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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
973c9f4f | 2 | /* Userspace key control operations |
1da177e4 | 3 | * |
3e30148c | 4 | * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. |
1da177e4 | 5 | * Written by David Howells (dhowells@redhat.com) |
1da177e4 LT |
6 | */ |
7 | ||
1da177e4 LT |
8 | #include <linux/init.h> |
9 | #include <linux/sched.h> | |
29930025 | 10 | #include <linux/sched/task.h> |
1da177e4 LT |
11 | #include <linux/slab.h> |
12 | #include <linux/syscalls.h> | |
59e6b9c1 | 13 | #include <linux/key.h> |
1da177e4 LT |
14 | #include <linux/keyctl.h> |
15 | #include <linux/fs.h> | |
c59ede7b | 16 | #include <linux/capability.h> |
5b825c3a | 17 | #include <linux/cred.h> |
0cb409d9 | 18 | #include <linux/string.h> |
1da177e4 | 19 | #include <linux/err.h> |
38bbca6b | 20 | #include <linux/vmalloc.h> |
70a5bb72 | 21 | #include <linux/security.h> |
a27bb332 | 22 | #include <linux/uio.h> |
7c0f6ba6 | 23 | #include <linux/uaccess.h> |
822ad64d | 24 | #include <keys/request_key_auth-type.h> |
1da177e4 LT |
25 | #include "internal.h" |
26 | ||
aa9d4437 DH |
27 | #define KEY_MAX_DESC_SIZE 4096 |
28 | ||
b206f281 | 29 | static const unsigned char keyrings_capabilities[2] = { |
45e0f30c DH |
30 | [0] = (KEYCTL_CAPS0_CAPABILITIES | |
31 | (IS_ENABLED(CONFIG_PERSISTENT_KEYRINGS) ? KEYCTL_CAPS0_PERSISTENT_KEYRINGS : 0) | | |
32 | (IS_ENABLED(CONFIG_KEY_DH_OPERATIONS) ? KEYCTL_CAPS0_DIFFIE_HELLMAN : 0) | | |
33 | (IS_ENABLED(CONFIG_ASYMMETRIC_KEY_TYPE) ? KEYCTL_CAPS0_PUBLIC_KEY : 0) | | |
34 | (IS_ENABLED(CONFIG_BIG_KEYS) ? KEYCTL_CAPS0_BIG_KEY : 0) | | |
35 | KEYCTL_CAPS0_INVALIDATE | | |
36 | KEYCTL_CAPS0_RESTRICT_KEYRING | | |
37 | KEYCTL_CAPS0_MOVE | |
38 | ), | |
3b6e4de0 | 39 | [1] = (KEYCTL_CAPS1_NS_KEYRING_NAME | |
f7e47677 DH |
40 | KEYCTL_CAPS1_NS_KEY_TAG | |
41 | (IS_ENABLED(CONFIG_KEY_NOTIFICATIONS) ? KEYCTL_CAPS1_NOTIFICATIONS : 0) | |
42 | ), | |
45e0f30c DH |
43 | }; |
44 | ||
0cb409d9 DA |
45 | static int key_get_type_from_user(char *type, |
46 | const char __user *_type, | |
47 | unsigned len) | |
48 | { | |
49 | int ret; | |
50 | ||
51 | ret = strncpy_from_user(type, _type, len); | |
0cb409d9 | 52 | if (ret < 0) |
4303ef19 | 53 | return ret; |
0cb409d9 DA |
54 | if (ret == 0 || ret >= len) |
55 | return -EINVAL; | |
54e2c2c1 DH |
56 | if (type[0] == '.') |
57 | return -EPERM; | |
0cb409d9 | 58 | type[len - 1] = '\0'; |
0cb409d9 DA |
59 | return 0; |
60 | } | |
61 | ||
1da177e4 | 62 | /* |
973c9f4f DH |
63 | * Extract the description of a new key from userspace and either add it as a |
64 | * new key to the specified keyring or update a matching key in that keyring. | |
65 | * | |
cf7f601c DH |
66 | * If the description is NULL or an empty string, the key type is asked to |
67 | * generate one from the payload. | |
68 | * | |
973c9f4f DH |
69 | * The keyring must be writable so that we can attach the key to it. |
70 | * | |
71 | * If successful, the new key's serial number is returned, otherwise an error | |
72 | * code is returned. | |
1da177e4 | 73 | */ |
1e7bfb21 HC |
74 | SYSCALL_DEFINE5(add_key, const char __user *, _type, |
75 | const char __user *, _description, | |
76 | const void __user *, _payload, | |
77 | size_t, plen, | |
78 | key_serial_t, ringid) | |
1da177e4 | 79 | { |
664cceb0 | 80 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
81 | char type[32], *description; |
82 | void *payload; | |
0cb409d9 | 83 | long ret; |
1da177e4 LT |
84 | |
85 | ret = -EINVAL; | |
38bbca6b | 86 | if (plen > 1024 * 1024 - 1) |
1da177e4 LT |
87 | goto error; |
88 | ||
89 | /* draw all the data into kernel space */ | |
0cb409d9 | 90 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
91 | if (ret < 0) |
92 | goto error; | |
1da177e4 | 93 | |
cf7f601c DH |
94 | description = NULL; |
95 | if (_description) { | |
aa9d4437 | 96 | description = strndup_user(_description, KEY_MAX_DESC_SIZE); |
cf7f601c DH |
97 | if (IS_ERR(description)) { |
98 | ret = PTR_ERR(description); | |
99 | goto error; | |
100 | } | |
101 | if (!*description) { | |
102 | kfree(description); | |
103 | description = NULL; | |
a4e3b8d7 MZ |
104 | } else if ((description[0] == '.') && |
105 | (strncmp(type, "keyring", 7) == 0)) { | |
106 | ret = -EPERM; | |
107 | goto error2; | |
cf7f601c | 108 | } |
0cb409d9 | 109 | } |
1da177e4 LT |
110 | |
111 | /* pull the payload in if one was supplied */ | |
112 | payload = NULL; | |
113 | ||
5649645d | 114 | if (plen) { |
1da177e4 | 115 | ret = -ENOMEM; |
752ade68 MH |
116 | payload = kvmalloc(plen, GFP_KERNEL); |
117 | if (!payload) | |
118 | goto error2; | |
1da177e4 LT |
119 | |
120 | ret = -EFAULT; | |
121 | if (copy_from_user(payload, _payload, plen) != 0) | |
122 | goto error3; | |
123 | } | |
124 | ||
125 | /* find the target keyring (which must be writable) */ | |
f5895943 | 126 | keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); |
664cceb0 DH |
127 | if (IS_ERR(keyring_ref)) { |
128 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
129 | goto error3; |
130 | } | |
131 | ||
132 | /* create or update the requested key and add it to the target | |
133 | * keyring */ | |
664cceb0 | 134 | key_ref = key_create_or_update(keyring_ref, type, description, |
028db3e2 LT |
135 | payload, plen, KEY_PERM_UNDEF, |
136 | KEY_ALLOC_IN_QUOTA); | |
664cceb0 DH |
137 | if (!IS_ERR(key_ref)) { |
138 | ret = key_ref_to_ptr(key_ref)->serial; | |
139 | key_ref_put(key_ref); | |
1da177e4 LT |
140 | } |
141 | else { | |
664cceb0 | 142 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
143 | } |
144 | ||
664cceb0 | 145 | key_ref_put(keyring_ref); |
1da177e4 | 146 | error3: |
d4eaa283 | 147 | kvfree_sensitive(payload, plen); |
1da177e4 LT |
148 | error2: |
149 | kfree(description); | |
150 | error: | |
151 | return ret; | |
a8b17ed0 | 152 | } |
1da177e4 | 153 | |
1da177e4 | 154 | /* |
973c9f4f DH |
155 | * Search the process keyrings and keyring trees linked from those for a |
156 | * matching key. Keyrings must have appropriate Search permission to be | |
157 | * searched. | |
158 | * | |
159 | * If a key is found, it will be attached to the destination keyring if there's | |
160 | * one specified and the serial number of the key will be returned. | |
161 | * | |
162 | * If no key is found, /sbin/request-key will be invoked if _callout_info is | |
163 | * non-NULL in an attempt to create a key. The _callout_info string will be | |
164 | * passed to /sbin/request-key to aid with completing the request. If the | |
165 | * _callout_info string is "" then it will be changed to "-". | |
1da177e4 | 166 | */ |
1e7bfb21 HC |
167 | SYSCALL_DEFINE4(request_key, const char __user *, _type, |
168 | const char __user *, _description, | |
169 | const char __user *, _callout_info, | |
170 | key_serial_t, destringid) | |
1da177e4 LT |
171 | { |
172 | struct key_type *ktype; | |
664cceb0 DH |
173 | struct key *key; |
174 | key_ref_t dest_ref; | |
4a38e122 | 175 | size_t callout_len; |
1da177e4 | 176 | char type[32], *description, *callout_info; |
0cb409d9 | 177 | long ret; |
1da177e4 LT |
178 | |
179 | /* pull the type into kernel space */ | |
0cb409d9 | 180 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
181 | if (ret < 0) |
182 | goto error; | |
1260f801 | 183 | |
1da177e4 | 184 | /* pull the description into kernel space */ |
aa9d4437 | 185 | description = strndup_user(_description, KEY_MAX_DESC_SIZE); |
0cb409d9 DA |
186 | if (IS_ERR(description)) { |
187 | ret = PTR_ERR(description); | |
1da177e4 | 188 | goto error; |
0cb409d9 | 189 | } |
1da177e4 LT |
190 | |
191 | /* pull the callout info into kernel space */ | |
192 | callout_info = NULL; | |
4a38e122 | 193 | callout_len = 0; |
1da177e4 | 194 | if (_callout_info) { |
0cb409d9 DA |
195 | callout_info = strndup_user(_callout_info, PAGE_SIZE); |
196 | if (IS_ERR(callout_info)) { | |
197 | ret = PTR_ERR(callout_info); | |
1da177e4 | 198 | goto error2; |
0cb409d9 | 199 | } |
4a38e122 | 200 | callout_len = strlen(callout_info); |
1da177e4 LT |
201 | } |
202 | ||
203 | /* get the destination keyring if specified */ | |
664cceb0 | 204 | dest_ref = NULL; |
1da177e4 | 205 | if (destringid) { |
5593122e | 206 | dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, |
f5895943 | 207 | KEY_NEED_WRITE); |
664cceb0 DH |
208 | if (IS_ERR(dest_ref)) { |
209 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
210 | goto error3; |
211 | } | |
212 | } | |
213 | ||
214 | /* find the key type */ | |
215 | ktype = key_type_lookup(type); | |
216 | if (IS_ERR(ktype)) { | |
217 | ret = PTR_ERR(ktype); | |
218 | goto error4; | |
219 | } | |
220 | ||
221 | /* do the search */ | |
a58946c1 | 222 | key = request_key_and_link(ktype, description, NULL, callout_info, |
028db3e2 | 223 | callout_len, NULL, key_ref_to_ptr(dest_ref), |
7e047ef5 | 224 | KEY_ALLOC_IN_QUOTA); |
1da177e4 LT |
225 | if (IS_ERR(key)) { |
226 | ret = PTR_ERR(key); | |
227 | goto error5; | |
228 | } | |
229 | ||
4aab1e89 DH |
230 | /* wait for the key to finish being constructed */ |
231 | ret = wait_for_key_construction(key, 1); | |
232 | if (ret < 0) | |
233 | goto error6; | |
234 | ||
1da177e4 LT |
235 | ret = key->serial; |
236 | ||
4aab1e89 | 237 | error6: |
3e30148c | 238 | key_put(key); |
c5b60b5e | 239 | error5: |
1da177e4 | 240 | key_type_put(ktype); |
c5b60b5e | 241 | error4: |
664cceb0 | 242 | key_ref_put(dest_ref); |
c5b60b5e | 243 | error3: |
1da177e4 | 244 | kfree(callout_info); |
c5b60b5e | 245 | error2: |
1da177e4 | 246 | kfree(description); |
c5b60b5e | 247 | error: |
