Commit | Line | Data |
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1da177e4 LT |
1 | /* keyctl.c: userspace keyctl operations |
2 | * | |
3e30148c | 3 | * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
4 | * Written by David Howells (dhowells@redhat.com) |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/syscalls.h> | |
17 | #include <linux/keyctl.h> | |
18 | #include <linux/fs.h> | |
c59ede7b | 19 | #include <linux/capability.h> |
0cb409d9 | 20 | #include <linux/string.h> |
1da177e4 LT |
21 | #include <linux/err.h> |
22 | #include <asm/uaccess.h> | |
23 | #include "internal.h" | |
24 | ||
0cb409d9 DA |
25 | static int key_get_type_from_user(char *type, |
26 | const char __user *_type, | |
27 | unsigned len) | |
28 | { | |
29 | int ret; | |
30 | ||
31 | ret = strncpy_from_user(type, _type, len); | |
32 | ||
33 | if (ret < 0) | |
34 | return -EFAULT; | |
35 | ||
36 | if (ret == 0 || ret >= len) | |
37 | return -EINVAL; | |
38 | ||
39 | if (type[0] == '.') | |
40 | return -EPERM; | |
41 | ||
42 | type[len - 1] = '\0'; | |
43 | ||
44 | return 0; | |
45 | } | |
46 | ||
1da177e4 LT |
47 | /*****************************************************************************/ |
48 | /* | |
49 | * extract the description of a new key from userspace and either add it as a | |
50 | * new key to the specified keyring or update a matching key in that keyring | |
51 | * - the keyring must be writable | |
52 | * - returns the new key's serial number | |
53 | * - implements add_key() | |
54 | */ | |
55 | asmlinkage long sys_add_key(const char __user *_type, | |
56 | const char __user *_description, | |
57 | const void __user *_payload, | |
58 | size_t plen, | |
59 | key_serial_t ringid) | |
60 | { | |
664cceb0 | 61 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
62 | char type[32], *description; |
63 | void *payload; | |
0cb409d9 | 64 | long ret; |
1da177e4 LT |
65 | |
66 | ret = -EINVAL; | |
67 | if (plen > 32767) | |
68 | goto error; | |
69 | ||
70 | /* draw all the data into kernel space */ | |
0cb409d9 | 71 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
72 | if (ret < 0) |
73 | goto error; | |
1da177e4 | 74 | |
0cb409d9 DA |
75 | description = strndup_user(_description, PAGE_SIZE); |
76 | if (IS_ERR(description)) { | |
77 | ret = PTR_ERR(description); | |
1da177e4 | 78 | goto error; |
0cb409d9 | 79 | } |
1da177e4 LT |
80 | |
81 | /* pull the payload in if one was supplied */ | |
82 | payload = NULL; | |
83 | ||
84 | if (_payload) { | |
85 | ret = -ENOMEM; | |
86 | payload = kmalloc(plen, GFP_KERNEL); | |
87 | if (!payload) | |
88 | goto error2; | |
89 | ||
90 | ret = -EFAULT; | |
91 | if (copy_from_user(payload, _payload, plen) != 0) | |
92 | goto error3; | |
93 | } | |
94 | ||
95 | /* find the target keyring (which must be writable) */ | |
664cceb0 DH |
96 | keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
97 | if (IS_ERR(keyring_ref)) { | |
98 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
99 | goto error3; |
100 | } | |
101 | ||
102 | /* create or update the requested key and add it to the target | |
103 | * keyring */ | |
664cceb0 | 104 | key_ref = key_create_or_update(keyring_ref, type, description, |
7e047ef5 | 105 | payload, plen, KEY_ALLOC_IN_QUOTA); |
664cceb0 DH |
106 | if (!IS_ERR(key_ref)) { |
107 | ret = key_ref_to_ptr(key_ref)->serial; | |
108 | key_ref_put(key_ref); | |
1da177e4 LT |
109 | } |
110 | else { | |
664cceb0 | 111 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
112 | } |
113 | ||
664cceb0 | 114 | key_ref_put(keyring_ref); |
1da177e4 LT |
115 | error3: |
116 | kfree(payload); | |
117 | error2: | |
118 | kfree(description); | |
119 | error: | |
120 | return ret; | |
121 | ||
122 | } /* end sys_add_key() */ | |
123 | ||
124 | /*****************************************************************************/ | |
125 | /* | |
126 | * search the process keyrings for a matching key | |
127 | * - nested keyrings may also be searched if they have Search permission | |
128 | * - if a key is found, it will be attached to the destination keyring if | |
129 | * there's one specified | |
130 | * - /sbin/request-key will be invoked if _callout_info is non-NULL | |
131 | * - the _callout_info string will be passed to /sbin/request-key | |
132 | * - if the _callout_info string is empty, it will be rendered as "-" | |
133 | * - implements request_key() | |
134 | */ | |
135 | asmlinkage long sys_request_key(const char __user *_type, | |
136 | const char __user *_description, | |
137 | const char __user *_callout_info, | |
138 | key_serial_t destringid) | |
139 | { | |
140 | struct key_type *ktype; | |
664cceb0 DH |
141 | struct key *key; |
142 | key_ref_t dest_ref; | |
1da177e4 | 143 | char type[32], *description, *callout_info; |
0cb409d9 | 144 | long ret; |
1da177e4 LT |
145 | |
146 | /* pull the type into kernel space */ | |
