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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 | |
028db3e2 | 40 | KEYCTL_CAPS1_NS_KEY_TAG), |
45e0f30c DH |
41 | }; |
42 | ||
0cb409d9 DA |
43 | static int key_get_type_from_user(char *type, |
44 | const char __user *_type, | |
45 | unsigned len) | |
46 | { | |
47 | int ret; | |
48 | ||
49 | ret = strncpy_from_user(type, _type, len); | |
0cb409d9 | 50 | if (ret < 0) |
4303ef19 | 51 | return ret; |
0cb409d9 DA |
52 | if (ret == 0 || ret >= len) |
53 | return -EINVAL; | |
54e2c2c1 DH |
54 | if (type[0] == '.') |
55 | return -EPERM; | |
0cb409d9 | 56 | type[len - 1] = '\0'; |
0cb409d9 DA |
57 | return 0; |
58 | } | |
59 | ||
1da177e4 | 60 | /* |
973c9f4f DH |
61 | * Extract the description of a new key from userspace and either add it as a |
62 | * new key to the specified keyring or update a matching key in that keyring. | |
63 | * | |
cf7f601c DH |
64 | * If the description is NULL or an empty string, the key type is asked to |
65 | * generate one from the payload. | |
66 | * | |
973c9f4f DH |
67 | * The keyring must be writable so that we can attach the key to it. |
68 | * | |
69 | * If successful, the new key's serial number is returned, otherwise an error | |
70 | * code is returned. | |
1da177e4 | 71 | */ |
1e7bfb21 HC |
72 | SYSCALL_DEFINE5(add_key, const char __user *, _type, |
73 | const char __user *, _description, | |
74 | const void __user *, _payload, | |
75 | size_t, plen, | |
76 | key_serial_t, ringid) | |
1da177e4 | 77 | { |
664cceb0 | 78 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
79 | char type[32], *description; |
80 | void *payload; | |
0cb409d9 | 81 | long ret; |
1da177e4 LT |
82 | |
83 | ret = -EINVAL; | |
38bbca6b | 84 | if (plen > 1024 * 1024 - 1) |
1da177e4 LT |
85 | goto error; |
86 | ||
87 | /* draw all the data into kernel space */ | |
0cb409d9 | 88 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
89 | if (ret < 0) |
90 | goto error; | |
1da177e4 | 91 | |
cf7f601c DH |
92 | description = NULL; |
93 | if (_description) { | |
aa9d4437 | 94 | description = strndup_user(_description, KEY_MAX_DESC_SIZE); |
cf7f601c DH |
95 | if (IS_ERR(description)) { |
96 | ret = PTR_ERR(description); | |
97 | goto error; | |
98 | } | |
99 | if (!*description) { | |
100 | kfree(description); | |
101 | description = NULL; | |
a4e3b8d7 MZ |
102 | } else if ((description[0] == '.') && |
103 | (strncmp(type, "keyring", 7) == 0)) { | |
104 | ret = -EPERM; | |
105 | goto error2; | |
cf7f601c | 106 | } |
0cb409d9 | 107 | } |
1da177e4 LT |
108 | |
109 | /* pull the payload in if one was supplied */ | |
110 | payload = NULL; | |
111 | ||
5649645d | 112 | if (plen) { |
1da177e4 | 113 | ret = -ENOMEM; |
752ade68 MH |
114 | payload = kvmalloc(plen, GFP_KERNEL); |
115 | if (!payload) | |
116 | goto error2; | |
1da177e4 LT |
117 | |
118 | ret = -EFAULT; | |
119 | if (copy_from_user(payload, _payload, plen) != 0) | |
120 | goto error3; | |
121 | } | |
122 | ||
123 | /* find the target keyring (which must be writable) */ | |
f5895943 | 124 | keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); |
664cceb0 DH |
125 | if (IS_ERR(keyring_ref)) { |
126 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
127 | goto error3; |
128 | } | |
129 | ||
130 | /* create or update the requested key and add it to the target | |
131 | * keyring */ | |
664cceb0 | 132 | key_ref = key_create_or_update(keyring_ref, type, description, |
028db3e2 LT |
133 | payload, plen, KEY_PERM_UNDEF, |
134 | KEY_ALLOC_IN_QUOTA); | |
664cceb0 DH |
135 | if (!IS_ERR(key_ref)) { |
136 | ret = key_ref_to_ptr(key_ref)->serial; | |
137 | key_ref_put(key_ref); | |
1da177e4 LT |
138 | } |
139 | else { | |
664cceb0 | 140 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
141 | } |
142 | ||
664cceb0 | 143 | key_ref_put(keyring_ref); |
1da177e4 | 144 | error3: |
57070c85 EB |
145 | if (payload) { |
146 | memzero_explicit(payload, plen); | |
147 | kvfree(payload); | |
148 | } | |
1da177e4 LT |
149 | error2: |
150 | kfree(description); | |
151 | error: | |
152 | return ret; | |
a8b17ed0 | 153 | } |
1da177e4 | 154 | |
1da177e4 | 155 | /* |
973c9f4f DH |
156 | * Search the process keyrings and keyring trees linked from those for a |
157 | * matching key. Keyrings must have appropriate Search permission to be | |
158 | * searched. | |
159 | * | |
160 | * If a key is found, it will be attached to the destination keyring if there's | |
161 | * one specified and the serial number of the key will be returned. | |
162 | * | |
163 | * If no key is found, /sbin/request-key will be invoked if _callout_info is | |
164 | * non-NULL in an attempt to create a key. The _callout_info string will be | |
165 | * passed to /sbin/request-key to aid with completing the request. If the | |
166 | * _callout_info string is "" then it will be changed to "-". | |
1da177e4 | 167 | */ |
1e7bfb21 HC |
168 | SYSCALL_DEFINE4(request_key, const char __user *, _type, |
169 | const char __user *, _description, | |
170 | const char __user *, _callout_info, | |
171 | key_serial_t, destringid) | |
1da177e4 LT |
172 | { |
173 | struct key_type *ktype; | |
664cceb0 DH |
174 | struct key *key; |
175 | key_ref_t dest_ref; | |
4a38e122 | 176 | size_t callout_len; |
1da177e4 | 177 | char type[32], *description, *callout_info; |
0cb409d9 | 178 | long ret; |
1da177e4 LT |
179 | |
180 | /* pull the type into kernel space */ | |
0cb409d9 | 181 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
182 | if (ret < 0) |
183 | goto error; | |
1260f801 | 184 | |
1da177e4 | 185 | /* pull the description into kernel space */ |
aa9d4437 | 186 | description = strndup_user(_description, KEY_MAX_DESC_SIZE); |
0cb409d9 DA |
187 | if (IS_ERR(description)) { |
188 | ret = PTR_ERR(description); | |
1da177e4 | 189 | goto error; |
0cb409d9 | 190 | } |
1da177e4 LT |
191 | |
192 | /* pull the callout info into kernel space */ | |
193 | callout_info = NULL; | |
4a38e122 | 194 | callout_len = 0; |
1da177e4 | 195 | if (_callout_info) { |
0cb409d9 DA |
196 | callout_info = strndup_user(_callout_info, PAGE_SIZE); |
197 | if (IS_ERR(callout_info)) { | |
198 | ret = PTR_ERR(callout_info); | |
1da177e4 | 199 | goto error2; |
0cb409d9 | 200 | } |
4a38e122 | 201 | callout_len = strlen(callout_info); |
1da177e4 LT |
202 | } |
203 | ||
204 | /* get the destination keyring if specified */ | |
664cceb0 | 205 | dest_ref = NULL; |
1da177e4 | 206 | if (destringid) { |
5593122e | 207 | dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, |
f5895943 | 208 | KEY_NEED_WRITE); |
664cceb0 DH |
209 | if (IS_ERR(dest_ref)) { |
210 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
211 | goto error3; |
212 | } | |
213 | } | |
214 | ||
215 | /* find the key type */ | |
216 | ktype = key_type_lookup(type); | |
217 | if (IS_ERR(ktype)) { | |
218 | ret = PTR_ERR(ktype); | |
219 | goto error4; | |
220 | } | |
221 | ||
222 | /* do the search */ | |
a58946c1 | 223 | key = request_key_and_link(ktype, description, NULL, callout_info, |
028db3e2 | 224 | callout_len, NULL, key_ref_to_ptr(dest_ref), |
7e047ef5 | 225 | KEY_ALLOC_IN_QUOTA); |
1da177e4 LT |
226 | if (IS_ERR(key)) { |
227 | ret = PTR_ERR(key); | |
228 | goto error5; | |
