236 | * be done by either never unregistering the key type, or making sure | |
237 | * key_alloc() calls don't race with module unloading. | |
1da177e4 LT |
238 | */ |
239 | struct key *key_alloc(struct key_type *type, const char *desc, | |
d84f4f99 | 240 | uid_t uid, gid_t gid, const struct cred *cred, |
7e047ef5 | 241 | key_perm_t perm, unsigned long flags) |
1da177e4 LT |
242 | { |
243 | struct key_user *user = NULL; | |
244 | struct key *key; | |
245 | size_t desclen, quotalen; | |
29db9190 | 246 | int ret; |
1da177e4 LT |
247 | |
248 | key = ERR_PTR(-EINVAL); | |
249 | if (!desc || !*desc) | |
250 | goto error; | |
251 | ||
b9fffa38 DH |
252 | if (type->vet_description) { |
253 | ret = type->vet_description(desc); | |
254 | if (ret < 0) { | |
255 | key = ERR_PTR(ret); | |
256 | goto error; | |
257 | } | |
258 | } | |
259 | ||
1da177e4 LT |
260 | desclen = strlen(desc) + 1; |
261 | quotalen = desclen + type->def_datalen; | |
262 | ||
263 | /* get hold of the key tracking for this user */ | |
1d1e9756 | 264 | user = key_user_lookup(uid, cred->user->user_ns); |
1da177e4 LT |
265 | if (!user) |
266 | goto no_memory_1; | |
267 | ||
268 | /* check that the user's quota permits allocation of another key and | |
269 | * its description */ | |
7e047ef5 | 270 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
0b77f5bf DH |
271 | unsigned maxkeys = (uid == 0) ? |
272 | key_quota_root_maxkeys : key_quota_maxkeys; | |
273 | unsigned maxbytes = (uid == 0) ? | |
274 | key_quota_root_maxbytes : key_quota_maxbytes; | |
275 | ||
1da177e4 | 276 | spin_lock(&user->lock); |
7e047ef5 | 277 | if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { |
0b77f5bf DH |
278 | if (user->qnkeys + 1 >= maxkeys || |
279 | user->qnbytes + quotalen >= maxbytes || | |
280 | user->qnbytes + quotalen < user->qnbytes) | |
7e047ef5 DH |
281 | goto no_quota; |
282 | } | |
1da177e4 LT |
283 | |
284 | user->qnkeys++; | |
285 | user->qnbytes += quotalen; | |
286 | spin_unlock(&user->lock); | |
287 | } | |
288 | ||
289 | /* allocate and initialise the key and its description */ | |
e94b1766 | 290 | key = kmem_cache_alloc(key_jar, GFP_KERNEL); |
1da177e4 LT |
291 | if (!key) |
292 | goto no_memory_2; | |
293 | ||
294 | if (desc) { | |
48ad504e | 295 | key->description = kmemdup(desc, desclen, GFP_KERNEL); |
1da177e4 LT |
296 | if (!key->description) |
297 | goto no_memory_3; | |
1da177e4 LT |
298 | } |
299 | ||
300 | atomic_set(&key->usage, 1); | |
1da177e4 LT |
301 | init_rwsem(&key->sem); |
302 | key->type = type; | |
303 | key->user = user; | |
304 | key->quotalen = quotalen; | |
305 | key->datalen = type->def_datalen; | |
306 | key->uid = uid; | |
307 | key->gid = gid; | |
308 | key->perm = perm; | |
309 | key->flags = 0; | |
310 | key->expiry = 0; | |
311 | key->payload.data = NULL; | |
29db9190 | 312 | key->security = NULL; |
1da177e4 | 313 | |
7e047ef5 | 314 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
76d8aeab | 315 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
1da177e4 LT |
316 | |
317 | memset(&key->type_data, 0, sizeof(key->type_data)); | |
318 | ||
319 | #ifdef KEY_DEBUGGING | |
320 | key->magic = KEY_DEBUG_MAGIC; | |
321 | #endif | |
322 | ||
29db9190 | 323 | /* let the security module know about the key */ |
d84f4f99 | 324 | ret = security_key_alloc(key, cred, flags); |
29db9190 DH |
325 | if (ret < 0) |
326 | goto security_error; | |
327 | ||
1da177e4 LT |
328 | /* publish the key by giving it a serial number */ |
329 | atomic_inc(&user->nkeys); | |
330 | key_alloc_serial(key); | |
331 | ||
29db9190 | 332 | error: |
1da177e4 LT |
333 | return key; |
334 | ||
29db9190 DH |
335 | security_error: |
336 | kfree(key->description); | |
1da177e4 | 337 | kmem_cache_free(key_jar, key); |
7e047ef5 | 338 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
1da177e4 LT |
339 | spin_lock(&user->lock); |
340 | user->qnkeys--; | |
341 | user->qnbytes -= quotalen; | |
342 | spin_unlock(&user->lock); | |
343 | } | |
344 | key_user_put(user); | |
29db9190 DH |
345 | key = ERR_PTR(ret); |
346 | goto error; | |
347 | ||
348 | no_memory_3: | |
349 | kmem_cache_free(key_jar, key); | |