0cb409d9 | 147 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
148 | if (ret < 0) |
149 | goto error; | |
1260f801 | 150 | |
1da177e4 | 151 | /* pull the description into kernel space */ |
0cb409d9 DA |
152 | description = strndup_user(_description, PAGE_SIZE); |
153 | if (IS_ERR(description)) { | |
154 | ret = PTR_ERR(description); | |
1da177e4 | 155 | goto error; |
0cb409d9 | 156 | } |
1da177e4 LT |
157 | |
158 | /* pull the callout info into kernel space */ | |
159 | callout_info = NULL; | |
160 | if (_callout_info) { | |
0cb409d9 DA |
161 | callout_info = strndup_user(_callout_info, PAGE_SIZE); |
162 | if (IS_ERR(callout_info)) { | |
163 | ret = PTR_ERR(callout_info); | |
1da177e4 | 164 | goto error2; |
0cb409d9 | 165 | } |
1da177e4 LT |
166 | } |
167 | ||
168 | /* get the destination keyring if specified */ | |
664cceb0 | 169 | dest_ref = NULL; |
1da177e4 | 170 | if (destringid) { |
664cceb0 DH |
171 | dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); |
172 | if (IS_ERR(dest_ref)) { | |
173 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
174 | goto error3; |
175 | } | |
176 | } | |
177 | ||
178 | /* find the key type */ | |
179 | ktype = key_type_lookup(type); | |
180 | if (IS_ERR(ktype)) { | |
181 | ret = PTR_ERR(ktype); | |
182 | goto error4; | |
183 | } | |
184 | ||
185 | /* do the search */ | |
4e54f085 | 186 | key = request_key_and_link(ktype, description, callout_info, NULL, |
7e047ef5 DH |
187 | key_ref_to_ptr(dest_ref), |
188 | KEY_ALLOC_IN_QUOTA); | |
1da177e4 LT |
189 | if (IS_ERR(key)) { |
190 | ret = PTR_ERR(key); | |
191 | goto error5; | |
192 | } | |
193 | ||
1da177e4 LT |
194 | ret = key->serial; |
195 | ||
3e30148c | 196 | key_put(key); |
1da177e4 LT |
197 | error5: |
198 | key_type_put(ktype); | |
199 | error4: | |
664cceb0 | 200 | key_ref_put(dest_ref); |
1da177e4 LT |
201 | error3: |
202 | kfree(callout_info); | |
203 | error2: | |
204 | kfree(description); | |
205 | error: | |
206 | return ret; | |
207 | ||
208 | } /* end sys_request_key() */ | |
209 | ||
210 | /*****************************************************************************/ | |
211 | /* | |
212 | * get the ID of the specified process keyring | |
213 | * - the keyring must have search permission to be found | |
214 | * - implements keyctl(KEYCTL_GET_KEYRING_ID) | |
215 | */ | |
216 | long keyctl_get_keyring_ID(key_serial_t id, int create) | |
217 | { | |
664cceb0 | 218 | key_ref_t key_ref; |
1da177e4 LT |
219 | long ret; |
220 | ||
664cceb0 DH |
221 | key_ref = lookup_user_key(NULL, id, create, 0, KEY_SEARCH); |
222 | if (IS_ERR(key_ref)) { | |
223 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
224 | goto error; |
225 | } | |
226 | ||
664cceb0 DH |
227 | ret = key_ref_to_ptr(key_ref)->serial; |
228 | key_ref_put(key_ref); | |
1da177e4 LT |
229 | error: |
230 | return ret; | |
231 | ||
232 | } /* end keyctl_get_keyring_ID() */ | |
233 | ||
234 | /*****************************************************************************/ | |
235 | /* | |
236 | * join the session keyring | |
237 | * - implements keyctl(KEYCTL_JOIN_SESSION_KEYRING) | |
238 | */ | |
239 | long keyctl_join_session_keyring(const char __user *_name) | |
240 | { | |
241 | char *name; | |
0cb409d9 | 242 | long ret; |
1da177e4 LT |
243 | |
244 | /* fetch the name from userspace */ | |
245 | name = NULL; | |
246 | if (_name) { | |
0cb409d9 DA |
247 | name = strndup_user(_name, PAGE_SIZE); |
248 | if (IS_ERR(name)) { | |
249 | ret = PTR_ERR(name); | |
1da177e4 | 250 | goto error; |
0cb409d9 | 251 | } |
1da177e4 LT |
252 | } |
253 | ||
254 | /* join the session */ | |
255 | ret = join_session_keyring(name); | |
256 | ||
1da177e4 LT |
257 | error: |
258 | return ret; | |
259 | ||
260 | } /* end keyctl_join_session_keyring() */ | |
261 | ||
262 | /*****************************************************************************/ | |
263 | /* | |
264 | * update a key's data payload | |
265 | * - the key must be writable | |
266 | * - implements keyctl(KEYCTL_UPDATE) | |
267 | */ | |
268 | long keyctl_update_key(key_serial_t id, | |
269 | const void __user *_payload, | |
270 | size_t plen) | |
271 | { | |
664cceb0 | 272 | key_ref_t key_ref; |
1da177e4 LT |
273 | void *payload; |
274 | long ret; | |
275 | ||
276 | ret = -EINVAL; | |
277 | if (plen > PAGE_SIZE) | |
278 | goto error; | |
279 | ||
280 | /* pull the payload in if one was supplied */ | |
281 | payload = NULL; | |
282 | if (_payload) { | |
283 | ret = -ENOMEM; | |
284 | payload = kmalloc(plen, GFP_KERNEL); | |
285 | if (!payload) | |
286 | goto error; | |
287 | ||
288 | ret = -EFAULT; | |
289 | if (copy_from_user(payload, _payload, plen) != 0) | |
290 | goto error2; | |
291 | } | |
292 | ||
293 | /* find the target key (which must be writable) */ | |
664cceb0 DH |
294 | key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); |
295 | if (IS_ERR(key_ref)) { | |