229 | } | |
230 | ||
4aab1e89 DH |
231 | /* wait for the key to finish being constructed */ |
232 | ret = wait_for_key_construction(key, 1); | |
233 | if (ret < 0) | |
234 | goto error6; | |
235 | ||
1da177e4 LT |
236 | ret = key->serial; |
237 | ||
4aab1e89 | 238 | error6: |
3e30148c | 239 | key_put(key); |
c5b60b5e | 240 | error5: |
1da177e4 | 241 | key_type_put(ktype); |
c5b60b5e | 242 | error4: |
664cceb0 | 243 | key_ref_put(dest_ref); |
c5b60b5e | 244 | error3: |
1da177e4 | 245 | kfree(callout_info); |
c5b60b5e | 246 | error2: |
1da177e4 | 247 | kfree(description); |
c5b60b5e | 248 | error: |
1da177e4 | 249 | return ret; |
a8b17ed0 | 250 | } |
1da177e4 | 251 | |
1da177e4 | 252 | /* |
973c9f4f DH |
253 | * Get the ID of the specified process keyring. |
254 | * | |
255 | * The requested keyring must have search permission to be found. | |
256 | * | |
257 | * If successful, the ID of the requested keyring will be returned. | |
1da177e4 LT |
258 | */ |
259 | long keyctl_get_keyring_ID(key_serial_t id, int create) | |
260 | { | |
664cceb0 | 261 | key_ref_t key_ref; |
5593122e | 262 | unsigned long lflags; |
1da177e4 LT |
263 | long ret; |
264 | ||
5593122e | 265 | lflags = create ? KEY_LOOKUP_CREATE : 0; |
f5895943 | 266 | key_ref = lookup_user_key(id, lflags, KEY_NEED_SEARCH); |
664cceb0 DH |
267 | if (IS_ERR(key_ref)) { |
268 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
269 | goto error; |
270 | } | |
271 | ||
664cceb0 DH |
272 | ret = key_ref_to_ptr(key_ref)->serial; |
273 | key_ref_put(key_ref); | |
c5b60b5e | 274 | error: |
1da177e4 | 275 | return ret; |
973c9f4f | 276 | } |
1da177e4 | 277 | |
1da177e4 | 278 | /* |
973c9f4f DH |
279 | * Join a (named) session keyring. |
280 | * | |
281 | * Create and join an anonymous session keyring or join a named session | |
282 | * keyring, creating it if necessary. A named session keyring must have Search | |
283 | * permission for it to be joined. Session keyrings without this permit will | |
ee8f844e DH |
284 | * be skipped over. It is not permitted for userspace to create or join |
285 | * keyrings whose name begin with a dot. | |
973c9f4f DH |
286 | * |
287 | * If successful, the ID of the joined session keyring will be returned. | |
1da177e4 LT |
288 | */ |
289 | long keyctl_join_session_keyring(const char __user *_name) | |
290 | { | |
291 | char *name; | |
0cb409d9 | 292 | long ret; |
1da177e4 LT |
293 | |
294 | /* fetch the name from userspace */ | |
295 | name = NULL; | |
296 | if (_name) { | |
aa9d4437 | 297 | name = strndup_user(_name, KEY_MAX_DESC_SIZE); |
0cb409d9 DA |
298 | if (IS_ERR(name)) { |
299 | ret = PTR_ERR(name); | |
1da177e4 | 300 | goto error; |
0cb409d9 | 301 | } |
ee8f844e DH |
302 | |
303 | ret = -EPERM; | |
304 | if (name[0] == '.') | |
305 | goto error_name; | |
1da177e4 LT |
306 | } |
307 | ||
308 | /* join the session */ | |
309 | ret = join_session_keyring(name); | |
ee8f844e | 310 | error_name: |
0d54ee1c | 311 | kfree(name); |
c5b60b5e | 312 | error: |
1da177e4 | 313 | return ret; |
a8b17ed0 | 314 | } |
1da177e4 | 315 | |
1da177e4 | 316 | /* |
973c9f4f DH |
317 | * Update a key's data payload from the given data. |
318 | * | |
319 | * The key must grant the caller Write permission and the key type must support | |
320 | * updating for this to work. A negative key can be positively instantiated | |
321 | * with this call. | |
322 | * | |
323 | * If successful, 0 will be returned. If the key type does not support | |
324 | * updating, then -EOPNOTSUPP will be returned. | |
1da177e4 LT |
325 | */ |
326 | long keyctl_update_key(key_serial_t id, | |
327 | const void __user *_payload, | |
328 | size_t plen) | |
329 | { | |
664cceb0 | 330 | key_ref_t key_ref; |
1da177e4 LT |
331 | void *payload; |
332 | long ret; | |
333 | ||
334 | ret = -EINVAL; | |
335 | if (plen > PAGE_SIZE) | |
336 | goto error; | |
337 | ||
338 | /* pull the payload in if one was supplied */ | |
339 | payload = NULL; | |
5649645d | 340 | if (plen) { |
1da177e4 LT |
341 | ret = -ENOMEM; |
342 | payload = kmalloc(plen, GFP_KERNEL); | |
343 | if (!payload) | |
344 | goto error; | |
345 | ||
346 | ret = -EFAULT; | |
347 | if (copy_from_user(payload, _payload, plen) != 0) | |
348 | goto error2; | |
349 | } | |
350 | ||
351 | /* find the target key (which must be writable) */ | |
f5895943 | 352 | key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); |
664cceb0 DH |
353 | if (IS_ERR(key_ref)) { |
354 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
355 | goto error2; |
356 | } | |
357 | ||
358 | /* update the key */ | |
664cceb0 | 359 | ret = key_update(key_ref, payload, plen); |
1da177e4 | 360 | |
664cceb0 | 361 | key_ref_put(key_ref); |
c5b60b5e | 362 | error2: |
57070c85 | 363 | kzfree(payload); |
c5b60b5e | 364 | error: |
1da177e4 | 365 | return ret; |
a8b17ed0 | 366 | } |
1da177e4 | 367 | |
1da177e4 | 368 | /* |
973c9f4f DH |
369 | * Revoke a key. |
370 | * | |
371 | * The key must be grant the caller Write or Setattr permission for this to | |
372 | * work. The key type should give up its quota claim when revoked. The key | |
373 | * and any links to the key will be automatically garbage collected after a | |
374 | * certain amount of time (/proc/sys/kernel/keys/gc_delay). | |
375 | * | |
d3600bcf MZ |
376 | * Keys with KEY_FLAG_KEEP set should not be revoked. |
377 | * | |
973c9f4f | 378 | * If successful, 0 is returned. |
1da177e4 LT |
379 | */ |
380 | long keyctl_revoke_key(key_serial_t id) | |
381 | { | |
664cceb0 | 382 | key_ref_t key_ref; |
d3600bcf | 383 | struct key *key; |
1da177e4 LT |
384 | long ret; |
385 | ||
028db3e2 | 386 | key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); |
664cceb0 DH |
387 | if (IS_ERR(key_ref)) { |
388 | ret = PTR_ERR(key_ref); | |
028db3e2 LT |
389 | if (ret != -EACCES) |
390 | goto error; | |
391 | key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR); | |
392 | if (IS_ERR(key_ref)) { | |
393 | ret = PTR_ERR(key_ref); | |
394 | goto error; | |
395 | } | |
1da177e4 LT |
396 | } |
397 | ||
d3600bcf | 398 | key = key_ref_to_ptr(key_ref); |
1da177e4 | 399 | ret = 0; |
d3600bcf | 400 | if (test_bit(KEY_FLAG_KEEP, &key->flags)) |
1d6d167c MZ |
401 | ret = -EPERM; |
402 | else | |
d3600bcf | 403 | key_revoke(key); |
1da177e4 | 404 | |
664cceb0 | 405 | key_ref_put(key_ref); |
c5b60b5e | 406 | error: |
1260f801 | 407 | return ret; |
a8b17ed0 | 408 | } |
1da177e4 | 409 | |
fd75815f DH |
410 | /* |
411 | * Invalidate a key. | |
412 | * | |
413 | * The key must be grant the caller Invalidate permission for this to work. | |
414 | * The key and any links to the key will be automatically garbage collected | |
415 | * immediately. | |
416 | * | |
d3600bcf MZ |
417 | * Keys with KEY_FLAG_KEEP set should not be invalidated. |
418 | * | |
fd75815f DH |
419 | * If successful, 0 is returned. |
420 | */ | |
421 | long keyctl_invalidate_key(key_serial_t id) | |
422 | { | |
423 | key_ref_t key_ref; | |
d3600bcf | 424 | struct key *key; |
fd75815f DH |
425 | long ret; |
426 | ||
427 | kenter("%d", id); | |
428 | ||
028db3e2 | 429 | key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH); |
fd75815f DH |
430 | if (IS_ERR(key_ref)) { |
431 | ret = PTR_ERR(key_ref); | |
0c7774ab DH |
