Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
76181c13 | 2 | /* Basic authentication token and access key management |
1da177e4 | 3 | * |
69664cf1 | 4 | * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. |
1da177e4 | 5 | * Written by David Howells (dhowells@redhat.com) |
1da177e4 LT |
6 | */ |
7 | ||
876979c9 | 8 | #include <linux/export.h> |
1da177e4 | 9 | #include <linux/init.h> |
a7807a32 | 10 | #include <linux/poison.h> |
1da177e4 LT |
11 | #include <linux/sched.h> |
12 | #include <linux/slab.h> | |
29db9190 | 13 | #include <linux/security.h> |
1da177e4 | 14 | #include <linux/workqueue.h> |
e51f6d34 | 15 | #include <linux/random.h> |
cb1aa382 | 16 | #include <linux/ima.h> |
1da177e4 LT |
17 | #include <linux/err.h> |
18 | #include "internal.h" | |
19 | ||
8bc16dea | 20 | struct kmem_cache *key_jar; |
1da177e4 LT |
21 | struct rb_root key_serial_tree; /* tree of keys indexed by serial */ |
22 | DEFINE_SPINLOCK(key_serial_lock); | |
23 | ||
24 | struct rb_root key_user_tree; /* tree of quota records indexed by UID */ | |
25 | DEFINE_SPINLOCK(key_user_lock); | |
26 | ||
738c5d19 SD |
27 | unsigned int key_quota_root_maxkeys = 1000000; /* root's key count quota */ |
28 | unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */ | |
0b77f5bf DH |
29 | unsigned int key_quota_maxkeys = 200; /* general key count quota */ |
30 | unsigned int key_quota_maxbytes = 20000; /* general key space quota */ | |
31 | ||
1da177e4 LT |
32 | static LIST_HEAD(key_types_list); |
33 | static DECLARE_RWSEM(key_types_sem); | |
34 | ||
973c9f4f | 35 | /* We serialise key instantiation and link */ |
76181c13 | 36 | DEFINE_MUTEX(key_construction_mutex); |
1da177e4 | 37 | |
1da177e4 LT |
38 | #ifdef KEY_DEBUGGING |
39 | void __key_check(const struct key *key) | |
40 | { | |
41 | printk("__key_check: key %p {%08x} should be {%08x}\n", | |
42 | key, key->magic, KEY_DEBUG_MAGIC); | |
43 | BUG(); | |
44 | } | |
45 | #endif | |
46 | ||
1da177e4 | 47 | /* |
973c9f4f DH |
48 | * Get the key quota record for a user, allocating a new record if one doesn't |
49 | * already exist. | |
1da177e4 | 50 | */ |
9a56c2db | 51 | struct key_user *key_user_lookup(kuid_t uid) |
1da177e4 LT |
52 | { |
53 | struct key_user *candidate = NULL, *user; | |
8f674565 | 54 | struct rb_node *parent, **p; |
1da177e4 | 55 | |
973c9f4f | 56 | try_again: |
8f674565 | 57 | parent = NULL; |
1da177e4 LT |
58 | p = &key_user_tree.rb_node; |
59 | spin_lock(&key_user_lock); | |
60 | ||
61 | /* search the tree for a user record with a matching UID */ | |
62 | while (*p) { | |
63 | parent = *p; | |
64 | user = rb_entry(parent, struct key_user, node); | |
65 | ||
9a56c2db | 66 | if (uid_lt(uid, user->uid)) |
1da177e4 | 67 | p = &(*p)->rb_left; |
9a56c2db | 68 | else if (uid_gt(uid, user->uid)) |
1d1e9756 | 69 | p = &(*p)->rb_right; |
1da177e4 LT |
70 | else |
71 | goto found; | |
72 | } | |
73 | ||
74 | /* if we get here, we failed to find a match in the tree */ | |
75 | if (!candidate) { | |
76 | /* allocate a candidate user record if we don't already have | |
77 | * one */ | |
78 | spin_unlock(&key_user_lock); | |
79 | ||
80 | user = NULL; | |
81 | candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); | |
82 | if (unlikely(!candidate)) | |
83 | goto out; | |
84 | ||
85 | /* the allocation may have scheduled, so we need to repeat the | |
86 | * search lest someone else added the record whilst we were | |
87 | * asleep */ | |
88 | goto try_again; | |
89 | } | |
90 | ||
91 | /* if we get here, then the user record still hadn't appeared on the | |
92 | * second pass - so we use the candidate record */ | |
ddb99e11 | 93 | refcount_set(&candidate->usage, 1); |
1da177e4 LT |
94 | atomic_set(&candidate->nkeys, 0); |
95 | atomic_set(&candidate->nikeys, 0); | |
96 | candidate->uid = uid; | |
97 | candidate->qnkeys = 0; | |
98 | candidate->qnbytes = 0; | |
99 | spin_lock_init(&candidate->lock); | |
76181c13 | 100 | mutex_init(&candidate->cons_lock); |
1da177e4 LT |
101 | |
102 | rb_link_node(&candidate->node, parent, p); | |
103 | rb_insert_color(&candidate->node, &key_user_tree); | |
104 | spin_unlock(&key_user_lock); | |
105 | user = candidate; | |
106 | goto out; | |
107 | ||
108 | /* okay - we found a user record for this UID */ | |
973c9f4f | 109 | found: |
ddb99e11 | 110 | refcount_inc(&user->usage); |
1da177e4 | 111 | spin_unlock(&key_user_lock); |
a7f988ba | 112 | kfree(candidate); |
973c9f4f | 113 | out: |
1da177e4 | 114 | return user; |
a8b17ed0 | 115 | } |
1da177e4 | 116 | |
1da177e4 | 117 | /* |
973c9f4f | 118 | * Dispose of a user structure |
1da177e4 LT |
119 | */ |
120 | void key_user_put(struct key_user *user) | |
121 | { | |
ddb99e11 | 122 | if (refcount_dec_and_lock(&user->usage, &key_user_lock)) { |
1da177e4 LT |
123 | rb_erase(&user->node, &key_user_tree); |
124 | spin_unlock(&key_user_lock); | |
125 | ||
126 | kfree(user); | |
127 | } | |
a8b17ed0 | 128 | } |
1da177e4 | 129 | |
1da177e4 | 130 | /* |
973c9f4f DH |
131 | * Allocate a serial number for a key. These are assigned randomly to avoid |
132 | * security issues through covert channel problems. | |
1da177e4 LT |
133 | */ |
134 | static inline void key_alloc_serial(struct key *key) | |
135 | { | |
136 | struct rb_node *parent, **p; | |
137 | struct key *xkey; | |
138 | ||
e51f6d34 | 139 | /* propose a random serial number and look for a hole for it in the |
1da177e4 | 140 | * serial number tree */ |
e51f6d34 ML |
141 | do { |
142 | get_random_bytes(&key->serial, sizeof(key->serial)); | |
143 | ||
144 | key->serial >>= 1; /* negative numbers are not permitted */ | |
145 | } while (key->serial < 3); | |
146 | ||
147 | spin_lock(&key_serial_lock); | |
1da177e4 | 148 | |
9ad0830f | 149 | attempt_insertion: |
1da177e4 LT |
150 | parent = NULL; |
151 | p = &key_serial_tree.rb_node; | |
152 | ||
153 | while (*p) { | |
154 | parent = *p; | |
155 | xkey = rb_entry(parent, struct key, serial_node); | |
156 | ||
157 | if (key->serial < xkey->serial) | |
158 | p = &(*p)->rb_left; | |
159 | else if (key->serial > xkey->serial) | |
160 | p = &(*p)->rb_right; | |
161 | else | |
162 | goto serial_exists; | |
163 | } | |
9ad0830f DH |
164 | |
165 | /* we've found a suitable hole - arrange for this key to occupy it */ | |
166 | rb_link_node(&key->serial_node, parent, p); | |
