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 | { | |
664cceb0 | 37 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
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) */ | |
664cceb0 DH |
89 | keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
90 | if (IS_ERR(keyring_ref)) { | |
91 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
92 | goto error3; |
93 | } | |
94 | ||
95 | /* create or update the requested key and add it to the target | |
96 | * keyring */ | |
664cceb0 DH |
97 | key_ref = key_create_or_update(keyring_ref, type, description, |
98 | payload, plen, 0); | |
99 | if (!IS_ERR(key_ref)) { | |
100 | ret = key_ref_to_ptr(key_ref)->serial; | |
101 | key_ref_put(key_ref); | |
1da177e4 LT |
102 | } |
103 | else { | |
664cceb0 | 104 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
105 | } |
106 | ||
664cceb0 | 107 | key_ref_put(keyring_ref); |
1da177e4 LT |
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; | |
664cceb0 DH |
134 | struct key *key; |
135 | key_ref_t dest_ref; | |
1da177e4 LT |
136 | char type[32], *description, *callout_info; |
137 | long dlen, ret; | |
138 | ||
139 | /* pull the type into kernel space */ | |
140 | ret = strncpy_from_user(type, _type, sizeof(type) - 1); | |
141 | if (ret < 0) | |
142 | goto error; | |
143 | type[31] = '\0'; | |
144 | ||
1260f801 DH |
145 | ret = -EPERM; |
146 | if (type[0] == '.') | |
147 | goto error; | |
148 | ||
1da177e4 LT |
149 | /* pull the description into kernel space */ |
150 | ret = -EFAULT; | |
151 | dlen = strnlen_user(_description, PAGE_SIZE - 1); | |
152 | if (dlen <= 0) | |
153 | goto error; | |
154 | ||
155 | ret = -EINVAL; | |
156 | if (dlen > PAGE_SIZE - 1) | |
157 | goto error; | |
158 | ||
159 | ret = -ENOMEM; | |
160 | description = kmalloc(dlen + 1, GFP_KERNEL); | |
161 | if (!description) | |
162 | goto error; | |
163 | ||
164 | ret = -EFAULT; | |
165 | if (copy_from_user(description, _description, dlen + 1) != 0) | |
166 | goto error2; | |
167 | ||
168 | /* pull the callout info into kernel space */ | |
169 | callout_info = NULL; | |
170 | if (_callout_info) { | |
171 | ret = -EFAULT; | |
172 | dlen = strnlen_user(_callout_info, PAGE_SIZE - 1); | |
173 | if (dlen <= 0) | |
174 | goto error2; | |
175 | ||
176 | ret = -EINVAL; | |
177 | if (dlen > PAGE_SIZE - 1) | |
178 | goto error2; | |
179 | ||
180 | ret = -ENOMEM; | |
181 | callout_info = kmalloc(dlen + 1, GFP_KERNEL); | |
182 | if (!callout_info) | |
183 | goto error2; | |
184 | ||
185 | ret = -EFAULT; | |
186 | if (copy_from_user(callout_info, _callout_info, dlen + 1) != 0) | |
187 | goto error3; | |
188 | } | |
189 | ||
190 | /* get the destination keyring if specified */ | |
664cceb0 | 191 | dest_ref = NULL; |
1da177e4 | 192 | if (destringid) { |
664cceb0 DH |
193 | dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); |
194 | if (IS_ERR(dest_ref)) { | |
195 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
196 | goto error3; |
197 | } | |
198 | } | |
199 | ||
200 | /* find the key type */ | |
201 | ktype = key_type_lookup(type); | |
202 | if (IS_ERR(ktype)) { | |
203 | ret = PTR_ERR(ktype); | |
204 | goto error4; | |
205 | } | |
206 | ||
207 | /* do the search */ | |
664cceb0 DH |
208 | key = request_key_and_link(ktype, description, callout_info, |
209 | key_ref_to_ptr(dest_ref)); | |
1da177e4 LT |
210 | if (IS_ERR(key)) { |
211 | ret = PTR_ERR(key); | |
212 | goto error5; | |
213 | } | |
214 | ||
1da177e4 LT |
215 | ret = key->serial; |
216 | ||
3e30148c | 217 | key_put(key); |
1da177e4 LT |
218 | error5: |
219 | key_type_put(ktype); | |
220 | error4: | |
664cceb0 | 221 | key_ref_put(dest_ref); |
1da177e4 LT |
222 | error3: |
223 | kfree(callout_info); | |
224 | error2: | |
225 | kfree(description); | |
226 | error: | |
227 | return ret; | |
228 | ||
229 | } /* end sys_request_key() */ | |
230 | ||
231 | /*****************************************************************************/ | |
232 | /* | |
233 | * get the ID of the specified process keyring | |
234 | * - the keyring must have search permission to be found | |
235 | * - implements keyctl(KEYCTL_GET_KEYRING_ID) | |
236 | */ | |
237 | long keyctl_get_keyring_ID(key_serial_t id, int create) | |
238 | { | |
664cceb0 | 239 | key_ref_t key_ref; |
1da177e4 LT |
240 | long ret; |
241 | ||
664cceb0 DH |
242 | key_ref = lookup_user_key(NULL, id, create, 0, KEY_SEARCH); |