296 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
297 | goto error2; |
298 | } | |
299 | ||
300 | /* update the key */ | |
664cceb0 | 301 | ret = key_update(key_ref, payload, plen); |
1da177e4 | 302 | |
664cceb0 | 303 | key_ref_put(key_ref); |
1da177e4 LT |
304 | error2: |
305 | kfree(payload); | |
306 | error: | |
307 | return ret; | |
308 | ||
309 | } /* end keyctl_update_key() */ | |
310 | ||
311 | /*****************************************************************************/ | |
312 | /* | |
313 | * revoke a key | |
314 | * - the key must be writable | |
315 | * - implements keyctl(KEYCTL_REVOKE) | |
316 | */ | |
317 | long keyctl_revoke_key(key_serial_t id) | |
318 | { | |
664cceb0 | 319 | key_ref_t key_ref; |
1da177e4 LT |
320 | long ret; |
321 | ||
664cceb0 DH |
322 | key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); |
323 | if (IS_ERR(key_ref)) { | |
324 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
325 | goto error; |
326 | } | |
327 | ||
664cceb0 | 328 | key_revoke(key_ref_to_ptr(key_ref)); |
1da177e4 LT |
329 | ret = 0; |
330 | ||
664cceb0 | 331 | key_ref_put(key_ref); |
1da177e4 | 332 | error: |
1260f801 | 333 | return ret; |
1da177e4 LT |
334 | |
335 | } /* end keyctl_revoke_key() */ | |
336 | ||
337 | /*****************************************************************************/ | |
338 | /* | |
339 | * clear the specified process keyring | |
340 | * - the keyring must be writable | |
341 | * - implements keyctl(KEYCTL_CLEAR) | |
342 | */ | |
343 | long keyctl_keyring_clear(key_serial_t ringid) | |
344 | { | |
664cceb0 | 345 | key_ref_t keyring_ref; |
1da177e4 LT |
346 | long ret; |
347 | ||
664cceb0 DH |
348 | keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
349 | if (IS_ERR(keyring_ref)) { | |
350 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
351 | goto error; |
352 | } | |
353 | ||
664cceb0 | 354 | ret = keyring_clear(key_ref_to_ptr(keyring_ref)); |
1da177e4 | 355 | |
664cceb0 | 356 | key_ref_put(keyring_ref); |
1da177e4 LT |
357 | error: |
358 | return ret; | |
359 | ||
360 | } /* end keyctl_keyring_clear() */ | |
361 | ||
362 | /*****************************************************************************/ | |
363 | /* | |
364 | * link a key into a keyring | |
365 | * - the keyring must be writable | |
366 | * - the key must be linkable | |
367 | * - implements keyctl(KEYCTL_LINK) | |
368 | */ | |
369 | long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) | |
370 | { | |
664cceb0 | 371 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
372 | long ret; |
373 | ||
664cceb0 DH |
374 | keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
375 | if (IS_ERR(keyring_ref)) { | |
376 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
377 | goto error; |
378 | } | |
379 | ||
664cceb0 DH |
380 | key_ref = lookup_user_key(NULL, id, 1, 0, KEY_LINK); |
381 | if (IS_ERR(key_ref)) { | |
382 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
383 | goto error2; |
384 | } | |
385 | ||
664cceb0 | 386 | ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); |
1da177e4 | 387 | |
664cceb0 | 388 | key_ref_put(key_ref); |
1da177e4 | 389 | error2: |
664cceb0 | 390 | key_ref_put(keyring_ref); |
1da177e4 LT |
391 | error: |
392 | return ret; | |
393 | ||
394 | } /* end keyctl_keyring_link() */ | |
395 | ||
396 | /*****************************************************************************/ | |
397 | /* | |
398 | * unlink the first attachment of a key from a keyring | |
399 | * - the keyring must be writable | |
400 | * - we don't need any permissions on the key | |
401 | * - implements keyctl(KEYCTL_UNLINK) | |
402 | */ | |
403 | long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) | |
404 | { | |
664cceb0 | 405 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
406 | long ret; |
407 | ||
664cceb0 DH |
408 | keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_WRITE); |
409 | if (IS_ERR(keyring_ref)) { | |
410 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
411 | goto error; |
412 | } | |
413 | ||
664cceb0 DH |
414 | key_ref = lookup_user_key(NULL, id, 0, 0, 0); |
415 | if (IS_ERR(key_ref)) { | |
416 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
417 | goto error2; |
418 | } | |
419 | ||
664cceb0 | 420 | ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); |
1da177e4 | 421 | |
664cceb0 | 422 | key_ref_put(key_ref); |
1da177e4 | 423 | error2: |
664cceb0 | 424 | key_ref_put(keyring_ref); |
1da177e4 LT |
425 | error: |
426 | return ret; | |
427 | ||
428 | } /* end keyctl_keyring_unlink() */ | |
429 | ||
430 | /*****************************************************************************/ | |
431 | /* | |
432 | * describe a user key | |
433 | * - the key must have view permission | |
434 | * - if there's a buffer, we place up to buflen bytes of data into it | |
435 | * - unless there's an error, we return the amount of description available, | |