167 | rb_insert_color(&key->serial_node, &key_serial_tree); | |
168 | ||
169 | spin_unlock(&key_serial_lock); | |
170 | return; | |
1da177e4 LT |
171 | |
172 | /* we found a key with the proposed serial number - walk the tree from | |
173 | * that point looking for the next unused serial number */ | |
e51f6d34 | 174 | serial_exists: |
1da177e4 | 175 | for (;;) { |
e51f6d34 | 176 | key->serial++; |
9ad0830f DH |
177 | if (key->serial < 3) { |
178 | key->serial = 3; | |
179 | goto attempt_insertion; | |
180 | } | |
1da177e4 LT |
181 | |
182 | parent = rb_next(parent); | |
183 | if (!parent) | |
9ad0830f | 184 | goto attempt_insertion; |
1da177e4 LT |
185 | |
186 | xkey = rb_entry(parent, struct key, serial_node); | |
187 | if (key->serial < xkey->serial) | |
9ad0830f | 188 | goto attempt_insertion; |
1da177e4 | 189 | } |
a8b17ed0 | 190 | } |
1da177e4 | 191 | |
973c9f4f DH |
192 | /** |
193 | * key_alloc - Allocate a key of the specified type. | |
194 | * @type: The type of key to allocate. | |
195 | * @desc: The key description to allow the key to be searched out. | |
196 | * @uid: The owner of the new key. | |
197 | * @gid: The group ID for the new key's group permissions. | |
198 | * @cred: The credentials specifying UID namespace. | |
028db3e2 | 199 | * @perm: The permissions mask of the new key. |
973c9f4f | 200 | * @flags: Flags specifying quota properties. |
2b6aa412 | 201 | * @restrict_link: Optional link restriction for new keyrings. |
973c9f4f DH |
202 | * |
203 | * Allocate a key of the specified type with the attributes given. The key is | |
204 | * returned in an uninstantiated state and the caller needs to instantiate the | |
205 | * key before returning. | |
206 | * | |
2b6aa412 MM |
207 | * The restrict_link structure (if not NULL) will be freed when the |
208 | * keyring is destroyed, so it must be dynamically allocated. | |
209 | * | |
973c9f4f DH |
210 | * The user's key count quota is updated to reflect the creation of the key and |
211 | * the user's key data quota has the default for the key type reserved. The | |
212 | * instantiation function should amend this as necessary. If insufficient | |
213 | * quota is available, -EDQUOT will be returned. | |
214 | * | |
215 | * The LSM security modules can prevent a key being created, in which case | |
216 | * -EACCES will be returned. | |
217 | * | |
218 | * Returns a pointer to the new key if successful and an error code otherwise. | |
219 | * | |
220 | * Note that the caller needs to ensure the key type isn't uninstantiated. | |
221 | * Internally this can be done by locking key_types_sem. Externally, this can | |
222 | * be done by either never unregistering the key type, or making sure | |
223 | * key_alloc() calls don't race with module unloading. | |
1da177e4 LT |
224 | */ |
225 | struct key *key_alloc(struct key_type *type, const char *desc, | |
9a56c2db | 226 | kuid_t uid, kgid_t gid, const struct cred *cred, |
028db3e2 | 227 | key_perm_t perm, unsigned long flags, |
2b6aa412 | 228 | struct key_restriction *restrict_link) |
1da177e4 LT |
229 | { |
230 | struct key_user *user = NULL; | |
231 | struct key *key; | |
232 | size_t desclen, quotalen; | |
29db9190 | 233 | int ret; |
1da177e4 LT |
234 | |
235 | key = ERR_PTR(-EINVAL); | |
236 | if (!desc || !*desc) | |
237 | goto error; | |
238 | ||
b9fffa38 DH |
239 | if (type->vet_description) { |
240 | ret = type->vet_description(desc); | |
241 | if (ret < 0) { | |
242 | key = ERR_PTR(ret); | |
243 | goto error; | |
244 | } | |
245 | } | |
246 | ||
16feef43 DH |
247 | desclen = strlen(desc); |
248 | quotalen = desclen + 1 + type->def_datalen; | |
1da177e4 LT |
249 | |
250 | /* get hold of the key tracking for this user */ | |
9a56c2db | 251 | user = key_user_lookup(uid); |
1da177e4 LT |
252 | if (!user) |
253 | goto no_memory_1; | |
254 | ||
255 | /* check that the user's quota permits allocation of another key and | |
256 | * its description */ | |
7e047ef5 | 257 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
9a56c2db | 258 | unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf | 259 | key_quota_root_maxkeys : key_quota_maxkeys; |
9a56c2db | 260 | unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
261 | key_quota_root_maxbytes : key_quota_maxbytes; |
262 | ||
1da177e4 | 263 | spin_lock(&user->lock); |
7e047ef5 | 264 | if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { |
a08bf91c EB |
265 | if (user->qnkeys + 1 > maxkeys || |
266 | user->qnbytes + quotalen > maxbytes || | |
0b77f5bf | 267 | user->qnbytes + quotalen < user->qnbytes) |
7e047ef5 DH |
268 | goto no_quota; |
269 | } | |
1da177e4 LT |
270 | |
271 | user->qnkeys++; | |
272 | user->qnbytes += quotalen; | |
273 | spin_unlock(&user->lock); | |
274 | } | |
275 | ||
276 | /* allocate and initialise the key and its description */ | |
2480f57f | 277 | key = kmem_cache_zalloc(key_jar, GFP_KERNEL); |
1da177e4 LT |
278 | if (!key) |
279 | goto no_memory_2; | |
280 | ||
5057975a DC |
281 | key->index_key.desc_len = desclen; |
282 | key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); | |
27720e75 | 283 | if (!key->index_key.description) |
5057975a | 284 | goto no_memory_3; |
355ef8e1 | 285 | key->index_key.type = type; |
f771fde8 | 286 | key_set_index_key(&key->index_key); |
1da177e4 | 287 | |
fff29291 | 288 | refcount_set(&key->usage, 1); |
1da177e4 | 289 | init_rwsem(&key->sem); |
7845bc39 | 290 | lockdep_set_class(&key->sem, &type->lock_class); |
1da177e4 LT |
291 | key->user = user; |
292 | key->quotalen = quotalen; | |
293 | key->datalen = type->def_datalen; | |
294 | key->uid = uid; | |
295 | key->gid = gid; | |
028db3e2 | 296 | key->perm = perm; |
39299bdd | 297 | key->expiry = TIME64_MAX; |
5ac7eace | 298 | key->restrict_link = restrict_link; |
7c1857bd | 299 | key->last_used_at = ktime_get_real_seconds(); |
1da177e4 | 300 | |
7e047ef5 | 301 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
76d8aeab | 302 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
5d2787cf DH |
303 | if (flags & KEY_ALLOC_BUILT_IN) |
304 | key->flags |= 1 << KEY_FLAG_BUILTIN; | |
237bbd29 EB |
305 | if (flags & KEY_ALLOC_UID_KEYRING) |
306 | key->flags |= 1 << KEY_FLAG_UID_KEYRING; | |
4993e1f9 DH |
307 | if (flags & KEY_ALLOC_SET_KEEP) |