350 | no_memory_2: | |
7e047ef5 | 351 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
29db9190 DH |
352 | spin_lock(&user->lock); |
353 | user->qnkeys--; | |
354 | user->qnbytes -= quotalen; | |
355 | spin_unlock(&user->lock); | |
356 | } | |
357 | key_user_put(user); | |
358 | no_memory_1: | |
1da177e4 LT |
359 | key = ERR_PTR(-ENOMEM); |
360 | goto error; | |
361 | ||
29db9190 | 362 | no_quota: |
1da177e4 LT |
363 | spin_unlock(&user->lock); |
364 | key_user_put(user); | |
365 | key = ERR_PTR(-EDQUOT); | |
366 | goto error; | |
a8b17ed0 | 367 | } |
1da177e4 LT |
368 | EXPORT_SYMBOL(key_alloc); |
369 | ||
973c9f4f DH |
370 | /** |
371 | * key_payload_reserve - Adjust data quota reservation for the key's payload | |
372 | * @key: The key to make the reservation for. | |
373 | * @datalen: The amount of data payload the caller now wants. | |
374 | * | |
375 | * Adjust the amount of the owning user's key data quota that a key reserves. | |
376 | * If the amount is increased, then -EDQUOT may be returned if there isn't | |
377 | * enough free quota available. | |
378 | * | |
379 | * If successful, 0 is returned. | |
1da177e4 LT |
380 | */ |
381 | int key_payload_reserve(struct key *key, size_t datalen) | |
382 | { | |
c5b60b5e | 383 | int delta = (int)datalen - key->datalen; |
1da177e4 LT |
384 | int ret = 0; |
385 | ||
386 | key_check(key); | |
387 | ||
388 | /* contemplate the quota adjustment */ | |
76d8aeab | 389 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
0b77f5bf DH |
390 | unsigned maxbytes = (key->user->uid == 0) ? |
391 | key_quota_root_maxbytes : key_quota_maxbytes; | |
392 | ||
1da177e4 LT |
393 | spin_lock(&key->user->lock); |
394 | ||
395 | if (delta > 0 && | |
0b77f5bf DH |
396 | (key->user->qnbytes + delta >= maxbytes || |
397 | key->user->qnbytes + delta < key->user->qnbytes)) { | |
1da177e4 LT |
398 | ret = -EDQUOT; |
399 | } | |
400 | else { | |
401 | key->user->qnbytes += delta; | |
402 | key->quotalen += delta; | |
403 | } | |
404 | spin_unlock(&key->user->lock); | |
405 | } | |
406 | ||
407 | /* change the recorded data length if that didn't generate an error */ | |
408 | if (ret == 0) | |
409 | key->datalen = datalen; | |
410 | ||
411 | return ret; | |
a8b17ed0 | 412 | } |
1da177e4 LT |
413 | EXPORT_SYMBOL(key_payload_reserve); |
414 | ||
1da177e4 | 415 | /* |
973c9f4f DH |
416 | * Instantiate a key and link it into the target keyring atomically. Must be |
417 | * called with the target keyring's semaphore writelocked. The target key's | |
418 | * semaphore need not be locked as instantiation is serialised by | |
419 | * key_construction_mutex. | |
1da177e4 LT |
420 | */ |
421 | static int __key_instantiate_and_link(struct key *key, | |
422 | const void *data, | |
423 | size_t datalen, | |
3e30148c | 424 | struct key *keyring, |
f70e2e06 | 425 | struct key *authkey, |
ceb73c12 | 426 | unsigned long *_prealloc) |
1da177e4 LT |
427 | { |
428 | int ret, awaken; | |
429 | ||
430 | key_check(key); | |
431 | key_check(keyring); | |
432 | ||
433 | awaken = 0; | |
434 | ret = -EBUSY; | |
435 | ||
76181c13 | 436 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
437 | |
438 | /* can't instantiate twice */ | |
76d8aeab | 439 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
1da177e4 LT |
440 | /* instantiate the key */ |
441 | ret = key->type->instantiate(key, data, datalen); | |
442 | ||
443 | if (ret == 0) { | |
444 | /* mark the key as being instantiated */ | |
1da177e4 | 445 | atomic_inc(&key->user->nikeys); |
76d8aeab | 446 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); |
1da177e4 | 447 | |
76d8aeab | 448 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 449 | awaken = 1; |
1da177e4 LT |
450 | |
451 | /* and link it into the destination keyring */ | |
452 | if (keyring) | |
f70e2e06 | 453 | __key_link(keyring, key, _prealloc); |
3e30148c DH |
454 | |
455 | /* disable the authorisation key */ | |
d84f4f99 DH |
456 | if (authkey) |
457 | key_revoke(authkey); | |
1da177e4 LT |
458 | } |
459 | } | |
460 | ||
76181c13 | 461 | mutex_unlock(&key_construction_mutex); |
1da177e4 LT |
462 | |