436 | * irrespective of how much we may have copied | |
437 | * - the description is formatted thus: | |
438 | * type;uid;gid;perm;description<NUL> | |
439 | * - implements keyctl(KEYCTL_DESCRIBE) | |
440 | */ | |
441 | long keyctl_describe_key(key_serial_t keyid, | |
442 | char __user *buffer, | |
443 | size_t buflen) | |
444 | { | |
3e30148c | 445 | struct key *key, *instkey; |
664cceb0 | 446 | key_ref_t key_ref; |
1da177e4 LT |
447 | char *tmpbuf; |
448 | long ret; | |
449 | ||
664cceb0 DH |
450 | key_ref = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW); |
451 | if (IS_ERR(key_ref)) { | |
3e30148c DH |
452 | /* viewing a key under construction is permitted if we have the |
453 | * authorisation token handy */ | |
664cceb0 | 454 | if (PTR_ERR(key_ref) == -EACCES) { |
3e30148c DH |
455 | instkey = key_get_instantiation_authkey(keyid); |
456 | if (!IS_ERR(instkey)) { | |
457 | key_put(instkey); | |
664cceb0 DH |
458 | key_ref = lookup_user_key(NULL, keyid, |
459 | 0, 1, 0); | |
460 | if (!IS_ERR(key_ref)) | |
3e30148c DH |
461 | goto okay; |
462 | } | |
463 | } | |
464 | ||
664cceb0 | 465 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
466 | goto error; |
467 | } | |
468 | ||
3e30148c | 469 | okay: |
1da177e4 LT |
470 | /* calculate how much description we're going to return */ |
471 | ret = -ENOMEM; | |
472 | tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
473 | if (!tmpbuf) | |
474 | goto error2; | |
475 | ||
664cceb0 DH |
476 | key = key_ref_to_ptr(key_ref); |
477 | ||
1da177e4 | 478 | ret = snprintf(tmpbuf, PAGE_SIZE - 1, |
664cceb0 DH |
479 | "%s;%d;%d;%08x;%s", |
480 | key_ref_to_ptr(key_ref)->type->name, | |
481 | key_ref_to_ptr(key_ref)->uid, | |
482 | key_ref_to_ptr(key_ref)->gid, | |
483 | key_ref_to_ptr(key_ref)->perm, | |
484 | key_ref_to_ptr(key_ref)->description ? | |
485 | key_ref_to_ptr(key_ref)->description : "" | |
1da177e4 LT |
486 | ); |
487 | ||
488 | /* include a NUL char at the end of the data */ | |
489 | if (ret > PAGE_SIZE - 1) | |
490 | ret = PAGE_SIZE - 1; | |
491 | tmpbuf[ret] = 0; | |
492 | ret++; | |
493 | ||
494 | /* consider returning the data */ | |
495 | if (buffer && buflen > 0) { | |
496 | if (buflen > ret) | |
497 | buflen = ret; | |
498 | ||
499 | if (copy_to_user(buffer, tmpbuf, buflen) != 0) | |
500 | ret = -EFAULT; | |
501 | } | |
502 | ||
503 | kfree(tmpbuf); | |
504 | error2: | |
664cceb0 | 505 | key_ref_put(key_ref); |
1da177e4 LT |
506 | error: |
507 | return ret; | |
508 | ||
509 | } /* end keyctl_describe_key() */ | |
510 | ||
511 | /*****************************************************************************/ | |
512 | /* | |
513 | * search the specified keyring for a matching key | |
514 | * - the start keyring must be searchable | |
515 | * - nested keyrings may also be searched if they are searchable | |
516 | * - only keys with search permission may be found | |
517 | * - if a key is found, it will be attached to the destination keyring if | |
518 | * there's one specified | |
519 | * - implements keyctl(KEYCTL_SEARCH) | |
520 | */ | |
521 | long keyctl_keyring_search(key_serial_t ringid, | |
522 | const char __user *_type, | |
523 | const char __user *_description, | |
524 | key_serial_t destringid) | |
525 | { | |
526 | struct key_type *ktype; | |
664cceb0 | 527 | key_ref_t keyring_ref, key_ref, dest_ref; |
1da177e4 | 528 | char type[32], *description; |
0cb409d9 | 529 | long ret; |
1da177e4 LT |
530 | |
531 | /* pull the type and description into kernel space */ | |
0cb409d9 | 532 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
533 | if (ret < 0) |
534 | goto error; | |
1da177e4 | 535 | |
0cb409d9 DA |
536 | description = strndup_user(_description, PAGE_SIZE); |
537 | if (IS_ERR(description)) { | |
538 | ret = PTR_ERR(description); | |
1da177e4 | 539 | goto error; |
0cb409d9 | 540 | } |
1da177e4 LT |
541 | |
542 | /* get the keyring at which to begin the search */ | |
664cceb0 DH |
543 | keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH); |
544 | if (IS_ERR(keyring_ref)) { | |
545 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
546 | goto error2; |
547 | } | |
548 | ||
549 | /* get the destination keyring if specified */ | |
664cceb0 | 550 | dest_ref = NULL; |
1da177e4 | 551 | if (destringid) { |
664cceb0 DH |
552 | dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); |
553 | if (IS_ERR(dest_ref)) { | |
554 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
555 | goto error3; |
556 | } | |
557 | } | |
558 | ||
559 | /* find the key type */ | |
560 | ktype = key_type_lookup(type); | |
561 | if (IS_ERR(ktype)) { | |
562 | ret = PTR_ERR(ktype); | |
563 | goto error4; | |
564 | } | |
565 | ||
566 | /* do the search */ | |
664cceb0 DH |
567 | key_ref = keyring_search(keyring_ref, ktype, description); |
568 | if (IS_ERR(key_ref)) { | |