308 | key->flags |= 1 << KEY_FLAG_KEEP; | |
1da177e4 | 309 | |
1da177e4 LT |
310 | #ifdef KEY_DEBUGGING |
311 | key->magic = KEY_DEBUG_MAGIC; | |
312 | #endif | |
313 | ||
29db9190 | 314 | /* let the security module know about the key */ |
d84f4f99 | 315 | ret = security_key_alloc(key, cred, flags); |
29db9190 DH |
316 | if (ret < 0) |
317 | goto security_error; | |
318 | ||
1da177e4 | 319 | /* publish the key by giving it a serial number */ |
3b6e4de0 | 320 | refcount_inc(&key->domain_tag->usage); |
1da177e4 LT |
321 | atomic_inc(&user->nkeys); |
322 | key_alloc_serial(key); | |
323 | ||
29db9190 | 324 | error: |
1da177e4 LT |
325 | return key; |
326 | ||
29db9190 DH |
327 | security_error: |
328 | kfree(key->description); | |
1da177e4 | 329 | kmem_cache_free(key_jar, key); |
7e047ef5 | 330 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
1da177e4 LT |
331 | spin_lock(&user->lock); |
332 | user->qnkeys--; | |
333 | user->qnbytes -= quotalen; | |
334 | spin_unlock(&user->lock); | |
335 | } | |
336 | key_user_put(user); | |
29db9190 DH |
337 | key = ERR_PTR(ret); |
338 | goto error; | |
339 | ||
340 | no_memory_3: | |
341 | kmem_cache_free(key_jar, key); | |
342 | no_memory_2: | |
7e047ef5 | 343 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
29db9190 DH |
344 | spin_lock(&user->lock); |
345 | user->qnkeys--; | |
346 | user->qnbytes -= quotalen; | |
347 | spin_unlock(&user->lock); | |
348 | } | |
349 | key_user_put(user); | |
350 | no_memory_1: | |
1da177e4 LT |
351 | key = ERR_PTR(-ENOMEM); |
352 | goto error; | |
353 | ||
29db9190 | 354 | no_quota: |
1da177e4 LT |
355 | spin_unlock(&user->lock); |
356 | key_user_put(user); | |
357 | key = ERR_PTR(-EDQUOT); | |
358 | goto error; | |
a8b17ed0 | 359 | } |
1da177e4 LT |
360 | EXPORT_SYMBOL(key_alloc); |
361 | ||
973c9f4f DH |
362 | /** |
363 | * key_payload_reserve - Adjust data quota reservation for the key's payload | |
364 | * @key: The key to make the reservation for. | |
365 | * @datalen: The amount of data payload the caller now wants. | |
366 | * | |
367 | * Adjust the amount of the owning user's key data quota that a key reserves. | |
368 | * If the amount is increased, then -EDQUOT may be returned if there isn't | |
369 | * enough free quota available. | |
370 | * | |
371 | * If successful, 0 is returned. | |
1da177e4 LT |
372 | */ |
373 | int key_payload_reserve(struct key *key, size_t datalen) | |
374 | { | |
c5b60b5e | 375 | int delta = (int)datalen - key->datalen; |
1da177e4 LT |
376 | int ret = 0; |
377 | ||
378 | key_check(key); | |
379 | ||
380 | /* contemplate the quota adjustment */ | |
76d8aeab | 381 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
9a56c2db | 382 | unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
383 | key_quota_root_maxbytes : key_quota_maxbytes; |
384 | ||
1da177e4 LT |
385 | spin_lock(&key->user->lock); |
386 | ||
387 | if (delta > 0 && | |
2e356101 | 388 | (key->user->qnbytes + delta > maxbytes || |
0b77f5bf | 389 | key->user->qnbytes + delta < key->user->qnbytes)) { |
1da177e4 LT |
390 | ret = -EDQUOT; |
391 | } | |
392 | else { | |
393 | key->user->qnbytes += delta; | |
394 | key->quotalen += delta; | |
395 | } | |
396 | spin_unlock(&key->user->lock); | |
397 | } | |
398 | ||
399 | /* change the recorded data length if that didn't generate an error */ | |
400 | if (ret == 0) | |
401 | key->datalen = datalen; | |
402 | ||
403 | return ret; | |
a8b17ed0 | 404 | } |
1da177e4 LT |
405 | EXPORT_SYMBOL(key_payload_reserve); |
406 | ||
363b02da DH |
407 | /* |
408 | * Change the key state to being instantiated. | |
409 | */ | |
410 | static void mark_key_instantiated(struct key *key, int reject_error) | |
411 | { | |
412 | /* Commit the payload before setting the state; barrier versus | |
413 | * key_read_state(). | |
414 | */ | |
415 | smp_store_release(&key->state, | |
416 | (reject_error < 0) ? reject_error : KEY_IS_POSITIVE); | |
417 | } | |
418 | ||
1da177e4 | 419 | /* |
973c9f4f DH |
420 | * Instantiate a key and link it into the target keyring atomically. Must be |
421 | * called with the target keyring's semaphore writelocked. The target key's | |
422 | * semaphore need not be locked as instantiation is serialised by | |
423 | * key_construction_mutex. | |
1da177e4 LT |
424 | */ |
425 | static int __key_instantiate_and_link(struct key *key, | |
cf7f601c | 426 | struct key_preparsed_payload *prep, |
3e30148c | 427 | struct key *keyring, |
f70e2e06 | 428 | struct key *authkey, |
b2a4df20 | 429 | struct assoc_array_edit **_edit) |
1da177e4 LT |
430 | { |
431 | int ret, awaken; | |
432 | ||
433 | key_check(key); | |
434 | key_check(keyring); | |
435 | ||
436 | awaken = 0; | |
437 | ret = -EBUSY; | |
438 | ||
76181c13 | 439 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
440 | |
441 | /* can't instantiate twice */ | |
363b02da | 442 | if (key->state == KEY_IS_UNINSTANTIATED) { |
1da177e4 | 443 | /* instantiate the key */ |
cf7f601c | 444 | ret = key->type->instantiate(key, prep); |
1da177e4 LT |
445 | |
446 | if (ret == 0) { | |
447 | /* mark the key as being instantiated */ | |
1da177e4 | 448 | atomic_inc(&key->user->nikeys); |
363b02da | 449 | mark_key_instantiated(key, 0); |
f7e47677 | 450 | notify_key(key, NOTIFY_KEY_INSTANTIATED, 0); |
1da177e4 | 451 | |
76d8aeab | 452 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 453 | awaken = 1; |
1da177e4 LT |
454 | |
455 | /* and link it into the destination keyring */ | |
d3600bcf | 456 | if (keyring) { |
eee04502 DH |
457 | if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) |
458 | set_bit(KEY_FLAG_KEEP, &key->flags); | |
d3600bcf | 459 | |
f7e47677 | 460 | __key_link(keyring, key, _edit); |
d3600bcf | 461 | } |
3e30148c DH |
462 | |
463 | /* disable the authorisation key */ | |
d84f4f99 | 464 | if (authkey) |
a09003b5 | 465 | key_invalidate(authkey); |
7dfa0ca6 | 466 | |
39299bdd | 467 | key_set_expiry(key, prep->expiry); |
1da177e4 LT |
468 | } |
469 | } | |
470 | ||
76181c13 | 471 | mutex_unlock(&key_construction_mutex); |
1da177e4 LT |
472 | |
473 | /* wake up anyone waiting for a key to be constructed */ | |
474 | if (awaken) | |
76181c13 | 475 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 LT |
476 | |
477 | return ret; | |
a8b17ed0 | 478 | } |
1da177e4 | 479 | |
973c9f4f DH |
480 | /** |