243 | if (IS_ERR(key_ref)) { | |
244 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
245 | goto error; |
246 | } | |
247 | ||
664cceb0 DH |
248 | ret = key_ref_to_ptr(key_ref)->serial; |
249 | key_ref_put(key_ref); | |
1da177e4 LT |
250 | error: |
251 | return ret; | |
252 | ||
253 | } /* end keyctl_get_keyring_ID() */ | |
254 | ||
255 | /*****************************************************************************/ | |
256 | /* | |
257 | * join the session keyring | |
258 | * - implements keyctl(KEYCTL_JOIN_SESSION_KEYRING) | |
259 | */ | |
260 | long keyctl_join_session_keyring(const char __user *_name) | |
261 | { | |
262 | char *name; | |
263 | long nlen, ret; | |
264 | ||
265 | /* fetch the name from userspace */ | |
266 | name = NULL; | |
267 | if (_name) { | |
268 | ret = -EFAULT; | |
269 | nlen = strnlen_user(_name, PAGE_SIZE - 1); | |
270 | if (nlen <= 0) | |
271 | goto error; | |
272 | ||
273 | ret = -EINVAL; | |
274 | if (nlen > PAGE_SIZE - 1) | |
275 | goto error; | |
276 | ||
277 | ret = -ENOMEM; | |
278 | name = kmalloc(nlen + 1, GFP_KERNEL); | |
279 | if (!name) | |
280 | goto error; | |
281 | ||
282 | ret = -EFAULT; | |
283 | if (copy_from_user(name, _name, nlen + 1) != 0) | |
284 | goto error2; | |
285 | } | |
286 | ||
287 | /* join the session */ | |
288 | ret = join_session_keyring(name); | |
289 | ||
290 | error2: | |
291 | kfree(name); | |
292 | error: | |
293 | return ret; | |
294 | ||
295 | } /* end keyctl_join_session_keyring() */ | |
296 | ||
297 | /*****************************************************************************/ | |
298 | /* | |
299 | * update a key's data payload | |
300 | * - the key must be writable | |
301 | * - implements keyctl(KEYCTL_UPDATE) | |
302 | */ | |
303 | long keyctl_update_key(key_serial_t id, | |
304 | const void __user *_payload, | |
305 | size_t plen) | |
306 | { | |
664cceb0 | 307 | key_ref_t key_ref; |
1da177e4 LT |
308 | void *payload; |
309 | long ret; | |
310 | ||
311 | ret = -EINVAL; | |
312 | if (plen > PAGE_SIZE) | |
313 | goto error; | |
314 | ||
315 | /* pull the payload in if one was supplied */ | |
316 | payload = NULL; | |
317 | if (_payload) { | |
318 | ret = -ENOMEM; | |
319 | payload = kmalloc(plen, GFP_KERNEL); | |
320 | if (!payload) | |
321 | goto error; | |
322 | ||
323 | ret = -EFAULT; | |
324 | if (copy_from_user(payload, _payload, plen) != 0) | |
325 | goto error2; | |
326 | } | |
327 | ||
328 | /* find the target key (which must be writable) */ | |
664cceb0 DH |
329 | key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); |
330 | if (IS_ERR(key_ref)) { | |
331 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
332 | goto error2; |
333 | } | |
334 | ||
335 | /* update the key */ | |
664cceb0 | 336 | ret = key_update(key_ref, payload, plen); |
1da177e4 | 337 | |
664cceb0 | 338 | key_ref_put(key_ref); |
1da177e4 LT |
339 | error2: |
340 | kfree(payload); | |
341 | error: | |
342 | return ret; | |
343 | ||
344 | } /* end keyctl_update_key() */ | |
345 | ||
346 | /*****************************************************************************/ | |
347 | /* | |
348 | * revoke a key | |
349 | * - the key must be writable | |
350 | * - implements keyctl(KEYCTL_REVOKE) | |
351 | */ | |
352 | long keyctl_revoke_key(key_serial_t id) | |
353 | { | |
664cceb0 | 354 | key_ref_t key_ref; |
1da177e4 LT |
355 | long ret; |
356 | ||
664cceb0 DH |
357 | key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); |
358 | if (IS_ERR(key_ref)) { | |
359 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
360 | goto error; |
361 | } | |
362 | ||
664cceb0 | 363 | key_revoke(key_ref_to_ptr(key_ref)); |
1da177e4 LT |
364 | ret = 0; |
365 | ||
664cceb0 | 366 | key_ref_put(key_ref); |
1da177e4 | 367 | error: |
1260f801 | 368 | return ret; |
1da177e4 LT |
369 | |
370 | } /* end keyctl_revoke_key() */ | |
371 | ||
372 | /*****************************************************************************/ | |
373 | /* | |
374 | * clear the specified process keyring | |
375 | * - the keyring must be writable | |
376 | * - implements keyctl(KEYCTL_CLEAR) | |
377 | */ | |
378 | long keyctl_keyring_clear(key_serial_t ringid) | |
379 | { | |
664cceb0 | 380 | key_ref_t keyring_ref; |
1da177e4 LT |
381 | long ret; |
382 | ||
664cceb0 DH |
383 | keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
384 | if (IS_ERR(keyring_ref)) { | |
385 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