463 | /* wake up anyone waiting for a key to be constructed */ | |
464 | if (awaken) | |
76181c13 | 465 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 LT |
466 | |
467 | return ret; | |
a8b17ed0 | 468 | } |
1da177e4 | 469 | |
973c9f4f DH |
470 | /** |
471 | * key_instantiate_and_link - Instantiate a key and link it into the keyring. | |
472 | * @key: The key to instantiate. | |
473 | * @data: The data to use to instantiate the keyring. | |
474 | * @datalen: The length of @data. | |
475 | * @keyring: Keyring to create a link in on success (or NULL). | |
476 | * @authkey: The authorisation token permitting instantiation. | |
477 | * | |
478 | * Instantiate a key that's in the uninstantiated state using the provided data | |
479 | * and, if successful, link it in to the destination keyring if one is | |
480 | * supplied. | |
481 | * | |
482 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
483 | * waiting for the key is woken up. If the key was already instantiated, | |
484 | * -EBUSY will be returned. | |
1da177e4 LT |
485 | */ |
486 | int key_instantiate_and_link(struct key *key, | |
487 | const void *data, | |
488 | size_t datalen, | |
3e30148c | 489 | struct key *keyring, |
d84f4f99 | 490 | struct key *authkey) |
1da177e4 | 491 | { |
ceb73c12 | 492 | unsigned long prealloc; |
1da177e4 LT |
493 | int ret; |
494 | ||
f70e2e06 DH |
495 | if (keyring) { |
496 | ret = __key_link_begin(keyring, key->type, key->description, | |
497 | &prealloc); | |
498 | if (ret < 0) | |
499 | return ret; | |
500 | } | |
1da177e4 | 501 | |
f70e2e06 DH |
502 | ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey, |
503 | &prealloc); | |
1da177e4 LT |
504 | |
505 | if (keyring) | |
f70e2e06 | 506 | __key_link_end(keyring, key->type, prealloc); |
1da177e4 LT |
507 | |
508 | return ret; | |
a8b17ed0 | 509 | } |
1da177e4 LT |
510 | |
511 | EXPORT_SYMBOL(key_instantiate_and_link); | |
512 | ||
973c9f4f | 513 | /** |
fdd1b945 | 514 | * key_reject_and_link - Negatively instantiate a key and link it into the keyring. |
973c9f4f DH |
515 | * @key: The key to instantiate. |
516 | * @timeout: The timeout on the negative key. | |
fdd1b945 | 517 | * @error: The error to return when the key is hit. |
973c9f4f DH |
518 | * @keyring: Keyring to create a link in on success (or NULL). |
519 | * @authkey: The authorisation token permitting instantiation. | |
520 | * | |
521 | * Negatively instantiate a key that's in the uninstantiated state and, if | |
fdd1b945 DH |
522 | * successful, set its timeout and stored error and link it in to the |
523 | * destination keyring if one is supplied. The key and any links to the key | |
524 | * will be automatically garbage collected after the timeout expires. | |
973c9f4f DH |
525 | * |
526 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
fdd1b945 DH |
527 | * them to return the stored error code (typically ENOKEY) until the negative |
528 | * key expires. | |
973c9f4f DH |
529 | * |
530 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
531 | * waiting for the key is woken up. If the key was already instantiated, | |
532 | * -EBUSY will be returned. | |
1da177e4 | 533 | */ |
fdd1b945 | 534 | int key_reject_and_link(struct key *key, |
1da177e4 | 535 | unsigned timeout, |
fdd1b945 | 536 | unsigned error, |
3e30148c | 537 | struct key *keyring, |
d84f4f99 | 538 | struct key *authkey) |
1da177e4 | 539 | { |
ceb73c12 | 540 | unsigned long prealloc; |
1da177e4 | 541 | struct timespec now; |
f70e2e06 | 542 | int ret, awaken, link_ret = 0; |
1da177e4 LT |
543 | |
544 | key_check(key); | |
545 | key_check(keyring); | |
546 | ||
547 | awaken = 0; | |
548 | ret = -EBUSY; | |
549 | ||
550 | if (keyring) | |
f70e2e06 DH |
551 | link_ret = __key_link_begin(keyring, key->type, |
552 | key->description, &prealloc); | |
1da177e4 | 553 | |
76181c13 | 554 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
555 | |
556 | /* can't instantiate twice */ | |
76d8aeab | 557 | if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { |
1da177e4 | 558 | /* mark the key as being negatively instantiated */ |
1da177e4 | 559 | atomic_inc(&key->user->nikeys); |
76d8aeab DH |