432 | |
433 | /* Root is permitted to invalidate certain special keys */ | |
434 | if (capable(CAP_SYS_ADMIN)) { | |
435 | key_ref = lookup_user_key(id, 0, 0); | |
436 | if (IS_ERR(key_ref)) | |
437 | goto error; | |
438 | if (test_bit(KEY_FLAG_ROOT_CAN_INVAL, | |
439 | &key_ref_to_ptr(key_ref)->flags)) | |
440 | goto invalidate; | |
441 | goto error_put; | |
442 | } | |
443 | ||
fd75815f DH |
444 | goto error; |
445 | } | |
446 | ||
0c7774ab | 447 | invalidate: |
d3600bcf | 448 | key = key_ref_to_ptr(key_ref); |
fd75815f | 449 | ret = 0; |
d3600bcf MZ |
450 | if (test_bit(KEY_FLAG_KEEP, &key->flags)) |
451 | ret = -EPERM; | |
1d6d167c | 452 | else |
d3600bcf | 453 | key_invalidate(key); |
0c7774ab | 454 | error_put: |
fd75815f DH |
455 | key_ref_put(key_ref); |
456 | error: | |
457 | kleave(" = %ld", ret); | |
458 | return ret; | |
459 | } | |
460 | ||
1da177e4 | 461 | /* |
973c9f4f DH |
462 | * Clear the specified keyring, creating an empty process keyring if one of the |
463 | * special keyring IDs is used. | |
464 | * | |
d3600bcf MZ |
465 | * The keyring must grant the caller Write permission and not have |
466 | * KEY_FLAG_KEEP set for this to work. If successful, 0 will be returned. | |
1da177e4 LT |
467 | */ |
468 | long keyctl_keyring_clear(key_serial_t ringid) | |
469 | { | |
664cceb0 | 470 | key_ref_t keyring_ref; |
d3600bcf | 471 | struct key *keyring; |
1da177e4 LT |
472 | long ret; |
473 | ||
028db3e2 | 474 | keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); |
664cceb0 DH |
475 | if (IS_ERR(keyring_ref)) { |
476 | ret = PTR_ERR(keyring_ref); | |
700920eb DH |
477 | |
478 | /* Root is permitted to invalidate certain special keyrings */ | |
479 | if (capable(CAP_SYS_ADMIN)) { | |
480 | keyring_ref = lookup_user_key(ringid, 0, 0); | |
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 | * | |
509 | * The key must grant the caller Link permission and the the keyring must grant | |
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 | ||
5593122e | 564 | key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0); |
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 DH |
663 | KEY_LOOKUP_PARTIAL, |
664 | 0); | |
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 | |
1da177e4 | 800 | /* |
973c9f4f DH |
801 | * Read a key's payload. |
802 | * | |
803 | * The key must either grant the caller Read permission, or it must grant the | |
804 | * caller Search permission when searched for from the process keyrings. | |
805 | * | |
806 | * If successful, we place up to buflen bytes of data into the buffer, if one | |
807 | * is provided, and return the amount of data that is available in the key, | |
808 | * irrespective of how much we copied into the buffer. | |
1da177e4 LT |
809 | */ |
810 | long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) | |
811 | { | |
664cceb0 DH |
812 | struct key *key; |
813 | key_ref_t key_ref; | |
1da177e4 LT |
814 | long ret; |
815 | ||
816 | /* find the key first */ | |
5593122e | 817 | key_ref = lookup_user_key(keyid, 0, 0); |
664cceb0 DH |
818 | if (IS_ERR(key_ref)) { |
819 | ret = -ENOKEY; | |
820 | goto error; | |
1da177e4 LT |
821 | } |
822 | ||
664cceb0 DH |
823 | key = key_ref_to_ptr(key_ref); |
824 | ||
363b02da DH |
825 | ret = key_read_state(key); |
826 | if (ret < 0) | |
827 | goto error2; /* Negatively instantiated */ | |
37863c43 | 828 | |
664cceb0 | 829 | /* see if we can read it directly */ |
f5895943 | 830 | ret = key_permission(key_ref, KEY_NEED_READ); |
29db9190 | 831 | if (ret == 0) |
664cceb0 | 832 | goto can_read_key; |
29db9190 | 833 | if (ret != -EACCES) |
7fc0786d | 834 | goto error2; |
664cceb0 DH |
835 | |
836 | /* we can't; see if it's searchable from this process's keyrings | |
837 | * - we automatically take account of the fact that it may be | |
838 | * dangling off an instantiation key | |
839 | */ | |
840 | if (!is_key_possessed(key_ref)) { | |
841 | ret = -EACCES; | |
842 | goto error2; | |
843 | } | |
1da177e4 LT |
844 | |
845 | /* the key is probably readable - now try to read it */ | |
c5b60b5e | 846 | can_read_key: |
b4a1b4f5 DH |
847 | ret = -EOPNOTSUPP; |
848 | if (key->type->read) { | |
849 | /* Read the data with the semaphore held (since we might sleep) | |
850 | * to protect against the key being updated or revoked. | |
851 | */ | |
852 | down_read(&key->sem); | |
853 | ret = key_validate(key); | |
854 | if (ret == 0) | |
1da177e4 | 855 | ret = key->type->read(key, buffer, buflen); |
b4a1b4f5 | 856 | up_read(&key->sem); |
1da177e4 LT |
857 | } |
858 | ||
c5b60b5e | 859 | error2: |
1da177e4 | 860 | key_put(key); |
c5b60b5e | 861 | error: |
1da177e4 | 862 | return ret; |
a8b17ed0 | 863 | } |
1da177e4 | 864 | |
1da177e4 | 865 | /* |
973c9f4f DH |
866 | * Change the ownership of a key |
867 | * | |
868 | * The key must grant the caller Setattr permission for this to work, though | |
869 | * the key need not be fully instantiated yet. For the UID to be changed, or | |
870 | * for the GID to be changed to a group the caller is not a member of, the | |
871 | * caller must have sysadmin capability. If either uid or gid is -1 then that | |
872 | * attribute is not changed. | |
873 | * | |
874 | * If the UID is to be changed, the new user must have sufficient quota to | |
875 | * accept the key. The quota deduction will be removed from the old user to | |
876 | * the new user should the attribute be changed. | |
877 | * | |
878 | * If successful, 0 will be returned. | |
1da177e4 | 879 | */ |
9a56c2db | 880 | long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) |
1da177e4 | 881 | { |
5801649d | 882 | struct key_user *newowner, *zapowner = NULL; |
1da177e4 | 883 | struct key *key; |
664cceb0 | 884 | key_ref_t key_ref; |
1da177e4 | 885 | long ret; |
9a56c2db EB |
886 | kuid_t uid; |
887 | kgid_t gid; | |
888 | ||
889 | uid = make_kuid(current_user_ns(), user); | |
890 | gid = make_kgid(current_user_ns(), group); | |
891 | ret = -EINVAL; | |
892 | if ((user != (uid_t) -1) && !uid_valid(uid)) | |
893 | goto error; | |
894 | if ((group != (gid_t) -1) && !gid_valid(gid)) | |
895 | goto error; | |
1da177e4 LT |
896 | |
897 | ret = 0; | |
9a56c2db | 898 | if (user == (uid_t) -1 && group == (gid_t) -1) |
1da177e4 LT |
899 | goto error; |
900 | ||
5593122e | 901 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
028db3e2 | 902 | KEY_NEED_SETATTR); |
664cceb0 DH |
903 | if (IS_ERR(key_ref)) { |
904 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
905 | goto error; |
906 | } | |
907 | ||
664cceb0 DH |
908 | key = key_ref_to_ptr(key_ref); |
909 | ||
1da177e4 LT |
910 | /* make the changes with the locks held to prevent chown/chown races */ |
911 | ret = -EACCES; | |
912 | down_write(&key->sem); | |
1da177e4 LT |
913 | |
914 | if (!capable(CAP_SYS_ADMIN)) { | |
915 | /* only the sysadmin can chown a key to some other UID */ | |
9a56c2db | 916 | if (user != (uid_t) -1 && !uid_eq(key->uid, uid)) |
5801649d | 917 | goto error_put; |
1da177e4 LT |
918 | |
919 | /* only the sysadmin can set the key's GID to a group other | |
920 | * than one of those that the current process subscribes to */ | |
9a56c2db | 921 | if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid)) |