386 | goto error; |
387 | } | |
388 | ||
664cceb0 | 389 | ret = keyring_clear(key_ref_to_ptr(keyring_ref)); |
1da177e4 | 390 | |
664cceb0 | 391 | key_ref_put(keyring_ref); |
1da177e4 LT |
392 | error: |
393 | return ret; | |
394 | ||
395 | } /* end keyctl_keyring_clear() */ | |
396 | ||
397 | /*****************************************************************************/ | |
398 | /* | |
399 | * link a key into a keyring | |
400 | * - the keyring must be writable | |
401 | * - the key must be linkable | |
402 | * - implements keyctl(KEYCTL_LINK) | |
403 | */ | |
404 | long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) | |
405 | { | |
664cceb0 | 406 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
407 | long ret; |
408 | ||
664cceb0 DH |
409 | keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
410 | if (IS_ERR(keyring_ref)) { | |
411 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
412 | goto error; |
413 | } | |
414 | ||
664cceb0 DH |
415 | key_ref = lookup_user_key(NULL, id, 1, 0, KEY_LINK); |
416 | if (IS_ERR(key_ref)) { | |
417 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
418 | goto error2; |
419 | } | |
420 | ||
664cceb0 | 421 | ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); |
1da177e4 | 422 | |
664cceb0 | 423 | key_ref_put(key_ref); |
1da177e4 | 424 | error2: |
664cceb0 | 425 | key_ref_put(keyring_ref); |
1da177e4 LT |
426 | error: |
427 | return ret; | |
428 | ||
429 | } /* end keyctl_keyring_link() */ | |
430 | ||
431 | /*****************************************************************************/ | |
432 | /* | |
433 | * unlink the first attachment of a key from a keyring | |
434 | * - the keyring must be writable | |
435 | * - we don't need any permissions on the key | |
436 | * - implements keyctl(KEYCTL_UNLINK) | |
437 | */ | |
438 | long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) | |
439 | { | |
664cceb0 | 440 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
441 | long ret; |
442 | ||
664cceb0 DH |
443 | keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_WRITE); |
444 | if (IS_ERR(keyring_ref)) { | |
445 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
446 | goto error; |
447 | } | |
448 | ||
664cceb0 DH |
449 | key_ref = lookup_user_key(NULL, id, 0, 0, 0); |
450 | if (IS_ERR(key_ref)) { | |
451 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
452 | goto error2; |
453 | } | |
454 | ||
664cceb0 | 455 | ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); |
1da177e4 | 456 | |
664cceb0 | 457 | key_ref_put(key_ref); |
1da177e4 | 458 | error2: |
664cceb0 | 459 | key_ref_put(keyring_ref); |
1da177e4 LT |
460 | error: |
461 | return ret; | |
462 | ||
463 | } /* end keyctl_keyring_unlink() */ | |
464 | ||
465 | /*****************************************************************************/ | |
466 | /* | |
467 | * describe a user key | |
468 | * - the key must have view permission | |
469 | * - if there's a buffer, we place up to buflen bytes of data into it | |
470 | * - unless there's an error, we return the amount of description available, | |
471 | * irrespective of how much we may have copied | |
472 | * - the description is formatted thus: | |
473 | * type;uid;gid;perm;description<NUL> | |
474 | * - implements keyctl(KEYCTL_DESCRIBE) | |
475 | */ | |
476 | long keyctl_describe_key(key_serial_t keyid, | |
477 | char __user *buffer, | |
478 | size_t buflen) | |
479 | { | |
3e30148c | 480 | struct key *key, *instkey; |
664cceb0 | 481 | key_ref_t key_ref; |
1da177e4 LT |
482 | char *tmpbuf; |
483 | long ret; | |
484 | ||
664cceb0 DH |
485 | key_ref = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW); |
486 | if (IS_ERR(key_ref)) { | |
3e30148c DH |
487 | /* viewing a key under construction is permitted if we have the |
488 | * authorisation token handy */ | |
664cceb0 | 489 | if (PTR_ERR(key_ref) == -EACCES) { |
3e30148c DH |
490 | instkey = key_get_instantiation_authkey(keyid); |
491 | if (!IS_ERR(instkey)) { | |
492 | key_put(instkey); | |
664cceb0 DH |
493 | key_ref = lookup_user_key(NULL, keyid, |
494 | 0, 1, 0); | |
495 | if (!IS_ERR(key_ref)) | |
3e30148c DH |
496 | goto okay; |
497 | } | |
498 | } | |
499 | ||
664cceb0 | 500 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
501 | goto error; |
502 | } | |
503 | ||
3e30148c | 504 | okay: |
1da177e4 LT |