560 | set_bit(KEY_FLAG_NEGATIVE, &key->flags); |
561 | set_bit(KEY_FLAG_INSTANTIATED, &key->flags); | |
fdd1b945 | 562 | key->type_data.reject_error = -error; |
1da177e4 LT |
563 | now = current_kernel_time(); |
564 | key->expiry = now.tv_sec + timeout; | |
c08ef808 | 565 | key_schedule_gc(key->expiry + key_gc_delay); |
1da177e4 | 566 | |
76d8aeab | 567 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 568 | awaken = 1; |
1da177e4 | 569 | |
1da177e4 LT |
570 | ret = 0; |
571 | ||
572 | /* and link it into the destination keyring */ | |
f70e2e06 DH |
573 | if (keyring && link_ret == 0) |
574 | __key_link(keyring, key, &prealloc); | |
3e30148c DH |
575 | |
576 | /* disable the authorisation key */ | |
d84f4f99 DH |
577 | if (authkey) |
578 | key_revoke(authkey); | |
1da177e4 LT |
579 | } |
580 | ||
76181c13 | 581 | mutex_unlock(&key_construction_mutex); |
1da177e4 LT |
582 | |
583 | if (keyring) | |
f70e2e06 | 584 | __key_link_end(keyring, key->type, prealloc); |
1da177e4 LT |
585 | |
586 | /* wake up anyone waiting for a key to be constructed */ | |
587 | if (awaken) | |
76181c13 | 588 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 | 589 | |
f70e2e06 | 590 | return ret == 0 ? link_ret : ret; |
a8b17ed0 | 591 | } |
fdd1b945 | 592 | EXPORT_SYMBOL(key_reject_and_link); |
1da177e4 | 593 | |
1da177e4 | 594 | /* |
973c9f4f DH |
595 | * Garbage collect keys in process context so that we don't have to disable |
596 | * interrupts all over the place. | |
597 | * | |
598 | * key_put() schedules this rather than trying to do the cleanup itself, which | |
599 | * means key_put() doesn't have to sleep. | |
1da177e4 | 600 | */ |
65f27f38 | 601 | static void key_cleanup(struct work_struct *work) |
1da177e4 LT |
602 | { |
603 | struct rb_node *_n; | |
604 | struct key *key; | |
605 | ||
973c9f4f | 606 | go_again: |
1da177e4 LT |
607 | /* look for a dead key in the tree */ |
608 | spin_lock(&key_serial_lock); | |
609 | ||
610 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { | |
611 | key = rb_entry(_n, struct key, serial_node); | |
612 | ||
613 | if (atomic_read(&key->usage) == 0) | |
614 | goto found_dead_key; | |
615 | } | |
616 | ||
617 | spin_unlock(&key_serial_lock); | |
618 | return; | |
619 | ||
973c9f4f | 620 | found_dead_key: |
1da177e4 LT |
621 | /* we found a dead key - once we've removed it from the tree, we can |
622 | * drop the lock */ | |
623 | rb_erase(&key->serial_node, &key_serial_tree); | |
624 | spin_unlock(&key_serial_lock); | |
625 | ||
76d8aeab DH |
626 | key_check(key); |
627 | ||
29db9190 DH |
628 | security_key_free(key); |
629 | ||
1da177e4 | 630 | /* deal with the user's key tracking and quota */ |
76d8aeab | 631 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
1da177e4 LT |
632 | spin_lock(&key->user->lock); |
633 | key->user->qnkeys--; | |
634 | key->user->qnbytes -= key->quotalen; | |
635 | spin_unlock(&key->user->lock); | |
636 | } | |
637 | ||
638 | atomic_dec(&key->user->nkeys); | |
76d8aeab | 639 | if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) |
1da177e4 LT |
640 | atomic_dec(&key->user->nikeys); |
641 | ||
642 | key_user_put(key->user); | |
643 | ||
644 | /* now throw away the key memory */ | |
645 | if (key->type->destroy) | |
646 | key->type->destroy(key); | |
647 | ||
648 | kfree(key->description); | |
649 | ||
650 | #ifdef KEY_DEBUGGING | |
651 | key->magic = KEY_DEBUG_MAGIC_X; | |
652 | #endif | |
653 | kmem_cache_free(key_jar, key); | |
654 | ||
655 | /* there may, of course, be more than one key to destroy */ | |
656 | goto go_again; | |
a8b17ed0 | 657 | } |
1da177e4 | 658 | |
973c9f4f DH |
659 | /** |
660 | * key_put - Discard a reference to a key. | |
661 | * @key: The key to discard a reference from. | |
662 | * | |
663 | * Discard a reference to a key, and when all the references are gone, we | |
664 | * schedule the cleanup task to come and pull it out of the tree in process | |
665 | * context at some later time. | |
1da177e4 LT |
666 | */ |
667 | void key_put(struct key *key) | |
668 | { | |
669 | if (key) { | |
670 | key_check(key); | |
671 | ||
672 | if (atomic_dec_and_test(&key->usage)) | |