5801649d | 922 | goto error_put; |
1da177e4 LT |
923 | } |
924 | ||
5801649d | 925 | /* change the UID */ |
9a56c2db | 926 | if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) { |
5801649d | 927 | ret = -ENOMEM; |
9a56c2db | 928 | newowner = key_user_lookup(uid); |
5801649d FT |
929 | if (!newowner) |
930 | goto error_put; | |
931 | ||
932 | /* transfer the quota burden to the new user */ | |
933 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { | |
9a56c2db | 934 | unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf | 935 | key_quota_root_maxkeys : key_quota_maxkeys; |
9a56c2db | 936 | unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
937 | key_quota_root_maxbytes : key_quota_maxbytes; |
938 | ||
5801649d | 939 | spin_lock(&newowner->lock); |
0b77f5bf DH |
940 | if (newowner->qnkeys + 1 >= maxkeys || |
941 | newowner->qnbytes + key->quotalen >= maxbytes || | |
942 | newowner->qnbytes + key->quotalen < | |
943 | newowner->qnbytes) | |
5801649d FT |
944 | goto quota_overrun; |
945 | ||
946 | newowner->qnkeys++; | |
947 | newowner->qnbytes += key->quotalen; | |
948 | spin_unlock(&newowner->lock); | |
949 | ||
950 | spin_lock(&key->user->lock); | |
951 | key->user->qnkeys--; | |
952 | key->user->qnbytes -= key->quotalen; | |
953 | spin_unlock(&key->user->lock); | |
954 | } | |
955 | ||
956 | atomic_dec(&key->user->nkeys); | |
957 | atomic_inc(&newowner->nkeys); | |
958 | ||
363b02da | 959 | if (key->state != KEY_IS_UNINSTANTIATED) { |
5801649d FT |
960 | atomic_dec(&key->user->nikeys); |
961 | atomic_inc(&newowner->nikeys); | |
962 | } | |
963 | ||
964 | zapowner = key->user; | |
965 | key->user = newowner; | |
966 | key->uid = uid; | |
1da177e4 LT |
967 | } |
968 | ||
969 | /* change the GID */ | |
9a56c2db | 970 | if (group != (gid_t) -1) |
1da177e4 LT |
971 | key->gid = gid; |
972 | ||
973 | ret = 0; | |
974 | ||
5801649d | 975 | error_put: |
1da177e4 LT |
976 | up_write(&key->sem); |
977 | key_put(key); | |
5801649d FT |
978 | if (zapowner) |
979 | key_user_put(zapowner); | |
980 | error: | |
1da177e4 LT |
981 | return ret; |
982 | ||
5801649d FT |
983 | quota_overrun: |
984 | spin_unlock(&newowner->lock); | |
985 | zapowner = newowner; | |
986 | ret = -EDQUOT; | |
987 | goto error_put; | |
a8b17ed0 | 988 | } |
5801649d | 989 | |
1da177e4 | 990 | /* |
973c9f4f DH |
991 | * Change the permission mask on a key. |
992 | * | |
993 | * The key must grant the caller Setattr permission for this to work, though | |
994 | * the key need not be fully instantiated yet. If the caller does not have | |
995 | * sysadmin capability, it may only change the permission on keys that it owns. | |
1da177e4 | 996 | */ |
028db3e2 | 997 | long keyctl_setperm_key(key_serial_t id, key_perm_t perm) |
1da177e4 LT |
998 | { |
999 | struct key *key; | |
664cceb0 | 1000 | key_ref_t key_ref; |
1da177e4 LT |
1001 | long ret; |
1002 | ||
028db3e2 | 1003 | ret = -EINVAL; |
664cceb0 | 1004 | if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) |
028db3e2 | 1005 | goto error; |
1da177e4 | 1006 | |
5593122e | 1007 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
028db3e2 | 1008 | KEY_NEED_SETATTR); |
664cceb0 DH |
1009 | if (IS_ERR(key_ref)) { |
1010 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
1011 | goto error; |
1012 | } | |
1013 | ||
664cceb0 DH |
1014 | key = key_ref_to_ptr(key_ref); |
1015 | ||
028db3e2 LT |
1016 | /* make the changes with the locks held to prevent chown/chmod races */ |
1017 | ret = -EACCES; | |
1018 | down_write(&key->sem); | |
1da177e4 | 1019 | |
028db3e2 LT |
1020 | /* if we're not the sysadmin, we can only change a key that we own */ |
1021 | if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) { | |
1022 | key->perm = perm; | |
1023 | ret = 0; | |
76d8aeab | 1024 | } |
1da177e4 | 1025 | |
1da177e4 LT |
1026 | up_write(&key->sem); |
1027 | key_put(key); | |
76d8aeab | 1028 | error: |
1da177e4 | 1029 | return ret; |
a8b17ed0 | 1030 | } |
1da177e4 | 1031 | |
8bbf4976 | 1032 | /* |
973c9f4f DH |
1033 | * Get the destination keyring for instantiation and check that the caller has |
1034 | * Write permission on it. | |
8bbf4976 DH |
1035 | */ |
1036 | static long get_instantiation_keyring(key_serial_t ringid, | |
1037 | struct request_key_auth *rka, | |
1038 | struct key **_dest_keyring) | |
1039 | { | |
1040 | key_ref_t dkref; | |
1041 | ||
eca1bf5b DH |
1042 | *_dest_keyring = NULL; |
1043 | ||
8bbf4976 | 1044 | /* just return a NULL pointer if we weren't asked to make a link */ |
eca1bf5b | 1045 | if (ringid == 0) |
8bbf4976 | 1046 | return 0; |
8bbf4976 DH |
1047 | |
1048 | /* if a specific keyring is nominated by ID, then use that */ | |
1049 | if (ringid > 0) { | |
f5895943 | 1050 | dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); |
8bbf4976 DH |
1051 | if (IS_ERR(dkref)) |
1052 | return PTR_ERR(dkref); | |
1053 | *_dest_keyring = key_ref_to_ptr(dkref); | |
1054 | return 0; | |
1055 | } | |
1056 | ||
1057 | if (ringid == KEY_SPEC_REQKEY_AUTH_KEY) | |
1058 | return -EINVAL; | |
1059 | ||
1060 | /* otherwise specify the destination keyring recorded in the | |
1061 | * authorisation key (any KEY_SPEC_*_KEYRING) */ | |
1062 | if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) { | |
21279cfa | 1063 | *_dest_keyring = key_get(rka->dest_keyring); |
8bbf4976 DH |
1064 | return 0; |
1065 | } | |
1066 | ||
1067 | return -ENOKEY; | |
1068 | } | |
1069 | ||
d84f4f99 | 1070 | /* |
973c9f4f | 1071 | * Change the request_key authorisation key on the current process. |
d84f4f99 DH |
1072 | */ |
1073 | static int keyctl_change_reqkey_auth(struct key *key) | |
1074 | { | |
1075 | struct cred *new; | |
1076 | ||
1077 | new = prepare_creds(); | |
1078 | if (!new) | |
1079 | return -ENOMEM; | |
1080 | ||
1081 | key_put(new->request_key_auth); | |
1082 | new->request_key_auth = key_get(key); | |
1083 | ||
1084 | return commit_creds(new); | |
1085 | } | |
1086 | ||
1da177e4 | 1087 | /* |
973c9f4f DH |
1088 | * Instantiate a key with the specified payload and link the key into the |
1089 | * destination keyring if one is given. | |
1090 | * | |
1091 | * The caller must have the appropriate instantiation permit set for this to | |
1092 | * work (see keyctl_assume_authority). No other permissions are required. | |
1093 | * | |
1094 | * If successful, 0 will be returned. | |
1da177e4 | 1095 | */ |
ee009e4a | 1096 | long keyctl_instantiate_key_common(key_serial_t id, |
b353a1f7 | 1097 | struct iov_iter *from, |
ee009e4a | 1098 | key_serial_t ringid) |
1da177e4 | 1099 | { |
d84f4f99 | 1100 | const struct cred *cred = current_cred(); |
3e30148c | 1101 | struct request_key_auth *rka; |
8bbf4976 | 1102 | struct key *instkey, *dest_keyring; |
b353a1f7 | 1103 | size_t plen = from ? iov_iter_count(from) : 0; |
1da177e4 LT |
1104 | void *payload; |
1105 | long ret; | |
1106 | ||
d84f4f99 DH |
1107 | kenter("%d,,%zu,%d", id, plen, ringid); |
1108 | ||
b353a1f7 AV |
1109 | if (!plen) |
1110 | from = NULL; | |
1111 | ||
1da177e4 | 1112 | ret = -EINVAL; |
38bbca6b | 1113 | if (plen > 1024 * 1024 - 1) |
1da177e4 LT |
1114 | goto error; |
1115 | ||
b5f545c8 DH |
1116 | /* the appropriate instantiation authorisation key must have been |