569 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
570 | |
571 | /* treat lack or presence of a negative key the same */ | |
572 | if (ret == -EAGAIN) | |
573 | ret = -ENOKEY; | |
574 | goto error5; | |
575 | } | |
576 | ||
577 | /* link the resulting key to the destination keyring if we can */ | |
664cceb0 | 578 | if (dest_ref) { |
29db9190 DH |
579 | ret = key_permission(key_ref, KEY_LINK); |
580 | if (ret < 0) | |
1da177e4 LT |
581 | goto error6; |
582 | ||
664cceb0 | 583 | ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref)); |
1da177e4 LT |
584 | if (ret < 0) |
585 | goto error6; | |
586 | } | |
587 | ||
664cceb0 | 588 | ret = key_ref_to_ptr(key_ref)->serial; |
1da177e4 LT |
589 | |
590 | error6: | |
664cceb0 | 591 | key_ref_put(key_ref); |
1da177e4 LT |
592 | error5: |
593 | key_type_put(ktype); | |
594 | error4: | |
664cceb0 | 595 | key_ref_put(dest_ref); |
1da177e4 | 596 | error3: |
664cceb0 | 597 | key_ref_put(keyring_ref); |
1da177e4 LT |
598 | error2: |
599 | kfree(description); | |
600 | error: | |
601 | return ret; | |
602 | ||
603 | } /* end keyctl_keyring_search() */ | |
604 | ||
1da177e4 LT |
605 | /*****************************************************************************/ |
606 | /* | |
607 | * read a user key's payload | |
608 | * - the keyring must be readable or the key must be searchable from the | |
609 | * process's keyrings | |
610 | * - if there's a buffer, we place up to buflen bytes of data into it | |
611 | * - unless there's an error, we return the amount of data in the key, | |
612 | * irrespective of how much we may have copied | |
613 | * - implements keyctl(KEYCTL_READ) | |
614 | */ | |
615 | long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) | |
616 | { | |
664cceb0 DH |
617 | struct key *key; |
618 | key_ref_t key_ref; | |
1da177e4 LT |
619 | long ret; |
620 | ||
621 | /* find the key first */ | |
664cceb0 DH |
622 | key_ref = lookup_user_key(NULL, keyid, 0, 0, 0); |
623 | if (IS_ERR(key_ref)) { | |
624 | ret = -ENOKEY; | |
625 | goto error; | |
1da177e4 LT |
626 | } |
627 | ||
664cceb0 DH |
628 | key = key_ref_to_ptr(key_ref); |
629 | ||
630 | /* see if we can read it directly */ | |
29db9190 DH |
631 | ret = key_permission(key_ref, KEY_READ); |
632 | if (ret == 0) | |
664cceb0 | 633 | goto can_read_key; |
29db9190 DH |
634 | if (ret != -EACCES) |
635 | goto error; | |
664cceb0 DH |
636 | |
637 | /* we can't; see if it's searchable from this process's keyrings | |
638 | * - we automatically take account of the fact that it may be | |
639 | * dangling off an instantiation key | |
640 | */ | |
641 | if (!is_key_possessed(key_ref)) { | |
642 | ret = -EACCES; | |
643 | goto error2; | |
644 | } | |
1da177e4 LT |
645 | |
646 | /* the key is probably readable - now try to read it */ | |
1da177e4 LT |
647 | can_read_key: |
648 | ret = key_validate(key); | |
649 | if (ret == 0) { | |
650 | ret = -EOPNOTSUPP; | |
651 | if (key->type->read) { | |
652 | /* read the data with the semaphore held (since we | |
653 | * might sleep) */ | |
654 | down_read(&key->sem); | |
655 | ret = key->type->read(key, buffer, buflen); | |
656 | up_read(&key->sem); | |
657 | } | |
658 | } | |
659 | ||
660 | error2: | |
661 | key_put(key); | |
662 | error: | |
663 | return ret; | |
664 | ||
665 | } /* end keyctl_read_key() */ | |
666 | ||
667 | /*****************************************************************************/ | |
668 | /* | |
669 | * change the ownership of a key | |
670 | * - the keyring owned by the changer | |
671 | * - if the uid or gid is -1, then that parameter is not changed | |
672 | * - implements keyctl(KEYCTL_CHOWN) | |
673 | */ | |
674 | long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) | |
675 | { | |
5801649d | 676 | struct key_user *newowner, *zapowner = NULL; |
1da177e4 | 677 | struct key *key; |
664cceb0 | 678 | key_ref_t key_ref; |
1da177e4 LT |
679 | long ret; |
680 | ||
681 | ret = 0; | |
682 | if (uid == (uid_t) -1 && gid == (gid_t) -1) | |
683 | goto error; | |
684 | ||
29db9190 | 685 | key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); |
664cceb0 DH |
686 | if (IS_ERR(key_ref)) { |
687 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
688 | goto error; |
689 | } | |
690 | ||
664cceb0 DH |
691 | key = key_ref_to_ptr(key_ref); |
692 | ||
1da177e4 LT |
693 | /* make the changes with the locks held to prevent chown/chown races */ |
694 | ret = -EACCES; | |
695 | down_write(&key->sem); | |
1da177e4 LT |
696 | |
697 | if (!capable(CAP_SYS_ADMIN)) { | |
698 | /* only the sysadmin can chown a key to some other UID */ | |
699 | if (uid != (uid_t) -1 && key->uid != uid) | |
5801649d | 700 | goto error_put; |
1da177e4 LT |
701 | |
702 | /* only the sysadmin can set the key's GID to a group other | |
703 | * than one of those that the current process subscribes to */ | |
704 | if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid)) | |