673 | schedule_work(&key_cleanup_task); | |
674 | } | |
a8b17ed0 | 675 | } |
1da177e4 LT |
676 | EXPORT_SYMBOL(key_put); |
677 | ||
1da177e4 | 678 | /* |
973c9f4f | 679 | * Find a key by its serial number. |
1da177e4 LT |
680 | */ |
681 | struct key *key_lookup(key_serial_t id) | |
682 | { | |
683 | struct rb_node *n; | |
684 | struct key *key; | |
685 | ||
686 | spin_lock(&key_serial_lock); | |
687 | ||
688 | /* search the tree for the specified key */ | |
689 | n = key_serial_tree.rb_node; | |
690 | while (n) { | |
691 | key = rb_entry(n, struct key, serial_node); | |
692 | ||
693 | if (id < key->serial) | |
694 | n = n->rb_left; | |
695 | else if (id > key->serial) | |
696 | n = n->rb_right; | |
697 | else | |
698 | goto found; | |
699 | } | |
700 | ||
973c9f4f | 701 | not_found: |
1da177e4 LT |
702 | key = ERR_PTR(-ENOKEY); |
703 | goto error; | |
704 | ||
973c9f4f | 705 | found: |
5593122e DH |
706 | /* pretend it doesn't exist if it is awaiting deletion */ |
707 | if (atomic_read(&key->usage) == 0) | |
1da177e4 LT |
708 | goto not_found; |
709 | ||
710 | /* this races with key_put(), but that doesn't matter since key_put() | |
711 | * doesn't actually change the key | |
712 | */ | |
713 | atomic_inc(&key->usage); | |
714 | ||
973c9f4f | 715 | error: |
1da177e4 LT |
716 | spin_unlock(&key_serial_lock); |
717 | return key; | |
a8b17ed0 | 718 | } |
1da177e4 | 719 | |
1da177e4 | 720 | /* |
973c9f4f DH |
721 | * Find and lock the specified key type against removal. |
722 | * | |
723 | * We return with the sem read-locked if successful. If the type wasn't | |
724 | * available -ENOKEY is returned instead. | |
1da177e4 LT |
725 | */ |
726 | struct key_type *key_type_lookup(const char *type) | |
727 | { | |
728 | struct key_type *ktype; | |
729 | ||
730 | down_read(&key_types_sem); | |
731 | ||
732 | /* look up the key type to see if it's one of the registered kernel | |
733 | * types */ | |
734 | list_for_each_entry(ktype, &key_types_list, link) { | |
735 | if (strcmp(ktype->name, type) == 0) | |
736 | goto found_kernel_type; | |
737 | } | |
738 | ||
739 | up_read(&key_types_sem); | |
740 | ktype = ERR_PTR(-ENOKEY); | |
741 | ||
973c9f4f | 742 | found_kernel_type: |
1da177e4 | 743 | return ktype; |
a8b17ed0 | 744 | } |
1da177e4 | 745 | |
1da177e4 | 746 | /* |
973c9f4f | 747 | * Unlock a key type locked by key_type_lookup(). |
1da177e4 LT |
748 | */ |
749 | void key_type_put(struct key_type *ktype) | |
750 | { | |
751 | up_read(&key_types_sem); | |
a8b17ed0 | 752 | } |
1da177e4 | 753 | |
1da177e4 | 754 | /* |
973c9f4f DH |
755 | * Attempt to update an existing key. |
756 | * | |
757 | * The key is given to us with an incremented refcount that we need to discard | |
758 | * if we get an error. | |
1da177e4 | 759 | */ |
664cceb0 DH |
760 | static inline key_ref_t __key_update(key_ref_t key_ref, |
761 | const void *payload, size_t plen) | |
1da177e4 | 762 | { |
664cceb0 | 763 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
764 | int ret; |
765 | ||
766 | /* need write permission on the key to update it */ | |
29db9190 DH |
767 | ret = key_permission(key_ref, KEY_WRITE); |
768 | if (ret < 0) | |
1da177e4 LT |
769 | goto error; |
770 | ||
771 | ret = -EEXIST; | |
772 | if (!key->type->update) | |
773 | goto error; | |
774 | ||
775 | down_write(&key->sem); | |
776 | ||
777 | ret = key->type->update(key, payload, plen); | |
76d8aeab | 778 | if (ret == 0) |
1da177e4 | 779 | /* updating a negative key instantiates it */ |
76d8aeab | 780 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
1da177e4 LT |
781 | |
782 | up_write(&key->sem); | |
783 | ||
784 | if (ret < 0) | |
785 | goto error; | |
664cceb0 DH |
786 | out: |
787 | return key_ref; | |
1da177e4 | 788 | |
664cceb0 | 789 | error: |
1da177e4 | 790 | key_put(key); |
664cceb0 | 791 | key_ref = ERR_PTR(ret); |
1da177e4 | 792 | goto out; |
a8b17ed0 | 793 | } |
1da177e4 | 794 | |
973c9f4f DH |
795 | /** |
796 | * key_create_or_update - Update or create and instantiate a key. | |
797 | * @keyring_ref: A pointer to the destination keyring with possession flag. | |
798 | * @type: The type of key. | |