1117 | * assumed before calling this */ | |
1118 | ret = -EPERM; | |
d84f4f99 | 1119 | instkey = cred->request_key_auth; |
b5f545c8 DH |
1120 | if (!instkey) |
1121 | goto error; | |
1122 | ||
146aa8b1 | 1123 | rka = instkey->payload.data[0]; |
b5f545c8 DH |
1124 | if (rka->target_key->serial != id) |
1125 | goto error; | |
1126 | ||
1da177e4 LT |
1127 | /* pull the payload in if one was supplied */ |
1128 | payload = NULL; | |
1129 | ||
b353a1f7 | 1130 | if (from) { |
1da177e4 | 1131 | ret = -ENOMEM; |
752ade68 MH |
1132 | payload = kvmalloc(plen, GFP_KERNEL); |
1133 | if (!payload) | |
1134 | goto error; | |
1da177e4 | 1135 | |
b353a1f7 | 1136 | ret = -EFAULT; |
cbbd26b8 | 1137 | if (!copy_from_iter_full(payload, plen, from)) |
1da177e4 LT |
1138 | goto error2; |
1139 | } | |
1140 | ||
3e30148c DH |
1141 | /* find the destination keyring amongst those belonging to the |
1142 | * requesting task */ | |
8bbf4976 DH |
1143 | ret = get_instantiation_keyring(ringid, rka, &dest_keyring); |
1144 | if (ret < 0) | |
1145 | goto error2; | |
1da177e4 LT |
1146 | |
1147 | /* instantiate the key and link it into a keyring */ | |
3e30148c | 1148 | ret = key_instantiate_and_link(rka->target_key, payload, plen, |
8bbf4976 | 1149 | dest_keyring, instkey); |
1da177e4 | 1150 | |
8bbf4976 | 1151 | key_put(dest_keyring); |
b5f545c8 DH |
1152 | |
1153 | /* discard the assumed authority if it's just been disabled by | |
1154 | * instantiation of the key */ | |
d84f4f99 DH |
1155 | if (ret == 0) |
1156 | keyctl_change_reqkey_auth(NULL); | |
b5f545c8 DH |
1157 | |
1158 | error2: | |
57070c85 EB |
1159 | if (payload) { |
1160 | memzero_explicit(payload, plen); | |
1161 | kvfree(payload); | |
1162 | } | |
b5f545c8 | 1163 | error: |
1da177e4 | 1164 | return ret; |
a8b17ed0 | 1165 | } |
1da177e4 | 1166 | |
ee009e4a DH |
1167 | /* |
1168 | * Instantiate a key with the specified payload and link the key into the | |
1169 | * destination keyring if one is given. | |
1170 | * | |
1171 | * The caller must have the appropriate instantiation permit set for this to | |
1172 | * work (see keyctl_assume_authority). No other permissions are required. | |
1173 | * | |
1174 | * If successful, 0 will be returned. | |
1175 | */ | |
1176 | long keyctl_instantiate_key(key_serial_t id, | |
1177 | const void __user *_payload, | |
1178 | size_t plen, | |
1179 | key_serial_t ringid) | |
1180 | { | |
1181 | if (_payload && plen) { | |
b353a1f7 AV |
1182 | struct iovec iov; |
1183 | struct iov_iter from; | |
1184 | int ret; | |
ee009e4a | 1185 | |
b353a1f7 AV |
1186 | ret = import_single_range(WRITE, (void __user *)_payload, plen, |
1187 | &iov, &from); | |
1188 | if (unlikely(ret)) | |
1189 | return ret; | |
1190 | ||
1191 | return keyctl_instantiate_key_common(id, &from, ringid); | |
ee009e4a DH |
1192 | } |
1193 | ||
b353a1f7 | 1194 | return keyctl_instantiate_key_common(id, NULL, ringid); |
ee009e4a DH |
1195 | } |
1196 | ||
1197 | /* | |
1198 | * Instantiate a key with the specified multipart payload and link the key into | |
1199 | * the destination keyring if one is given. | |
1200 | * | |
1201 | * The caller must have the appropriate instantiation permit set for this to | |
1202 | * work (see keyctl_assume_authority). No other permissions are required. | |
1203 | * | |
1204 | * If successful, 0 will be returned. | |
1205 | */ | |
1206 | long keyctl_instantiate_key_iov(key_serial_t id, | |
1207 | const struct iovec __user *_payload_iov, | |
1208 | unsigned ioc, | |
1209 | key_serial_t ringid) | |
1210 | { | |
1211 | struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; | |
b353a1f7 | 1212 | struct iov_iter from; |
ee009e4a DH |
1213 | long ret; |
1214 | ||
b353a1f7 AV |
1215 | if (!_payload_iov) |
1216 | ioc = 0; | |
ee009e4a | 1217 | |
b353a1f7 AV |
1218 | ret = import_iovec(WRITE, _payload_iov, ioc, |
1219 | ARRAY_SIZE(iovstack), &iov, &from); | |
ee009e4a | 1220 | if (ret < 0) |
b353a1f7 AV |
1221 | return ret; |
1222 | ret = keyctl_instantiate_key_common(id, &from, ringid); | |
1223 | kfree(iov); | |
ee009e4a | 1224 | return ret; |
ee009e4a DH |
1225 | } |
1226 | ||
1da177e4 | 1227 | /* |
973c9f4f DH |
1228 | * Negatively instantiate the key with the given timeout (in seconds) and link |
1229 | * the key into the destination keyring if one is given. | |
1230 | * | |
1231 | * The caller must have the appropriate instantiation permit set for this to | |
1232 | * work (see keyctl_assume_authority). No other permissions are required. | |
1233 | * | |
1234 | * The key and any links to the key will be automatically garbage collected | |
1235 | * after the timeout expires. | |
1236 | * | |
1237 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
1238 | * them to return -ENOKEY until the negative key expires. | |
1239 | * | |
1240 | * If successful, 0 will be returned. | |
1da177e4 LT |
1241 | */ |
1242 | long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) | |
fdd1b945 DH |
1243 | { |
1244 | return keyctl_reject_key(id, timeout, ENOKEY, ringid); | |
1245 | } | |
1246 | ||
1247 | /* | |
1248 | * Negatively instantiate the key with the given timeout (in seconds) and error | |
1249 | * code and link the key into the destination keyring if one is given. | |
1250 | * | |
1251 | * The caller must have the appropriate instantiation permit set for this to | |
1252 | * work (see keyctl_assume_authority). No other permissions are required. | |
1253 | * | |
1254 | * The key and any links to the key will be automatically garbage collected | |
1255 | * after the timeout expires. | |
1256 | * | |
1257 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
1258 | * them to return the specified error code until the negative key expires. | |
1259 | * | |
1260 | * If successful, 0 will be returned. | |
1261 | */ | |
1262 | long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error, | |
1263 | key_serial_t ringid) | |
1da177e4 | 1264 | { |
d84f4f99 | 1265 | const struct cred *cred = current_cred(); |
3e30148c | 1266 | struct request_key_auth *rka; |
8bbf4976 | 1267 | struct key *instkey, *dest_keyring; |
1da177e4 LT |
1268 | long ret; |
1269 | ||
fdd1b945 DH |
1270 | kenter("%d,%u,%u,%d", id, timeout, error, ringid); |
1271 | ||
1272 | /* must be a valid error code and mustn't be a kernel special */ | |
1273 | if (error <= 0 || | |
1274 | error >= MAX_ERRNO || | |
1275 | error == ERESTARTSYS || | |
1276 | error == ERESTARTNOINTR || | |
1277 | error == ERESTARTNOHAND || | |
1278 | error == ERESTART_RESTARTBLOCK) | |
1279 | return -EINVAL; | |
d84f4f99 | 1280 | |
b5f545c8 DH |
1281 | /* the appropriate instantiation authorisation key must have been |
1282 | * assumed before calling this */ | |
1283 | ret = -EPERM; | |
d84f4f99 | 1284 | instkey = cred->request_key_auth; |
b5f545c8 | 1285 | if (!instkey) |
1da177e4 | 1286 | goto error; |
1da177e4 | 1287 | |
146aa8b1 | 1288 | rka = instkey->payload.data[0]; |
b5f545c8 DH |
1289 | if (rka->target_key->serial != id) |
1290 | goto error; | |
3e30148c | 1291 | |
1da177e4 LT |
1292 | /* find the destination keyring if present (which must also be |
1293 | * writable) */ | |
8bbf4976 DH |
1294 | ret = get_instantiation_keyring(ringid, rka, &dest_keyring); |
1295 | if (ret < 0) | |
1296 | goto error; | |
