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> | |
19 | #include <linux/err.h> | |
20 | #include <asm/uaccess.h> | |
21 | #include "internal.h" | |
22 | ||
23 | /*****************************************************************************/ | |
24 | /* | |
25 | * extract the description of a new key from userspace and either add it as a | |
26 | * new key to the specified keyring or update a matching key in that keyring | |
27 | * - the keyring must be writable | |
28 | * - returns the new key's serial number | |
29 | * - implements add_key() | |
30 | */ | |
31 | asmlinkage long sys_add_key(const char __user *_type, | |
32 | const char __user *_description, | |
33 | const void __user *_payload, | |
34 | size_t plen, | |
35 | key_serial_t ringid) | |
36 | { | |
37 | struct key *keyring, *key; | |
38 | char type[32], *description; | |
39 | void *payload; | |
40 | long dlen, ret; | |
41 | ||
42 | ret = -EINVAL; | |
43 | if (plen > 32767) | |
44 | goto error; | |
45 | ||
46 | /* draw all the data into kernel space */ | |
47 | ret = strncpy_from_user(type, _type, sizeof(type) - 1); | |
48 | if (ret < 0) | |
49 | goto error; | |
50 | type[31] = '\0'; | |
51 | ||
3e30148c DH |
52 | ret = -EPERM; |
53 | if (type[0] == '.') | |
54 | goto error; | |
55 | ||
1da177e4 LT |
56 | ret = -EFAULT; |
57 | dlen = strnlen_user(_description, PAGE_SIZE - 1); | |
58 | if (dlen <= 0) | |
59 | goto error; | |
60 | ||
61 | ret = -EINVAL; | |
62 | if (dlen > PAGE_SIZE - 1) | |
63 | goto error; | |
64 | ||
65 | ret = -ENOMEM; | |
66 | description = kmalloc(dlen + 1, GFP_KERNEL); | |
67 | if (!description) | |
68 | goto error; | |
69 | ||
70 | ret = -EFAULT; | |
71 | if (copy_from_user(description, _description, dlen + 1) != 0) | |
72 | goto error2; | |
73 | ||
74 | /* pull the payload in if one was supplied */ | |
75 | payload = NULL; | |
76 | ||
77 | if (_payload) { | |
78 | ret = -ENOMEM; | |
79 | payload = kmalloc(plen, GFP_KERNEL); | |
80 | if (!payload) | |
81 | goto error2; | |
82 | ||
83 | ret = -EFAULT; | |
84 | if (copy_from_user(payload, _payload, plen) != 0) | |
85 | goto error3; | |
86 | } | |
87 | ||
88 | /* find the target keyring (which must be writable) */ | |
3e30148c | 89 | keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
1da177e4 LT |
90 | if (IS_ERR(keyring)) { |
91 | ret = PTR_ERR(keyring); | |
92 | goto error3; | |
93 | } | |
94 | ||
95 | /* create or update the requested key and add it to the target | |
96 | * keyring */ | |
97 | key = key_create_or_update(keyring, type, description, | |
98 | payload, plen, 0); | |
99 | if (!IS_ERR(key)) { | |
100 | ret = key->serial; | |
101 | key_put(key); | |
102 | } | |
103 | else { | |
104 | ret = PTR_ERR(key); | |
105 | } | |
106 | ||
107 | key_put(keyring); | |
108 | error3: | |
109 | kfree(payload); | |
110 | error2: | |
111 | kfree(description); | |
112 | error: | |
113 | return ret; | |
114 | ||
115 | } /* end sys_add_key() */ | |
116 | ||
117 | /*****************************************************************************/ | |
118 | /* | |
119 | * search the process keyrings for a matching key | |
120 | * - nested keyrings may also be searched if they have Search permission | |
121 | * - if a key is found, it will be attached to the destination keyring if | |
122 | * there's one specified | |
123 | * - /sbin/request-key will be invoked if _callout_info is non-NULL | |
124 | * - the _callout_info string will be passed to /sbin/request-key | |
125 | * - if the _callout_info string is empty, it will be rendered as "-" | |
126 | * - implements request_key() | |
127 | */ | |
128 | asmlinkage long sys_request_key(const char __user *_type, | |
129 | const char __user *_description, | |
130 | const char __user *_callout_info, | |
131 | key_serial_t destringid) | |
132 | { | |
133 | struct key_type *ktype; | |
134 | struct key *key, *dest; | |
135 | char type[32], *description, *callout_info; | |
136 | long dlen, ret; | |
137 | ||
138 | /* pull the type into kernel space */ | |
139 | ret = strncpy_from_user(type, _type, sizeof(type) - 1); | |
140 | if (ret < 0) | |