5801649d | 705 | goto error_put; |
1da177e4 LT |
706 | } |
707 | ||
5801649d | 708 | /* change the UID */ |
1da177e4 | 709 | if (uid != (uid_t) -1 && uid != key->uid) { |
5801649d FT |
710 | ret = -ENOMEM; |
711 | newowner = key_user_lookup(uid); | |
712 | if (!newowner) | |
713 | goto error_put; | |
714 | ||
715 | /* transfer the quota burden to the new user */ | |
716 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { | |
717 | spin_lock(&newowner->lock); | |
718 | if (newowner->qnkeys + 1 >= KEYQUOTA_MAX_KEYS || | |
719 | newowner->qnbytes + key->quotalen >= | |
720 | KEYQUOTA_MAX_BYTES) | |
721 | goto quota_overrun; | |
722 | ||
723 | newowner->qnkeys++; | |
724 | newowner->qnbytes += key->quotalen; | |
725 | spin_unlock(&newowner->lock); | |
726 | ||
727 | spin_lock(&key->user->lock); | |
728 | key->user->qnkeys--; | |
729 | key->user->qnbytes -= key->quotalen; | |
730 | spin_unlock(&key->user->lock); | |
731 | } | |
732 | ||
733 | atomic_dec(&key->user->nkeys); | |
734 | atomic_inc(&newowner->nkeys); | |
735 | ||
736 | if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { | |
737 | atomic_dec(&key->user->nikeys); | |
738 | atomic_inc(&newowner->nikeys); | |
739 | } | |
740 | ||
741 | zapowner = key->user; | |
742 | key->user = newowner; | |
743 | key->uid = uid; | |
1da177e4 LT |
744 | } |
745 | ||
746 | /* change the GID */ | |
747 | if (gid != (gid_t) -1) | |
748 | key->gid = gid; | |
749 | ||
750 | ret = 0; | |
751 | ||
5801649d | 752 | error_put: |
1da177e4 LT |
753 | up_write(&key->sem); |
754 | key_put(key); | |
5801649d FT |
755 | if (zapowner) |
756 | key_user_put(zapowner); | |
757 | error: | |
1da177e4 LT |
758 | return ret; |
759 | ||
5801649d FT |
760 | quota_overrun: |
761 | spin_unlock(&newowner->lock); | |
762 | zapowner = newowner; | |
763 | ret = -EDQUOT; | |
764 | goto error_put; | |
765 | ||
1da177e4 LT |
766 | } /* end keyctl_chown_key() */ |
767 | ||
768 | /*****************************************************************************/ | |
769 | /* | |
770 | * change the permission mask on a key | |
771 | * - the keyring owned by the changer | |
772 | * - implements keyctl(KEYCTL_SETPERM) | |
773 | */ | |
774 | long keyctl_setperm_key(key_serial_t id, key_perm_t perm) | |
775 | { | |
776 | struct key *key; | |
664cceb0 | 777 | key_ref_t key_ref; |
1da177e4 LT |
778 | long ret; |
779 | ||
780 | ret = -EINVAL; | |
664cceb0 | 781 | if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) |
1da177e4 LT |
782 | goto error; |
783 | ||
29db9190 | 784 | key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); |
664cceb0 DH |
785 | if (IS_ERR(key_ref)) { |
786 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
787 | goto error; |
788 | } | |
789 | ||
664cceb0 DH |
790 | key = key_ref_to_ptr(key_ref); |
791 | ||
76d8aeab | 792 | /* make the changes with the locks held to prevent chown/chmod races */ |
1da177e4 LT |
793 | ret = -EACCES; |
794 | down_write(&key->sem); | |
1da177e4 | 795 | |
76d8aeab DH |
796 | /* if we're not the sysadmin, we can only change a key that we own */ |
797 | if (capable(CAP_SYS_ADMIN) || key->uid == current->fsuid) { | |
798 | key->perm = perm; | |
799 | ret = 0; | |
800 | } | |
1da177e4 | 801 | |
1da177e4 LT |
802 | up_write(&key->sem); |
803 | key_put(key); | |
76d8aeab | 804 | error: |
1da177e4 LT |
805 | return ret; |
806 | ||
807 | } /* end keyctl_setperm_key() */ | |
808 | ||
809 | /*****************************************************************************/ | |
810 | /* | |
811 | * instantiate the key with the specified payload, and, if one is given, link | |
812 | * the key into the keyring | |
813 | */ | |
814 | long keyctl_instantiate_key(key_serial_t id, | |
815 | const void __user *_payload, | |
816 | size_t plen, | |
817 | key_serial_t ringid) | |
818 | { | |
3e30148c | 819 | struct request_key_auth *rka; |
664cceb0 DH |
820 | struct key *instkey; |
821 | key_ref_t keyring_ref; | |
1da177e4 LT |
822 | void *payload; |
823 | long ret; | |
824 | ||
825 | ret = -EINVAL; | |
826 | if (plen > 32767) | |
827 | goto error; | |
828 | ||
b5f545c8 DH |
829 | /* the appropriate instantiation authorisation key must have been |
830 | * assumed before calling this */ | |
831 | ret = -EPERM; | |
832 | instkey = current->request_key_auth; | |
833 | if (!instkey) | |
834 | goto error; | |
835 | ||
836 | rka = instkey->payload.data; | |
837 | if (rka->target_key->serial != id) | |
838 | goto error; | |
839 | ||
1da177e4 LT |
840 | /* pull the payload in if one was supplied */ |
841 | payload = NULL; | |
842 | ||
843 | if (_payload) { | |
844 | ret = -ENOMEM; | |
845 | payload = kmalloc(plen, GFP_KERNEL); | |
846 | if (!payload) | |
847 | goto error; | |
848 | ||
849 | ret = -EFAULT; | |
850 | if (copy_from_user(payload, _payload, plen) != 0) | |
851 | goto error2; | |
852 | } | |
853 | ||
3e30148c DH |