1da177e4 LT |
1297 | |
1298 | /* instantiate the key and link it into a keyring */ | |
fdd1b945 | 1299 | ret = key_reject_and_link(rka->target_key, timeout, error, |
8bbf4976 | 1300 | dest_keyring, instkey); |
1da177e4 | 1301 | |
8bbf4976 | 1302 | key_put(dest_keyring); |
b5f545c8 DH |
1303 | |
1304 | /* discard the assumed authority if it's just been disabled by | |
1305 | * instantiation of the key */ | |
d84f4f99 DH |
1306 | if (ret == 0) |
1307 | keyctl_change_reqkey_auth(NULL); | |
b5f545c8 DH |
1308 | |
1309 | error: | |
1da177e4 | 1310 | return ret; |
a8b17ed0 | 1311 | } |
1da177e4 | 1312 | |
3e30148c | 1313 | /* |
973c9f4f DH |
1314 | * Read or set the default keyring in which request_key() will cache keys and |
1315 | * return the old setting. | |
1316 | * | |
c9f838d1 EB |
1317 | * If a thread or process keyring is specified then it will be created if it |
1318 | * doesn't yet exist. The old setting will be returned if successful. | |
3e30148c DH |
1319 | */ |
1320 | long keyctl_set_reqkey_keyring(int reqkey_defl) | |
1321 | { | |
d84f4f99 DH |
1322 | struct cred *new; |
1323 | int ret, old_setting; | |
1324 | ||
1325 | old_setting = current_cred_xxx(jit_keyring); | |
1326 | ||
1327 | if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE) | |
1328 | return old_setting; | |
1329 | ||
1330 | new = prepare_creds(); | |
1331 | if (!new) | |
1332 | return -ENOMEM; | |
3e30148c DH |
1333 | |
1334 | switch (reqkey_defl) { | |
1335 | case KEY_REQKEY_DEFL_THREAD_KEYRING: | |
d84f4f99 | 1336 | ret = install_thread_keyring_to_cred(new); |
3e30148c | 1337 | if (ret < 0) |
d84f4f99 | 1338 | goto error; |
3e30148c DH |
1339 | goto set; |
1340 | ||
1341 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: | |
d84f4f99 | 1342 | ret = install_process_keyring_to_cred(new); |
c9f838d1 EB |
1343 | if (ret < 0) |
1344 | goto error; | |
d84f4f99 | 1345 | goto set; |
3e30148c DH |
1346 | |
1347 | case KEY_REQKEY_DEFL_DEFAULT: | |
1348 | case KEY_REQKEY_DEFL_SESSION_KEYRING: | |
1349 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
1350 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: | |
d84f4f99 DH |
1351 | case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: |
1352 | goto set; | |
3e30148c DH |
1353 | |
1354 | case KEY_REQKEY_DEFL_NO_CHANGE: | |
3e30148c DH |
1355 | case KEY_REQKEY_DEFL_GROUP_KEYRING: |
1356 | default: | |
d84f4f99 DH |
1357 | ret = -EINVAL; |
1358 | goto error; | |
3e30148c DH |
1359 | } |
1360 | ||
d84f4f99 DH |
1361 | set: |
1362 | new->jit_keyring = reqkey_defl; | |
1363 | commit_creds(new); | |
1364 | return old_setting; | |
1365 | error: | |
1366 | abort_creds(new); | |
4303ef19 | 1367 | return ret; |
a8b17ed0 | 1368 | } |
d84f4f99 | 1369 | |
017679c4 | 1370 | /* |
973c9f4f DH |
1371 | * Set or clear the timeout on a key. |
1372 | * | |
1373 | * Either the key must grant the caller Setattr permission or else the caller | |
1374 | * must hold an instantiation authorisation token for the key. | |
1375 | * | |
1376 | * The timeout is either 0 to clear the timeout, or a number of seconds from | |
1377 | * the current time. The key and any links to the key will be automatically | |
1378 | * garbage collected after the timeout expires. | |
1379 | * | |
d3600bcf MZ |
1380 | * Keys with KEY_FLAG_KEEP set should not be timed out. |
1381 | * | |
973c9f4f | 1382 | * If successful, 0 is returned. |
017679c4 DH |
1383 | */ |
1384 | long keyctl_set_timeout(key_serial_t id, unsigned timeout) | |
1385 | { | |
9156235b | 1386 | struct key *key, *instkey; |
017679c4 | 1387 | key_ref_t key_ref; |
017679c4 DH |
1388 | long ret; |
1389 | ||
5593122e | 1390 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
028db3e2 | 1391 | KEY_NEED_SETATTR); |
017679c4 | 1392 | if (IS_ERR(key_ref)) { |
9156235b DH |
1393 | /* setting the timeout on a key under construction is permitted |
1394 | * if we have the authorisation token handy */ | |
1395 | if (PTR_ERR(key_ref) == -EACCES) { | |
1396 | instkey = key_get_instantiation_authkey(id); | |
1397 | if (!IS_ERR(instkey)) { | |
1398 | key_put(instkey); | |
1399 | key_ref = lookup_user_key(id, | |
1400 | KEY_LOOKUP_PARTIAL, | |
1401 | 0); | |
1402 | if (!IS_ERR(key_ref)) | |
1403 | goto okay; | |
1404 | } | |
1405 | } | |
1406 | ||
017679c4 DH |
1407 | ret = PTR_ERR(key_ref); |
1408 | goto error; | |
1409 | } | |
1410 | ||
9156235b | 1411 | okay: |
017679c4 | 1412 | key = key_ref_to_ptr(key_ref); |
1d6d167c | 1413 | ret = 0; |
d3600bcf MZ |
1414 | if (test_bit(KEY_FLAG_KEEP, &key->flags)) |
1415 | ret = -EPERM; | |
1d6d167c | 1416 | else |
d3600bcf | 1417 | key_set_timeout(key, timeout); |
017679c4 DH |
1418 | key_put(key); |
1419 | ||
017679c4 DH |
1420 | error: |
1421 | return ret; | |
a8b17ed0 | 1422 | } |
017679c4 | 1423 | |
b5f545c8 | 1424 | /* |
973c9f4f DH |
1425 | * Assume (or clear) the authority to instantiate the specified key. |
1426 | * | |
1427 | * This sets the authoritative token currently in force for key instantiation. | |
1428 | * This must be done for a key to be instantiated. It has the effect of making | |
1429 | * available all the keys from the caller of the request_key() that created a | |
1430 | * key to request_key() calls made by the caller of this function. | |
1431 | * | |
1432 | * The caller must have the instantiation key in their process keyrings with a | |
1433 | * Search permission grant available to the caller. | |
1434 | * | |
1435 | * If the ID given is 0, then the setting will be cleared and 0 returned. | |
1436 | * | |
1437 | * If the ID given has a matching an authorisation key, then that key will be | |
1438 | * set and its ID will be returned. The authorisation key can be read to get | |
1439 | * the callout information passed to request_key(). | |
b5f545c8 DH |
1440 | */ |
1441 | long keyctl_assume_authority(key_serial_t id) | |
1442 | { | |
1443 | struct key *authkey; | |
1444 | long ret; | |
1445 | ||
1446 | /* special key IDs aren't permitted */ | |
1447 | ret = -EINVAL; | |
1448 | if (id < 0) | |
1449 | goto error; | |
1450 | ||
1451 | /* we divest ourselves of authority if given an ID of 0 */ | |
1452 | if (id == 0) { | |
d84f4f99 | 1453 | ret = keyctl_change_reqkey_auth(NULL); |
b5f545c8 DH |
1454 | goto error; |
1455 | } | |
1456 | ||
1457 | /* attempt to assume the authority temporarily granted to us whilst we | |
1458 | * instantiate the specified key | |
1459 | * - the authorisation key must be in the current task's keyrings | |
1460 | * somewhere | |
1461 | */ | |
1462 | authkey = key_get_instantiation_authkey(id); | |
1463 | if (IS_ERR(authkey)) { | |
1464 | ret = PTR_ERR(authkey); | |
1465 | goto error; | |
1466 | } | |
1467 | ||
d84f4f99 | 1468 | ret = keyctl_change_reqkey_auth(authkey); |
884bee02 EB |
1469 | if (ret == 0) |
1470 | ret = authkey->serial; | |
d84f4f99 | 1471 | key_put(authkey); |
b5f545c8 DH |
1472 | error: |
1473 | return ret; | |
a8b17ed0 | 1474 | } |
b5f545c8 | 1475 | |
70a5bb72 | 1476 | /* |
973c9f4f DH |
1477 | * Get a key's the LSM security label. |
1478 | * | |
1479 | * The key must grant the caller View permission for this to work. | |
1480 | * | |
1481 | * If there's a buffer, then up to buflen bytes of data will be placed into it. | |