141 | goto error; | |
142 | type[31] = '\0'; | |
143 | ||
1260f801 DH |
144 | ret = -EPERM; |
145 | if (type[0] == '.') | |
146 | goto error; | |
147 | ||
1da177e4 LT |
148 | /* pull the description into kernel space */ |
149 | ret = -EFAULT; | |
150 | dlen = strnlen_user(_description, PAGE_SIZE - 1); | |
151 | if (dlen <= 0) | |
152 | goto error; | |
153 | ||
154 | ret = -EINVAL; | |
155 | if (dlen > PAGE_SIZE - 1) | |
156 | goto error; | |
157 | ||
158 | ret = -ENOMEM; | |
159 | description = kmalloc(dlen + 1, GFP_KERNEL); | |
160 | if (!description) | |
161 | goto error; | |
162 | ||
163 | ret = -EFAULT; | |
164 | if (copy_from_user(description, _description, dlen + 1) != 0) | |
165 | goto error2; | |
166 | ||
167 | /* pull the callout info into kernel space */ | |
168 | callout_info = NULL; | |
169 | if (_callout_info) { | |
170 | ret = -EFAULT; | |
171 | dlen = strnlen_user(_callout_info, PAGE_SIZE - 1); | |
172 | if (dlen <= 0) | |
173 | goto error2; | |
174 | ||
175 | ret = -EINVAL; | |
176 | if (dlen > PAGE_SIZE - 1) | |
177 | goto error2; | |
178 | ||
179 | ret = -ENOMEM; | |
180 | callout_info = kmalloc(dlen + 1, GFP_KERNEL); | |
181 | if (!callout_info) | |
182 | goto error2; | |
183 | ||
184 | ret = -EFAULT; | |
185 | if (copy_from_user(callout_info, _callout_info, dlen + 1) != 0) | |
186 | goto error3; | |
187 | } | |
188 | ||
189 | /* get the destination keyring if specified */ | |
190 | dest = NULL; | |
191 | if (destringid) { | |
3e30148c | 192 | dest = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); |
1da177e4 LT |
193 | if (IS_ERR(dest)) { |
194 | ret = PTR_ERR(dest); | |
195 | goto error3; | |
196 | } | |
197 | } | |
198 | ||
199 | /* find the key type */ | |
200 | ktype = key_type_lookup(type); | |
201 | if (IS_ERR(ktype)) { | |
202 | ret = PTR_ERR(ktype); | |
203 | goto error4; | |
204 | } | |
205 | ||
206 | /* do the search */ | |
3e30148c | 207 | key = request_key_and_link(ktype, description, callout_info, dest); |
1da177e4 LT |
208 | if (IS_ERR(key)) { |
209 | ret = PTR_ERR(key); | |
210 | goto error5; | |
211 | } | |
212 | ||
1da177e4 LT |
213 | ret = key->serial; |
214 | ||
3e30148c | 215 | key_put(key); |
1da177e4 LT |
216 | error5: |
217 | key_type_put(ktype); | |
218 | error4: | |
219 | key_put(dest); | |
220 | error3: | |
221 | kfree(callout_info); | |
222 | error2: | |
223 | kfree(description); | |
224 | error: | |
225 | return ret; | |
226 | ||
227 | } /* end sys_request_key() */ | |
228 | ||
229 | /*****************************************************************************/ | |
230 | /* | |
231 | * get the ID of the specified process keyring | |
232 | * - the keyring must have search permission to be found | |
233 | * - implements keyctl(KEYCTL_GET_KEYRING_ID) | |
234 | */ | |
235 | long keyctl_get_keyring_ID(key_serial_t id, int create) | |
236 | { | |
237 | struct key *key; | |
238 | long ret; | |
239 | ||
3e30148c | 240 | key = lookup_user_key(NULL, id, create, 0, KEY_SEARCH); |
1da177e4 LT |
241 | if (IS_ERR(key)) { |
242 | ret = PTR_ERR(key); | |
243 | goto error; | |
244 | } | |
245 | ||
246 | ret = key->serial; | |
247 | key_put(key); | |
248 | error: | |
249 | return ret; | |
250 | ||
251 | } /* end keyctl_get_keyring_ID() */ | |
252 | ||
253 | /*****************************************************************************/ | |
254 | /* | |
255 | * join the session keyring | |
256 | * - implements keyctl(KEYCTL_JOIN_SESSION_KEYRING) | |
257 | */ | |
258 | long keyctl_join_session_keyring(const char __user *_name) | |
259 | { | |
260 | char *name; | |
261 | long nlen, ret; | |
262 | ||
263 | /* fetch the name from userspace */ | |
264 | name = NULL; | |
265 | if (_name) { | |
266 | ret = -EFAULT; | |
267 | nlen = strnlen_user(_name, PAGE_SIZE - 1); | |
268 | if (nlen <= 0) | |
269 | goto error; | |
270 | ||
271 | ret = -EINVAL; | |
272 | if (nlen > PAGE_SIZE - 1) | |
273 | goto error; | |
274 | ||
275 | ret = -ENOMEM; | |
276 | name = kmalloc(nlen + 1, GFP_KERNEL); | |
277 | if (!name) | |
278 | goto error; | |
279 | ||
280 | ret = -EFAULT; | |