481 | * key_instantiate_and_link - Instantiate a key and link it into the keyring. | |
482 | * @key: The key to instantiate. | |
483 | * @data: The data to use to instantiate the keyring. | |
484 | * @datalen: The length of @data. | |
485 | * @keyring: Keyring to create a link in on success (or NULL). | |
486 | * @authkey: The authorisation token permitting instantiation. | |
487 | * | |
488 | * Instantiate a key that's in the uninstantiated state using the provided data | |
489 | * and, if successful, link it in to the destination keyring if one is | |
490 | * supplied. | |
491 | * | |
492 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
493 | * waiting for the key is woken up. If the key was already instantiated, | |
494 | * -EBUSY will be returned. | |
1da177e4 LT |
495 | */ |
496 | int key_instantiate_and_link(struct key *key, | |
497 | const void *data, | |
498 | size_t datalen, | |
3e30148c | 499 | struct key *keyring, |
d84f4f99 | 500 | struct key *authkey) |
1da177e4 | 501 | { |
cf7f601c | 502 | struct key_preparsed_payload prep; |
df593ee2 | 503 | struct assoc_array_edit *edit = NULL; |
1da177e4 LT |
504 | int ret; |
505 | ||
cf7f601c | 506 | memset(&prep, 0, sizeof(prep)); |
8eb62169 | 507 | prep.orig_description = key->description; |
cf7f601c DH |
508 | prep.data = data; |
509 | prep.datalen = datalen; | |
510 | prep.quotalen = key->type->def_datalen; | |
0a9dd0e0 | 511 | prep.expiry = TIME64_MAX; |
cf7f601c DH |
512 | if (key->type->preparse) { |
513 | ret = key->type->preparse(&prep); | |
514 | if (ret < 0) | |
515 | goto error; | |
516 | } | |
517 | ||
f70e2e06 | 518 | if (keyring) { |
df593ee2 | 519 | ret = __key_link_lock(keyring, &key->index_key); |
4a420896 MM |
520 | if (ret < 0) |
521 | goto error; | |
522 | ||
df593ee2 DH |
523 | ret = __key_link_begin(keyring, &key->index_key, &edit); |
524 | if (ret < 0) | |
525 | goto error_link_end; | |
526 | ||
2b6aa412 MM |
527 | if (keyring->restrict_link && keyring->restrict_link->check) { |
528 | struct key_restriction *keyres = keyring->restrict_link; | |
529 | ||
530 | ret = keyres->check(keyring, key->type, &prep.payload, | |
531 | keyres->key); | |
5ac7eace | 532 | if (ret < 0) |
4a420896 | 533 | goto error_link_end; |
5ac7eace | 534 | } |
f70e2e06 | 535 | } |
1da177e4 | 536 | |
b2a4df20 | 537 | ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit); |
1da177e4 | 538 | |
4a420896 | 539 | error_link_end: |
1da177e4 | 540 | if (keyring) |
b2a4df20 | 541 | __key_link_end(keyring, &key->index_key, edit); |
1da177e4 | 542 | |
4d8c0250 | 543 | error: |
cf7f601c DH |
544 | if (key->type->preparse) |
545 | key->type->free_preparse(&prep); | |
1da177e4 | 546 | return ret; |
a8b17ed0 | 547 | } |
1da177e4 LT |
548 | |
549 | EXPORT_SYMBOL(key_instantiate_and_link); | |
550 | ||
973c9f4f | 551 | /** |
fdd1b945 | 552 | * key_reject_and_link - Negatively instantiate a key and link it into the keyring. |
973c9f4f DH |
553 | * @key: The key to instantiate. |
554 | * @timeout: The timeout on the negative key. | |
fdd1b945 | 555 | * @error: The error to return when the key is hit. |
973c9f4f DH |
556 | * @keyring: Keyring to create a link in on success (or NULL). |
557 | * @authkey: The authorisation token permitting instantiation. | |
558 | * | |
559 | * Negatively instantiate a key that's in the uninstantiated state and, if | |
fdd1b945 DH |
560 | * successful, set its timeout and stored error and link it in to the |
561 | * destination keyring if one is supplied. The key and any links to the key | |
562 | * will be automatically garbage collected after the timeout expires. | |
973c9f4f DH |
563 | * |
564 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
fdd1b945 DH |
565 | * them to return the stored error code (typically ENOKEY) until the negative |
566 | * key expires. | |
973c9f4f DH |
567 | * |
568 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
569 | * waiting for the key is woken up. If the key was already instantiated, | |
570 | * -EBUSY will be returned. | |
1da177e4 | 571 | */ |
fdd1b945 | 572 | int key_reject_and_link(struct key *key, |
1da177e4 | 573 | unsigned timeout, |
fdd1b945 | 574 | unsigned error, |
3e30148c | 575 | struct key *keyring, |
d84f4f99 | 576 | struct key *authkey) |
1da177e4 | 577 | { |
df593ee2 | 578 | struct assoc_array_edit *edit = NULL; |
f70e2e06 | 579 | int ret, awaken, link_ret = 0; |
1da177e4 LT |
580 | |
581 | key_check(key); | |
582 | key_check(keyring); | |
583 | ||
584 | awaken = 0; | |
585 | ret = -EBUSY; | |
586 | ||
5ac7eace DH |
587 | if (keyring) { |
588 | if (keyring->restrict_link) | |
589 | return -EPERM; | |
590 | ||
df593ee2 DH |
591 | link_ret = __key_link_lock(keyring, &key->index_key); |
592 | if (link_ret == 0) { | |
593 | link_ret = __key_link_begin(keyring, &key->index_key, &edit); | |
594 | if (link_ret < 0) | |
595 | __key_link_end(keyring, &key->index_key, edit); | |
596 | } | |
5ac7eace | 597 | } |
1da177e4 | 598 | |
76181c13 | 599 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
600 | |
601 | /* can't instantiate twice */ | |
363b02da | 602 | if (key->state == KEY_IS_UNINSTANTIATED) { |
1da177e4 | 603 | /* mark the key as being negatively instantiated */ |
1da177e4 | 604 | atomic_inc(&key->user->nikeys); |
363b02da | 605 | mark_key_instantiated(key, -error); |
f7e47677 | 606 | notify_key(key, NOTIFY_KEY_INSTANTIATED, -error); |
39299bdd | 607 | key_set_expiry(key, ktime_get_real_seconds() + timeout); |
1da177e4 | 608 | |
76d8aeab | 609 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 610 | awaken = 1; |
1da177e4 | 611 | |
1da177e4 LT |
612 | ret = 0; |
613 | ||
614 | /* and link it into the destination keyring */ | |
f70e2e06 | 615 | if (keyring && link_ret == 0) |
f7e47677 | 616 | __key_link(keyring, key, &edit); |
3e30148c DH |
617 | |
618 | /* disable the authorisation key */ | |
d84f4f99 | 619 | if (authkey) |
a09003b5 | 620 | key_invalidate(authkey); |
1da177e4 LT |
621 | } |
622 | ||
76181c13 | 623 | mutex_unlock(&key_construction_mutex); |
1da177e4 | 624 | |
38327424 | 625 | if (keyring && link_ret == 0) |
b2a4df20 | 626 | __key_link_end(keyring, &key->index_key, edit); |
1da177e4 LT |
627 | |
628 | /* wake up anyone waiting for a key to be constructed */ | |
629 | if (awaken) | |