1482 | * | |
1483 | * If successful, the amount of information available will be returned, | |
1484 | * irrespective of how much was copied (including the terminal NUL). | |
70a5bb72 DH |
1485 | */ |
1486 | long keyctl_get_security(key_serial_t keyid, | |
1487 | char __user *buffer, | |
1488 | size_t buflen) | |
1489 | { | |
1490 | struct key *key, *instkey; | |
1491 | key_ref_t key_ref; | |
1492 | char *context; | |
1493 | long ret; | |
1494 | ||
f5895943 | 1495 | key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); |
70a5bb72 DH |
1496 | if (IS_ERR(key_ref)) { |
1497 | if (PTR_ERR(key_ref) != -EACCES) | |
1498 | return PTR_ERR(key_ref); | |
1499 | ||
1500 | /* viewing a key under construction is also permitted if we | |
1501 | * have the authorisation token handy */ | |
1502 | instkey = key_get_instantiation_authkey(keyid); | |
1503 | if (IS_ERR(instkey)) | |
fa1cc7b5 | 1504 | return PTR_ERR(instkey); |
70a5bb72 DH |
1505 | key_put(instkey); |
1506 | ||
5593122e | 1507 | key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0); |
70a5bb72 DH |
1508 | if (IS_ERR(key_ref)) |
1509 | return PTR_ERR(key_ref); | |
1510 | } | |
1511 | ||
1512 | key = key_ref_to_ptr(key_ref); | |
1513 | ret = security_key_getsecurity(key, &context); | |
1514 | if (ret == 0) { | |
1515 | /* if no information was returned, give userspace an empty | |
1516 | * string */ | |
1517 | ret = 1; | |
1518 | if (buffer && buflen > 0 && | |
1519 | copy_to_user(buffer, "", 1) != 0) | |
1520 | ret = -EFAULT; | |
1521 | } else if (ret > 0) { | |
1522 | /* return as much data as there's room for */ | |
1523 | if (buffer && buflen > 0) { | |
1524 | if (buflen > ret) | |
1525 | buflen = ret; | |
1526 | ||
1527 | if (copy_to_user(buffer, context, buflen) != 0) | |
1528 | ret = -EFAULT; | |
1529 | } | |
1530 | ||
1531 | kfree(context); | |
1532 | } | |
1533 | ||
1534 | key_ref_put(key_ref); | |
1535 | return ret; | |
1536 | } | |
1537 | ||
ee18d64c | 1538 | /* |
973c9f4f DH |
1539 | * Attempt to install the calling process's session keyring on the process's |
1540 | * parent process. | |
1541 | * | |
028db3e2 | 1542 | * The keyring must exist and must grant the caller LINK permission, and the |
973c9f4f DH |
1543 | * parent process must be single-threaded and must have the same effective |
1544 | * ownership as this process and mustn't be SUID/SGID. | |
1545 | * | |
1546 | * The keyring will be emplaced on the parent when it next resumes userspace. | |
1547 | * | |
1548 | * If successful, 0 will be returned. | |
ee18d64c DH |
1549 | */ |
1550 | long keyctl_session_to_parent(void) | |
1551 | { | |
1552 | struct task_struct *me, *parent; | |
1553 | const struct cred *mycred, *pcred; | |
67d12145 | 1554 | struct callback_head *newwork, *oldwork; |
ee18d64c | 1555 | key_ref_t keyring_r; |
413cd3d9 | 1556 | struct cred *cred; |
ee18d64c DH |
1557 | int ret; |
1558 | ||
028db3e2 | 1559 | keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_NEED_LINK); |
ee18d64c DH |
1560 | if (IS_ERR(keyring_r)) |
1561 | return PTR_ERR(keyring_r); | |
1562 | ||
413cd3d9 | 1563 | ret = -ENOMEM; |
413cd3d9 | 1564 | |
ee18d64c DH |
1565 | /* our parent is going to need a new cred struct, a new tgcred struct |
1566 | * and new security data, so we allocate them here to prevent ENOMEM in | |
1567 | * our parent */ | |
ee18d64c DH |
1568 | cred = cred_alloc_blank(); |
1569 | if (!cred) | |
67d12145 AV |
1570 | goto error_keyring; |
1571 | newwork = &cred->rcu; | |
ee18d64c | 1572 | |
3a50597d DH |
1573 | cred->session_keyring = key_ref_to_ptr(keyring_r); |
1574 | keyring_r = NULL; | |
67d12145 | 1575 | init_task_work(newwork, key_change_session_keyring); |
ee18d64c DH |
1576 | |
1577 | me = current; | |
9d1ac65a | 1578 | rcu_read_lock(); |
ee18d64c DH |
1579 | write_lock_irq(&tasklist_lock); |
1580 | ||
ee18d64c | 1581 | ret = -EPERM; |
413cd3d9 | 1582 | oldwork = NULL; |
7936d16d DH |
1583 | parent = rcu_dereference_protected(me->real_parent, |
1584 | lockdep_is_held(&tasklist_lock)); | |
ee18d64c DH |
1585 | |
1586 | /* the parent mustn't be init and mustn't be a kernel thread */ | |
1587 | if (parent->pid <= 1 || !parent->mm) | |
413cd3d9 | 1588 | goto unlock; |
ee18d64c DH |
1589 | |
1590 | /* the parent must be single threaded */ | |
dd98acf7 | 1591 | if (!thread_group_empty(parent)) |
413cd3d9 | 1592 | goto unlock; |
ee18d64c DH |
1593 | |
1594 | /* the parent and the child must have different session keyrings or | |
1595 | * there's no point */ | |
1596 | mycred = current_cred(); | |
1597 | pcred = __task_cred(parent); | |
1598 | if (mycred == pcred || | |
3a50597d | 1599 | mycred->session_keyring == pcred->session_keyring) { |
413cd3d9 ON |
1600 | ret = 0; |
1601 | goto unlock; | |
1602 | } | |
ee18d64c DH |
1603 | |
1604 | /* the parent must have the same effective ownership and mustn't be | |
1605 | * SUID/SGID */ | |
9a56c2db EB |
1606 | if (!uid_eq(pcred->uid, mycred->euid) || |
1607 | !uid_eq(pcred->euid, mycred->euid) || | |
1608 | !uid_eq(pcred->suid, mycred->euid) || | |
1609 | !gid_eq(pcred->gid, mycred->egid) || | |
1610 | !gid_eq(pcred->egid, mycred->egid) || | |
1611 | !gid_eq(pcred->sgid, mycred->egid)) | |
413cd3d9 | 1612 | goto unlock; |
ee18d64c DH |
1613 | |
1614 | /* the keyrings must have the same UID */ | |
3a50597d | 1615 | if ((pcred->session_keyring && |
2a74dbb9 LT |
1616 | !uid_eq(pcred->session_keyring->uid, mycred->euid)) || |
1617 | !uid_eq(mycred->session_keyring->uid, mycred->euid)) | |
413cd3d9 | 1618 | goto unlock; |
ee18d64c | 1619 | |
413cd3d9 ON |
1620 | /* cancel an already pending keyring replacement */ |
1621 | oldwork = task_work_cancel(parent, key_change_session_keyring); | |
ee18d64c DH |
1622 | |
1623 | /* the replacement session keyring is applied just prior to userspace | |
1624 | * restarting */ | |
67d12145 | 1625 | ret = task_work_add(parent, newwork, true); |
413cd3d9 ON |
1626 | if (!ret) |
1627 | newwork = NULL; | |
1628 | unlock: | |
ee18d64c | 1629 | write_unlock_irq(&tasklist_lock); |
9d1ac65a | 1630 | rcu_read_unlock(); |
67d12145 AV |
1631 | if (oldwork) |
1632 | put_cred(container_of(oldwork, struct cred, rcu)); | |
1633 | if (newwork) | |
1634 | put_cred(cred); | |
ee18d64c DH |
1635 | return ret; |
1636 | ||
1637 | error_keyring: | |
1638 | key_ref_put(keyring_r); | |
1639 | return ret; | |
1640 | } | |
1641 | ||
6563c91f MM |
1642 | /* |
1643 | * Apply a restriction to a given keyring. | |
1644 | * | |
1645 | * The caller must have Setattr permission to change keyring restrictions. | |
1646 | * | |
1647 | * The requested type name may be a NULL pointer to reject all attempts | |
18026d86 EB |
1648 | * to link to the keyring. In this case, _restriction must also be NULL. |
1649 | * Otherwise, both _type and _restriction must be non-NULL. | |
6563c91f MM |
1650 | * |
1651 | * Returns 0 if successful. | |
1652 | */ | |
1653 | long keyctl_restrict_keyring(key_serial_t id, const char __user *_type, | |
1654 | const char __user *_restriction) | |
1655 | { | |
1656 | key_ref_t key_ref; | |
6563c91f MM |
1657 | char type[32]; |
1658 | char *restriction = NULL; | |
1659 | long ret; | |
1660 | ||
028db3e2 | 1661 | key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR); |