281 | if (copy_from_user(name, _name, nlen + 1) != 0) | |
282 | goto error2; | |
283 | } | |
284 | ||
285 | /* join the session */ | |
286 | ret = join_session_keyring(name); | |
287 | ||
288 | error2: | |
289 | kfree(name); | |
290 | error: | |
291 | return ret; | |
292 | ||
293 | } /* end keyctl_join_session_keyring() */ | |
294 | ||
295 | /*****************************************************************************/ | |
296 | /* | |
297 | * update a key's data payload | |
298 | * - the key must be writable | |
299 | * - implements keyctl(KEYCTL_UPDATE) | |
300 | */ | |
301 | long keyctl_update_key(key_serial_t id, | |
302 | const void __user *_payload, | |
303 | size_t plen) | |
304 | { | |
305 | struct key *key; | |
306 | void *payload; | |
307 | long ret; | |
308 | ||
309 | ret = -EINVAL; | |
310 | if (plen > PAGE_SIZE) | |
311 | goto error; | |
312 | ||
313 | /* pull the payload in if one was supplied */ | |
314 | payload = NULL; | |
315 | if (_payload) { | |
316 | ret = -ENOMEM; | |
317 | payload = kmalloc(plen, GFP_KERNEL); | |
318 | if (!payload) | |
319 | goto error; | |
320 | ||
321 | ret = -EFAULT; | |
322 | if (copy_from_user(payload, _payload, plen) != 0) | |
323 | goto error2; | |
324 | } | |
325 | ||
326 | /* find the target key (which must be writable) */ | |
3e30148c | 327 | key = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); |
1da177e4 LT |
328 | if (IS_ERR(key)) { |
329 | ret = PTR_ERR(key); | |
330 | goto error2; | |
331 | } | |
332 | ||
333 | /* update the key */ | |
334 | ret = key_update(key, payload, plen); | |
335 | ||
336 | key_put(key); | |
337 | error2: | |
338 | kfree(payload); | |
339 | error: | |
340 | return ret; | |
341 | ||
342 | } /* end keyctl_update_key() */ | |
343 | ||
344 | /*****************************************************************************/ | |
345 | /* | |
346 | * revoke a key | |
347 | * - the key must be writable | |
348 | * - implements keyctl(KEYCTL_REVOKE) | |
349 | */ | |
350 | long keyctl_revoke_key(key_serial_t id) | |
351 | { | |
352 | struct key *key; | |
353 | long ret; | |
354 | ||
3e30148c | 355 | key = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); |
1da177e4 LT |
356 | if (IS_ERR(key)) { |
357 | ret = PTR_ERR(key); | |
358 | goto error; | |
359 | } | |
360 | ||
361 | key_revoke(key); | |
362 | ret = 0; | |
363 | ||
364 | key_put(key); | |
365 | error: | |
1260f801 | 366 | return ret; |
1da177e4 LT |
367 | |
368 | } /* end keyctl_revoke_key() */ | |
369 | ||
370 | /*****************************************************************************/ | |
371 | /* | |
372 | * clear the specified process keyring | |
373 | * - the keyring must be writable | |
374 | * - implements keyctl(KEYCTL_CLEAR) | |
375 | */ | |
376 | long keyctl_keyring_clear(key_serial_t ringid) | |
377 | { | |
378 | struct key *keyring; | |
379 | long ret; | |
380 | ||
3e30148c | 381 | keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
1da177e4 LT |
382 | if (IS_ERR(keyring)) { |
383 | ret = PTR_ERR(keyring); | |
384 | goto error; | |
385 | } | |
386 | ||
387 | ret = keyring_clear(keyring); | |
388 | ||
389 | key_put(keyring); | |
390 | error: | |
391 | return ret; | |
392 | ||
393 | } /* end keyctl_keyring_clear() */ | |
394 | ||
395 | /*****************************************************************************/ | |
396 | /* | |
397 | * link a key into a keyring | |
398 | * - the keyring must be writable | |
399 | * - the key must be linkable | |
400 | * - implements keyctl(KEYCTL_LINK) | |
401 | */ | |
402 | long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) | |
403 | { | |
404 | struct key *keyring, *key; | |
405 | long ret; | |
406 | ||
3e30148c | 407 | keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
1da177e4 LT |
408 | if (IS_ERR(keyring)) { |
409 | ret = PTR_ERR(keyring); | |
410 | goto error; | |
411 | } | |
412 | ||
3e30148c | 413 | key = lookup_user_key(NULL, id, 1, 0, KEY_LINK); |
1da177e4 LT |
414 | if (IS_ERR(key)) { |
415 | ret = PTR_ERR(key); | |
416 | goto error2; | |
417 | } | |
418 | ||
419 | ret = key_link(keyring, key); | |