799 | * @description: The searchable description for the key. | |
800 | * @payload: The data to use to instantiate or update the key. | |
801 | * @plen: The length of @payload. | |
802 | * @perm: The permissions mask for a new key. | |
803 | * @flags: The quota flags for a new key. | |
804 | * | |
805 | * Search the destination keyring for a key of the same description and if one | |
806 | * is found, update it, otherwise create and instantiate a new one and create a | |
807 | * link to it from that keyring. | |
808 | * | |
809 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be | |
810 | * concocted. | |
811 | * | |
812 | * Returns a pointer to the new key if successful, -ENODEV if the key type | |
813 | * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the | |
814 | * caller isn't permitted to modify the keyring or the LSM did not permit | |
815 | * creation of the key. | |
816 | * | |
817 | * On success, the possession flag from the keyring ref will be tacked on to | |
818 | * the key ref before it is returned. | |
1da177e4 | 819 | */ |
664cceb0 DH |
820 | key_ref_t key_create_or_update(key_ref_t keyring_ref, |
821 | const char *type, | |
822 | const char *description, | |
823 | const void *payload, | |
824 | size_t plen, | |
6b79ccb5 | 825 | key_perm_t perm, |
7e047ef5 | 826 | unsigned long flags) |
1da177e4 | 827 | { |
ceb73c12 | 828 | unsigned long prealloc; |
d84f4f99 | 829 | const struct cred *cred = current_cred(); |
1da177e4 | 830 | struct key_type *ktype; |
664cceb0 | 831 | struct key *keyring, *key = NULL; |
664cceb0 | 832 | key_ref_t key_ref; |
1da177e4 LT |
833 | int ret; |
834 | ||
1da177e4 LT |
835 | /* look up the key type to see if it's one of the registered kernel |
836 | * types */ | |
837 | ktype = key_type_lookup(type); | |
838 | if (IS_ERR(ktype)) { | |
664cceb0 | 839 | key_ref = ERR_PTR(-ENODEV); |
1da177e4 LT |
840 | goto error; |
841 | } | |
842 | ||
664cceb0 | 843 | key_ref = ERR_PTR(-EINVAL); |
1da177e4 LT |
844 | if (!ktype->match || !ktype->instantiate) |
845 | goto error_2; | |
846 | ||
664cceb0 DH |
847 | keyring = key_ref_to_ptr(keyring_ref); |
848 | ||
849 | key_check(keyring); | |
850 | ||
c3a9d654 DH |
851 | key_ref = ERR_PTR(-ENOTDIR); |
852 | if (keyring->type != &key_type_keyring) | |
853 | goto error_2; | |
854 | ||
f70e2e06 DH |
855 | ret = __key_link_begin(keyring, ktype, description, &prealloc); |
856 | if (ret < 0) | |
857 | goto error_2; | |
664cceb0 DH |
858 | |
859 | /* if we're going to allocate a new key, we're going to have | |
860 | * to modify the keyring */ | |
29db9190 DH |
861 | ret = key_permission(keyring_ref, KEY_WRITE); |
862 | if (ret < 0) { | |
863 | key_ref = ERR_PTR(ret); | |
664cceb0 | 864 | goto error_3; |
29db9190 | 865 | } |
664cceb0 | 866 | |
1d9b7d97 DH |
867 | /* if it's possible to update this type of key, search for an existing |
868 | * key of the same type and description in the destination keyring and | |
869 | * update that instead if possible | |
1da177e4 | 870 | */ |
1d9b7d97 DH |
871 | if (ktype->update) { |
872 | key_ref = __keyring_search_one(keyring_ref, ktype, description, | |
873 | 0); | |
874 | if (!IS_ERR(key_ref)) | |
875 | goto found_matching_key; | |
876 | } | |
1da177e4 | 877 | |
6b79ccb5 AR |
878 | /* if the client doesn't provide, decide on the permissions we want */ |
879 | if (perm == KEY_PERM_UNDEF) { | |
880 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; | |
881 | perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR; | |
1da177e4 | 882 | |
6b79ccb5 AR |
883 | if (ktype->read) |
884 | perm |= KEY_POS_READ | KEY_USR_READ; | |
1da177e4 | 885 | |
6b79ccb5 AR |
886 | if (ktype == &key_type_keyring || ktype->update) |
887 | perm |= KEY_USR_WRITE; | |
888 | } | |
1da177e4 LT |
889 | |
890 | /* allocate a new key */ | |
d84f4f99 DH |
891 | key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred, |
892 | perm, flags); | |
1da177e4 | 893 | if (IS_ERR(key)) { |
e231c2ee | 894 | key_ref = ERR_CAST(key); |
1da177e4 LT |
895 | goto error_3; |
896 | } | |
897 | ||
898 | /* instantiate it and link it into the target keyring */ | |
f70e2e06 DH |