76181c13 | 630 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 | 631 | |
f70e2e06 | 632 | return ret == 0 ? link_ret : ret; |
a8b17ed0 | 633 | } |
fdd1b945 | 634 | EXPORT_SYMBOL(key_reject_and_link); |
1da177e4 | 635 | |
973c9f4f DH |
636 | /** |
637 | * key_put - Discard a reference to a key. | |
638 | * @key: The key to discard a reference from. | |
639 | * | |
640 | * Discard a reference to a key, and when all the references are gone, we | |
641 | * schedule the cleanup task to come and pull it out of the tree in process | |
642 | * context at some later time. | |
1da177e4 LT |
643 | */ |
644 | void key_put(struct key *key) | |
645 | { | |
646 | if (key) { | |
647 | key_check(key); | |
648 | ||
fff29291 | 649 | if (refcount_dec_and_test(&key->usage)) |
3b07e9ca | 650 | schedule_work(&key_gc_work); |
1da177e4 | 651 | } |
a8b17ed0 | 652 | } |
1da177e4 LT |
653 | EXPORT_SYMBOL(key_put); |
654 | ||
1da177e4 | 655 | /* |
973c9f4f | 656 | * Find a key by its serial number. |
1da177e4 LT |
657 | */ |
658 | struct key *key_lookup(key_serial_t id) | |
659 | { | |
660 | struct rb_node *n; | |
661 | struct key *key; | |
662 | ||
663 | spin_lock(&key_serial_lock); | |
664 | ||
665 | /* search the tree for the specified key */ | |
666 | n = key_serial_tree.rb_node; | |
667 | while (n) { | |
668 | key = rb_entry(n, struct key, serial_node); | |
669 | ||
670 | if (id < key->serial) | |
671 | n = n->rb_left; | |
672 | else if (id > key->serial) | |
673 | n = n->rb_right; | |
674 | else | |
675 | goto found; | |
676 | } | |
677 | ||
973c9f4f | 678 | not_found: |
1da177e4 LT |
679 | key = ERR_PTR(-ENOKEY); |
680 | goto error; | |
681 | ||
973c9f4f | 682 | found: |
92347cfd MR |
683 | /* A key is allowed to be looked up only if someone still owns a |
684 | * reference to it - otherwise it's awaiting the gc. | |
1da177e4 | 685 | */ |
92347cfd MR |
686 | if (!refcount_inc_not_zero(&key->usage)) |
687 | goto not_found; | |
1da177e4 | 688 | |
973c9f4f | 689 | error: |
1da177e4 LT |
690 | spin_unlock(&key_serial_lock); |
691 | return key; | |
a8b17ed0 | 692 | } |
037c3431 | 693 | EXPORT_SYMBOL(key_lookup); |
1da177e4 | 694 | |
1da177e4 | 695 | /* |
973c9f4f DH |
696 | * Find and lock the specified key type against removal. |
697 | * | |
698 | * We return with the sem read-locked if successful. If the type wasn't | |
699 | * available -ENOKEY is returned instead. | |
1da177e4 LT |
700 | */ |
701 | struct key_type *key_type_lookup(const char *type) | |
702 | { | |
703 | struct key_type *ktype; | |
704 | ||
705 | down_read(&key_types_sem); | |
706 | ||
707 | /* look up the key type to see if it's one of the registered kernel | |
708 | * types */ | |
709 | list_for_each_entry(ktype, &key_types_list, link) { | |
710 | if (strcmp(ktype->name, type) == 0) | |
711 | goto found_kernel_type; | |
712 | } | |
713 | ||
714 | up_read(&key_types_sem); | |
715 | ktype = ERR_PTR(-ENOKEY); | |
716 | ||
973c9f4f | 717 | found_kernel_type: |
1da177e4 | 718 | return ktype; |
a8b17ed0 | 719 | } |
1da177e4 | 720 | |
59e6b9c1 BS |
721 | void key_set_timeout(struct key *key, unsigned timeout) |
722 | { | |
39299bdd | 723 | time64_t expiry = TIME64_MAX; |
59e6b9c1 BS |
724 | |
725 | /* make the changes with the locks held to prevent races */ | |
726 | down_write(&key->sem); | |
727 | ||
074d5898 BW |
728 | if (timeout > 0) |
729 | expiry = ktime_get_real_seconds() + timeout; | |
39299bdd | 730 | key_set_expiry(key, expiry); |
59e6b9c1 BS |
731 | |
732 | up_write(&key->sem); | |
733 | } | |
734 | EXPORT_SYMBOL_GPL(key_set_timeout); | |
735 | ||
1da177e4 | 736 | /* |
973c9f4f | 737 | * Unlock a key type locked by key_type_lookup(). |
1da177e4 LT |
738 | */ |
739 | void key_type_put(struct key_type *ktype) | |
740 | { | |
741 | up_read(&key_types_sem); | |
a8b17ed0 | 742 | } |
1da177e4 | 743 | |
1da177e4 | 744 | /* |
973c9f4f DH |
745 | * Attempt to update an existing key. |
746 | * | |
747 | * The key is given to us with an incremented refcount that we need to discard | |
748 | * if we get an error. | |
1da177e4 | 749 | */ |
664cceb0 | 750 | static inline key_ref_t __key_update(key_ref_t key_ref, |
cf7f601c | 751 | struct key_preparsed_payload *prep) |
1da177e4 | 752 | { |
664cceb0 | 753 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
754 | int ret; |
755 | ||
756 | /* need write permission on the key to update it */ | |
f5895943 | 757 | ret = key_permission(key_ref, KEY_NEED_WRITE); |
29db9190 | 758 | if (ret < 0) |
1da177e4 LT |
759 | goto error; |
760 | ||
761 | ret = -EEXIST; | |
762 | if (!key->type->update) | |
763 | goto error; | |
764 | ||
765 | down_write(&key->sem); | |
766 | ||
cf7f601c | 767 | ret = key->type->update(key, prep); |
f7e47677 | 768 | if (ret == 0) { |
363b02da DH |
769 | /* Updating a negative key positively instantiates it */ |
770 | mark_key_instantiated(key, 0); | |
f7e47677 DH |
771 | notify_key(key, NOTIFY_KEY_UPDATED, 0); |
772 | } | |
1da177e4 LT |
773 | |
774 | up_write(&key->sem); | |
775 | ||
776 | if (ret < 0) | |
777 | goto error; | |
664cceb0 DH |
778 | out: |
779 | return key_ref; | |
1da177e4 | 780 | |
664cceb0 | 781 | error: |
1da177e4 | 782 | key_put(key); |
664cceb0 | 783 | key_ref = ERR_PTR(ret); |
1da177e4 | 784 | goto out; |
a8b17ed0 | 785 | } |
1da177e4 | 786 | |
6c1976ad TW |
787 | /* |
788 | * Create or potentially update a key. The combined logic behind | |
789 | * key_create_or_update() and key_create() | |
1da177e4 | 790 | */ |
6c1976ad TW |
791 | static key_ref_t __key_create_or_update(key_ref_t keyring_ref, |
792 | const char *type, | |
793 | const char *description, | |
794 | const void *payload, | |
795 | size_t plen, | |
796 | key_perm_t perm, | |
797 | unsigned long flags, | |
798 | bool allow_update) | |
1da177e4 | 799 | { |
16feef43 DH |
800 | struct keyring_index_key index_key = { |
801 | .description = description, | |
802 | }; | |
cf7f601c | 803 | struct key_preparsed_payload prep; |
df593ee2 | 804 | struct assoc_array_edit *edit = NULL; |
d84f4f99 | 805 | const struct cred *cred = current_cred(); |
664cceb0 | 806 | struct key *keyring, *key = NULL; |
664cceb0 | 807 | key_ref_t key_ref; |
1da177e4 | 808 | int ret; |
2b6aa412 | 809 | struct key_restriction *restrict_link = NULL; |
1da177e4 | 810 | |
1da177e4 LT |
811 | /* look up the key type to see if it's one of the registered kernel |