420 | ||
421 | key_put(key); | |
422 | error2: | |
423 | key_put(keyring); | |
424 | error: | |
425 | return ret; | |
426 | ||
427 | } /* end keyctl_keyring_link() */ | |
428 | ||
429 | /*****************************************************************************/ | |
430 | /* | |
431 | * unlink the first attachment of a key from a keyring | |
432 | * - the keyring must be writable | |
433 | * - we don't need any permissions on the key | |
434 | * - implements keyctl(KEYCTL_UNLINK) | |
435 | */ | |
436 | long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) | |
437 | { | |
438 | struct key *keyring, *key; | |
439 | long ret; | |
440 | ||
3e30148c | 441 | keyring = lookup_user_key(NULL, ringid, 0, 0, KEY_WRITE); |
1da177e4 LT |
442 | if (IS_ERR(keyring)) { |
443 | ret = PTR_ERR(keyring); | |
444 | goto error; | |
445 | } | |
446 | ||
3e30148c | 447 | key = lookup_user_key(NULL, id, 0, 0, 0); |
1da177e4 LT |
448 | if (IS_ERR(key)) { |
449 | ret = PTR_ERR(key); | |
450 | goto error2; | |
451 | } | |
452 | ||
453 | ret = key_unlink(keyring, key); | |
454 | ||
455 | key_put(key); | |
456 | error2: | |
457 | key_put(keyring); | |
458 | error: | |
459 | return ret; | |
460 | ||
461 | } /* end keyctl_keyring_unlink() */ | |
462 | ||
463 | /*****************************************************************************/ | |
464 | /* | |
465 | * describe a user key | |
466 | * - the key must have view permission | |
467 | * - if there's a buffer, we place up to buflen bytes of data into it | |
468 | * - unless there's an error, we return the amount of description available, | |
469 | * irrespective of how much we may have copied | |
470 | * - the description is formatted thus: | |
471 | * type;uid;gid;perm;description<NUL> | |
472 | * - implements keyctl(KEYCTL_DESCRIBE) | |
473 | */ | |
474 | long keyctl_describe_key(key_serial_t keyid, | |
475 | char __user *buffer, | |
476 | size_t buflen) | |
477 | { | |
3e30148c | 478 | struct key *key, *instkey; |
1da177e4 LT |
479 | char *tmpbuf; |
480 | long ret; | |
481 | ||
3e30148c | 482 | key = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW); |
1da177e4 | 483 | if (IS_ERR(key)) { |
3e30148c DH |
484 | /* viewing a key under construction is permitted if we have the |
485 | * authorisation token handy */ | |
486 | if (PTR_ERR(key) == -EACCES) { | |
487 | instkey = key_get_instantiation_authkey(keyid); | |
488 | if (!IS_ERR(instkey)) { | |
489 | key_put(instkey); | |
490 | key = lookup_user_key(NULL, keyid, 0, 1, 0); | |
491 | if (!IS_ERR(key)) | |
492 | goto okay; | |
493 | } | |
494 | } | |
495 | ||
1da177e4 LT |
496 | ret = PTR_ERR(key); |
497 | goto error; | |
498 | } | |
499 | ||
3e30148c | 500 | okay: |
1da177e4 LT |
501 | /* calculate how much description we're going to return */ |
502 | ret = -ENOMEM; | |
503 | tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
504 | if (!tmpbuf) | |
505 | goto error2; | |
506 | ||
507 | ret = snprintf(tmpbuf, PAGE_SIZE - 1, | |
508 | "%s;%d;%d;%06x;%s", | |
509 | key->type->name, | |
510 | key->uid, | |
511 | key->gid, | |
512 | key->perm, | |
513 | key->description ? key->description :"" | |
514 | ); | |
515 | ||
516 | /* include a NUL char at the end of the data */ | |
517 | if (ret > PAGE_SIZE - 1) | |
518 | ret = PAGE_SIZE - 1; | |
519 | tmpbuf[ret] = 0; | |
520 | ret++; | |
521 | ||
522 | /* consider returning the data */ | |
523 | if (buffer && buflen > 0) { | |
524 | if (buflen > ret) | |
525 | buflen = ret; | |
526 | ||
527 | if (copy_to_user(buffer, tmpbuf, buflen) != 0) | |
528 | ret = -EFAULT; | |
529 | } | |
530 | ||
531 | kfree(tmpbuf); | |
532 | error2: | |
533 | key_put(key); | |
534 | error: | |
535 | return ret; | |
536 | ||
537 | } /* end keyctl_describe_key() */ | |
538 | ||
539 | /*****************************************************************************/ | |
540 | /* | |
541 | * search the specified keyring for a matching key | |
542 | * - the start keyring must be searchable | |
543 | * - nested keyrings may also be searched if they are searchable | |
544 | * - only keys with search permission may be found | |