505 | /* calculate how much description we're going to return */ |
506 | ret = -ENOMEM; | |
507 | tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
508 | if (!tmpbuf) | |
509 | goto error2; | |
510 | ||
664cceb0 DH |
511 | key = key_ref_to_ptr(key_ref); |
512 | ||
1da177e4 | 513 | ret = snprintf(tmpbuf, PAGE_SIZE - 1, |
664cceb0 DH |
514 | "%s;%d;%d;%08x;%s", |
515 | key_ref_to_ptr(key_ref)->type->name, | |
516 | key_ref_to_ptr(key_ref)->uid, | |
517 | key_ref_to_ptr(key_ref)->gid, | |
518 | key_ref_to_ptr(key_ref)->perm, | |
519 | key_ref_to_ptr(key_ref)->description ? | |
520 | key_ref_to_ptr(key_ref)->description : "" | |
1da177e4 LT |
521 | ); |
522 | ||
523 | /* include a NUL char at the end of the data */ | |
524 | if (ret > PAGE_SIZE - 1) | |
525 | ret = PAGE_SIZE - 1; | |
526 | tmpbuf[ret] = 0; | |
527 | ret++; | |
528 | ||
529 | /* consider returning the data */ | |
530 | if (buffer && buflen > 0) { | |
531 | if (buflen > ret) | |
532 | buflen = ret; | |
533 | ||
534 | if (copy_to_user(buffer, tmpbuf, buflen) != 0) | |
535 | ret = -EFAULT; | |
536 | } | |
537 | ||
538 | kfree(tmpbuf); | |
539 | error2: | |
664cceb0 | 540 | key_ref_put(key_ref); |
1da177e4 LT |
541 | error: |
542 | return ret; | |
543 | ||
544 | } /* end keyctl_describe_key() */ | |
545 | ||
546 | /*****************************************************************************/ | |
547 | /* | |
548 | * search the specified keyring for a matching key | |
549 | * - the start keyring must be searchable | |
550 | * - nested keyrings may also be searched if they are searchable | |
551 | * - only keys with search permission may be found | |
552 | * - if a key is found, it will be attached to the destination keyring if | |
553 | * there's one specified | |
554 | * - implements keyctl(KEYCTL_SEARCH) | |
555 | */ | |
556 | long keyctl_keyring_search(key_serial_t ringid, | |
557 | const char __user *_type, | |
558 | const char __user *_description, | |
559 | key_serial_t destringid) | |
560 | { | |
561 | struct key_type *ktype; | |
664cceb0 | 562 | key_ref_t keyring_ref, key_ref, dest_ref; |
1da177e4 LT |
563 | char type[32], *description; |
564 | long dlen, ret; | |
565 | ||
566 | /* pull the type and description into kernel space */ | |
567 | ret = strncpy_from_user(type, _type, sizeof(type) - 1); | |
568 | if (ret < 0) | |
569 | goto error; | |
570 | type[31] = '\0'; | |
571 | ||
572 | ret = -EFAULT; | |
573 | dlen = strnlen_user(_description, PAGE_SIZE - 1); | |
574 | if (dlen <= 0) | |
575 | goto error; | |
576 | ||
577 | ret = -EINVAL; | |
578 | if (dlen > PAGE_SIZE - 1) | |
579 | goto error; | |
580 | ||
581 | ret = -ENOMEM; | |
582 | description = kmalloc(dlen + 1, GFP_KERNEL); | |
583 | if (!description) | |
584 | goto error; | |
585 | ||
586 | ret = -EFAULT; | |
587 | if (copy_from_user(description, _description, dlen + 1) != 0) | |
588 | goto error2; | |
589 | ||
590 | /* get the keyring at which to begin the search */ | |
664cceb0 DH |
591 | keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH); |
592 | if (IS_ERR(keyring_ref)) { | |
593 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
594 | goto error2; |
595 | } | |
596 | ||
597 | /* get the destination keyring if specified */ | |
664cceb0 | 598 | dest_ref = NULL; |
1da177e4 | 599 | if (destringid) { |
664cceb0 DH |
600 | dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); |
601 | if (IS_ERR(dest_ref)) { | |
602 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
603 | goto error3; |
604 | } | |
605 | } | |
606 | ||
607 | /* find the key type */ | |
608 | ktype = key_type_lookup(type); | |
609 | if (IS_ERR(ktype)) { | |
610 | ret = PTR_ERR(ktype); | |
611 | goto error4; | |
612 | } | |
613 | ||
614 | /* do the search */ | |
664cceb0 DH |
615 | key_ref = keyring_search(keyring_ref, ktype, description); |
616 | if (IS_ERR(key_ref)) { | |
617 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
618 | |
619 | /* treat lack or presence of a negative key the same */ | |
620 | if (ret == -EAGAIN) | |
621 | ret = -ENOKEY; | |
622 | goto error5; | |
623 | } | |
624 | ||
625 | /* link the resulting key to the destination keyring if we can */ | |
664cceb0 | 626 | if (dest_ref) { |
29db9190 DH |
627 | ret = key_permission(key_ref, KEY_LINK); |
628 | if (ret < 0) | |
1da177e4 LT |
629 | goto error6; |
630 | ||
664cceb0 | 631 | ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref)); |
1da177e4 LT |