1da177e4 | 248 | return ret; |
a8b17ed0 | 249 | } |
1da177e4 | 250 | |
1da177e4 | 251 | /* |
973c9f4f DH |
252 | * Get the ID of the specified process keyring. |
253 | * | |
254 | * The requested keyring must have search permission to be found. | |
255 | * | |
256 | * If successful, the ID of the requested keyring will be returned. | |
1da177e4 LT |
257 | */ |
258 | long keyctl_get_keyring_ID(key_serial_t id, int create) | |
259 | { | |
664cceb0 | 260 | key_ref_t key_ref; |
5593122e | 261 | unsigned long lflags; |
1da177e4 LT |
262 | long ret; |
263 | ||
5593122e | 264 | lflags = create ? KEY_LOOKUP_CREATE : 0; |
f5895943 | 265 | key_ref = lookup_user_key(id, lflags, KEY_NEED_SEARCH); |
664cceb0 DH |
266 | if (IS_ERR(key_ref)) { |
267 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
268 | goto error; |
269 | } | |
270 | ||
664cceb0 DH |
271 | ret = key_ref_to_ptr(key_ref)->serial; |
272 | key_ref_put(key_ref); | |
c5b60b5e | 273 | error: |
1da177e4 | 274 | return ret; |
973c9f4f | 275 | } |
1da177e4 | 276 | |
1da177e4 | 277 | /* |
973c9f4f DH |
278 | * Join a (named) session keyring. |
279 | * | |
280 | * Create and join an anonymous session keyring or join a named session | |
281 | * keyring, creating it if necessary. A named session keyring must have Search | |
282 | * permission for it to be joined. Session keyrings without this permit will | |
ee8f844e DH |
283 | * be skipped over. It is not permitted for userspace to create or join |
284 | * keyrings whose name begin with a dot. | |
973c9f4f DH |
285 | * |
286 | * If successful, the ID of the joined session keyring will be returned. | |
1da177e4 LT |
287 | */ |
288 | long keyctl_join_session_keyring(const char __user *_name) | |
289 | { | |
290 | char *name; | |
0cb409d9 | 291 | long ret; |
1da177e4 LT |
292 | |
293 | /* fetch the name from userspace */ | |
294 | name = NULL; | |
295 | if (_name) { | |
aa9d4437 | 296 | name = strndup_user(_name, KEY_MAX_DESC_SIZE); |
0cb409d9 DA |
297 | if (IS_ERR(name)) { |
298 | ret = PTR_ERR(name); | |
1da177e4 | 299 | goto error; |
0cb409d9 | 300 | } |
ee8f844e DH |
301 | |
302 | ret = -EPERM; | |
303 | if (name[0] == '.') | |
304 | goto error_name; | |
1da177e4 LT |
305 | } |
306 | ||
307 | /* join the session */ | |
308 | ret = join_session_keyring(name); | |
ee8f844e | 309 | error_name: |
0d54ee1c | 310 | kfree(name); |
c5b60b5e | 311 | error: |
1da177e4 | 312 | return ret; |
a8b17ed0 | 313 | } |
1da177e4 | 314 | |
1da177e4 | 315 | /* |
973c9f4f DH |
316 | * Update a key's data payload from the given data. |
317 | * | |
318 | * The key must grant the caller Write permission and the key type must support | |
319 | * updating for this to work. A negative key can be positively instantiated | |
320 | * with this call. | |
321 | * | |
322 | * If successful, 0 will be returned. If the key type does not support | |
323 | * updating, then -EOPNOTSUPP will be returned. | |
1da177e4 LT |
324 | */ |
325 | long keyctl_update_key(key_serial_t id, | |
326 | const void __user *_payload, | |
327 | size_t plen) | |
328 | { | |
664cceb0 | 329 | key_ref_t key_ref; |
1da177e4 LT |
330 | void *payload; |
331 | long ret; | |
332 | ||
333 | ret = -EINVAL; | |
334 | if (plen > PAGE_SIZE) | |
335 | goto error; | |
336 | ||
337 | /* pull the payload in if one was supplied */ | |
338 | payload = NULL; | |
5649645d | 339 | if (plen) { |
1da177e4 | 340 | ret = -ENOMEM; |
4f088249 | 341 | payload = kvmalloc(plen, GFP_KERNEL); |
1da177e4 LT |
342 | if (!payload) |
343 | goto error; | |
344 | ||
345 | ret = -EFAULT; | |
346 | if (copy_from_user(payload, _payload, plen) != 0) | |
347 | goto error2; | |
348 | } | |
349 | ||
350 | /* find the target key (which must be writable) */ | |
f5895943 | 351 | key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); |
664cceb0 DH |
352 | if (IS_ERR(key_ref)) { |
353 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
354 | goto error2; |
355 | } | |
356 | ||
357 | /* update the key */ | |
664cceb0 | 358 | ret = key_update(key_ref, payload, plen); |
1da177e4 | 359 | |
664cceb0 | 360 | key_ref_put(key_ref); |
c5b60b5e | 361 | error2: |
d4eaa283 | 362 | kvfree_sensitive(payload, plen); |
c5b60b5e | 363 | error: |
1da177e4 | 364 | return ret; |
a8b17ed0 | 365 | } |
1da177e4 | 366 | |
1da177e4 | 367 | /* |
973c9f4f DH |
368 | * Revoke a key. |
369 | * | |
370 | * The key must be grant the caller Write or Setattr permission for this to | |
371 | * work. The key type should give up its quota claim when revoked. The key | |
372 | * and any links to the key will be automatically garbage collected after a | |
373 | * certain amount of time (/proc/sys/kernel/keys/gc_delay). | |
374 | * | |
d3600bcf MZ |
375 | * Keys with KEY_FLAG_KEEP set should not be revoked. |
376 | * | |
973c9f4f | 377 | * If successful, 0 is returned. |
1da177e4 LT |
378 | */ |
379 | long keyctl_revoke_key(key_serial_t id) | |
380 | { | |
664cceb0 | 381 | key_ref_t key_ref; |
d3600bcf | 382 | struct key *key; |
1da177e4 LT |
383 | long ret; |
384 | ||
028db3e2 | 385 | key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); |
664cceb0 DH |
386 | if (IS_ERR(key_ref)) { |
387 | ret = PTR_ERR(key_ref); | |
028db3e2 LT |
388 | if (ret != -EACCES) |
389 | goto error; | |
390 | key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR); | |
391 | if (IS_ERR(key_ref)) { | |
392 | ret = PTR_ERR(key_ref); | |
393 | goto error; | |
394 | } | |
1da177e4 LT |
395 | } |
396 | ||
d3600bcf | 397 | key = key_ref_to_ptr(key_ref); |
1da177e4 | 398 | ret = 0; |
d3600bcf | 399 | if (test_bit(KEY_FLAG_KEEP, &key->flags)) |
1d6d167c MZ |
400 | ret = -EPERM; |
401 | else | |
d3600bcf | 402 | key_revoke(key); |
1da177e4 | 403 | |
664cceb0 | 404 | key_ref_put(key_ref); |
c5b60b5e | 405 | error: |
1260f801 | 406 | return ret; |
a8b17ed0 | 407 | } |
1da177e4 | 408 | |
fd75815f DH |
409 | /* |
410 | * Invalidate a key. | |
411 | * | |
412 | * The key must be grant the caller Invalidate permission for this to work. | |
413 | * The key and any links to the key will be automatically garbage collected | |
414 | * immediately. | |
415 | * | |
d3600bcf MZ |
416 | * Keys with KEY_FLAG_KEEP set should not be invalidated. |
417 | * | |
fd75815f DH |
418 | * If successful, 0 is returned. |
419 | */ | |
420 | long keyctl_invalidate_key(key_serial_t id) | |
421 | { | |
422 | key_ref_t key_ref; | |
d3600bcf | 423 | struct key *key; |
fd75815f DH |
424 | long ret; |
425 | ||
426 | kenter("%d", id); | |
427 | ||
028db3e2 | 428 | key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH); |
fd75815f DH |
429 | if (IS_ERR(key_ref)) { |
430 | ret = PTR_ERR(key_ref); | |
0c7774ab DH |
431 | |
432 | /* Root is permitted to invalidate certain special keys */ | |
433 | if (capable(CAP_SYS_ADMIN)) { | |
8c0637e9 | 434 | key_ref = lookup_user_key(id, 0, KEY_SYSADMIN_OVERRIDE); |
0c7774ab DH |
435 | if (IS_ERR(key_ref)) |
436 | goto error; | |
437 | if (test_bit(KEY_FLAG_ROOT_CAN_INVAL, | |
438 | &key_ref_to_ptr(key_ref)->flags)) | |
439 | goto invalidate; | |
440 | goto error_put; | |
441 | } | |
442 | ||
fd75815f DH |
443 | goto error; |
444 | } | |
445 | ||
0c7774ab | 446 | invalidate: |
d3600bcf | 447 | key = key_ref_to_ptr(key_ref); |
fd75815f | 448 | ret = 0; |
d3600bcf MZ |
449 | if (test_bit(KEY_FLAG_KEEP, &key->flags)) |
450 | ret = -EPERM; | |
1d6d167c | 451 | else |
d3600bcf | 452 | key_invalidate(key); |
0c7774ab | 453 | error_put: |
fd75815f DH |
454 | key_ref_put(key_ref); |
455 | error: | |
456 | kleave(" = %ld", ret); | |
457 | return ret; | |
458 | } | |
459 | ||
1da177e4 | 460 | /* |
973c9f4f DH |
461 | * Clear the specified keyring, creating an empty process keyring if one of the |
462 | * special keyring IDs is used. | |
463 | * | |
d3600bcf MZ |
464 | * The keyring must grant the caller Write permission and not have |
465 | * KEY_FLAG_KEEP set for this to work. If successful, 0 will be returned. | |
1da177e4 LT |
466 | */ |
467 | long keyctl_keyring_clear(key_serial_t ringid) | |
468 | { | |
664cceb0 | 469 | key_ref_t keyring_ref; |
d3600bcf | 470 | struct key *keyring; |
1da177e4 LT |
471 | long ret; |
472 | ||
028db3e2 | 473 | keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); |
664cceb0 DH |
474 | if (IS_ERR(keyring_ref)) { |
475 | ret = PTR_ERR(keyring_ref); | |
700920eb DH |
476 | |
477 | /* Root is permitted to invalidate certain special keyrings */ | |
478 | if (capable(CAP_SYS_ADMIN)) { | |
8c0637e9 DH |
479 | keyring_ref = lookup_user_key(ringid, 0, |
480 | KEY_SYSADMIN_OVERRIDE); | |
700920eb DH |
481 | if (IS_ERR(keyring_ref)) |
482 | goto error; | |
483 | if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR, | |
484 | &key_ref_to_ptr(keyring_ref)->flags)) | |
485 | goto clear; | |
486 | goto error_put; | |
487 | } | |
488 | ||
1da177e4 LT |
489 | goto error; |
490 | } | |
491 | ||
700920eb | 492 | clear: |
d3600bcf MZ |
493 | keyring = key_ref_to_ptr(keyring_ref); |
494 | if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) | |
495 | ret = -EPERM; | |
496 | else | |
497 | ret = keyring_clear(keyring); | |
700920eb | 498 | error_put: |
664cceb0 | 499 | key_ref_put(keyring_ref); |
c5b60b5e | 500 | error: |
1da177e4 | 501 | return ret; |
a8b17ed0 | 502 | } |
1da177e4 | 503 | |
1da177e4 | 504 | /* |
973c9f4f DH |
505 | * Create a link from a keyring to a key if there's no matching key in the |
506 | * keyring, otherwise replace the link to the matching key with a link to the | |
507 | * new key. | |
508 | * | |
328c95db | 509 | * The key must grant the caller Link permission and the keyring must grant |
973c9f4f DH |