545 | * - if a key is found, it will be attached to the destination keyring if | |
546 | * there's one specified | |
547 | * - implements keyctl(KEYCTL_SEARCH) | |
548 | */ | |
549 | long keyctl_keyring_search(key_serial_t ringid, | |
550 | const char __user *_type, | |
551 | const char __user *_description, | |
552 | key_serial_t destringid) | |
553 | { | |
554 | struct key_type *ktype; | |
555 | struct key *keyring, *key, *dest; | |
556 | char type[32], *description; | |
557 | long dlen, ret; | |
558 | ||
559 | /* pull the type and description into kernel space */ | |
560 | ret = strncpy_from_user(type, _type, sizeof(type) - 1); | |
561 | if (ret < 0) | |
562 | goto error; | |
563 | type[31] = '\0'; | |
564 | ||
565 | ret = -EFAULT; | |
566 | dlen = strnlen_user(_description, PAGE_SIZE - 1); | |
567 | if (dlen <= 0) | |
568 | goto error; | |
569 | ||
570 | ret = -EINVAL; | |
571 | if (dlen > PAGE_SIZE - 1) | |
572 | goto error; | |
573 | ||
574 | ret = -ENOMEM; | |
575 | description = kmalloc(dlen + 1, GFP_KERNEL); | |
576 | if (!description) | |
577 | goto error; | |
578 | ||
579 | ret = -EFAULT; | |
580 | if (copy_from_user(description, _description, dlen + 1) != 0) | |
581 | goto error2; | |
582 | ||
583 | /* get the keyring at which to begin the search */ | |
3e30148c | 584 | keyring = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH); |
1da177e4 LT |
585 | if (IS_ERR(keyring)) { |
586 | ret = PTR_ERR(keyring); | |
587 | goto error2; | |
588 | } | |
589 | ||
590 | /* get the destination keyring if specified */ | |
591 | dest = NULL; | |
592 | if (destringid) { | |
3e30148c | 593 | dest = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); |
1da177e4 LT |
594 | if (IS_ERR(dest)) { |
595 | ret = PTR_ERR(dest); | |
596 | goto error3; | |
597 | } | |
598 | } | |
599 | ||
600 | /* find the key type */ | |
601 | ktype = key_type_lookup(type); | |
602 | if (IS_ERR(ktype)) { | |
603 | ret = PTR_ERR(ktype); | |
604 | goto error4; | |
605 | } | |
606 | ||
607 | /* do the search */ | |
608 | key = keyring_search(keyring, ktype, description); | |
609 | if (IS_ERR(key)) { | |
610 | ret = PTR_ERR(key); | |
611 | ||
612 | /* treat lack or presence of a negative key the same */ | |
613 | if (ret == -EAGAIN) | |
614 | ret = -ENOKEY; | |
615 | goto error5; | |
616 | } | |
617 | ||
618 | /* link the resulting key to the destination keyring if we can */ | |
619 | if (dest) { | |
620 | ret = -EACCES; | |
621 | if (!key_permission(key, KEY_LINK)) | |
622 | goto error6; | |
623 | ||
624 | ret = key_link(dest, key); | |
625 | if (ret < 0) | |
626 | goto error6; | |
627 | } | |
628 | ||
629 | ret = key->serial; | |
630 | ||
631 | error6: | |
632 | key_put(key); | |
633 | error5: | |
634 | key_type_put(ktype); | |
635 | error4: | |
636 | key_put(dest); | |
637 | error3: | |
638 | key_put(keyring); | |
639 | error2: | |
640 | kfree(description); | |
641 | error: | |
642 | return ret; | |
643 | ||
644 | } /* end keyctl_keyring_search() */ | |
645 | ||
646 | /*****************************************************************************/ | |
647 | /* | |
648 | * see if the key we're looking at is the target key | |
649 | */ | |
650 | static int keyctl_read_key_same(const struct key *key, const void *target) | |
651 | { | |
652 | return key == target; | |
653 | ||
654 | } /* end keyctl_read_key_same() */ | |
655 | ||
656 | /*****************************************************************************/ | |
657 | /* | |
658 | * read a user key's payload | |
659 | * - the keyring must be readable or the key must be searchable from the | |
660 | * process's keyrings | |
661 | * - if there's a buffer, we place up to buflen bytes of data into it | |
662 | * - unless there's an error, we return the amount of data in the key, | |
663 | * irrespective of how much we may have copied | |
664 | * - implements keyctl(KEYCTL_READ) | |
665 | */ | |
666 | long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) | |
667 | { | |
668 | struct key *key, *skey; | |
669 | long ret; | |
670 | ||
671 | /* find the key first */ | |