632 | if (ret < 0) |
633 | goto error6; | |
634 | } | |
635 | ||
664cceb0 | 636 | ret = key_ref_to_ptr(key_ref)->serial; |
1da177e4 LT |
637 | |
638 | error6: | |
664cceb0 | 639 | key_ref_put(key_ref); |
1da177e4 LT |
640 | error5: |
641 | key_type_put(ktype); | |
642 | error4: | |
664cceb0 | 643 | key_ref_put(dest_ref); |
1da177e4 | 644 | error3: |
664cceb0 | 645 | key_ref_put(keyring_ref); |
1da177e4 LT |
646 | error2: |
647 | kfree(description); | |
648 | error: | |
649 | return ret; | |
650 | ||
651 | } /* end keyctl_keyring_search() */ | |
652 | ||
1da177e4 LT |
653 | /*****************************************************************************/ |
654 | /* | |
655 | * read a user key's payload | |
656 | * - the keyring must be readable or the key must be searchable from the | |
657 | * process's keyrings | |
658 | * - if there's a buffer, we place up to buflen bytes of data into it | |
659 | * - unless there's an error, we return the amount of data in the key, | |
660 | * irrespective of how much we may have copied | |
661 | * - implements keyctl(KEYCTL_READ) | |
662 | */ | |
663 | long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) | |
664 | { | |
664cceb0 DH |
665 | struct key *key; |
666 | key_ref_t key_ref; | |
1da177e4 LT |
667 | long ret; |
668 | ||
669 | /* find the key first */ | |
664cceb0 DH |
670 | key_ref = lookup_user_key(NULL, keyid, 0, 0, 0); |
671 | if (IS_ERR(key_ref)) { | |
672 | ret = -ENOKEY; | |
673 | goto error; | |
1da177e4 LT |
674 | } |
675 | ||
664cceb0 DH |
676 | key = key_ref_to_ptr(key_ref); |
677 | ||
678 | /* see if we can read it directly */ | |
29db9190 DH |
679 | ret = key_permission(key_ref, KEY_READ); |
680 | if (ret == 0) | |
664cceb0 | 681 | goto can_read_key; |
29db9190 DH |
682 | if (ret != -EACCES) |
683 | goto error; | |
664cceb0 DH |
684 | |
685 | /* we can't; see if it's searchable from this process's keyrings | |
686 | * - we automatically take account of the fact that it may be | |
687 | * dangling off an instantiation key | |
688 | */ | |
689 | if (!is_key_possessed(key_ref)) { | |
690 | ret = -EACCES; | |
691 | goto error2; | |
692 | } | |
1da177e4 LT |
693 | |
694 | /* the key is probably readable - now try to read it */ | |
1da177e4 LT |
695 | can_read_key: |
696 | ret = key_validate(key); | |
697 | if (ret == 0) { | |
698 | ret = -EOPNOTSUPP; | |
699 | if (key->type->read) { | |
700 | /* read the data with the semaphore held (since we | |
701 | * might sleep) */ | |
702 | down_read(&key->sem); | |
703 | ret = key->type->read(key, buffer, buflen); | |
704 | up_read(&key->sem); | |
705 | } | |
706 | } | |
707 | ||
708 | error2: | |
709 | key_put(key); | |
710 | error: | |
711 | return ret; | |
712 | ||
713 | } /* end keyctl_read_key() */ | |
714 | ||
715 | /*****************************************************************************/ | |
716 | /* | |
717 | * change the ownership of a key | |
718 | * - the keyring owned by the changer | |
719 | * - if the uid or gid is -1, then that parameter is not changed | |
720 | * - implements keyctl(KEYCTL_CHOWN) | |
721 | */ | |
722 | long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) | |
723 | { | |
724 | struct key *key; | |
664cceb0 | 725 | key_ref_t key_ref; |
1da177e4 LT |
726 | long ret; |
727 | ||
728 | ret = 0; | |
729 | if (uid == (uid_t) -1 && gid == (gid_t) -1) | |
730 | goto error; | |
731 | ||
29db9190 | 732 | key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); |
664cceb0 DH |
733 | if (IS_ERR(key_ref)) { |
734 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
735 | goto error; |
736 | } | |
737 | ||
664cceb0 DH |
738 | key = key_ref_to_ptr(key_ref); |
739 | ||
1da177e4 LT |
740 | /* make the changes with the locks held to prevent chown/chown races */ |
741 | ret = -EACCES; | |
742 | down_write(&key->sem); | |
1da177e4 LT |
743 | |
744 | if (!capable(CAP_SYS_ADMIN)) { | |
745 | /* only the sysadmin can chown a key to some other UID */ | |
746 | if (uid != (uid_t) -1 && key->uid != uid) | |
747 | goto no_access; | |
748 | ||
749 | /* only the sysadmin can set the key's GID to a group other | |
750 | * than one of those that the current process subscribes to */ | |
751 | if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid)) | |
752 | goto no_access; | |
753 | } | |
754 | ||
755 | /* change the UID (have to update the quotas) */ | |
756 | if (uid != (uid_t) -1 && uid != key->uid) { | |