510 | * the caller Write permission. Furthermore, if an additional link is created, |
511 | * the keyring's quota will be extended. | |
512 | * | |
513 | * If successful, 0 will be returned. | |
1da177e4 LT |
514 | */ |
515 | long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) | |
516 | { | |
664cceb0 | 517 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
518 | long ret; |
519 | ||
f5895943 | 520 | keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); |
664cceb0 DH |
521 | if (IS_ERR(keyring_ref)) { |
522 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
523 | goto error; |
524 | } | |
525 | ||
f5895943 | 526 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK); |
664cceb0 DH |
527 | if (IS_ERR(key_ref)) { |
528 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
529 | goto error2; |
530 | } | |
531 | ||
664cceb0 | 532 | ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); |
1da177e4 | 533 | |
664cceb0 | 534 | key_ref_put(key_ref); |
c5b60b5e | 535 | error2: |
664cceb0 | 536 | key_ref_put(keyring_ref); |
c5b60b5e | 537 | error: |
1da177e4 | 538 | return ret; |
a8b17ed0 | 539 | } |
1da177e4 | 540 | |
1da177e4 | 541 | /* |
973c9f4f DH |
542 | * Unlink a key from a keyring. |
543 | * | |
544 | * The keyring must grant the caller Write permission for this to work; the key | |
545 | * itself need not grant the caller anything. If the last link to a key is | |
546 | * removed then that key will be scheduled for destruction. | |
547 | * | |
d3600bcf MZ |
548 | * Keys or keyrings with KEY_FLAG_KEEP set should not be unlinked. |
549 | * | |
973c9f4f | 550 | * If successful, 0 will be returned. |
1da177e4 LT |
551 | */ |
552 | long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) | |
553 | { | |
664cceb0 | 554 | key_ref_t keyring_ref, key_ref; |
d3600bcf | 555 | struct key *keyring, *key; |
1da177e4 LT |
556 | long ret; |
557 | ||
f5895943 | 558 | keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_WRITE); |
664cceb0 DH |
559 | if (IS_ERR(keyring_ref)) { |
560 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
561 | goto error; |
562 | } | |
563 | ||
8c0637e9 | 564 | key_ref = lookup_user_key(id, KEY_LOOKUP_PARTIAL, KEY_NEED_UNLINK); |
664cceb0 DH |
565 | if (IS_ERR(key_ref)) { |
566 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
567 | goto error2; |
568 | } | |
569 | ||
d3600bcf MZ |
570 | keyring = key_ref_to_ptr(keyring_ref); |
571 | key = key_ref_to_ptr(key_ref); | |
572 | if (test_bit(KEY_FLAG_KEEP, &keyring->flags) && | |
573 | test_bit(KEY_FLAG_KEEP, &key->flags)) | |
574 | ret = -EPERM; | |
575 | else | |
576 | ret = key_unlink(keyring, key); | |
1da177e4 | 577 | |
664cceb0 | 578 | key_ref_put(key_ref); |
c5b60b5e | 579 | error2: |
664cceb0 | 580 | key_ref_put(keyring_ref); |
c5b60b5e | 581 | error: |
1da177e4 | 582 | return ret; |
a8b17ed0 | 583 | } |
1da177e4 | 584 | |
ed0ac5c7 DH |
585 | /* |
586 | * Move a link to a key from one keyring to another, displacing any matching | |
587 | * key from the destination keyring. | |
588 | * | |
589 | * The key must grant the caller Link permission and both keyrings must grant | |
590 | * the caller Write permission. There must also be a link in the from keyring | |
591 | * to the key. If both keyrings are the same, nothing is done. | |
592 | * | |
593 | * If successful, 0 will be returned. | |
594 | */ | |
595 | long keyctl_keyring_move(key_serial_t id, key_serial_t from_ringid, | |
596 | key_serial_t to_ringid, unsigned int flags) | |
597 | { | |
598 | key_ref_t key_ref, from_ref, to_ref; | |
599 | long ret; | |
600 | ||
601 | if (flags & ~KEYCTL_MOVE_EXCL) | |
602 | return -EINVAL; | |
603 | ||
604 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK); | |
605 | if (IS_ERR(key_ref)) | |
606 | return PTR_ERR(key_ref); | |
607 | ||
608 | from_ref = lookup_user_key(from_ringid, 0, KEY_NEED_WRITE); | |
609 | if (IS_ERR(from_ref)) { | |
610 | ret = PTR_ERR(from_ref); | |
611 | goto error2; | |
612 | } | |
613 | ||
614 | to_ref = lookup_user_key(to_ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); | |
615 | if (IS_ERR(to_ref)) { | |
616 | ret = PTR_ERR(to_ref); | |
617 | goto error3; | |
618 | } | |
619 | ||
620 | ret = key_move(key_ref_to_ptr(key_ref), key_ref_to_ptr(from_ref), | |
621 | key_ref_to_ptr(to_ref), flags); | |
622 | ||
623 | key_ref_put(to_ref); | |
624 | error3: | |
625 | key_ref_put(from_ref); | |
626 | error2: | |
627 | key_ref_put(key_ref); | |
628 | return ret; | |
629 | } | |
630 | ||
1da177e4 | 631 | /* |
973c9f4f DH |
632 | * Return a description of a key to userspace. |
633 | * | |
634 | * The key must grant the caller View permission for this to work. | |
635 | * | |
636 | * If there's a buffer, we place up to buflen bytes of data into it formatted | |
637 | * in the following way: | |
638 | * | |
1da177e4 | 639 | * type;uid;gid;perm;description<NUL> |
973c9f4f DH |
640 | * |
641 | * If successful, we return the amount of description available, irrespective | |
642 | * of how much we may have copied into the buffer. | |
1da177e4 LT |
643 | */ |
644 | long keyctl_describe_key(key_serial_t keyid, | |
645 | char __user *buffer, | |
646 | size_t buflen) | |
647 | { | |
3e30148c | 648 | struct key *key, *instkey; |
664cceb0 | 649 | key_ref_t key_ref; |
aa9d4437 | 650 | char *infobuf; |
1da177e4 | 651 | long ret; |
aa9d4437 | 652 | int desclen, infolen; |
1da177e4 | 653 | |
f5895943 | 654 | key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); |
664cceb0 | 655 | if (IS_ERR(key_ref)) { |
3e30148c DH |
656 | /* viewing a key under construction is permitted if we have the |
657 | * authorisation token handy */ | |
664cceb0 | 658 | if (PTR_ERR(key_ref) == -EACCES) { |
3e30148c DH |
659 | instkey = key_get_instantiation_authkey(keyid); |
660 | if (!IS_ERR(instkey)) { | |
661 | key_put(instkey); | |
8bbf4976 | 662 | key_ref = lookup_user_key(keyid, |
5593122e | 663 | KEY_LOOKUP_PARTIAL, |
8c0637e9 | 664 | KEY_AUTHTOKEN_OVERRIDE); |
664cceb0 | 665 | if (!IS_ERR(key_ref)) |
3e30148c DH |
666 | goto okay; |
667 | } | |
668 | } | |
669 | ||
664cceb0 | 670 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
671 | goto error; |
672 | } | |
673 | ||
3e30148c | 674 | okay: |
664cceb0 | 675 | key = key_ref_to_ptr(key_ref); |
aa9d4437 | 676 | desclen = strlen(key->description); |
664cceb0 | 677 | |
aa9d4437 DH |
678 | /* calculate how much information we're going to return */ |
679 | ret = -ENOMEM; | |
680 | infobuf = kasprintf(GFP_KERNEL, | |
681 | "%s;%d;%d;%08x;", | |
682 | key->type->name, | |
683 | from_kuid_munged(current_user_ns(), key->uid), | |
684 | from_kgid_munged(current_user_ns(), key->gid), | |
028db3e2 | 685 | key->perm); |
aa9d4437 DH |
686 | if (!infobuf) |
687 | goto error2; | |
688 | infolen = strlen(infobuf); | |
689 | ret = infolen + desclen + 1; | |
1da177e4 LT |
690 | |
691 | /* consider returning the data */ | |
aa9d4437 DH |
692 | if (buffer && buflen >= ret) { |
693 | if (copy_to_user(buffer, infobuf, infolen) != 0 || | |
694 | copy_to_user(buffer + infolen, key->description, | |
695 | desclen + 1) != 0) | |
1da177e4 LT |
696 | ret = -EFAULT; |
697 | } | |
698 | ||
aa9d4437 | 699 | kfree(infobuf); |
c5b60b5e | 700 | error2: |
664cceb0 | 701 | key_ref_put(key_ref); |
c5b60b5e | 702 | error: |
1da177e4 | 703 | return ret; |
a8b17ed0 | 704 | } |
1da177e4 | 705 | |
1da177e4 | 706 | /* |
973c9f4f DH |
707 | * Search the specified keyring and any keyrings it links to for a matching |
708 | * key. Only keyrings that grant the caller Search permission will be searched | |
709 | * (this includes the starting keyring). Only keys with Search permission can | |
710 | * be found. | |
711 | * | |
712 | * If successful, the found key will be linked to the destination keyring if | |
713 | * supplied and the key has Link permission, and the found key ID will be | |
714 | * returned. | |
1da177e4 LT |
715 | */ |
716 | long keyctl_keyring_search(key_serial_t ringid, | |
717 | const char __user *_type, | |
718 | const char __user *_description, | |
719 | key_serial_t destringid) | |
720 | { | |
721 | struct key_type *ktype; | |
664cceb0 | 722 | key_ref_t keyring_ref, key_ref, dest_ref; |
1da177e4 | 723 | char type[32], *description; |
0cb409d9 | 724 | long ret; |
1da177e4 LT |
725 | |
726 | /* pull the type and description into kernel space */ | |
0cb409d9 | 727 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
728 | if (ret < 0) |
729 | goto error; | |
1da177e4 | 730 | |
aa9d4437 | 731 | description = strndup_user(_description, KEY_MAX_DESC_SIZE); |
0cb409d9 DA |
732 | if (IS_ERR(description)) { |
733 | ret = PTR_ERR(description); | |
1da177e4 | 734 | goto error; |
0cb409d9 | 735 | } |
1da177e4 LT |
736 | |
737 | /* get the keyring at which to begin the search */ | |
f5895943 | 738 | keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_SEARCH); |
664cceb0 DH |
739 | if (IS_ERR(keyring_ref)) { |
740 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
741 | goto error2; |
742 | } | |
743 | ||
744 | /* get the destination keyring if specified */ | |
664cceb0 | 745 | dest_ref = NULL; |
1da177e4 | 746 | if (destringid) { |
5593122e | 747 | dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, |
f5895943 | 748 | KEY_NEED_WRITE); |
664cceb0 DH |
749 | if (IS_ERR(dest_ref)) { |
750 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
751 | goto error3; |
752 | } | |
753 | } | |
754 | ||
755 | /* find the key type */ | |
756 | ktype = key_type_lookup(type); | |
757 | if (IS_ERR(ktype)) { | |
758 | ret = PTR_ERR(ktype); | |
759 | goto error4; | |
760 | } | |