3e30148c | 672 | key = lookup_user_key(NULL, keyid, 0, 0, 0); |
1da177e4 LT |
673 | if (!IS_ERR(key)) { |
674 | /* see if we can read it directly */ | |
675 | if (key_permission(key, KEY_READ)) | |
676 | goto can_read_key; | |
677 | ||
3e30148c DH |
678 | /* we can't; see if it's searchable from this process's |
679 | * keyrings | |
680 | * - we automatically take account of the fact that it may be | |
681 | * dangling off an instantiation key | |
682 | */ | |
683 | skey = search_process_keyrings(key->type, key, | |
684 | keyctl_read_key_same, current); | |
685 | if (!IS_ERR(skey)) | |
686 | goto can_read_key2; | |
687 | ||
688 | ret = PTR_ERR(skey); | |
1260f801 DH |
689 | if (ret == -EAGAIN) |
690 | ret = -EACCES; | |
1da177e4 LT |
691 | goto error2; |
692 | } | |
693 | ||
694 | ret = -ENOKEY; | |
695 | goto error; | |
696 | ||
697 | /* the key is probably readable - now try to read it */ | |
698 | can_read_key2: | |
699 | key_put(skey); | |
700 | can_read_key: | |
701 | ret = key_validate(key); | |
702 | if (ret == 0) { | |
703 | ret = -EOPNOTSUPP; | |
704 | if (key->type->read) { | |
705 | /* read the data with the semaphore held (since we | |
706 | * might sleep) */ | |
707 | down_read(&key->sem); | |
708 | ret = key->type->read(key, buffer, buflen); | |
709 | up_read(&key->sem); | |
710 | } | |
711 | } | |
712 | ||
713 | error2: | |
714 | key_put(key); | |
715 | error: | |
716 | return ret; | |
717 | ||
718 | } /* end keyctl_read_key() */ | |
719 | ||
720 | /*****************************************************************************/ | |
721 | /* | |
722 | * change the ownership of a key | |
723 | * - the keyring owned by the changer | |
724 | * - if the uid or gid is -1, then that parameter is not changed | |
725 | * - implements keyctl(KEYCTL_CHOWN) | |
726 | */ | |
727 | long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) | |
728 | { | |
729 | struct key *key; | |
730 | long ret; | |
731 | ||
732 | ret = 0; | |
733 | if (uid == (uid_t) -1 && gid == (gid_t) -1) | |
734 | goto error; | |
735 | ||
3e30148c | 736 | key = lookup_user_key(NULL, id, 1, 1, 0); |
1da177e4 LT |
737 | if (IS_ERR(key)) { |
738 | ret = PTR_ERR(key); | |
739 | goto error; | |
740 | } | |
741 | ||
742 | /* make the changes with the locks held to prevent chown/chown races */ | |
743 | ret = -EACCES; | |
744 | down_write(&key->sem); | |
1da177e4 LT |
745 | |
746 | if (!capable(CAP_SYS_ADMIN)) { | |
747 | /* only the sysadmin can chown a key to some other UID */ | |
748 | if (uid != (uid_t) -1 && key->uid != uid) | |
749 | goto no_access; | |
750 | ||
751 | /* only the sysadmin can set the key's GID to a group other | |
752 | * than one of those that the current process subscribes to */ | |
753 | if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid)) | |
754 | goto no_access; | |
755 | } | |
756 | ||
757 | /* change the UID (have to update the quotas) */ | |
758 | if (uid != (uid_t) -1 && uid != key->uid) { | |
759 | /* don't support UID changing yet */ | |
760 | ret = -EOPNOTSUPP; | |
761 | goto no_access; | |
762 | } | |
763 | ||
764 | /* change the GID */ | |
765 | if (gid != (gid_t) -1) | |
766 | key->gid = gid; | |
767 | ||
768 | ret = 0; | |
769 | ||
770 | no_access: | |
1da177e4 LT |
771 | up_write(&key->sem); |
772 | key_put(key); | |
773 | error: | |
774 | return ret; | |
775 | ||
776 | } /* end keyctl_chown_key() */ | |
777 | ||
778 | /*****************************************************************************/ | |
779 | /* | |
780 | * change the permission mask on a key | |
781 | * - the keyring owned by the changer | |
782 | * - implements keyctl(KEYCTL_SETPERM) | |
783 | */ | |
784 | long keyctl_setperm_key(key_serial_t id, key_perm_t perm) | |
785 | { | |
786 | struct key *key; | |
787 | long ret; | |
788 | ||
789 | ret = -EINVAL; | |
790 | if (perm & ~(KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) | |
791 | goto error; | |
792 | ||
3e30148c | 793 | key = lookup_user_key(NULL, id, 1, 1, 0); |
1da177e4 LT |
794 | if (IS_ERR(key)) { |
795 | ret = PTR_ERR(key); | |
796 | goto error; | |