757 | /* don't support UID changing yet */ | |
758 | ret = -EOPNOTSUPP; | |
759 | goto no_access; | |
760 | } | |
761 | ||
762 | /* change the GID */ | |
763 | if (gid != (gid_t) -1) | |
764 | key->gid = gid; | |
765 | ||
766 | ret = 0; | |
767 | ||
768 | no_access: | |
1da177e4 LT |
769 | up_write(&key->sem); |
770 | key_put(key); | |
771 | error: | |
772 | return ret; | |
773 | ||
774 | } /* end keyctl_chown_key() */ | |
775 | ||
776 | /*****************************************************************************/ | |
777 | /* | |
778 | * change the permission mask on a key | |
779 | * - the keyring owned by the changer | |
780 | * - implements keyctl(KEYCTL_SETPERM) | |
781 | */ | |
782 | long keyctl_setperm_key(key_serial_t id, key_perm_t perm) | |
783 | { | |
784 | struct key *key; | |
664cceb0 | 785 | key_ref_t key_ref; |
1da177e4 LT |
786 | long ret; |
787 | ||
788 | ret = -EINVAL; | |
664cceb0 | 789 | if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) |
1da177e4 LT |
790 | goto error; |
791 | ||
29db9190 | 792 | key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); |
664cceb0 DH |
793 | if (IS_ERR(key_ref)) { |
794 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
795 | goto error; |
796 | } | |
797 | ||
664cceb0 DH |
798 | key = key_ref_to_ptr(key_ref); |
799 | ||
76d8aeab | 800 | /* make the changes with the locks held to prevent chown/chmod races */ |
1da177e4 LT |
801 | ret = -EACCES; |
802 | down_write(&key->sem); | |
1da177e4 | 803 | |
76d8aeab DH |
804 | /* if we're not the sysadmin, we can only change a key that we own */ |
805 | if (capable(CAP_SYS_ADMIN) || key->uid == current->fsuid) { | |
806 | key->perm = perm; | |
807 | ret = 0; | |
808 | } | |
1da177e4 | 809 | |
1da177e4 LT |
810 | up_write(&key->sem); |
811 | key_put(key); | |
76d8aeab | 812 | error: |
1da177e4 LT |
813 | return ret; |
814 | ||
815 | } /* end keyctl_setperm_key() */ | |
816 | ||
817 | /*****************************************************************************/ | |
818 | /* | |
819 | * instantiate the key with the specified payload, and, if one is given, link | |
820 | * the key into the keyring | |
821 | */ | |
822 | long keyctl_instantiate_key(key_serial_t id, | |
823 | const void __user *_payload, | |
824 | size_t plen, | |
825 | key_serial_t ringid) | |
826 | { | |
3e30148c | 827 | struct request_key_auth *rka; |
664cceb0 DH |
828 | struct key *instkey; |
829 | key_ref_t keyring_ref; | |
1da177e4 LT |
830 | void *payload; |
831 | long ret; | |
832 | ||
833 | ret = -EINVAL; | |
834 | if (plen > 32767) | |
835 | goto error; | |
836 | ||
b5f545c8 DH |
837 | /* the appropriate instantiation authorisation key must have been |
838 | * assumed before calling this */ | |
839 | ret = -EPERM; | |
840 | instkey = current->request_key_auth; | |
841 | if (!instkey) | |
842 | goto error; | |
843 | ||
844 | rka = instkey->payload.data; | |
845 | if (rka->target_key->serial != id) | |
846 | goto error; | |
847 | ||
1da177e4 LT |
848 | /* pull the payload in if one was supplied */ |
849 | payload = NULL; | |
850 | ||
851 | if (_payload) { | |
852 | ret = -ENOMEM; | |
853 | payload = kmalloc(plen, GFP_KERNEL); | |
854 | if (!payload) | |
855 | goto error; | |
856 | ||
857 | ret = -EFAULT; | |
858 | if (copy_from_user(payload, _payload, plen) != 0) | |
859 | goto error2; | |
860 | } | |
861 | ||
3e30148c DH |
862 | /* find the destination keyring amongst those belonging to the |
863 | * requesting task */ | |
664cceb0 | 864 | keyring_ref = NULL; |
1da177e4 | 865 | if (ringid) { |
664cceb0 DH |
866 | keyring_ref = lookup_user_key(rka->context, ringid, 1, 0, |
867 | KEY_WRITE); | |
868 | if (IS_ERR(keyring_ref)) { | |
869 | ret = PTR_ERR(keyring_ref); | |
b5f545c8 | 870 | goto error2; |
1da177e4 LT |
871 | } |
872 | } | |
873 | ||
874 | /* instantiate the key and link it into a keyring */ | |
3e30148c | 875 | ret = key_instantiate_and_link(rka->target_key, payload, plen, |
664cceb0 | 876 | key_ref_to_ptr(keyring_ref), instkey); |
1da177e4 | 877 | |
664cceb0 | 878 | key_ref_put(keyring_ref); |
b5f545c8 DH |
879 | |
880 | /* discard the assumed authority if it's just been disabled by | |
881 | * instantiation of the key */ | |
882 | if (ret == 0) { | |
883 | key_put(current->request_key_auth); | |
884 | current->request_key_auth = NULL; | |
885 | } | |
886 | ||
887 | error2: | |
1da177e4 | 888 | kfree(payload); |