812 | * types */ | |
16feef43 DH |
813 | index_key.type = key_type_lookup(type); |
814 | if (IS_ERR(index_key.type)) { | |
664cceb0 | 815 | key_ref = ERR_PTR(-ENODEV); |
1da177e4 LT |
816 | goto error; |
817 | } | |
818 | ||
664cceb0 | 819 | key_ref = ERR_PTR(-EINVAL); |
c06cfb08 | 820 | if (!index_key.type->instantiate || |
16feef43 | 821 | (!index_key.description && !index_key.type->preparse)) |
cf7f601c | 822 | goto error_put_type; |
1da177e4 | 823 | |
664cceb0 DH |
824 | keyring = key_ref_to_ptr(keyring_ref); |
825 | ||
826 | key_check(keyring); | |
827 | ||
5ac7eace DH |
828 | if (!(flags & KEY_ALLOC_BYPASS_RESTRICTION)) |
829 | restrict_link = keyring->restrict_link; | |
830 | ||
c3a9d654 DH |
831 | key_ref = ERR_PTR(-ENOTDIR); |
832 | if (keyring->type != &key_type_keyring) | |
cf7f601c DH |
833 | goto error_put_type; |
834 | ||
835 | memset(&prep, 0, sizeof(prep)); | |
8eb62169 | 836 | prep.orig_description = description; |
cf7f601c DH |
837 | prep.data = payload; |
838 | prep.datalen = plen; | |
16feef43 | 839 | prep.quotalen = index_key.type->def_datalen; |
0a9dd0e0 | 840 | prep.expiry = TIME64_MAX; |
16feef43 DH |
841 | if (index_key.type->preparse) { |
842 | ret = index_key.type->preparse(&prep); | |
cf7f601c DH |
843 | if (ret < 0) { |
844 | key_ref = ERR_PTR(ret); | |
4d8c0250 | 845 | goto error_free_prep; |
cf7f601c | 846 | } |
16feef43 DH |
847 | if (!index_key.description) |
848 | index_key.description = prep.description; | |
cf7f601c | 849 | key_ref = ERR_PTR(-EINVAL); |
16feef43 | 850 | if (!index_key.description) |
cf7f601c DH |
851 | goto error_free_prep; |
852 | } | |
16feef43 | 853 | index_key.desc_len = strlen(index_key.description); |
f771fde8 | 854 | key_set_index_key(&index_key); |
c3a9d654 | 855 | |
df593ee2 | 856 | ret = __key_link_lock(keyring, &index_key); |
4a420896 MM |
857 | if (ret < 0) { |
858 | key_ref = ERR_PTR(ret); | |
859 | goto error_free_prep; | |
860 | } | |
861 | ||
df593ee2 DH |
862 | ret = __key_link_begin(keyring, &index_key, &edit); |
863 | if (ret < 0) { | |
864 | key_ref = ERR_PTR(ret); | |
865 | goto error_link_end; | |
866 | } | |
867 | ||
2b6aa412 MM |
868 | if (restrict_link && restrict_link->check) { |
869 | ret = restrict_link->check(keyring, index_key.type, | |
870 | &prep.payload, restrict_link->key); | |
5ac7eace DH |
871 | if (ret < 0) { |
872 | key_ref = ERR_PTR(ret); | |
4a420896 | 873 | goto error_link_end; |
5ac7eace DH |
874 | } |
875 | } | |
008643b8 | 876 | |
664cceb0 DH |
877 | /* if we're going to allocate a new key, we're going to have |
878 | * to modify the keyring */ | |
f5895943 | 879 | ret = key_permission(keyring_ref, KEY_NEED_WRITE); |
29db9190 DH |
880 | if (ret < 0) { |
881 | key_ref = ERR_PTR(ret); | |
cf7f601c | 882 | goto error_link_end; |
29db9190 | 883 | } |
664cceb0 | 884 | |
6c1976ad TW |
885 | /* if it's requested and possible to update this type of key, search |
886 | * for an existing key of the same type and description in the | |
887 | * destination keyring and update that instead if possible | |
1da177e4 | 888 | */ |
6c1976ad TW |
889 | if (allow_update) { |
890 | if (index_key.type->update) { | |
891 | key_ref = find_key_to_update(keyring_ref, &index_key); | |
892 | if (key_ref) | |
893 | goto found_matching_key; | |
894 | } | |
895 | } else { | |
b2a4df20 | 896 | key_ref = find_key_to_update(keyring_ref, &index_key); |
6c1976ad TW |
897 | if (key_ref) { |
898 | key_ref_put(key_ref); | |
899 | key_ref = ERR_PTR(-EEXIST); | |
900 | goto error_link_end; | |
901 | } | |
1d9b7d97 | 902 | } |
1da177e4 | 903 | |
028db3e2 LT |
904 | /* if the client doesn't provide, decide on the permissions we want */ |
905 | if (perm == KEY_PERM_UNDEF) { | |
906 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; | |
907 | perm |= KEY_USR_VIEW; | |
908 | ||
909 | if (index_key.type->read) | |
910 | perm |= KEY_POS_READ; | |
911 | ||
912 | if (index_key.type == &key_type_keyring || | |
913 | index_key.type->update) | |
914 | perm |= KEY_POS_WRITE; | |
915 | } | |
916 | ||
1da177e4 | 917 | /* allocate a new key */ |
16feef43 | 918 | key = key_alloc(index_key.type, index_key.description, |
028db3e2 | 919 | cred->fsuid, cred->fsgid, cred, perm, flags, NULL); |
1da177e4 | 920 | if (IS_ERR(key)) { |
e231c2ee | 921 | key_ref = ERR_CAST(key); |
cf7f601c | 922 | goto error_link_end; |
1da177e4 LT |
923 | } |
924 | ||
925 | /* instantiate it and link it into the target keyring */ | |
b2a4df20 | 926 | ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit); |
1da177e4 LT |
927 | if (ret < 0) { |
928 | key_put(key); | |
664cceb0 | 929 | key_ref = ERR_PTR(ret); |
cf7f601c | 930 | goto error_link_end; |
1da177e4 LT |
931 | } |
932 | ||
cb1aa382 LR |
933 | ima_post_key_create_or_update(keyring, key, payload, plen, |
934 | flags, true); | |
935 | ||
664cceb0 DH |
936 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
937 | ||
cf7f601c | 938 | error_link_end: |
b2a4df20 | 939 | __key_link_end(keyring, &index_key, edit); |
cf7f601c | 940 | error_free_prep: |
16feef43 DH |
941 | if (index_key.type->preparse) |
942 | index_key.type->free_preparse(&prep); | |
cf7f601c | 943 | error_put_type: |
16feef43 | 944 | key_type_put(index_key.type); |
cf7f601c | 945 | error: |
664cceb0 | 946 | return key_ref; |
1da177e4 LT |
947 | |
948 | found_matching_key: | |
949 | /* we found a matching key, so we're going to try to update it | |
950 | * - we can drop the locks first as we have the key pinned | |
951 | */ | |
b2a4df20 | 952 | __key_link_end(keyring, &index_key, edit); |
1da177e4 | 953 | |
60ff5b2f DH |
954 | key = key_ref_to_ptr(key_ref); |
955 | if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) { | |
956 | ret = wait_for_key_construction(key, true); | |
957 | if (ret < 0) { | |
958 | key_ref_put(key_ref); | |
959 | key_ref = ERR_PTR(ret); | |
960 | goto error_free_prep; | |
961 | } | |
962 | } | |
963 | ||
cf7f601c | 964 | key_ref = __key_update(key_ref, &prep); |
cb1aa382 LR |
965 | |
966 | if (!IS_ERR(key_ref)) | |
967 | ima_post_key_create_or_update(keyring, key, | |
968 | payload, plen, | |
969 | flags, false); | |
970 | ||
cf7f601c | 971 | goto error_free_prep; |
a8b17ed0 | 972 | } |
6c1976ad TW |
973 | |
974 | /** | |
975 | * key_create_or_update - Update or create and instantiate a key. | |