854 | /* find the destination keyring amongst those belonging to the |
855 | * requesting task */ | |
664cceb0 | 856 | keyring_ref = NULL; |
1da177e4 | 857 | if (ringid) { |
664cceb0 DH |
858 | keyring_ref = lookup_user_key(rka->context, ringid, 1, 0, |
859 | KEY_WRITE); | |
860 | if (IS_ERR(keyring_ref)) { | |
861 | ret = PTR_ERR(keyring_ref); | |
b5f545c8 | 862 | goto error2; |
1da177e4 LT |
863 | } |
864 | } | |
865 | ||
866 | /* instantiate the key and link it into a keyring */ | |
3e30148c | 867 | ret = key_instantiate_and_link(rka->target_key, payload, plen, |
664cceb0 | 868 | key_ref_to_ptr(keyring_ref), instkey); |
1da177e4 | 869 | |
664cceb0 | 870 | key_ref_put(keyring_ref); |
b5f545c8 DH |
871 | |
872 | /* discard the assumed authority if it's just been disabled by | |
873 | * instantiation of the key */ | |
874 | if (ret == 0) { | |
875 | key_put(current->request_key_auth); | |
876 | current->request_key_auth = NULL; | |
877 | } | |
878 | ||
879 | error2: | |
1da177e4 | 880 | kfree(payload); |
b5f545c8 | 881 | error: |
1da177e4 LT |
882 | return ret; |
883 | ||
884 | } /* end keyctl_instantiate_key() */ | |
885 | ||
886 | /*****************************************************************************/ | |
887 | /* | |
888 | * negatively instantiate the key with the given timeout (in seconds), and, if | |
889 | * one is given, link the key into the keyring | |
890 | */ | |
891 | long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) | |
892 | { | |
3e30148c | 893 | struct request_key_auth *rka; |
664cceb0 DH |
894 | struct key *instkey; |
895 | key_ref_t keyring_ref; | |
1da177e4 LT |
896 | long ret; |
897 | ||
b5f545c8 DH |
898 | /* the appropriate instantiation authorisation key must have been |
899 | * assumed before calling this */ | |
900 | ret = -EPERM; | |
901 | instkey = current->request_key_auth; | |
902 | if (!instkey) | |
1da177e4 | 903 | goto error; |
1da177e4 | 904 | |
3e30148c | 905 | rka = instkey->payload.data; |
b5f545c8 DH |
906 | if (rka->target_key->serial != id) |
907 | goto error; | |
3e30148c | 908 | |
1da177e4 LT |
909 | /* find the destination keyring if present (which must also be |
910 | * writable) */ | |
664cceb0 | 911 | keyring_ref = NULL; |
1da177e4 | 912 | if (ringid) { |
664cceb0 DH |
913 | keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
914 | if (IS_ERR(keyring_ref)) { | |
915 | ret = PTR_ERR(keyring_ref); | |
b5f545c8 | 916 | goto error; |
1da177e4 LT |
917 | } |
918 | } | |
919 | ||
920 | /* instantiate the key and link it into a keyring */ | |
664cceb0 DH |
921 | ret = key_negate_and_link(rka->target_key, timeout, |
922 | key_ref_to_ptr(keyring_ref), instkey); | |
1da177e4 | 923 | |
664cceb0 | 924 | key_ref_put(keyring_ref); |
b5f545c8 DH |
925 | |
926 | /* discard the assumed authority if it's just been disabled by | |
927 | * instantiation of the key */ | |
928 | if (ret == 0) { | |
929 | key_put(current->request_key_auth); | |
930 | current->request_key_auth = NULL; | |
931 | } | |
932 | ||
933 | error: | |
1da177e4 LT |
934 | return ret; |
935 | ||
936 | } /* end keyctl_negate_key() */ | |
937 | ||
3e30148c DH |
938 | /*****************************************************************************/ |
939 | /* | |
940 | * set the default keyring in which request_key() will cache keys | |
941 | * - return the old setting | |
942 | */ | |
943 | long keyctl_set_reqkey_keyring(int reqkey_defl) | |
944 | { | |
945 | int ret; | |
946 | ||
947 | switch (reqkey_defl) { | |
948 | case KEY_REQKEY_DEFL_THREAD_KEYRING: | |
949 | ret = install_thread_keyring(current); | |
950 | if (ret < 0) | |
951 | return ret; | |
952 | goto set; | |
953 | ||
954 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: | |
955 | ret = install_process_keyring(current); | |
956 | if (ret < 0) | |
957 | return ret; | |
958 | ||
959 | case KEY_REQKEY_DEFL_DEFAULT: | |
960 | case KEY_REQKEY_DEFL_SESSION_KEYRING: | |
961 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
962 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: | |
963 | set: | |
964 | current->jit_keyring = reqkey_defl; | |
965 | ||
966 | case KEY_REQKEY_DEFL_NO_CHANGE: | |
967 | return current->jit_keyring; | |
968 | ||
969 | case KEY_REQKEY_DEFL_GROUP_KEYRING: | |
970 | default: | |
971 | return -EINVAL; | |
972 | } | |
973 | ||
974 | } /* end keyctl_set_reqkey_keyring() */ | |
975 | ||
017679c4 DH |
976 | /*****************************************************************************/ |
977 | /* | |
978 | * set or clear the timeout for a key | |
979 | */ | |
980 | long keyctl_set_timeout(key_serial_t id, unsigned timeout) | |
981 | { | |
982 | struct timespec now; | |
983 | struct key *key; | |
984 | key_ref_t key_ref; | |
985 | time_t expiry; | |
986 | long ret; | |
987 | ||
988 | key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); | |
989 | if (IS_ERR(key_ref)) { | |
990 | ret = PTR_ERR(key_ref); | |