6563c91f MM |
1662 | if (IS_ERR(key_ref)) |
1663 | return PTR_ERR(key_ref); | |
1664 | ||
18026d86 | 1665 | ret = -EINVAL; |
6563c91f | 1666 | if (_type) { |
18026d86 | 1667 | if (!_restriction) |
6563c91f | 1668 | goto error; |
6563c91f | 1669 | |
18026d86 EB |
1670 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1671 | if (ret < 0) | |
6563c91f | 1672 | goto error; |
6563c91f MM |
1673 | |
1674 | restriction = strndup_user(_restriction, PAGE_SIZE); | |
1675 | if (IS_ERR(restriction)) { | |
1676 | ret = PTR_ERR(restriction); | |
1677 | goto error; | |
1678 | } | |
18026d86 EB |
1679 | } else { |
1680 | if (_restriction) | |
1681 | goto error; | |
6563c91f MM |
1682 | } |
1683 | ||
18026d86 | 1684 | ret = keyring_restrict(key_ref, _type ? type : NULL, restriction); |
6563c91f | 1685 | kfree(restriction); |
6563c91f MM |
1686 | error: |
1687 | key_ref_put(key_ref); | |
6563c91f MM |
1688 | return ret; |
1689 | } | |
1690 | ||
45e0f30c DH |
1691 | /* |
1692 | * Get keyrings subsystem capabilities. | |
1693 | */ | |
1694 | long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen) | |
1695 | { | |
1696 | size_t size = buflen; | |
1697 | ||
1698 | if (size > 0) { | |
1699 | if (size > sizeof(keyrings_capabilities)) | |
1700 | size = sizeof(keyrings_capabilities); | |
1701 | if (copy_to_user(_buffer, keyrings_capabilities, size) != 0) | |
1702 | return -EFAULT; | |
1703 | if (size < buflen && | |
1704 | clear_user(_buffer + size, buflen - size) != 0) | |
1705 | return -EFAULT; | |
1706 | } | |
1707 | ||
1708 | return sizeof(keyrings_capabilities); | |
1709 | } | |
1710 | ||
1da177e4 | 1711 | /* |
973c9f4f | 1712 | * The key control system call |
1da177e4 | 1713 | */ |
938bb9f5 HC |
1714 | SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, |
1715 | unsigned long, arg4, unsigned long, arg5) | |
1da177e4 LT |
1716 | { |
1717 | switch (option) { | |
1718 | case KEYCTL_GET_KEYRING_ID: | |
1719 | return keyctl_get_keyring_ID((key_serial_t) arg2, | |
1720 | (int) arg3); | |
1721 | ||
1722 | case KEYCTL_JOIN_SESSION_KEYRING: | |
1723 | return keyctl_join_session_keyring((const char __user *) arg2); | |
1724 | ||
1725 | case KEYCTL_UPDATE: | |
1726 | return keyctl_update_key((key_serial_t) arg2, | |
1727 | (const void __user *) arg3, | |
1728 | (size_t) arg4); | |
1729 | ||
1730 | case KEYCTL_REVOKE: | |
1731 | return keyctl_revoke_key((key_serial_t) arg2); | |
1732 | ||
1733 | case KEYCTL_DESCRIBE: | |
1734 | return keyctl_describe_key((key_serial_t) arg2, | |
1735 | (char __user *) arg3, | |
1736 | (unsigned) arg4); | |
1737 | ||
1738 | case KEYCTL_CLEAR: | |
1739 | return keyctl_keyring_clear((key_serial_t) arg2); | |
1740 | ||
1741 | case KEYCTL_LINK: | |
1742 | return keyctl_keyring_link((key_serial_t) arg2, | |
1743 | (key_serial_t) arg3); | |
1744 | ||
1745 | case KEYCTL_UNLINK: | |
1746 | return keyctl_keyring_unlink((key_serial_t) arg2, | |
1747 | (key_serial_t) arg3); | |
1748 | ||
1749 | case KEYCTL_SEARCH: | |
1750 | return keyctl_keyring_search((key_serial_t) arg2, | |
1751 | (const char __user *) arg3, | |
1752 | (const char __user *) arg4, | |
1753 | (key_serial_t) arg5); | |
1754 | ||
1755 | case KEYCTL_READ: | |
1756 | return keyctl_read_key((key_serial_t) arg2, | |
1757 | (char __user *) arg3, | |
1758 | (size_t) arg4); | |
1759 | ||
1760 | case KEYCTL_CHOWN: | |
1761 | return keyctl_chown_key((key_serial_t) arg2, | |
1762 | (uid_t) arg3, | |
1763 | (gid_t) arg4); | |
1764 | ||
1765 | case KEYCTL_SETPERM: | |
1766 | return keyctl_setperm_key((key_serial_t) arg2, | |
028db3e2 | 1767 | (key_perm_t) arg3); |
1da177e4 LT |
1768 | |
1769 | case KEYCTL_INSTANTIATE: | |
1770 | return keyctl_instantiate_key((key_serial_t) arg2, | |
1771 | (const void __user *) arg3, | |
1772 | (size_t) arg4, | |
1773 | (key_serial_t) arg5); | |
1774 | ||
1775 | case KEYCTL_NEGATE: | |
1776 | return keyctl_negate_key((key_serial_t) arg2, | |
1777 | (unsigned) arg3, | |
1778 | (key_serial_t) arg4); | |
1779 | ||
3e30148c DH |
1780 | case KEYCTL_SET_REQKEY_KEYRING: |
1781 | return keyctl_set_reqkey_keyring(arg2); | |
1782 | ||
017679c4 DH |
1783 | case KEYCTL_SET_TIMEOUT: |
1784 | return keyctl_set_timeout((key_serial_t) arg2, | |
1785 | (unsigned) arg3); | |
1786 | ||
b5f545c8 DH |
1787 | case KEYCTL_ASSUME_AUTHORITY: |
1788 | return keyctl_assume_authority((key_serial_t) arg2); | |
1789 | ||
70a5bb72 DH |
1790 | case KEYCTL_GET_SECURITY: |
1791 | return keyctl_get_security((key_serial_t) arg2, | |
90bd49ab | 1792 | (char __user *) arg3, |
70a5bb72 DH |
1793 | (size_t) arg4); |
1794 | ||
ee18d64c DH |
1795 | case KEYCTL_SESSION_TO_PARENT: |
1796 | return keyctl_session_to_parent(); | |
1797 | ||
fdd1b945 DH |
1798 | case KEYCTL_REJECT: |
1799 | return keyctl_reject_key((key_serial_t) arg2, | |
1800 | (unsigned) arg3, | |
1801 | (unsigned) arg4, | |
1802 | (key_serial_t) arg5); | |
1803 | ||
ee009e4a DH |
1804 | case KEYCTL_INSTANTIATE_IOV: |
1805 | return keyctl_instantiate_key_iov( | |
1806 | (key_serial_t) arg2, | |
1807 | (const struct iovec __user *) arg3, | |
1808 | (unsigned) arg4, | |
1809 | (key_serial_t) arg5); | |
1810 | ||
fd75815f DH |
1811 | case KEYCTL_INVALIDATE: |
1812 | return keyctl_invalidate_key((key_serial_t) arg2); | |
1813 | ||
f36f8c75 DH |
1814 | case KEYCTL_GET_PERSISTENT: |
1815 | return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3); | |
1816 | ||
ddbb4114 MM |
1817 | case KEYCTL_DH_COMPUTE: |
1818 | return keyctl_dh_compute((struct keyctl_dh_params __user *) arg2, | |
4693fc73 | 1819 | (char __user *) arg3, (size_t) arg4, |
f1c316a3 | 1820 | (struct keyctl_kdf_params __user *) arg5); |
ddbb4114 | 1821 | |
6563c91f MM |
1822 | case KEYCTL_RESTRICT_KEYRING: |
1823 | return keyctl_restrict_keyring((key_serial_t) arg2, | |
1824 | (const char __user *) arg3, | |
1825 | (const char __user *) arg4); | |
ddbb4114 | 1826 | |
00d60fd3 DH |
1827 | case KEYCTL_PKEY_QUERY: |
1828 | if (arg3 != 0) | |
1829 | return -EINVAL; | |
1830 | return keyctl_pkey_query((key_serial_t)arg2, | |
1831 | (const char __user *)arg4, | |
468e91ce | 1832 | (struct keyctl_pkey_query __user *)arg5); |
00d60fd3 DH |
1833 | |
1834 | case KEYCTL_PKEY_ENCRYPT: | |
1835 | case KEYCTL_PKEY_DECRYPT: | |
1836 | case KEYCTL_PKEY_SIGN: | |
1837 | return keyctl_pkey_e_d_s( | |
1838 | option, | |
1839 | (const struct keyctl_pkey_params __user *)arg2, | |
1840 | (const char __user *)arg3, | |
1841 | (const void __user *)arg4, | |
1842 | (void __user *)arg5); | |
1843 | ||
1844 | case KEYCTL_PKEY_VERIFY: | |
1845 | return keyctl_pkey_verify( | |
1846 | (const struct keyctl_pkey_params __user *)arg2, | |
1847 | (const char __user *)arg3, | |
1848 | (const void __user *)arg4, | |
1849 | (const void __user *)arg5); | |
1850 | ||
ed0ac5c7 DH |
1851 | case KEYCTL_MOVE: |
1852 | return keyctl_keyring_move((key_serial_t)arg2, | |
1853 | (key_serial_t)arg3, | |
1854 | (key_serial_t)arg4, | |
1855 | (unsigned int)arg5); | |
1856 | ||
45e0f30c DH |
1857 | case KEYCTL_CAPABILITIES: |
1858 | return keyctl_capabilities((unsigned char __user *)arg2, (size_t)arg3); | |
1859 | ||
1da177e4 LT |
1860 | default: |
1861 | return -EOPNOTSUPP; | |
1862 | } | |
a8b17ed0 | 1863 | } |