761 | ||
762 | /* do the search */ | |
dcf49dbc | 763 | key_ref = keyring_search(keyring_ref, ktype, description, true); |
664cceb0 DH |
764 | if (IS_ERR(key_ref)) { |
765 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
766 | |
767 | /* treat lack or presence of a negative key the same */ | |
768 | if (ret == -EAGAIN) | |
769 | ret = -ENOKEY; | |
770 | goto error5; | |
771 | } | |
772 | ||
773 | /* link the resulting key to the destination keyring if we can */ | |
664cceb0 | 774 | if (dest_ref) { |
f5895943 | 775 | ret = key_permission(key_ref, KEY_NEED_LINK); |
29db9190 | 776 | if (ret < 0) |
1da177e4 LT |
777 | goto error6; |
778 | ||
664cceb0 | 779 | ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref)); |
1da177e4 LT |
780 | if (ret < 0) |
781 | goto error6; | |
782 | } | |
783 | ||
664cceb0 | 784 | ret = key_ref_to_ptr(key_ref)->serial; |
1da177e4 | 785 | |
c5b60b5e | 786 | error6: |
664cceb0 | 787 | key_ref_put(key_ref); |
c5b60b5e | 788 | error5: |
1da177e4 | 789 | key_type_put(ktype); |
c5b60b5e | 790 | error4: |
664cceb0 | 791 | key_ref_put(dest_ref); |
c5b60b5e | 792 | error3: |
664cceb0 | 793 | key_ref_put(keyring_ref); |
c5b60b5e | 794 | error2: |
1da177e4 | 795 | kfree(description); |
c5b60b5e | 796 | error: |
1da177e4 | 797 | return ret; |
a8b17ed0 | 798 | } |
1da177e4 | 799 | |
d3ec10aa WL |
800 | /* |
801 | * Call the read method | |
802 | */ | |
803 | static long __keyctl_read_key(struct key *key, char *buffer, size_t buflen) | |
804 | { | |
805 | long ret; | |
806 | ||
807 | down_read(&key->sem); | |
808 | ret = key_validate(key); | |
809 | if (ret == 0) | |
810 | ret = key->type->read(key, buffer, buflen); | |
811 | up_read(&key->sem); | |
812 | return ret; | |
813 | } | |
814 | ||
1da177e4 | 815 | /* |
973c9f4f DH |
816 | * Read a key's payload. |
817 | * | |
818 | * The key must either grant the caller Read permission, or it must grant the | |
819 | * caller Search permission when searched for from the process keyrings. | |
820 | * | |
821 | * If successful, we place up to buflen bytes of data into the buffer, if one | |
822 | * is provided, and return the amount of data that is available in the key, | |
823 | * irrespective of how much we copied into the buffer. | |
1da177e4 LT |
824 | */ |
825 | long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) | |
826 | { | |
664cceb0 DH |
827 | struct key *key; |
828 | key_ref_t key_ref; | |
1da177e4 | 829 | long ret; |
4f088249 WL |
830 | char *key_data = NULL; |
831 | size_t key_data_len; | |
1da177e4 LT |
832 | |
833 | /* find the key first */ | |
8c0637e9 | 834 | key_ref = lookup_user_key(keyid, 0, KEY_DEFER_PERM_CHECK); |
664cceb0 DH |
835 | if (IS_ERR(key_ref)) { |
836 | ret = -ENOKEY; | |
d3ec10aa | 837 | goto out; |
1da177e4 LT |
838 | } |
839 | ||
664cceb0 DH |
840 | key = key_ref_to_ptr(key_ref); |
841 | ||
363b02da DH |
842 | ret = key_read_state(key); |
843 | if (ret < 0) | |
d3ec10aa | 844 | goto key_put_out; /* Negatively instantiated */ |
37863c43 | 845 | |
664cceb0 | 846 | /* see if we can read it directly */ |
f5895943 | 847 | ret = key_permission(key_ref, KEY_NEED_READ); |
29db9190 | 848 | if (ret == 0) |
664cceb0 | 849 | goto can_read_key; |
29db9190 | 850 | if (ret != -EACCES) |
d3ec10aa | 851 | goto key_put_out; |
664cceb0 DH |
852 | |
853 | /* we can't; see if it's searchable from this process's keyrings | |
854 | * - we automatically take account of the fact that it may be | |
855 | * dangling off an instantiation key | |
856 | */ | |
857 | if (!is_key_possessed(key_ref)) { | |
858 | ret = -EACCES; | |
d3ec10aa | 859 | goto key_put_out; |
664cceb0 | 860 | } |
1da177e4 LT |
861 | |
862 | /* the key is probably readable - now try to read it */ | |
c5b60b5e | 863 | can_read_key: |
d3ec10aa WL |
864 | if (!key->type->read) { |
865 | ret = -EOPNOTSUPP; | |
866 | goto key_put_out; | |
1da177e4 LT |
867 | } |
868 | ||
d3ec10aa WL |
869 | if (!buffer || !buflen) { |
870 | /* Get the key length from the read method */ | |
871 | ret = __keyctl_read_key(key, NULL, 0); | |
872 | goto key_put_out; | |
873 | } | |
874 | ||
875 | /* | |
876 | * Read the data with the semaphore held (since we might sleep) | |
877 | * to protect against the key being updated or revoked. | |
878 | * | |
879 | * Allocating a temporary buffer to hold the keys before | |
880 | * transferring them to user buffer to avoid potential | |
c1e8d7c6 | 881 | * deadlock involving page fault and mmap_lock. |
4f088249 WL |
882 | * |
883 | * key_data_len = (buflen <= PAGE_SIZE) | |
884 | * ? buflen : actual length of key data | |
885 | * | |
886 | * This prevents allocating arbitrary large buffer which can | |
887 | * be much larger than the actual key length. In the latter case, | |
888 | * at least 2 passes of this loop is required. | |
d3ec10aa | 889 | */ |
4f088249 WL |
890 | key_data_len = (buflen <= PAGE_SIZE) ? buflen : 0; |
891 | for (;;) { | |
892 | if (key_data_len) { | |
893 | key_data = kvmalloc(key_data_len, GFP_KERNEL); | |
894 | if (!key_data) { | |
895 | ret = -ENOMEM; | |
896 | goto key_put_out; | |
897 | } | |
898 | } | |
d3ec10aa | 899 | |
4f088249 WL |
900 | ret = __keyctl_read_key(key, key_data, key_data_len); |
901 | ||
902 | /* | |
903 | * Read methods will just return the required length without | |
904 | * any copying if the provided length isn't large enough. | |
b4a1b4f5 | 905 | */ |
4f088249 WL |
906 | if (ret <= 0 || ret > buflen) |
907 | break; | |
908 | ||
909 | /* | |
910 | * The key may change (unlikely) in between 2 consecutive | |
911 | * __keyctl_read_key() calls. In this case, we reallocate | |
912 | * a larger buffer and redo the key read when | |
913 | * key_data_len < ret <= buflen. | |
914 | */ | |
915 | if (ret > key_data_len) { | |
916 | if (unlikely(key_data)) | |
d4eaa283 | 917 | kvfree_sensitive(key_data, key_data_len); |
4f088249 WL |
918 | key_data_len = ret; |
919 | continue; /* Allocate buffer */ | |
920 | } | |
d3ec10aa | 921 | |
d3ec10aa WL |
922 | if (copy_to_user(buffer, key_data, ret)) |
923 | ret = -EFAULT; | |
4f088249 | 924 | break; |
1da177e4 | 925 | } |
d4eaa283 | 926 | kvfree_sensitive(key_data, key_data_len); |
1da177e4 | 927 | |
d3ec10aa | 928 | key_put_out: |
1da177e4 | 929 | key_put(key); |
d3ec10aa | 930 | out: |
1da177e4 | 931 | return ret; |
a8b17ed0 | 932 | } |
1da177e4 | 933 | |
1da177e4 | 934 | /* |
973c9f4f DH |
935 | * Change the ownership of a key |
936 | * | |
937 | * The key must grant the caller Setattr permission for this to work, though | |
938 | * the key need not be fully instantiated yet. For the UID to be changed, or | |
939 | * for the GID to be changed to a group the caller is not a member of, the | |
940 | * caller must have sysadmin capability. If either uid or gid is -1 then that | |
941 | * attribute is not changed. | |
942 | * | |
943 | * If the UID is to be changed, the new user must have sufficient quota to | |
944 | * accept the key. The quota deduction will be removed from the old user to | |
945 | * the new user should the attribute be changed. | |
946 | * | |
947 | * If successful, 0 will be returned. | |
1da177e4 | 948 | */ |
9a56c2db | 949 | long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) |
1da177e4 | 950 | { |
5801649d | 951 | struct key_user *newowner, *zapowner = NULL; |
1da177e4 | 952 | struct key *key; |
664cceb0 | 953 | key_ref_t key_ref; |
1da177e4 | 954 | long ret; |
9a56c2db EB |
955 | kuid_t uid; |
956 | kgid_t gid; | |
957 | ||
958 | uid = make_kuid(current_user_ns(), user); | |
959 | gid = make_kgid(current_user_ns(), group); | |
960 | ret = -EINVAL; | |
961 | if ((user != (uid_t) -1) && !uid_valid(uid)) | |
962 | goto error; | |
963 | if ((group != (gid_t) -1) && !gid_valid(gid)) | |
964 | goto error; | |
1da177e4 LT |
965 | |
966 | ret = 0; | |
9a56c2db | 967 | if (user == (uid_t) -1 && group == (gid_t) -1) |
1da177e4 LT |
968 | goto error; |
969 | ||
5593122e | 970 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
028db3e2 | 971 | KEY_NEED_SETATTR); |
664cceb0 DH |
972 | if (IS_ERR(key_ref)) { |
973 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
974 | goto error; |
975 | } | |
976 | ||
664cceb0 DH |
977 | key = key_ref_to_ptr(key_ref); |
978 | ||
1da177e4 LT |
979 | /* make the changes with the locks held to prevent chown/chown races */ |
980 | ret = -EACCES; | |
981 | down_write(&key->sem); | |
1da177e4 LT |
982 | |
983 | if (!capable(CAP_SYS_ADMIN)) { | |
984 | /* only the sysadmin can chown a key to some other UID */ | |
9a56c2db | 985 | if (user != (uid_t) -1 && !uid_eq(key->uid, uid)) |
5801649d | 986 | goto error_put; |
1da177e4 LT |
987 | |
988 | /* only the sysadmin can set the key's GID to a group other | |
989 | * than one of those that the current process subscribes to */ | |
9a56c2db | 990 | if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid)) |
5801649d | 991 | goto error_put; |
1da177e4 LT |
992 | } |
993 | ||
5801649d | 994 | /* change the UID */ |
9a56c2db | 995 | if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) { |
5801649d | 996 | ret = -ENOMEM; |
9a56c2db | 997 | newowner = key_user_lookup(uid); |
5801649d FT |
998 | if (!newowner) |
999 | goto error_put; | |
1000 | ||
1001 | /* transfer the quota burden to the new user */ | |
1002 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { | |
9a56c2db | 1003 | unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf | 1004 | key_quota_root_maxkeys : key_quota_maxkeys; |
9a56c2db | 1005 | unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
1006 | key_quota_root_maxbytes : key_quota_maxbytes; |
1007 | ||