991 | goto error; | |
992 | } | |
993 | ||
994 | key = key_ref_to_ptr(key_ref); | |
995 | ||
996 | /* make the changes with the locks held to prevent races */ | |
997 | down_write(&key->sem); | |
998 | ||
999 | expiry = 0; | |
1000 | if (timeout > 0) { | |
1001 | now = current_kernel_time(); | |
1002 | expiry = now.tv_sec + timeout; | |
1003 | } | |
1004 | ||
1005 | key->expiry = expiry; | |
1006 | ||
1007 | up_write(&key->sem); | |
1008 | key_put(key); | |
1009 | ||
1010 | ret = 0; | |
1011 | error: | |
1012 | return ret; | |
1013 | ||
1014 | } /* end keyctl_set_timeout() */ | |
1015 | ||
b5f545c8 DH |
1016 | /*****************************************************************************/ |
1017 | /* | |
1018 | * assume the authority to instantiate the specified key | |
1019 | */ | |
1020 | long keyctl_assume_authority(key_serial_t id) | |
1021 | { | |
1022 | struct key *authkey; | |
1023 | long ret; | |
1024 | ||
1025 | /* special key IDs aren't permitted */ | |
1026 | ret = -EINVAL; | |
1027 | if (id < 0) | |
1028 | goto error; | |
1029 | ||
1030 | /* we divest ourselves of authority if given an ID of 0 */ | |
1031 | if (id == 0) { | |
1032 | key_put(current->request_key_auth); | |
1033 | current->request_key_auth = NULL; | |
1034 | ret = 0; | |
1035 | goto error; | |
1036 | } | |
1037 | ||
1038 | /* attempt to assume the authority temporarily granted to us whilst we | |
1039 | * instantiate the specified key | |
1040 | * - the authorisation key must be in the current task's keyrings | |
1041 | * somewhere | |
1042 | */ | |
1043 | authkey = key_get_instantiation_authkey(id); | |
1044 | if (IS_ERR(authkey)) { | |
1045 | ret = PTR_ERR(authkey); | |
1046 | goto error; | |
1047 | } | |
1048 | ||
1049 | key_put(current->request_key_auth); | |
1050 | current->request_key_auth = authkey; | |
1051 | ret = authkey->serial; | |
1052 | ||
1053 | error: | |
1054 | return ret; | |
1055 | ||
1056 | } /* end keyctl_assume_authority() */ | |
1057 | ||
1da177e4 LT |
1058 | /*****************************************************************************/ |
1059 | /* | |
1060 | * the key control system call | |
1061 | */ | |
1062 | asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3, | |
1063 | unsigned long arg4, unsigned long arg5) | |
1064 | { | |
1065 | switch (option) { | |
1066 | case KEYCTL_GET_KEYRING_ID: | |
1067 | return keyctl_get_keyring_ID((key_serial_t) arg2, | |
1068 | (int) arg3); | |
1069 | ||
1070 | case KEYCTL_JOIN_SESSION_KEYRING: | |
1071 | return keyctl_join_session_keyring((const char __user *) arg2); | |
1072 | ||
1073 | case KEYCTL_UPDATE: | |
1074 | return keyctl_update_key((key_serial_t) arg2, | |
1075 | (const void __user *) arg3, | |
1076 | (size_t) arg4); | |
1077 | ||
1078 | case KEYCTL_REVOKE: | |
1079 | return keyctl_revoke_key((key_serial_t) arg2); | |
1080 | ||
1081 | case KEYCTL_DESCRIBE: | |
1082 | return keyctl_describe_key((key_serial_t) arg2, | |
1083 | (char __user *) arg3, | |
1084 | (unsigned) arg4); | |
1085 | ||
1086 | case KEYCTL_CLEAR: | |
1087 | return keyctl_keyring_clear((key_serial_t) arg2); | |
1088 | ||
1089 | case KEYCTL_LINK: | |
1090 | return keyctl_keyring_link((key_serial_t) arg2, | |
1091 | (key_serial_t) arg3); | |
1092 | ||
1093 | case KEYCTL_UNLINK: | |
1094 | return keyctl_keyring_unlink((key_serial_t) arg2, | |
1095 | (key_serial_t) arg3); | |
1096 | ||
1097 | case KEYCTL_SEARCH: | |
1098 | return keyctl_keyring_search((key_serial_t) arg2, | |
1099 | (const char __user *) arg3, | |
1100 | (const char __user *) arg4, | |
1101 | (key_serial_t) arg5); | |
1102 | ||
1103 | case KEYCTL_READ: | |
1104 | return keyctl_read_key((key_serial_t) arg2, | |
1105 | (char __user *) arg3, | |
1106 | (size_t) arg4); | |
1107 | ||
1108 | case KEYCTL_CHOWN: | |
1109 | return keyctl_chown_key((key_serial_t) arg2, | |
1110 | (uid_t) arg3, | |
1111 | (gid_t) arg4); | |
1112 | ||
1113 | case KEYCTL_SETPERM: | |
1114 | return keyctl_setperm_key((key_serial_t) arg2, | |
1115 | (key_perm_t) arg3); | |
1116 | ||
1117 | case KEYCTL_INSTANTIATE: | |
1118 | return keyctl_instantiate_key((key_serial_t) arg2, | |
1119 | (const void __user *) arg3, | |
1120 | (size_t) arg4, | |
1121 | (key_serial_t) arg5); | |
1122 | ||
1123 | case KEYCTL_NEGATE: | |
1124 | return keyctl_negate_key((key_serial_t) arg2, | |
1125 | (unsigned) arg3, | |
1126 | (key_serial_t) arg4); | |
1127 | ||
3e30148c DH |
1128 | case KEYCTL_SET_REQKEY_KEYRING: |
1129 | return keyctl_set_reqkey_keyring(arg2); | |
1130 | ||
017679c4 DH |
1131 | case KEYCTL_SET_TIMEOUT: |
1132 | return keyctl_set_timeout((key_serial_t) arg2, | |
1133 | (unsigned) arg3); | |
1134 | ||
b5f545c8 DH |
1135 | case KEYCTL_ASSUME_AUTHORITY: |
1136 | return keyctl_assume_authority((key_serial_t) arg2); | |
1137 | ||
1da177e4 LT |
1138 | default: |
1139 | return -EOPNOTSUPP; | |
1140 | } | |
1141 | ||
1142 | } /* end sys_keyctl() */ |