797 | } | |
798 | ||
76d8aeab | 799 | /* make the changes with the locks held to prevent chown/chmod races */ |
1da177e4 LT |
800 | ret = -EACCES; |
801 | down_write(&key->sem); | |
1da177e4 | 802 | |
76d8aeab DH |
803 | /* if we're not the sysadmin, we can only change a key that we own */ |
804 | if (capable(CAP_SYS_ADMIN) || key->uid == current->fsuid) { | |
805 | key->perm = perm; | |
806 | ret = 0; | |
807 | } | |
1da177e4 | 808 | |
1da177e4 LT |
809 | up_write(&key->sem); |
810 | key_put(key); | |
76d8aeab | 811 | error: |
1da177e4 LT |
812 | return ret; |
813 | ||
814 | } /* end keyctl_setperm_key() */ | |
815 | ||
816 | /*****************************************************************************/ | |
817 | /* | |
818 | * instantiate the key with the specified payload, and, if one is given, link | |
819 | * the key into the keyring | |
820 | */ | |
821 | long keyctl_instantiate_key(key_serial_t id, | |
822 | const void __user *_payload, | |
823 | size_t plen, | |
824 | key_serial_t ringid) | |
825 | { | |
3e30148c DH |
826 | struct request_key_auth *rka; |
827 | struct key *instkey, *keyring; | |
1da177e4 LT |
828 | void *payload; |
829 | long ret; | |
830 | ||
831 | ret = -EINVAL; | |
832 | if (plen > 32767) | |
833 | goto error; | |
834 | ||
835 | /* pull the payload in if one was supplied */ | |
836 | payload = NULL; | |
837 | ||
838 | if (_payload) { | |
839 | ret = -ENOMEM; | |
840 | payload = kmalloc(plen, GFP_KERNEL); | |
841 | if (!payload) | |
842 | goto error; | |
843 | ||
844 | ret = -EFAULT; | |
845 | if (copy_from_user(payload, _payload, plen) != 0) | |
846 | goto error2; | |
847 | } | |
848 | ||
3e30148c DH |
849 | /* find the instantiation authorisation key */ |
850 | instkey = key_get_instantiation_authkey(id); | |
851 | if (IS_ERR(instkey)) { | |
852 | ret = PTR_ERR(instkey); | |
1da177e4 LT |
853 | goto error2; |
854 | } | |
855 | ||
3e30148c DH |
856 | rka = instkey->payload.data; |
857 | ||
858 | /* find the destination keyring amongst those belonging to the | |
859 | * requesting task */ | |
1da177e4 LT |
860 | keyring = NULL; |
861 | if (ringid) { | |
3e30148c DH |
862 | keyring = lookup_user_key(rka->context, ringid, 1, 0, |
863 | KEY_WRITE); | |
1da177e4 LT |
864 | if (IS_ERR(keyring)) { |
865 | ret = PTR_ERR(keyring); | |
866 | goto error3; | |
867 | } | |
868 | } | |
869 | ||
870 | /* instantiate the key and link it into a keyring */ | |
3e30148c DH |
871 | ret = key_instantiate_and_link(rka->target_key, payload, plen, |
872 | keyring, instkey); | |
1da177e4 LT |
873 | |
874 | key_put(keyring); | |
875 | error3: | |
3e30148c | 876 | key_put(instkey); |
1da177e4 LT |
877 | error2: |
878 | kfree(payload); | |
879 | error: | |
880 | return ret; | |
881 | ||
882 | } /* end keyctl_instantiate_key() */ | |
883 | ||
884 | /*****************************************************************************/ | |
885 | /* | |
886 | * negatively instantiate the key with the given timeout (in seconds), and, if | |
887 | * one is given, link the key into the keyring | |
888 | */ | |
889 | long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) | |
890 | { | |
3e30148c DH |
891 | struct request_key_auth *rka; |
892 | struct key *instkey, *keyring; | |
1da177e4 LT |
893 | long ret; |
894 | ||
3e30148c DH |
895 | /* find the instantiation authorisation key */ |
896 | instkey = key_get_instantiation_authkey(id); | |
897 | if (IS_ERR(instkey)) { | |
898 | ret = PTR_ERR(instkey); | |
1da177e4 LT |
899 | goto error; |
900 | } | |
901 | ||
3e30148c DH |
902 | rka = instkey->payload.data; |
903 | ||
1da177e4 LT |
904 | /* find the destination keyring if present (which must also be |
905 | * writable) */ | |
906 | keyring = NULL; | |
907 | if (ringid) { | |
3e30148c | 908 | keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
1da177e4 LT |
909 | if (IS_ERR(keyring)) { |
910 | ret = PTR_ERR(keyring); | |
911 | goto error2; | |
912 | } | |
913 | } | |
914 | ||
915 | /* instantiate the key and link it into a keyring */ | |
3e30148c | 916 | ret = key_negate_and_link(rka->target_key, timeout, keyring, instkey); |