976 | * @keyring_ref: A pointer to the destination keyring with possession flag. | |
977 | * @type: The type of key. | |
978 | * @description: The searchable description for the key. | |
979 | * @payload: The data to use to instantiate or update the key. | |
980 | * @plen: The length of @payload. | |
981 | * @perm: The permissions mask for a new key. | |
982 | * @flags: The quota flags for a new key. | |
983 | * | |
984 | * Search the destination keyring for a key of the same description and if one | |
985 | * is found, update it, otherwise create and instantiate a new one and create a | |
986 | * link to it from that keyring. | |
987 | * | |
988 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be | |
989 | * concocted. | |
990 | * | |
991 | * Returns a pointer to the new key if successful, -ENODEV if the key type | |
992 | * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the | |
993 | * caller isn't permitted to modify the keyring or the LSM did not permit | |
994 | * creation of the key. | |
995 | * | |
996 | * On success, the possession flag from the keyring ref will be tacked on to | |
997 | * the key ref before it is returned. | |
998 | */ | |
999 | key_ref_t key_create_or_update(key_ref_t keyring_ref, | |
1000 | const char *type, | |
1001 | const char *description, | |
1002 | const void *payload, | |
1003 | size_t plen, | |
1004 | key_perm_t perm, | |
1005 | unsigned long flags) | |
1006 | { | |
1007 | return __key_create_or_update(keyring_ref, type, description, payload, | |
1008 | plen, perm, flags, true); | |
1009 | } | |
1da177e4 LT |
1010 | EXPORT_SYMBOL(key_create_or_update); |
1011 | ||
6c1976ad TW |
1012 | /** |
1013 | * key_create - Create and instantiate a key. | |
1014 | * @keyring_ref: A pointer to the destination keyring with possession flag. | |
1015 | * @type: The type of key. | |
1016 | * @description: The searchable description for the key. | |
1017 | * @payload: The data to use to instantiate or update the key. | |
1018 | * @plen: The length of @payload. | |
1019 | * @perm: The permissions mask for a new key. | |
1020 | * @flags: The quota flags for a new key. | |
1021 | * | |
1022 | * Create and instantiate a new key and link to it from the destination keyring. | |
1023 | * | |
1024 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be | |
1025 | * concocted. | |
1026 | * | |
1027 | * Returns a pointer to the new key if successful, -EEXIST if a key with the | |
1028 | * same description already exists, -ENODEV if the key type wasn't available, | |
1029 | * -ENOTDIR if the keyring wasn't a keyring, -EACCES if the caller isn't | |
1030 | * permitted to modify the keyring or the LSM did not permit creation of the | |
1031 | * key. | |
1032 | * | |
1033 | * On success, the possession flag from the keyring ref will be tacked on to | |
1034 | * the key ref before it is returned. | |
1035 | */ | |
1036 | key_ref_t key_create(key_ref_t keyring_ref, | |
1037 | const char *type, | |
1038 | const char *description, | |
1039 | const void *payload, | |
1040 | size_t plen, | |
1041 | key_perm_t perm, | |
1042 | unsigned long flags) | |
1043 | { | |
1044 | return __key_create_or_update(keyring_ref, type, description, payload, | |
1045 | plen, perm, flags, false); | |
1046 | } | |
1047 | EXPORT_SYMBOL(key_create); | |
1048 | ||
973c9f4f DH |
1049 | /** |
1050 | * key_update - Update a key's contents. | |
1051 | * @key_ref: The pointer (plus possession flag) to the key. | |
1052 | * @payload: The data to be used to update the key. | |
1053 | * @plen: The length of @payload. | |
1054 | * | |
1055 | * Attempt to update the contents of a key with the given payload data. The | |
1056 | * caller must be granted Write permission on the key. Negative keys can be | |
1057 | * instantiated by this method. | |
1058 | * | |
1059 | * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key | |
1060 | * type does not support updating. The key type may return other errors. | |
1da177e4 | 1061 | */ |
664cceb0 | 1062 | int key_update(key_ref_t key_ref, const void *payload, size_t plen) |
1da177e4 | 1063 | { |
cf7f601c | 1064 | struct key_preparsed_payload prep; |
664cceb0 | 1065 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
1066 | int ret; |
1067 | ||
1068 | key_check(key); | |
1069 | ||
1070 | /* the key must be writable */ | |
f5895943 | 1071 | ret = key_permission(key_ref, KEY_NEED_WRITE); |
29db9190 | 1072 | if (ret < 0) |
63a0b050 | 1073 | return ret; |
1da177e4 LT |
1074 | |
1075 | /* attempt to update it if supported */ | |
cf7f601c | 1076 | if (!key->type->update) |
63a0b050 | 1077 | return -EOPNOTSUPP; |
1da177e4 | 1078 | |
cf7f601c DH |
1079 | memset(&prep, 0, sizeof(prep)); |
1080 | prep.data = payload; | |
1081 | prep.datalen = plen; | |
1082 | prep.quotalen = key->type->def_datalen; | |
0a9dd0e0 | 1083 | prep.expiry = TIME64_MAX; |
cf7f601c DH |
1084 | if (key->type->preparse) { |
1085 | ret = key->type->preparse(&prep); | |
1086 | if (ret < 0) | |
1087 | goto error; | |
1da177e4 LT |
1088 | } |
1089 | ||
cf7f601c DH |
1090 | down_write(&key->sem); |
1091 | ||
1092 | ret = key->type->update(key, &prep); | |
f7e47677 | 1093 | if (ret == 0) { |
363b02da DH |
1094 | /* Updating a negative key positively instantiates it */ |
1095 | mark_key_instantiated(key, 0); | |
f7e47677 DH |
1096 | notify_key(key, NOTIFY_KEY_UPDATED, 0); |
1097 | } | |
cf7f601c DH |
1098 | |
1099 | up_write(&key->sem); | |
1100 | ||
4d8c0250 | 1101 | error: |
cf7f601c DH |
1102 | if (key->type->preparse) |
1103 | key->type->free_preparse(&prep); | |
1da177e4 | 1104 | return ret; |
a8b17ed0 | 1105 | } |
1da177e4 LT |
1106 | EXPORT_SYMBOL(key_update); |
1107 | ||
973c9f4f DH |
1108 | /** |
1109 | * key_revoke - Revoke a key. | |
1110 | * @key: The key to be revoked. | |
1111 | * | |
1112 | * Mark a key as being revoked and ask the type to free up its resources. The | |
1113 | * revocation timeout is set and the key and all its links will be | |
1114 | * automatically garbage collected after key_gc_delay amount of time if they | |
1115 | * are not manually dealt with first. | |
1da177e4 LT |
1116 | */ |
1117 | void key_revoke(struct key *key) | |
1118 | { | |
074d5898 | 1119 | time64_t time; |
5d135440 | 1120 | |
1da177e4 LT |
1121 | key_check(key); |