899 | ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL, |
900 | &prealloc); | |
1da177e4 LT |
901 | if (ret < 0) { |
902 | key_put(key); | |
664cceb0 DH |
903 | key_ref = ERR_PTR(ret); |
904 | goto error_3; | |
1da177e4 LT |
905 | } |
906 | ||
664cceb0 DH |
907 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
908 | ||
1da177e4 | 909 | error_3: |
f70e2e06 | 910 | __key_link_end(keyring, ktype, prealloc); |
1da177e4 LT |
911 | error_2: |
912 | key_type_put(ktype); | |
913 | error: | |
664cceb0 | 914 | return key_ref; |
1da177e4 LT |
915 | |
916 | found_matching_key: | |
917 | /* we found a matching key, so we're going to try to update it | |
918 | * - we can drop the locks first as we have the key pinned | |
919 | */ | |
f70e2e06 | 920 | __key_link_end(keyring, ktype, prealloc); |
1da177e4 LT |
921 | key_type_put(ktype); |
922 | ||
664cceb0 | 923 | key_ref = __key_update(key_ref, payload, plen); |
1da177e4 | 924 | goto error; |
a8b17ed0 | 925 | } |
1da177e4 LT |
926 | EXPORT_SYMBOL(key_create_or_update); |
927 | ||
973c9f4f DH |
928 | /** |
929 | * key_update - Update a key's contents. | |
930 | * @key_ref: The pointer (plus possession flag) to the key. | |
931 | * @payload: The data to be used to update the key. | |
932 | * @plen: The length of @payload. | |
933 | * | |
934 | * Attempt to update the contents of a key with the given payload data. The | |
935 | * caller must be granted Write permission on the key. Negative keys can be | |
936 | * instantiated by this method. | |
937 | * | |
938 | * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key | |
939 | * type does not support updating. The key type may return other errors. | |
1da177e4 | 940 | */ |
664cceb0 | 941 | int key_update(key_ref_t key_ref, const void *payload, size_t plen) |
1da177e4 | 942 | { |
664cceb0 | 943 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
944 | int ret; |
945 | ||
946 | key_check(key); | |
947 | ||
948 | /* the key must be writable */ | |
29db9190 DH |
949 | ret = key_permission(key_ref, KEY_WRITE); |
950 | if (ret < 0) | |
1da177e4 LT |
951 | goto error; |
952 | ||
953 | /* attempt to update it if supported */ | |
954 | ret = -EOPNOTSUPP; | |
955 | if (key->type->update) { | |
956 | down_write(&key->sem); | |
1da177e4 | 957 | |
29db9190 | 958 | ret = key->type->update(key, payload, plen); |
76d8aeab | 959 | if (ret == 0) |
1da177e4 | 960 | /* updating a negative key instantiates it */ |
76d8aeab | 961 | clear_bit(KEY_FLAG_NEGATIVE, &key->flags); |
1da177e4 LT |
962 | |
963 | up_write(&key->sem); | |
964 | } | |
965 | ||
966 | error: | |
967 | return ret; | |
a8b17ed0 | 968 | } |
1da177e4 LT |
969 | EXPORT_SYMBOL(key_update); |
970 | ||
973c9f4f DH |
971 | /** |
972 | * key_revoke - Revoke a key. | |
973 | * @key: The key to be revoked. | |
974 | * | |
975 | * Mark a key as being revoked and ask the type to free up its resources. The | |
976 | * revocation timeout is set and the key and all its links will be | |
977 | * automatically garbage collected after key_gc_delay amount of time if they | |
978 | * are not manually dealt with first. | |
1da177e4 LT |
979 | */ |
980 | void key_revoke(struct key *key) | |
981 | { | |
5d135440 DH |
982 | struct timespec now; |
983 | time_t time; | |
984 | ||
1da177e4 LT |
985 | key_check(key); |
986 | ||
76181c13 DH |
987 | /* make sure no one's trying to change or use the key when we mark it |
988 | * - we tell lockdep that we might nest because we might be revoking an | |
989 | * authorisation key whilst holding the sem on a key we've just | |
990 | * instantiated | |
991 | */ | |
992 | down_write_nested(&key->sem, 1); | |
993 | if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) && | |
994 | key->type->revoke) | |
04c567d9 DH |
995 | key->type->revoke(key); |
996 | ||
5d135440 DH |
997 | /* set the death time to no more than the expiry time */ |
998 | now = current_kernel_time(); | |
999 | time = now.tv_sec; | |
1000 | if (key->revoked_at == 0 || key->revoked_at > time) { | |
1001 | key->revoked_at = time; | |
c08ef808 | 1002 | key_schedule_gc(key->revoked_at + key_gc_delay); |
5d135440 DH |
1003 | } |
1004 | ||