5801649d | 1008 | spin_lock(&newowner->lock); |
2e356101 YX |
1009 | if (newowner->qnkeys + 1 > maxkeys || |
1010 | newowner->qnbytes + key->quotalen > maxbytes || | |
0b77f5bf DH |
1011 | newowner->qnbytes + key->quotalen < |
1012 | newowner->qnbytes) | |
5801649d FT |
1013 | goto quota_overrun; |
1014 | ||
1015 | newowner->qnkeys++; | |
1016 | newowner->qnbytes += key->quotalen; | |
1017 | spin_unlock(&newowner->lock); | |
1018 | ||
1019 | spin_lock(&key->user->lock); | |
1020 | key->user->qnkeys--; | |
1021 | key->user->qnbytes -= key->quotalen; | |
1022 | spin_unlock(&key->user->lock); | |
1023 | } | |
1024 | ||
1025 | atomic_dec(&key->user->nkeys); | |
1026 | atomic_inc(&newowner->nkeys); | |
1027 | ||
363b02da | 1028 | if (key->state != KEY_IS_UNINSTANTIATED) { |
5801649d FT |
1029 | atomic_dec(&key->user->nikeys); |
1030 | atomic_inc(&newowner->nikeys); | |
1031 | } | |
1032 | ||
1033 | zapowner = key->user; | |
1034 | key->user = newowner; | |
1035 | key->uid = uid; | |
1da177e4 LT |
1036 | } |
1037 | ||
1038 | /* change the GID */ | |
9a56c2db | 1039 | if (group != (gid_t) -1) |
1da177e4 LT |
1040 | key->gid = gid; |
1041 | ||
f7e47677 | 1042 | notify_key(key, NOTIFY_KEY_SETATTR, 0); |
1da177e4 LT |
1043 | ret = 0; |
1044 | ||
5801649d | 1045 | error_put: |
1da177e4 LT |
1046 | up_write(&key->sem); |
1047 | key_put(key); | |
5801649d FT |
1048 | if (zapowner) |
1049 | key_user_put(zapowner); | |
1050 | error: | |
1da177e4 LT |
1051 | return ret; |
1052 | ||
5801649d FT |
1053 | quota_overrun: |
1054 | spin_unlock(&newowner->lock); | |
1055 | zapowner = newowner; | |
1056 | ret = -EDQUOT; | |
1057 | goto error_put; | |
a8b17ed0 | 1058 | } |
5801649d | 1059 | |
1da177e4 | 1060 | /* |
973c9f4f DH |
1061 | * Change the permission mask on a key. |
1062 | * | |
1063 | * The key must grant the caller Setattr permission for this to work, though | |
1064 | * the key need not be fully instantiated yet. If the caller does not have | |
1065 | * sysadmin capability, it may only change the permission on keys that it owns. | |
1da177e4 | 1066 | */ |
028db3e2 | 1067 | long keyctl_setperm_key(key_serial_t id, key_perm_t perm) |
1da177e4 LT |
1068 | { |
1069 | struct key *key; | |
664cceb0 | 1070 | key_ref_t key_ref; |
1da177e4 LT |
1071 | long ret; |
1072 | ||
028db3e2 | 1073 | ret = -EINVAL; |
664cceb0 | 1074 | if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) |
028db3e2 | 1075 | goto error; |
1da177e4 | 1076 | |
5593122e | 1077 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
028db3e2 | 1078 | KEY_NEED_SETATTR); |
664cceb0 DH |
1079 | if (IS_ERR(key_ref)) { |
1080 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
1081 | goto error; |
1082 | } | |
1083 | ||
664cceb0 DH |
1084 | key = key_ref_to_ptr(key_ref); |
1085 | ||
028db3e2 LT |
1086 | /* make the changes with the locks held to prevent chown/chmod races */ |
1087 | ret = -EACCES; | |
1088 | down_write(&key->sem); | |
1da177e4 | 1089 | |
028db3e2 LT |
1090 | /* if we're not the sysadmin, we can only change a key that we own */ |
1091 | if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) { | |
1092 | key->perm = perm; | |
f7e47677 | 1093 | notify_key(key, NOTIFY_KEY_SETATTR, 0); |
028db3e2 | 1094 | ret = 0; |
76d8aeab | 1095 | } |
1da177e4 | 1096 | |
1da177e4 LT |
1097 | up_write(&key->sem); |
1098 | key_put(key); | |
76d8aeab | 1099 | error: |
1da177e4 | 1100 | return ret; |
a8b17ed0 | 1101 | } |
1da177e4 | 1102 | |
8bbf4976 | 1103 | /* |
973c9f4f DH |
1104 | * Get the destination keyring for instantiation and check that the caller has |
1105 | * Write permission on it. | |
8bbf4976 DH |
1106 | */ |
1107 | static long get_instantiation_keyring(key_serial_t ringid, | |
1108 | struct request_key_auth *rka, | |
1109 | struct key **_dest_keyring) | |
1110 | { | |
1111 | key_ref_t dkref; | |
1112 | ||
eca1bf5b DH |
1113 | *_dest_keyring = NULL; |
1114 | ||
8bbf4976 | 1115 | /* just return a NULL pointer if we weren't asked to make a link */ |
eca1bf5b | 1116 | if (ringid == 0) |
8bbf4976 | 1117 | return 0; |
8bbf4976 DH |
1118 | |
1119 | /* if a specific keyring is nominated by ID, then use that */ | |
1120 | if (ringid > 0) { | |
f5895943 | 1121 | dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); |
8bbf4976 DH |
1122 | if (IS_ERR(dkref)) |
1123 | return PTR_ERR(dkref); | |
1124 | *_dest_keyring = key_ref_to_ptr(dkref); | |
1125 | return 0; | |
1126 | } | |
1127 | ||
1128 | if (ringid == KEY_SPEC_REQKEY_AUTH_KEY) | |
1129 | return -EINVAL; | |
1130 | ||
1131 | /* otherwise specify the destination keyring recorded in the | |
1132 | * authorisation key (any KEY_SPEC_*_KEYRING) */ | |
1133 | if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) { | |
21279cfa | 1134 | *_dest_keyring = key_get(rka->dest_keyring); |
8bbf4976 DH |
1135 | return 0; |
1136 | } | |
1137 | ||
1138 | return -ENOKEY; | |
1139 | } | |
1140 | ||
d84f4f99 | 1141 | /* |
973c9f4f | 1142 | * Change the request_key authorisation key on the current process. |
d84f4f99 DH |
1143 | */ |
1144 | static int keyctl_change_reqkey_auth(struct key *key) | |
1145 | { | |
1146 | struct cred *new; | |
1147 | ||
1148 | new = prepare_creds(); | |
1149 | if (!new) | |
1150 | return -ENOMEM; | |
1151 | ||
1152 | key_put(new->request_key_auth); | |
1153 | new->request_key_auth = key_get(key); | |
1154 | ||
1155 | return commit_creds(new); | |
1156 | } | |
1157 | ||
1da177e4 | 1158 | /* |
973c9f4f DH |
1159 | * Instantiate a key with the specified payload and link the key into the |
1160 | * destination keyring if one is given. | |
1161 | * | |
1162 | * The caller must have the appropriate instantiation permit set for this to | |
1163 | * work (see keyctl_assume_authority). No other permissions are required. | |
1164 | * | |
1165 | * If successful, 0 will be returned. | |
1da177e4 | 1166 | */ |
5d47b394 | 1167 | static long keyctl_instantiate_key_common(key_serial_t id, |
b353a1f7 | 1168 | struct iov_iter *from, |
ee009e4a | 1169 | key_serial_t ringid) |
1da177e4 | 1170 | { |
d84f4f99 | 1171 | const struct cred *cred = current_cred(); |
3e30148c | 1172 | struct request_key_auth *rka; |
8bbf4976 | 1173 | struct key *instkey, *dest_keyring; |
b353a1f7 | 1174 | size_t plen = from ? iov_iter_count(from) : 0; |
1da177e4 LT |
1175 | void *payload; |
1176 | long ret; | |
1177 | ||
d84f4f99 DH |
1178 | kenter("%d,,%zu,%d", id, plen, ringid); |
1179 | ||
b353a1f7 AV |
1180 | if (!plen) |
1181 | from = NULL; | |
1182 | ||
1da177e4 | 1183 | ret = -EINVAL; |
38bbca6b | 1184 | if (plen > 1024 * 1024 - 1) |
1da177e4 LT |
1185 | goto error; |
1186 | ||
b5f545c8 DH |
1187 | /* the appropriate instantiation authorisation key must have been |
1188 | * assumed before calling this */ | |
1189 | ret = -EPERM; | |
d84f4f99 | 1190 | instkey = cred->request_key_auth; |
b5f545c8 DH |
1191 | if (!instkey) |
1192 | goto error; | |
1193 | ||
146aa8b1 | 1194 | rka = instkey->payload.data[0]; |
b5f545c8 DH |
1195 | if (rka->target_key->serial != id) |
1196 | goto error; | |
1197 | ||
1da177e4 LT |
1198 | /* pull the payload in if one was supplied */ |
1199 | payload = NULL; | |
1200 | ||
b353a1f7 | 1201 | if (from) { |
1da177e4 | 1202 | ret = -ENOMEM; |
752ade68 MH |
1203 | payload = kvmalloc(plen, GFP_KERNEL); |
1204 | if (!payload) | |
1205 | goto error; | |
1da177e4 | 1206 | |
b353a1f7 | 1207 | ret = -EFAULT; |
cbbd26b8 | 1208 | if (!copy_from_iter_full(payload, plen, from)) |
1da177e4 LT |
1209 | goto error2; |
1210 | } | |
1211 | ||
3e30148c DH |
1212 | /* find the destination keyring amongst those belonging to the |
1213 | * requesting task */ | |
8bbf4976 DH |
1214 | ret = get_instantiation_keyring(ringid, rka, &dest_keyring); |
1215 | if (ret < 0) | |
1216 | goto error2; | |
1da177e4 LT |
1217 | |
1218 | /* instantiate the key and link it into a keyring */ | |
3e30148c | 1219 | ret = key_instantiate_and_link(rka->target_key, payload, plen, |
8bbf4976 | 1220 | dest_keyring, instkey); |
1da177e4 | 1221 | |
8bbf4976 | 1222 | key_put(dest_keyring); |
b5f545c8 DH |
1223 | |
1224 | /* discard the assumed authority if it's just been disabled by | |
1225 | * instantiation of the key */ | |
d84f4f99 DH |
1226 | if (ret == 0) |
1227 | keyctl_change_reqkey_auth(NULL); | |
b5f545c8 DH |
1228 | |
1229 | error2: | |
d4eaa283 | 1230 | kvfree_sensitive(payload, plen); |
b5f545c8 | 1231 | error: |
1da177e4 | 1232 | return ret; |
a8b17ed0 | 1233 | } |
1da177e4 | 1234 | |
ee009e4a DH |
1235 | /* |
1236 | * Instantiate a key with the specified payload and link the key into the | |
1237 | * destination keyring if one is given. | |
1238 | * | |
1239 | * The caller must have the appropriate instantiation permit set for this to | |
1240 | * work (see keyctl_assume_authority). No other permissions are required. | |
1241 | * | |
1242 | * If successful, 0 will be returned. | |
1243 | */ | |
1244 | long keyctl_instantiate_key(key_serial_t id, | |
1245 | const void __user *_payload, | |
1246 | size_t plen, | |
1247 | key_serial_t ringid) | |
1248 | { | |
1249 | if (_payload && plen) { | |
b353a1f7 AV |
1250 | struct iovec iov; |
1251 | struct iov_iter from; | |
1252 | int ret; | |
ee009e4a | 1253 | |
b353a1f7 AV |
1254 | ret = import_single_range(WRITE, (void __user *)_payload, plen, |
1255 | &iov, &from); | |
1256 | if (unlikely(ret)) | |
1257 | return ret; | |
1258 | ||
1259 | return keyctl_instantiate_key_common(id, &from, ringid); | |
ee009e4a DH |
1260 | } |
1261 | ||
b353a1f7 | 1262 | return keyctl_instantiate_key_common(id, NULL, ringid); |
ee009e4a DH |
1263 | } |
1264 | ||
1265 | /* | |