b5f545c8 | 889 | error: |
1da177e4 LT |
890 | return ret; |
891 | ||
892 | } /* end keyctl_instantiate_key() */ | |
893 | ||
894 | /*****************************************************************************/ | |
895 | /* | |
896 | * negatively instantiate the key with the given timeout (in seconds), and, if | |
897 | * one is given, link the key into the keyring | |
898 | */ | |
899 | long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) | |
900 | { | |
3e30148c | 901 | struct request_key_auth *rka; |
664cceb0 DH |
902 | struct key *instkey; |
903 | key_ref_t keyring_ref; | |
1da177e4 LT |
904 | long ret; |
905 | ||
b5f545c8 DH |
906 | /* the appropriate instantiation authorisation key must have been |
907 | * assumed before calling this */ | |
908 | ret = -EPERM; | |
909 | instkey = current->request_key_auth; | |
910 | if (!instkey) | |
1da177e4 | 911 | goto error; |
1da177e4 | 912 | |
3e30148c | 913 | rka = instkey->payload.data; |
b5f545c8 DH |
914 | if (rka->target_key->serial != id) |
915 | goto error; | |
3e30148c | 916 | |
1da177e4 LT |
917 | /* find the destination keyring if present (which must also be |
918 | * writable) */ | |
664cceb0 | 919 | keyring_ref = NULL; |
1da177e4 | 920 | if (ringid) { |
664cceb0 DH |
921 | keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); |
922 | if (IS_ERR(keyring_ref)) { | |
923 | ret = PTR_ERR(keyring_ref); | |
b5f545c8 | 924 | goto error; |
1da177e4 LT |
925 | } |
926 | } | |
927 | ||
928 | /* instantiate the key and link it into a keyring */ | |
664cceb0 DH |
929 | ret = key_negate_and_link(rka->target_key, timeout, |
930 | key_ref_to_ptr(keyring_ref), instkey); | |
1da177e4 | 931 | |
664cceb0 | 932 | key_ref_put(keyring_ref); |
b5f545c8 DH |
933 | |
934 | /* discard the assumed authority if it's just been disabled by | |
935 | * instantiation of the key */ | |
936 | if (ret == 0) { | |
937 | key_put(current->request_key_auth); | |
938 | current->request_key_auth = NULL; | |
939 | } | |
940 | ||
941 | error: | |
1da177e4 LT |
942 | return ret; |
943 | ||
944 | } /* end keyctl_negate_key() */ | |
945 | ||
3e30148c DH |
946 | /*****************************************************************************/ |
947 | /* | |
948 | * set the default keyring in which request_key() will cache keys | |
949 | * - return the old setting | |
950 | */ | |
951 | long keyctl_set_reqkey_keyring(int reqkey_defl) | |
952 | { | |
953 | int ret; | |
954 | ||
955 | switch (reqkey_defl) { | |
956 | case KEY_REQKEY_DEFL_THREAD_KEYRING: | |
957 | ret = install_thread_keyring(current); | |
958 | if (ret < 0) | |
959 | return ret; | |
960 | goto set; | |
961 | ||
962 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: | |
963 | ret = install_process_keyring(current); | |
964 | if (ret < 0) | |
965 | return ret; | |
966 | ||
967 | case KEY_REQKEY_DEFL_DEFAULT: | |
968 | case KEY_REQKEY_DEFL_SESSION_KEYRING: | |
969 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
970 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: | |
971 | set: | |
972 | current->jit_keyring = reqkey_defl; | |
973 | ||
974 | case KEY_REQKEY_DEFL_NO_CHANGE: | |
975 | return current->jit_keyring; | |
976 | ||
977 | case KEY_REQKEY_DEFL_GROUP_KEYRING: | |
978 | default: | |
979 | return -EINVAL; | |
980 | } | |
981 | ||
982 | } /* end keyctl_set_reqkey_keyring() */ | |
983 | ||
017679c4 DH |
984 | /*****************************************************************************/ |
985 | /* | |
986 | * set or clear the timeout for a key | |
987 | */ | |
988 | long keyctl_set_timeout(key_serial_t id, unsigned timeout) | |
989 | { | |
990 | struct timespec now; | |
991 | struct key *key; | |
992 | key_ref_t key_ref; | |
993 | time_t expiry; | |
994 | long ret; | |
995 | ||
996 | key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); | |
997 | if (IS_ERR(key_ref)) { | |
998 | ret = PTR_ERR(key_ref); | |
999 | goto error; | |
1000 | } | |
1001 | ||
1002 | key = key_ref_to_ptr(key_ref); | |
1003 | ||
1004 | /* make the changes with the locks held to prevent races */ | |
1005 | down_write(&key->sem); | |
1006 | ||
1007 | expiry = 0; | |
1008 | if (timeout > 0) { | |
1009 | now = current_kernel_time(); | |
1010 | expiry = now.tv_sec + timeout; | |
1011 | } | |
1012 | ||
1013 | key->expiry = expiry; | |
1014 | ||
1015 | up_write(&key->sem); | |
1016 | key_put(key); | |
1017 | ||
1018 | ret = 0; | |