1122 | ||
76181c13 DH |
1123 | /* make sure no one's trying to change or use the key when we mark it |
1124 | * - we tell lockdep that we might nest because we might be revoking an | |
1125 | * authorisation key whilst holding the sem on a key we've just | |
1126 | * instantiated | |
1127 | */ | |
1128 | down_write_nested(&key->sem, 1); | |
f7e47677 DH |
1129 | if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags)) { |
1130 | notify_key(key, NOTIFY_KEY_REVOKED, 0); | |
1131 | if (key->type->revoke) | |
1132 | key->type->revoke(key); | |
1133 | ||
1134 | /* set the death time to no more than the expiry time */ | |
1135 | time = ktime_get_real_seconds(); | |
1136 | if (key->revoked_at == 0 || key->revoked_at > time) { | |
1137 | key->revoked_at = time; | |
1138 | key_schedule_gc(key->revoked_at + key_gc_delay); | |
1139 | } | |
5d135440 DH |
1140 | } |
1141 | ||
1da177e4 | 1142 | up_write(&key->sem); |
a8b17ed0 | 1143 | } |
1da177e4 LT |
1144 | EXPORT_SYMBOL(key_revoke); |
1145 | ||
fd75815f DH |
1146 | /** |
1147 | * key_invalidate - Invalidate a key. | |
1148 | * @key: The key to be invalidated. | |
1149 | * | |
1150 | * Mark a key as being invalidated and have it cleaned up immediately. The key | |
1151 | * is ignored by all searches and other operations from this point. | |
1152 | */ | |
1153 | void key_invalidate(struct key *key) | |
1154 | { | |
1155 | kenter("%d", key_serial(key)); | |
1156 | ||
1157 | key_check(key); | |
1158 | ||
1159 | if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { | |
1160 | down_write_nested(&key->sem, 1); | |
f7e47677 DH |
1161 | if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) { |
1162 | notify_key(key, NOTIFY_KEY_INVALIDATED, 0); | |
fd75815f | 1163 | key_schedule_gc_links(); |
f7e47677 | 1164 | } |
fd75815f DH |
1165 | up_write(&key->sem); |
1166 | } | |
1167 | } | |
1168 | EXPORT_SYMBOL(key_invalidate); | |
1169 | ||
6a09d17b DH |
1170 | /** |
1171 | * generic_key_instantiate - Simple instantiation of a key from preparsed data | |
1172 | * @key: The key to be instantiated | |
1173 | * @prep: The preparsed data to load. | |
1174 | * | |
1175 | * Instantiate a key from preparsed data. We assume we can just copy the data | |
1176 | * in directly and clear the old pointers. | |
1177 | * | |
1178 | * This can be pointed to directly by the key type instantiate op pointer. | |
1179 | */ | |
1180 | int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep) | |
1181 | { | |
1182 | int ret; | |
1183 | ||
1184 | pr_devel("==>%s()\n", __func__); | |
1185 | ||
1186 | ret = key_payload_reserve(key, prep->quotalen); | |
1187 | if (ret == 0) { | |
146aa8b1 DH |
1188 | rcu_assign_keypointer(key, prep->payload.data[0]); |
1189 | key->payload.data[1] = prep->payload.data[1]; | |
1190 | key->payload.data[2] = prep->payload.data[2]; | |
1191 | key->payload.data[3] = prep->payload.data[3]; | |
1192 | prep->payload.data[0] = NULL; | |
1193 | prep->payload.data[1] = NULL; | |
1194 | prep->payload.data[2] = NULL; | |
1195 | prep->payload.data[3] = NULL; | |
6a09d17b DH |
1196 | } |
1197 | pr_devel("<==%s() = %d\n", __func__, ret); | |
1198 | return ret; | |
1199 | } | |
1200 | EXPORT_SYMBOL(generic_key_instantiate); | |
1201 | ||
973c9f4f DH |
1202 | /** |
1203 | * register_key_type - Register a type of key. | |
1204 | * @ktype: The new key type. | |
1205 | * | |
1206 | * Register a new key type. | |
1207 | * | |
1208 | * Returns 0 on success or -EEXIST if a type of this name already exists. | |
1da177e4 LT |
1209 | */ |
1210 | int register_key_type(struct key_type *ktype) | |
1211 | { | |
1212 | struct key_type *p; | |
1213 | int ret; | |
1214 | ||
7845bc39 DH |
1215 | memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); |
1216 | ||
1da177e4 LT |
1217 | ret = -EEXIST; |
1218 | down_write(&key_types_sem); | |
1219 | ||
1220 | /* disallow key types with the same name */ | |
1221 | list_for_each_entry(p, &key_types_list, link) { | |
1222 | if (strcmp(p->name, ktype->name) == 0) | |
1223 | goto out; | |
1224 | } | |
1225 | ||
1226 | /* store the type */ | |
1227 | list_add(&ktype->link, &key_types_list); | |
1eb1bcf5 DH |
1228 | |
1229 | pr_notice("Key type %s registered\n", ktype->name); | |
1da177e4 LT |
1230 | ret = 0; |
1231 | ||
973c9f4f | 1232 | out: |
1da177e4 LT |
1233 | up_write(&key_types_sem); |
1234 | return ret; | |
a8b17ed0 | 1235 | } |
1da177e4 LT |
1236 | EXPORT_SYMBOL(register_key_type); |
1237 | ||
973c9f4f DH |
1238 | /** |
1239 | * unregister_key_type - Unregister a type of key. | |
1240 | * @ktype: The key type. | |
1241 | * | |
1242 | * Unregister a key type and mark all the extant keys of this type as dead. | |
1243 | * Those keys of this type are then destroyed to get rid of their payloads and | |
1244 | * they and their links will be garbage collected as soon as possible. | |
1da177e4 LT |
1245 | */ |
1246 | void unregister_key_type(struct key_type *ktype) | |
1247 | { | |
1da177e4 | 1248 | down_write(&key_types_sem); |
1da177e4 | 1249 | list_del_init(&ktype->link); |
0c061b57 DH |
1250 | downgrade_write(&key_types_sem); |
1251 | key_gc_keytype(ktype); | |
1eb1bcf5 | 1252 | pr_notice("Key type %s unregistered\n", ktype->name); |
0c061b57 | 1253 | up_read(&key_types_sem); |
a8b17ed0 | 1254 | } |
1da177e4 LT |
1255 | EXPORT_SYMBOL(unregister_key_type); |
1256 | ||
1da177e4 | 1257 | /* |
973c9f4f | 1258 | * Initialise the key management state. |
1da177e4 LT |
1259 | */ |
1260 | void __init key_init(void) | |
1261 | { | |
1262 | /* allocate a slab in which we can store keys */ | |
1263 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), | |
20c2df83 | 1264 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1265 | |
1266 | /* add the special key types */ | |
1267 | list_add_tail(&key_type_keyring.link, &key_types_list); | |
1268 | list_add_tail(&key_type_dead.link, &key_types_list); | |
1269 | list_add_tail(&key_type_user.link, &key_types_list); | |
9f6ed2ca | 1270 | list_add_tail(&key_type_logon.link, &key_types_list); |
1da177e4 LT |
1271 | |
1272 | /* record the root user tracking */ | |
1273 | rb_link_node(&root_key_user.node, | |
1274 | NULL, | |
1275 | &key_user_tree.rb_node); | |
1276 | ||
1277 | rb_insert_color(&root_key_user.node, | |
1278 | &key_user_tree); | |
a8b17ed0 | 1279 | } |