1266 | * Instantiate a key with the specified multipart payload and link the key into | |
1267 | * the destination keyring if one is given. | |
1268 | * | |
1269 | * The caller must have the appropriate instantiation permit set for this to | |
1270 | * work (see keyctl_assume_authority). No other permissions are required. | |
1271 | * | |
1272 | * If successful, 0 will be returned. | |
1273 | */ | |
1274 | long keyctl_instantiate_key_iov(key_serial_t id, | |
1275 | const struct iovec __user *_payload_iov, | |
1276 | unsigned ioc, | |
1277 | key_serial_t ringid) | |
1278 | { | |
1279 | struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; | |
b353a1f7 | 1280 | struct iov_iter from; |
ee009e4a DH |
1281 | long ret; |
1282 | ||
b353a1f7 AV |
1283 | if (!_payload_iov) |
1284 | ioc = 0; | |
ee009e4a | 1285 | |
b353a1f7 AV |
1286 | ret = import_iovec(WRITE, _payload_iov, ioc, |
1287 | ARRAY_SIZE(iovstack), &iov, &from); | |
ee009e4a | 1288 | if (ret < 0) |
b353a1f7 AV |
1289 | return ret; |
1290 | ret = keyctl_instantiate_key_common(id, &from, ringid); | |
1291 | kfree(iov); | |
ee009e4a | 1292 | return ret; |
ee009e4a DH |
1293 | } |
1294 | ||
1da177e4 | 1295 | /* |
973c9f4f DH |
1296 | * Negatively instantiate the key with the given timeout (in seconds) and link |
1297 | * the key into the destination keyring if one is given. | |
1298 | * | |
1299 | * The caller must have the appropriate instantiation permit set for this to | |
1300 | * work (see keyctl_assume_authority). No other permissions are required. | |
1301 | * | |
1302 | * The key and any links to the key will be automatically garbage collected | |
1303 | * after the timeout expires. | |
1304 | * | |
1305 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
1306 | * them to return -ENOKEY until the negative key expires. | |
1307 | * | |
1308 | * If successful, 0 will be returned. | |
1da177e4 LT |
1309 | */ |
1310 | long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) | |
fdd1b945 DH |
1311 | { |
1312 | return keyctl_reject_key(id, timeout, ENOKEY, ringid); | |
1313 | } | |
1314 | ||
1315 | /* | |
1316 | * Negatively instantiate the key with the given timeout (in seconds) and error | |
1317 | * code and link the key into the destination keyring if one is given. | |
1318 | * | |
1319 | * The caller must have the appropriate instantiation permit set for this to | |
1320 | * work (see keyctl_assume_authority). No other permissions are required. | |
1321 | * | |
1322 | * The key and any links to the key will be automatically garbage collected | |
1323 | * after the timeout expires. | |
1324 | * | |
1325 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
1326 | * them to return the specified error code until the negative key expires. | |
1327 | * | |
1328 | * If successful, 0 will be returned. | |
1329 | */ | |
1330 | long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error, | |
1331 | key_serial_t ringid) | |
1da177e4 | 1332 | { |
d84f4f99 | 1333 | const struct cred *cred = current_cred(); |
3e30148c | 1334 | struct request_key_auth *rka; |
8bbf4976 | 1335 | struct key *instkey, *dest_keyring; |
1da177e4 LT |
1336 | long ret; |
1337 | ||
fdd1b945 DH |
1338 | kenter("%d,%u,%u,%d", id, timeout, error, ringid); |
1339 | ||
1340 | /* must be a valid error code and mustn't be a kernel special */ | |
1341 | if (error <= 0 || | |
1342 | error >= MAX_ERRNO || | |
1343 | error == ERESTARTSYS || | |
1344 | error == ERESTARTNOINTR || | |
1345 | error == ERESTARTNOHAND || | |
1346 | error == ERESTART_RESTARTBLOCK) | |
1347 | return -EINVAL; | |
d84f4f99 | 1348 | |
b5f545c8 DH |
1349 | /* the appropriate instantiation authorisation key must have been |
1350 | * assumed before calling this */ | |
1351 | ret = -EPERM; | |
d84f4f99 | 1352 | instkey = cred->request_key_auth; |
b5f545c8 | 1353 | if (!instkey) |
1da177e4 | 1354 | goto error; |
1da177e4 | 1355 | |
146aa8b1 | 1356 | rka = instkey->payload.data[0]; |
b5f545c8 DH |
1357 | if (rka->target_key->serial != id) |
1358 | goto error; | |
3e30148c | 1359 | |
1da177e4 LT |
1360 | /* find the destination keyring if present (which must also be |
1361 | * writable) */ | |
8bbf4976 DH |
1362 | ret = get_instantiation_keyring(ringid, rka, &dest_keyring); |
1363 | if (ret < 0) | |
1364 | goto error; | |
1da177e4 LT |
1365 | |
1366 | /* instantiate the key and link it into a keyring */ | |
fdd1b945 | 1367 | ret = key_reject_and_link(rka->target_key, timeout, error, |
8bbf4976 | 1368 | dest_keyring, instkey); |
1da177e4 | 1369 | |
8bbf4976 | 1370 | key_put(dest_keyring); |
b5f545c8 DH |
1371 | |
1372 | /* discard the assumed authority if it's just been disabled by | |
1373 | * instantiation of the key */ | |
d84f4f99 DH |
1374 | if (ret == 0) |
1375 | keyctl_change_reqkey_auth(NULL); | |
b5f545c8 DH |
1376 | |
1377 | error: | |
1da177e4 | 1378 | return ret; |
a8b17ed0 | 1379 | } |
1da177e4 | 1380 | |
3e30148c | 1381 | /* |
973c9f4f DH |
1382 | * Read or set the default keyring in which request_key() will cache keys and |
1383 | * return the old setting. | |
1384 | * | |
c9f838d1 EB |
1385 | * If a thread or process keyring is specified then it will be created if it |
1386 | * doesn't yet exist. The old setting will be returned if successful. | |
3e30148c DH |
1387 | */ |
1388 | long keyctl_set_reqkey_keyring(int reqkey_defl) | |
1389 | { | |
d84f4f99 DH |
1390 | struct cred *new; |
1391 | int ret, old_setting; | |
1392 | ||
1393 | old_setting = current_cred_xxx(jit_keyring); | |
1394 | ||
1395 | if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE) | |
1396 | return old_setting; | |
1397 | ||
1398 | new = prepare_creds(); | |
1399 | if (!new) | |
1400 | return -ENOMEM; | |
3e30148c DH |
1401 | |
1402 | switch (reqkey_defl) { | |
1403 | case KEY_REQKEY_DEFL_THREAD_KEYRING: | |
d84f4f99 | 1404 | ret = install_thread_keyring_to_cred(new); |
3e30148c | 1405 | if (ret < 0) |
d84f4f99 | 1406 | goto error; |
3e30148c DH |
1407 | goto set; |
1408 | ||
1409 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: | |
d84f4f99 | 1410 | ret = install_process_keyring_to_cred(new); |
c9f838d1 EB |
1411 | if (ret < 0) |
1412 | goto error; | |
d84f4f99 | 1413 | goto set; |
3e30148c DH |
1414 | |
1415 | case KEY_REQKEY_DEFL_DEFAULT: | |
1416 | case KEY_REQKEY_DEFL_SESSION_KEYRING: | |
1417 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
1418 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: | |
d84f4f99 DH |
1419 | case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: |
1420 | goto set; | |
3e30148c DH |
1421 | |
1422 | case KEY_REQKEY_DEFL_NO_CHANGE: | |
3e30148c DH |
1423 | case KEY_REQKEY_DEFL_GROUP_KEYRING: |
1424 | default: | |
d84f4f99 DH |
1425 | ret = -EINVAL; |
1426 | goto error; | |
3e30148c DH |
1427 | } |
1428 | ||
d84f4f99 DH |
1429 | set: |
1430 | new->jit_keyring = reqkey_defl; | |
1431 | commit_creds(new); | |
1432 | return old_setting; | |
1433 | error: | |
1434 | abort_creds(new); | |
4303ef19 | 1435 | return ret; |
a8b17ed0 | 1436 | } |
d84f4f99 | 1437 | |
017679c4 | 1438 | /* |
973c9f4f DH |
1439 | * Set or clear the timeout on a key. |
1440 | * | |
1441 | * Either the key must grant the caller Setattr permission or else the caller | |
1442 | * must hold an instantiation authorisation token for the key. | |
1443 | * | |
1444 | * The timeout is either 0 to clear the timeout, or a number of seconds from | |
1445 | * the current time. The key and any links to the key will be automatically | |
1446 | * garbage collected after the timeout expires. | |
1447 | * | |
d3600bcf MZ |
1448 | * Keys with KEY_FLAG_KEEP set should not be timed out. |
1449 | * | |
973c9f4f | 1450 | * If successful, 0 is returned. |
017679c4 DH |
1451 | */ |
1452 | long keyctl_set_timeout(key_serial_t id, unsigned timeout) | |
1453 | { | |
9156235b | 1454 | struct key *key, *instkey; |
017679c4 | 1455 | key_ref_t key_ref; |
017679c4 DH |
1456 | long ret; |
1457 | ||
5593122e | 1458 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
028db3e2 | 1459 | KEY_NEED_SETATTR); |
017679c4 | 1460 | if (IS_ERR(key_ref)) { |
9156235b DH |
1461 | /* setting the timeout on a key under construction is permitted |
1462 | * if we have the authorisation token handy */ | |
1463 | if (PTR_ERR(key_ref) == -EACCES) { | |
1464 | instkey = key_get_instantiation_authkey(id); | |
1465 | if (!IS_ERR(instkey)) { | |
1466 | key_put(instkey); | |
1467 | key_ref = lookup_user_key(id, | |
1468 | KEY_LOOKUP_PARTIAL, | |
8c0637e9 | 1469 | KEY_AUTHTOKEN_OVERRIDE); |
9156235b DH |
1470 | if (!IS_ERR(key_ref)) |
1471 | goto okay; | |
1472 | } | |
1473 | } | |
1474 | ||
017679c4 DH |
1475 | ret = PTR_ERR(key_ref); |
1476 | goto error; | |
1477 | } | |
1478 | ||
9156235b | 1479 | okay: |
017679c4 | 1480 | key = key_ref_to_ptr(key_ref); |
1d6d167c | 1481 | ret = 0; |
f7e47677 | 1482 | if (test_bit(KEY_FLAG_KEEP, &key->flags)) { |
d3600bcf | 1483 | ret = -EPERM; |
f7e47677 | 1484 | } else { |
d3600bcf | 1485 | key_set_timeout(key, timeout); |
f7e47677 DH |
1486 | notify_key(key, NOTIFY_KEY_SETATTR, 0); |
1487 | } | |
017679c4 DH |
1488 | key_put(key); |
1489 | ||
017679c4 DH |
1490 | error: |
1491 | return ret; | |
a8b17ed0 | 1492 | } |
017679c4 | 1493 | |
b5f545c8 | 1494 | /* |
973c9f4f DH |
1495 | * Assume (or clear) the authority to instantiate the specified key. |
1496 | * | |
1497 | * This sets the authoritative token currently in force for key instantiation. | |
1498 | * This must be done for a key to be instantiated. It has the effect of making | |
1499 | * available all the keys from the caller of the request_key() that created a | |