1019 | error: | |
1020 | return ret; | |
1021 | ||
1022 | } /* end keyctl_set_timeout() */ | |
1023 | ||
b5f545c8 DH |
1024 | /*****************************************************************************/ |
1025 | /* | |
1026 | * assume the authority to instantiate the specified key | |
1027 | */ | |
1028 | long keyctl_assume_authority(key_serial_t id) | |
1029 | { | |
1030 | struct key *authkey; | |
1031 | long ret; | |
1032 | ||
1033 | /* special key IDs aren't permitted */ | |
1034 | ret = -EINVAL; | |
1035 | if (id < 0) | |
1036 | goto error; | |
1037 | ||
1038 | /* we divest ourselves of authority if given an ID of 0 */ | |
1039 | if (id == 0) { | |
1040 | key_put(current->request_key_auth); | |
1041 | current->request_key_auth = NULL; | |
1042 | ret = 0; | |
1043 | goto error; | |
1044 | } | |
1045 | ||
1046 | /* attempt to assume the authority temporarily granted to us whilst we | |
1047 | * instantiate the specified key | |
1048 | * - the authorisation key must be in the current task's keyrings | |
1049 | * somewhere | |
1050 | */ | |
1051 | authkey = key_get_instantiation_authkey(id); | |
1052 | if (IS_ERR(authkey)) { | |
1053 | ret = PTR_ERR(authkey); | |
1054 | goto error; | |
1055 | } | |
1056 | ||
1057 | key_put(current->request_key_auth); | |
1058 | current->request_key_auth = authkey; | |
1059 | ret = authkey->serial; | |
1060 | ||
1061 | error: | |
1062 | return ret; | |
1063 | ||
1064 | } /* end keyctl_assume_authority() */ | |
1065 | ||
1da177e4 LT |
1066 | /*****************************************************************************/ |
1067 | /* | |
1068 | * the key control system call | |
1069 | */ | |
1070 | asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3, | |
1071 | unsigned long arg4, unsigned long arg5) | |
1072 | { | |
1073 | switch (option) { | |
1074 | case KEYCTL_GET_KEYRING_ID: | |
1075 | return keyctl_get_keyring_ID((key_serial_t) arg2, | |
1076 | (int) arg3); | |
1077 | ||
1078 | case KEYCTL_JOIN_SESSION_KEYRING: | |
1079 | return keyctl_join_session_keyring((const char __user *) arg2); | |
1080 | ||
1081 | case KEYCTL_UPDATE: | |
1082 | return keyctl_update_key((key_serial_t) arg2, | |
1083 | (const void __user *) arg3, | |
1084 | (size_t) arg4); | |
1085 | ||
1086 | case KEYCTL_REVOKE: | |
1087 | return keyctl_revoke_key((key_serial_t) arg2); | |
1088 | ||
1089 | case KEYCTL_DESCRIBE: | |
1090 | return keyctl_describe_key((key_serial_t) arg2, | |
1091 | (char __user *) arg3, | |
1092 | (unsigned) arg4); | |
1093 | ||
1094 | case KEYCTL_CLEAR: | |
1095 | return keyctl_keyring_clear((key_serial_t) arg2); | |
1096 | ||
1097 | case KEYCTL_LINK: | |
1098 | return keyctl_keyring_link((key_serial_t) arg2, | |
1099 | (key_serial_t) arg3); | |
1100 | ||
1101 | case KEYCTL_UNLINK: | |
1102 | return keyctl_keyring_unlink((key_serial_t) arg2, | |
1103 | (key_serial_t) arg3); | |
1104 | ||
1105 | case KEYCTL_SEARCH: | |
1106 | return keyctl_keyring_search((key_serial_t) arg2, | |
1107 | (const char __user *) arg3, | |
1108 | (const char __user *) arg4, | |
1109 | (key_serial_t) arg5); | |
1110 | ||
1111 | case KEYCTL_READ: | |
1112 | return keyctl_read_key((key_serial_t) arg2, | |
1113 | (char __user *) arg3, | |
1114 | (size_t) arg4); | |
1115 | ||
1116 | case KEYCTL_CHOWN: | |
1117 | return keyctl_chown_key((key_serial_t) arg2, | |
1118 | (uid_t) arg3, | |
1119 | (gid_t) arg4); | |
1120 | ||
1121 | case KEYCTL_SETPERM: | |
1122 | return keyctl_setperm_key((key_serial_t) arg2, | |
1123 | (key_perm_t) arg3); | |
1124 | ||
1125 | case KEYCTL_INSTANTIATE: | |
1126 | return keyctl_instantiate_key((key_serial_t) arg2, | |
1127 | (const void __user *) arg3, | |
1128 | (size_t) arg4, | |
1129 | (key_serial_t) arg5); | |
1130 | ||
1131 | case KEYCTL_NEGATE: | |
1132 | return keyctl_negate_key((key_serial_t) arg2, | |
1133 | (unsigned) arg3, | |
1134 | (key_serial_t) arg4); | |
1135 | ||
3e30148c DH |
1136 | case KEYCTL_SET_REQKEY_KEYRING: |
1137 | return keyctl_set_reqkey_keyring(arg2); | |
1138 | ||
017679c4 DH |
1139 | case KEYCTL_SET_TIMEOUT: |
1140 | return keyctl_set_timeout((key_serial_t) arg2, | |
1141 | (unsigned) arg3); | |
1142 | ||
b5f545c8 DH |
1143 | case KEYCTL_ASSUME_AUTHORITY: |
1144 | return keyctl_assume_authority((key_serial_t) arg2); | |
1145 | ||
1da177e4 LT |
1146 | default: |
1147 | return -EOPNOTSUPP; | |
1148 | } | |
1149 | ||
1150 | } /* end sys_keyctl() */ |