1da177e4 | 1005 | up_write(&key->sem); |
a8b17ed0 | 1006 | } |
1da177e4 LT |
1007 | EXPORT_SYMBOL(key_revoke); |
1008 | ||
973c9f4f DH |
1009 | /** |
1010 | * register_key_type - Register a type of key. | |
1011 | * @ktype: The new key type. | |
1012 | * | |
1013 | * Register a new key type. | |
1014 | * | |
1015 | * Returns 0 on success or -EEXIST if a type of this name already exists. | |
1da177e4 LT |
1016 | */ |
1017 | int register_key_type(struct key_type *ktype) | |
1018 | { | |
1019 | struct key_type *p; | |
1020 | int ret; | |
1021 | ||
1022 | ret = -EEXIST; | |
1023 | down_write(&key_types_sem); | |
1024 | ||
1025 | /* disallow key types with the same name */ | |
1026 | list_for_each_entry(p, &key_types_list, link) { | |
1027 | if (strcmp(p->name, ktype->name) == 0) | |
1028 | goto out; | |
1029 | } | |
1030 | ||
1031 | /* store the type */ | |
1032 | list_add(&ktype->link, &key_types_list); | |
1033 | ret = 0; | |
1034 | ||
973c9f4f | 1035 | out: |
1da177e4 LT |
1036 | up_write(&key_types_sem); |
1037 | return ret; | |
a8b17ed0 | 1038 | } |
1da177e4 LT |
1039 | EXPORT_SYMBOL(register_key_type); |
1040 | ||
973c9f4f DH |
1041 | /** |
1042 | * unregister_key_type - Unregister a type of key. | |
1043 | * @ktype: The key type. | |
1044 | * | |
1045 | * Unregister a key type and mark all the extant keys of this type as dead. | |
1046 | * Those keys of this type are then destroyed to get rid of their payloads and | |
1047 | * they and their links will be garbage collected as soon as possible. | |
1da177e4 LT |
1048 | */ |
1049 | void unregister_key_type(struct key_type *ktype) | |
1050 | { | |
1051 | struct rb_node *_n; | |
1052 | struct key *key; | |
1053 | ||
1054 | down_write(&key_types_sem); | |
1055 | ||
1056 | /* withdraw the key type */ | |
1057 | list_del_init(&ktype->link); | |
1058 | ||
76d8aeab | 1059 | /* mark all the keys of this type dead */ |
1da177e4 LT |
1060 | spin_lock(&key_serial_lock); |
1061 | ||
1062 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { | |
1063 | key = rb_entry(_n, struct key, serial_node); | |
1064 | ||
f041ae2f | 1065 | if (key->type == ktype) { |
76d8aeab | 1066 | key->type = &key_type_dead; |
f041ae2f DH |
1067 | set_bit(KEY_FLAG_DEAD, &key->flags); |
1068 | } | |
76d8aeab DH |
1069 | } |
1070 | ||
1071 | spin_unlock(&key_serial_lock); | |
1072 | ||
1073 | /* make sure everyone revalidates their keys */ | |
b2b18660 | 1074 | synchronize_rcu(); |
76d8aeab DH |
1075 | |
1076 | /* we should now be able to destroy the payloads of all the keys of | |
1077 | * this type with impunity */ | |
1078 | spin_lock(&key_serial_lock); | |
1da177e4 | 1079 | |
76d8aeab DH |
1080 | for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { |
1081 | key = rb_entry(_n, struct key, serial_node); | |
1da177e4 | 1082 | |
76d8aeab DH |
1083 | if (key->type == ktype) { |
1084 | if (ktype->destroy) | |
1085 | ktype->destroy(key); | |
a7807a32 | 1086 | memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); |
76d8aeab | 1087 | } |
1da177e4 LT |
1088 | } |
1089 | ||
1090 | spin_unlock(&key_serial_lock); | |
1091 | up_write(&key_types_sem); | |
1092 | ||
5d135440 | 1093 | key_schedule_gc(0); |
a8b17ed0 | 1094 | } |
1da177e4 LT |
1095 | EXPORT_SYMBOL(unregister_key_type); |
1096 | ||
1da177e4 | 1097 | /* |
973c9f4f | 1098 | * Initialise the key management state. |
1da177e4 LT |
1099 | */ |
1100 | void __init key_init(void) | |
1101 | { | |
1102 | /* allocate a slab in which we can store keys */ | |
1103 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), | |
20c2df83 | 1104 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1105 | |
1106 | /* add the special key types */ | |
1107 | list_add_tail(&key_type_keyring.link, &key_types_list); | |
1108 | list_add_tail(&key_type_dead.link, &key_types_list); | |
1109 | list_add_tail(&key_type_user.link, &key_types_list); | |
1110 | ||
1111 | /* record the root user tracking */ | |
1112 | rb_link_node(&root_key_user.node, | |
1113 | NULL, | |
1114 | &key_user_tree.rb_node); | |
1115 | ||
1116 | rb_insert_color(&root_key_user.node, | |
1117 | &key_user_tree); | |
a8b17ed0 | 1118 | } |