1500 | * key to request_key() calls made by the caller of this function. | |
1501 | * | |
1502 | * The caller must have the instantiation key in their process keyrings with a | |
1503 | * Search permission grant available to the caller. | |
1504 | * | |
1505 | * If the ID given is 0, then the setting will be cleared and 0 returned. | |
1506 | * | |
1507 | * If the ID given has a matching an authorisation key, then that key will be | |
1508 | * set and its ID will be returned. The authorisation key can be read to get | |
1509 | * the callout information passed to request_key(). | |
b5f545c8 DH |
1510 | */ |
1511 | long keyctl_assume_authority(key_serial_t id) | |
1512 | { | |
1513 | struct key *authkey; | |
1514 | long ret; | |
1515 | ||
1516 | /* special key IDs aren't permitted */ | |
1517 | ret = -EINVAL; | |
1518 | if (id < 0) | |
1519 | goto error; | |
1520 | ||
1521 | /* we divest ourselves of authority if given an ID of 0 */ | |
1522 | if (id == 0) { | |
d84f4f99 | 1523 | ret = keyctl_change_reqkey_auth(NULL); |
b5f545c8 DH |
1524 | goto error; |
1525 | } | |
1526 | ||
1527 | /* attempt to assume the authority temporarily granted to us whilst we | |
1528 | * instantiate the specified key | |
1529 | * - the authorisation key must be in the current task's keyrings | |
1530 | * somewhere | |
1531 | */ | |
1532 | authkey = key_get_instantiation_authkey(id); | |
1533 | if (IS_ERR(authkey)) { | |
1534 | ret = PTR_ERR(authkey); | |
1535 | goto error; | |
1536 | } | |
1537 | ||
d84f4f99 | 1538 | ret = keyctl_change_reqkey_auth(authkey); |
884bee02 EB |
1539 | if (ret == 0) |
1540 | ret = authkey->serial; | |
d84f4f99 | 1541 | key_put(authkey); |
b5f545c8 DH |
1542 | error: |
1543 | return ret; | |
a8b17ed0 | 1544 | } |
b5f545c8 | 1545 | |
70a5bb72 | 1546 | /* |
973c9f4f DH |
1547 | * Get a key's the LSM security label. |
1548 | * | |
1549 | * The key must grant the caller View permission for this to work. | |
1550 | * | |
1551 | * If there's a buffer, then up to buflen bytes of data will be placed into it. | |
1552 | * | |
1553 | * If successful, the amount of information available will be returned, | |
1554 | * irrespective of how much was copied (including the terminal NUL). | |
70a5bb72 DH |
1555 | */ |
1556 | long keyctl_get_security(key_serial_t keyid, | |
1557 | char __user *buffer, | |
1558 | size_t buflen) | |
1559 | { | |
1560 | struct key *key, *instkey; | |
1561 | key_ref_t key_ref; | |
1562 | char *context; | |
1563 | long ret; | |
1564 | ||
f5895943 | 1565 | key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); |
70a5bb72 DH |
1566 | if (IS_ERR(key_ref)) { |
1567 | if (PTR_ERR(key_ref) != -EACCES) | |
1568 | return PTR_ERR(key_ref); | |
1569 | ||
1570 | /* viewing a key under construction is also permitted if we | |
1571 | * have the authorisation token handy */ | |
1572 | instkey = key_get_instantiation_authkey(keyid); | |
1573 | if (IS_ERR(instkey)) | |
fa1cc7b5 | 1574 | return PTR_ERR(instkey); |
70a5bb72 DH |
1575 | key_put(instkey); |
1576 | ||
8c0637e9 DH |
1577 | key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, |
1578 | KEY_AUTHTOKEN_OVERRIDE); | |
70a5bb72 DH |
1579 | if (IS_ERR(key_ref)) |
1580 | return PTR_ERR(key_ref); | |
1581 | } | |
1582 | ||
1583 | key = key_ref_to_ptr(key_ref); | |
1584 | ret = security_key_getsecurity(key, &context); | |
1585 | if (ret == 0) { | |
1586 | /* if no information was returned, give userspace an empty | |
1587 | * string */ | |
1588 | ret = 1; | |
1589 | if (buffer && buflen > 0 && | |
1590 | copy_to_user(buffer, "", 1) != 0) | |
1591 | ret = -EFAULT; | |
1592 | } else if (ret > 0) { | |
1593 | /* return as much data as there's room for */ | |
1594 | if (buffer && buflen > 0) { | |
1595 | if (buflen > ret) | |
1596 | buflen = ret; | |
1597 | ||
1598 | if (copy_to_user(buffer, context, buflen) != 0) | |
1599 | ret = -EFAULT; | |
1600 | } | |
1601 | ||
1602 | kfree(context); | |
1603 | } | |
1604 | ||
1605 | key_ref_put(key_ref); | |
1606 | return ret; | |
1607 | } | |
1608 | ||
ee18d64c | 1609 | /* |
973c9f4f DH |
1610 | * Attempt to install the calling process's session keyring on the process's |
1611 | * parent process. | |
1612 | * | |
028db3e2 | 1613 | * The keyring must exist and must grant the caller LINK permission, and the |
973c9f4f DH |
1614 | * parent process must be single-threaded and must have the same effective |
1615 | * ownership as this process and mustn't be SUID/SGID. | |
1616 | * | |
1617 | * The keyring will be emplaced on the parent when it next resumes userspace. | |
1618 | * | |
1619 | * If successful, 0 will be returned. | |
ee18d64c DH |
1620 | */ |
1621 | long keyctl_session_to_parent(void) | |
1622 | { | |
1623 | struct task_struct *me, *parent; | |
1624 | const struct cred *mycred, *pcred; | |
67d12145 | 1625 | struct callback_head *newwork, *oldwork; |
ee18d64c | 1626 | key_ref_t keyring_r; |
413cd3d9 | 1627 | struct cred *cred; |
ee18d64c DH |
1628 | int ret; |
1629 | ||
028db3e2 | 1630 | keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_NEED_LINK); |
ee18d64c DH |
1631 | if (IS_ERR(keyring_r)) |
1632 | return PTR_ERR(keyring_r); | |
1633 | ||
413cd3d9 | 1634 | ret = -ENOMEM; |
413cd3d9 | 1635 | |
ee18d64c DH |
1636 | /* our parent is going to need a new cred struct, a new tgcred struct |
1637 | * and new security data, so we allocate them here to prevent ENOMEM in | |
1638 | * our parent */ | |
ee18d64c DH |
1639 | cred = cred_alloc_blank(); |
1640 | if (!cred) | |
67d12145 AV |
1641 | goto error_keyring; |
1642 | newwork = &cred->rcu; | |
ee18d64c | 1643 | |
3a50597d DH |
1644 | cred->session_keyring = key_ref_to_ptr(keyring_r); |
1645 | keyring_r = NULL; | |
67d12145 | 1646 | init_task_work(newwork, key_change_session_keyring); |
ee18d64c DH |
1647 | |
1648 | me = current; | |
9d1ac65a | 1649 | rcu_read_lock(); |
ee18d64c DH |
1650 | write_lock_irq(&tasklist_lock); |
1651 | ||
ee18d64c | 1652 | ret = -EPERM; |
413cd3d9 | 1653 | oldwork = NULL; |
7936d16d DH |
1654 | parent = rcu_dereference_protected(me->real_parent, |
1655 | lockdep_is_held(&tasklist_lock)); | |
ee18d64c DH |
1656 | |
1657 | /* the parent mustn't be init and mustn't be a kernel thread */ | |
1658 | if (parent->pid <= 1 || !parent->mm) | |
413cd3d9 | 1659 | goto unlock; |
ee18d64c DH |
1660 | |
1661 | /* the parent must be single threaded */ | |
dd98acf7 | 1662 | if (!thread_group_empty(parent)) |
413cd3d9 | 1663 | goto unlock; |
ee18d64c DH |
1664 | |
1665 | /* the parent and the child must have different session keyrings or | |
1666 | * there's no point */ | |
1667 | mycred = current_cred(); | |
1668 | pcred = __task_cred(parent); | |
1669 | if (mycred == pcred || | |
3a50597d | 1670 | mycred->session_keyring == pcred->session_keyring) { |
413cd3d9 ON |
1671 | ret = 0; |
1672 | goto unlock; | |
1673 | } | |
ee18d64c DH |
1674 | |
1675 | /* the parent must have the same effective ownership and mustn't be | |
1676 | * SUID/SGID */ | |
9a56c2db EB |
1677 | if (!uid_eq(pcred->uid, mycred->euid) || |
1678 | !uid_eq(pcred->euid, mycred->euid) || | |
1679 | !uid_eq(pcred->suid, mycred->euid) || | |
1680 | !gid_eq(pcred->gid, mycred->egid) || | |
1681 | !gid_eq(pcred->egid, mycred->egid) || | |
1682 | !gid_eq(pcred->sgid, mycred->egid)) | |
413cd3d9 | 1683 | goto unlock; |
ee18d64c DH |
1684 | |
1685 | /* the keyrings must have the same UID */ | |
3a50597d | 1686 | if ((pcred->session_keyring && |
2a74dbb9 LT |
1687 | !uid_eq(pcred->session_keyring->uid, mycred->euid)) || |
1688 | !uid_eq(mycred->session_keyring->uid, mycred->euid)) | |
413cd3d9 | 1689 | goto unlock; |
ee18d64c | 1690 | |
413cd3d9 ON |
1691 | /* cancel an already pending keyring replacement */ |
1692 | oldwork = task_work_cancel(parent, key_change_session_keyring); | |
ee18d64c DH |
1693 | |
1694 | /* the replacement session keyring is applied just prior to userspace | |
1695 | * restarting */ | |
91989c70 | 1696 | ret = task_work_add(parent, newwork, TWA_RESUME); |
413cd3d9 ON |
1697 | if (!ret) |
1698 | newwork = NULL; | |
1699 | unlock: | |
ee18d64c | 1700 | write_unlock_irq(&tasklist_lock); |
9d1ac65a | 1701 | rcu_read_unlock(); |
67d12145 AV |
1702 | if (oldwork) |
1703 | put_cred(container_of(oldwork, struct cred, rcu)); | |
1704 | if (newwork) | |
1705 | put_cred(cred); | |
ee18d64c DH |
1706 | return ret; |
1707 | ||
1708 | error_keyring: | |
1709 | key_ref_put(keyring_r); | |
1710 | return ret; | |
1711 | } | |
1712 | ||
6563c91f MM |
1713 | /* |
1714 | * Apply a restriction to a given keyring. | |
1715 | * | |
1716 | * The caller must have Setattr permission to change keyring restrictions. | |
1717 | * | |
1718 | * The requested type name may be a NULL pointer to reject all attempts | |
18026d86 EB |
1719 | * to link to the keyring. In this case, _restriction must also be NULL. |
1720 | * Otherwise, both _type and _restriction must be non-NULL. | |
6563c91f MM |
1721 | * |
1722 | * Returns 0 if successful. | |
1723 | */ | |
1724 | long keyctl_restrict_keyring(key_serial_t id, const char __user *_type, | |
1725 | const char __user *_restriction) | |
1726 | { | |
1727 | key_ref_t key_ref; | |
6563c91f MM |
1728 | char type[32]; |
1729 | char *restriction = NULL; | |
1730 | long ret; | |
1731 | ||
028db3e2 | 1732 | key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR); |
6563c91f MM |
1733 | if (IS_ERR(key_ref)) |
1734 | return PTR_ERR(key_ref); | |
1735 | ||
18026d86 | 1736 | ret = -EINVAL; |
6563c91f | 1737 | if (_type) { |
18026d86 | 1738 | if (!_restriction) |
6563c91f | 1739 | goto error; |
6563c91f | 1740 | |