1da177e4 LT |
917 | |
918 | key_put(keyring); | |
919 | error2: | |
3e30148c | 920 | key_put(instkey); |
1da177e4 LT |
921 | error: |
922 | return ret; | |
923 | ||
924 | } /* end keyctl_negate_key() */ | |
925 | ||
3e30148c DH |
926 | /*****************************************************************************/ |
927 | /* | |
928 | * set the default keyring in which request_key() will cache keys | |
929 | * - return the old setting | |
930 | */ | |
931 | long keyctl_set_reqkey_keyring(int reqkey_defl) | |
932 | { | |
933 | int ret; | |
934 | ||
935 | switch (reqkey_defl) { | |
936 | case KEY_REQKEY_DEFL_THREAD_KEYRING: | |
937 | ret = install_thread_keyring(current); | |
938 | if (ret < 0) | |
939 | return ret; | |
940 | goto set; | |
941 | ||
942 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: | |
943 | ret = install_process_keyring(current); | |
944 | if (ret < 0) | |
945 | return ret; | |
946 | ||
947 | case KEY_REQKEY_DEFL_DEFAULT: | |
948 | case KEY_REQKEY_DEFL_SESSION_KEYRING: | |
949 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
950 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: | |
951 | set: | |
952 | current->jit_keyring = reqkey_defl; | |
953 | ||
954 | case KEY_REQKEY_DEFL_NO_CHANGE: | |
955 | return current->jit_keyring; | |
956 | ||
957 | case KEY_REQKEY_DEFL_GROUP_KEYRING: | |
958 | default: | |
959 | return -EINVAL; | |
960 | } | |
961 | ||
962 | } /* end keyctl_set_reqkey_keyring() */ | |
963 | ||
1da177e4 LT |
964 | /*****************************************************************************/ |
965 | /* | |
966 | * the key control system call | |
967 | */ | |
968 | asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3, | |
969 | unsigned long arg4, unsigned long arg5) | |
970 | { | |
971 | switch (option) { | |
972 | case KEYCTL_GET_KEYRING_ID: | |
973 | return keyctl_get_keyring_ID((key_serial_t) arg2, | |
974 | (int) arg3); | |
975 | ||
976 | case KEYCTL_JOIN_SESSION_KEYRING: | |
977 | return keyctl_join_session_keyring((const char __user *) arg2); | |
978 | ||
979 | case KEYCTL_UPDATE: | |
980 | return keyctl_update_key((key_serial_t) arg2, | |
981 | (const void __user *) arg3, | |
982 | (size_t) arg4); | |
983 | ||
984 | case KEYCTL_REVOKE: | |
985 | return keyctl_revoke_key((key_serial_t) arg2); | |
986 | ||
987 | case KEYCTL_DESCRIBE: | |
988 | return keyctl_describe_key((key_serial_t) arg2, | |
989 | (char __user *) arg3, | |
990 | (unsigned) arg4); | |
991 | ||
992 | case KEYCTL_CLEAR: | |
993 | return keyctl_keyring_clear((key_serial_t) arg2); | |
994 | ||
995 | case KEYCTL_LINK: | |
996 | return keyctl_keyring_link((key_serial_t) arg2, | |
997 | (key_serial_t) arg3); | |
998 | ||
999 | case KEYCTL_UNLINK: | |
1000 | return keyctl_keyring_unlink((key_serial_t) arg2, | |
1001 | (key_serial_t) arg3); | |
1002 | ||
1003 | case KEYCTL_SEARCH: | |
1004 | return keyctl_keyring_search((key_serial_t) arg2, | |
1005 | (const char __user *) arg3, | |
1006 | (const char __user *) arg4, | |
1007 | (key_serial_t) arg5); | |
1008 | ||
1009 | case KEYCTL_READ: | |
1010 | return keyctl_read_key((key_serial_t) arg2, | |
1011 | (char __user *) arg3, | |
1012 | (size_t) arg4); | |
1013 | ||
1014 | case KEYCTL_CHOWN: | |
1015 | return keyctl_chown_key((key_serial_t) arg2, | |
1016 | (uid_t) arg3, | |
1017 | (gid_t) arg4); | |
1018 | ||
1019 | case KEYCTL_SETPERM: | |
1020 | return keyctl_setperm_key((key_serial_t) arg2, | |
1021 | (key_perm_t) arg3); | |
1022 | ||
1023 | case KEYCTL_INSTANTIATE: | |
1024 | return keyctl_instantiate_key((key_serial_t) arg2, | |
1025 | (const void __user *) arg3, | |
1026 | (size_t) arg4, | |
1027 | (key_serial_t) arg5); | |
1028 | ||
1029 | case KEYCTL_NEGATE: | |
1030 | return keyctl_negate_key((key_serial_t) arg2, | |
1031 | (unsigned) arg3, | |
1032 | (key_serial_t) arg4); | |
1033 | ||
3e30148c DH |
1034 | case KEYCTL_SET_REQKEY_KEYRING: |
1035 | return keyctl_set_reqkey_keyring(arg2); | |
1036 | ||
1da177e4 LT |
1037 | default: |
1038 | return -EOPNOTSUPP; | |
1039 | } | |
1040 | ||
1041 | } /* end sys_keyctl() */ |