18026d86 EB |
1741 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1742 | if (ret < 0) | |
6563c91f | 1743 | goto error; |
6563c91f MM |
1744 | |
1745 | restriction = strndup_user(_restriction, PAGE_SIZE); | |
1746 | if (IS_ERR(restriction)) { | |
1747 | ret = PTR_ERR(restriction); | |
1748 | goto error; | |
1749 | } | |
18026d86 EB |
1750 | } else { |
1751 | if (_restriction) | |
1752 | goto error; | |
6563c91f MM |
1753 | } |
1754 | ||
18026d86 | 1755 | ret = keyring_restrict(key_ref, _type ? type : NULL, restriction); |
6563c91f | 1756 | kfree(restriction); |
6563c91f MM |
1757 | error: |
1758 | key_ref_put(key_ref); | |
6563c91f MM |
1759 | return ret; |
1760 | } | |
1761 | ||
f7e47677 DH |
1762 | #ifdef CONFIG_KEY_NOTIFICATIONS |
1763 | /* | |
1764 | * Watch for changes to a key. | |
1765 | * | |
1766 | * The caller must have View permission to watch a key or keyring. | |
1767 | */ | |
1768 | long keyctl_watch_key(key_serial_t id, int watch_queue_fd, int watch_id) | |
1769 | { | |
1770 | struct watch_queue *wqueue; | |
1771 | struct watch_list *wlist = NULL; | |
1772 | struct watch *watch = NULL; | |
1773 | struct key *key; | |
1774 | key_ref_t key_ref; | |
1775 | long ret; | |
1776 | ||
1777 | if (watch_id < -1 || watch_id > 0xff) | |
1778 | return -EINVAL; | |
1779 | ||
1780 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_VIEW); | |
1781 | if (IS_ERR(key_ref)) | |
1782 | return PTR_ERR(key_ref); | |
1783 | key = key_ref_to_ptr(key_ref); | |
1784 | ||
1785 | wqueue = get_watch_queue(watch_queue_fd); | |
1786 | if (IS_ERR(wqueue)) { | |
1787 | ret = PTR_ERR(wqueue); | |
1788 | goto err_key; | |
1789 | } | |
1790 | ||
1791 | if (watch_id >= 0) { | |
1792 | ret = -ENOMEM; | |
1793 | if (!key->watchers) { | |
1794 | wlist = kzalloc(sizeof(*wlist), GFP_KERNEL); | |
1795 | if (!wlist) | |
1796 | goto err_wqueue; | |
1797 | init_watch_list(wlist, NULL); | |
1798 | } | |
1799 | ||
1800 | watch = kzalloc(sizeof(*watch), GFP_KERNEL); | |
1801 | if (!watch) | |
1802 | goto err_wlist; | |
1803 | ||
1804 | init_watch(watch, wqueue); | |
1805 | watch->id = key->serial; | |
1806 | watch->info_id = (u32)watch_id << WATCH_INFO_ID__SHIFT; | |
1807 | ||
1808 | ret = security_watch_key(key); | |
1809 | if (ret < 0) | |
1810 | goto err_watch; | |
1811 | ||
1812 | down_write(&key->sem); | |
1813 | if (!key->watchers) { | |
1814 | key->watchers = wlist; | |
1815 | wlist = NULL; | |
1816 | } | |
1817 | ||
1818 | ret = add_watch_to_object(watch, key->watchers); | |
1819 | up_write(&key->sem); | |
1820 | ||
1821 | if (ret == 0) | |
1822 | watch = NULL; | |
1823 | } else { | |
1824 | ret = -EBADSLT; | |
1825 | if (key->watchers) { | |
1826 | down_write(&key->sem); | |
1827 | ret = remove_watch_from_object(key->watchers, | |
1828 | wqueue, key_serial(key), | |
1829 | false); | |
1830 | up_write(&key->sem); | |
1831 | } | |
1832 | } | |
1833 | ||
1834 | err_watch: | |
1835 | kfree(watch); | |
1836 | err_wlist: | |
1837 | kfree(wlist); | |
1838 | err_wqueue: | |
1839 | put_watch_queue(wqueue); | |
1840 | err_key: | |
1841 | key_put(key); | |
1842 | return ret; | |
1843 | } | |
1844 | #endif /* CONFIG_KEY_NOTIFICATIONS */ | |
1845 | ||
45e0f30c DH |
1846 | /* |
1847 | * Get keyrings subsystem capabilities. | |
1848 | */ | |
1849 | long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen) | |
1850 | { | |
1851 | size_t size = buflen; | |
1852 | ||
1853 | if (size > 0) { | |
1854 | if (size > sizeof(keyrings_capabilities)) | |
1855 | size = sizeof(keyrings_capabilities); | |
1856 | if (copy_to_user(_buffer, keyrings_capabilities, size) != 0) | |
1857 | return -EFAULT; | |
1858 | if (size < buflen && | |
1859 | clear_user(_buffer + size, buflen - size) != 0) | |
1860 | return -EFAULT; | |
1861 | } | |
1862 | ||
1863 | return sizeof(keyrings_capabilities); | |
1864 | } | |
1865 | ||
1da177e4 | 1866 | /* |
973c9f4f | 1867 | * The key control system call |
1da177e4 | 1868 | */ |
938bb9f5 HC |
1869 | SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, |
1870 | unsigned long, arg4, unsigned long, arg5) | |
1da177e4 LT |
1871 | { |
1872 | switch (option) { | |
1873 | case KEYCTL_GET_KEYRING_ID: | |
1874 | return keyctl_get_keyring_ID((key_serial_t) arg2, | |
1875 | (int) arg3); | |
1876 | ||
1877 | case KEYCTL_JOIN_SESSION_KEYRING: | |
1878 | return keyctl_join_session_keyring((const char __user *) arg2); | |
1879 | ||
1880 | case KEYCTL_UPDATE: | |
1881 | return keyctl_update_key((key_serial_t) arg2, | |
1882 | (const void __user *) arg3, | |
1883 | (size_t) arg4); | |
1884 | ||
1885 | case KEYCTL_REVOKE: | |
1886 | return keyctl_revoke_key((key_serial_t) arg2); | |
1887 | ||
1888 | case KEYCTL_DESCRIBE: | |
1889 | return keyctl_describe_key((key_serial_t) arg2, | |
1890 | (char __user *) arg3, | |
1891 | (unsigned) arg4); | |
1892 | ||
1893 | case KEYCTL_CLEAR: | |
1894 | return keyctl_keyring_clear((key_serial_t) arg2); | |
1895 | ||
1896 | case KEYCTL_LINK: | |
1897 | return keyctl_keyring_link((key_serial_t) arg2, | |
1898 | (key_serial_t) arg3); | |
1899 | ||
1900 | case KEYCTL_UNLINK: | |
1901 | return keyctl_keyring_unlink((key_serial_t) arg2, | |
1902 | (key_serial_t) arg3); | |
1903 | ||
1904 | case KEYCTL_SEARCH: | |
1905 | return keyctl_keyring_search((key_serial_t) arg2, | |
1906 | (const char __user *) arg3, | |
1907 | (const char __user *) arg4, | |
1908 | (key_serial_t) arg5); | |
1909 | ||
1910 | case KEYCTL_READ: | |
1911 | return keyctl_read_key((key_serial_t) arg2, | |
1912 | (char __user *) arg3, | |
1913 | (size_t) arg4); | |
1914 | ||
1915 | case KEYCTL_CHOWN: | |
1916 | return keyctl_chown_key((key_serial_t) arg2, | |
1917 | (uid_t) arg3, | |
1918 | (gid_t) arg4); | |
1919 | ||
1920 | case KEYCTL_SETPERM: | |
1921 | return keyctl_setperm_key((key_serial_t) arg2, | |
028db3e2 | 1922 | (key_perm_t) arg3); |
1da177e4 LT |
1923 | |
1924 | case KEYCTL_INSTANTIATE: | |
1925 | return keyctl_instantiate_key((key_serial_t) arg2, | |
1926 | (const void __user *) arg3, | |
1927 | (size_t) arg4, | |
1928 | (key_serial_t) arg5); | |
1929 | ||
1930 | case KEYCTL_NEGATE: | |
1931 | return keyctl_negate_key((key_serial_t) arg2, | |
1932 | (unsigned) arg3, | |
1933 | (key_serial_t) arg4); | |
1934 | ||
3e30148c DH |
1935 | case KEYCTL_SET_REQKEY_KEYRING: |
1936 | return keyctl_set_reqkey_keyring(arg2); | |
1937 | ||
017679c4 DH |
1938 | case KEYCTL_SET_TIMEOUT: |
1939 | return keyctl_set_timeout((key_serial_t) arg2, | |
1940 | (unsigned) arg3); | |
1941 | ||
b5f545c8 DH |
1942 | case KEYCTL_ASSUME_AUTHORITY: |
1943 | return keyctl_assume_authority((key_serial_t) arg2); | |
1944 | ||
70a5bb72 DH |
1945 | case KEYCTL_GET_SECURITY: |
1946 | return keyctl_get_security((key_serial_t) arg2, | |
90bd49ab | 1947 | (char __user *) arg3, |
70a5bb72 DH |
1948 | (size_t) arg4); |
1949 | ||
ee18d64c DH |
1950 | case KEYCTL_SESSION_TO_PARENT: |
1951 | return keyctl_session_to_parent(); | |
1952 | ||
fdd1b945 DH |
1953 | case KEYCTL_REJECT: |
1954 | return keyctl_reject_key((key_serial_t) arg2, | |
1955 | (unsigned) arg3, | |
1956 | (unsigned) arg4, | |
1957 | (key_serial_t) arg5); | |
1958 | ||
ee009e4a DH |
1959 | case KEYCTL_INSTANTIATE_IOV: |
1960 | return keyctl_instantiate_key_iov( | |
1961 | (key_serial_t) arg2, | |
1962 | (const struct iovec __user *) arg3, | |
1963 | (unsigned) arg4, | |
1964 | (key_serial_t) arg5); | |
1965 | ||
fd75815f DH |
1966 | case KEYCTL_INVALIDATE: |
1967 | return keyctl_invalidate_key((key_serial_t) arg2); | |
1968 | ||
f36f8c75 DH |
1969 | case KEYCTL_GET_PERSISTENT: |
1970 | return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3); | |
1971 | ||
ddbb4114 MM |
1972 | case KEYCTL_DH_COMPUTE: |
1973 | return keyctl_dh_compute((struct keyctl_dh_params __user *) arg2, | |
4693fc73 | 1974 | (char __user *) arg3, (size_t) arg4, |
f1c316a3 | 1975 | (struct keyctl_kdf_params __user *) arg5); |
ddbb4114 | 1976 | |
6563c91f MM |
1977 | case KEYCTL_RESTRICT_KEYRING: |
1978 | return keyctl_restrict_keyring((key_serial_t) arg2, | |
1979 | (const char __user *) arg3, | |
1980 | (const char __user *) arg4); | |
ddbb4114 | 1981 | |
00d60fd3 DH |
1982 | case KEYCTL_PKEY_QUERY: |
1983 | if (arg3 != 0) | |
1984 | return -EINVAL; | |
1985 | return keyctl_pkey_query((key_serial_t)arg2, | |
1986 | (const char __user *)arg4, | |
468e91ce | 1987 | (struct keyctl_pkey_query __user *)arg5); |
00d60fd3 DH |
1988 | |
1989 | case KEYCTL_PKEY_ENCRYPT: | |
1990 | case KEYCTL_PKEY_DECRYPT: | |
1991 | case KEYCTL_PKEY_SIGN: | |
1992 | return keyctl_pkey_e_d_s( | |
1993 | option, | |
1994 | (const struct keyctl_pkey_params __user *)arg2, | |
1995 | (const char __user *)arg3, | |
1996 | (const void __user *)arg4, | |
1997 | (void __user *)arg5); | |
1998 | ||
1999 | case KEYCTL_PKEY_VERIFY: | |
2000 | return keyctl_pkey_verify( | |
2001 | (const struct keyctl_pkey_params __user *)arg2, | |
2002 | (const char __user *)arg3, | |
2003 | (const void __user *)arg4, | |
2004 | (const void __user *)arg5); | |
2005 | ||
ed0ac5c7 DH |
2006 | case KEYCTL_MOVE: |
2007 | return keyctl_keyring_move((key_serial_t)arg2, | |
2008 | (key_serial_t)arg3, | |
2009 | (key_serial_t)arg4, | |
2010 | (unsigned int)arg5); | |
2011 | ||
45e0f30c DH |
2012 | case KEYCTL_CAPABILITIES: |
2013 | return keyctl_capabilities((unsigned char __user *)arg2, (size_t)arg3); | |
2014 | ||
f7e47677 DH |
2015 | case KEYCTL_WATCH_KEY: |
2016 | return keyctl_watch_key((key_serial_t)arg2, (int)arg3, (int)arg4); | |
2017 | ||
1da177e4 LT |
2018 | default: |
2019 | return -EOPNOTSUPP; | |
2020 | } | |
a8b17ed0 | 2021 | } |