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 | 21 | #include <linux/err.h> |
38bbca6b | 22 | #include <linux/vmalloc.h> |
70a5bb72 | 23 | #include <linux/security.h> |
1da177e4 LT |
24 | #include <asm/uaccess.h> |
25 | #include "internal.h" | |
26 | ||
0cb409d9 DA |
27 | static int key_get_type_from_user(char *type, |
28 | const char __user *_type, | |
29 | unsigned len) | |
30 | { | |
31 | int ret; | |
32 | ||
33 | ret = strncpy_from_user(type, _type, len); | |
34 | ||
35 | if (ret < 0) | |
4303ef19 | 36 | return ret; |
0cb409d9 DA |
37 | |
38 | if (ret == 0 || ret >= len) | |
39 | return -EINVAL; | |
40 | ||
41 | if (type[0] == '.') | |
42 | return -EPERM; | |
43 | ||
44 | type[len - 1] = '\0'; | |
45 | ||
46 | return 0; | |
47 | } | |
48 | ||
1da177e4 LT |
49 | /*****************************************************************************/ |
50 | /* | |
51 | * extract the description of a new key from userspace and either add it as a | |
52 | * new key to the specified keyring or update a matching key in that keyring | |
53 | * - the keyring must be writable | |
54 | * - returns the new key's serial number | |
55 | * - implements add_key() | |
56 | */ | |
1e7bfb21 HC |
57 | SYSCALL_DEFINE5(add_key, const char __user *, _type, |
58 | const char __user *, _description, | |
59 | const void __user *, _payload, | |
60 | size_t, plen, | |
61 | key_serial_t, ringid) | |
1da177e4 | 62 | { |
664cceb0 | 63 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
64 | char type[32], *description; |
65 | void *payload; | |
0cb409d9 | 66 | long ret; |
38bbca6b | 67 | bool vm; |
1da177e4 LT |
68 | |
69 | ret = -EINVAL; | |
38bbca6b | 70 | if (plen > 1024 * 1024 - 1) |
1da177e4 LT |
71 | goto error; |
72 | ||
73 | /* draw all the data into kernel space */ | |
0cb409d9 | 74 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
75 | if (ret < 0) |
76 | goto error; | |
1da177e4 | 77 | |
0cb409d9 DA |
78 | description = strndup_user(_description, PAGE_SIZE); |
79 | if (IS_ERR(description)) { | |
80 | ret = PTR_ERR(description); | |
1da177e4 | 81 | goto error; |
0cb409d9 | 82 | } |
1da177e4 LT |
83 | |
84 | /* pull the payload in if one was supplied */ | |
85 | payload = NULL; | |
86 | ||
38bbca6b | 87 | vm = false; |
1da177e4 LT |
88 | if (_payload) { |
89 | ret = -ENOMEM; | |
90 | payload = kmalloc(plen, GFP_KERNEL); | |
38bbca6b DH |
91 | if (!payload) { |
92 | if (plen <= PAGE_SIZE) | |
93 | goto error2; | |
94 | vm = true; | |
95 | payload = vmalloc(plen); | |
96 | if (!payload) | |
97 | goto error2; | |
98 | } | |
1da177e4 LT |
99 | |
100 | ret = -EFAULT; | |
101 | if (copy_from_user(payload, _payload, plen) != 0) | |
102 | goto error3; | |
103 | } | |
104 | ||
105 | /* find the target keyring (which must be writable) */ | |
5593122e | 106 | keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); |
664cceb0 DH |
107 | if (IS_ERR(keyring_ref)) { |
108 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
109 | goto error3; |
110 | } | |
111 | ||
112 | /* create or update the requested key and add it to the target | |
113 | * keyring */ | |
664cceb0 | 114 | key_ref = key_create_or_update(keyring_ref, type, description, |
6b79ccb5 AR |
115 | payload, plen, KEY_PERM_UNDEF, |
116 | KEY_ALLOC_IN_QUOTA); | |
664cceb0 DH |
117 | if (!IS_ERR(key_ref)) { |
118 | ret = key_ref_to_ptr(key_ref)->serial; | |
119 | key_ref_put(key_ref); | |
1da177e4 LT |
120 | } |
121 | else { | |
664cceb0 | 122 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
123 | } |
124 | ||
664cceb0 | 125 | key_ref_put(keyring_ref); |
1da177e4 | 126 | error3: |
38bbca6b DH |
127 | if (!vm) |
128 | kfree(payload); | |
129 | else | |
130 | vfree(payload); | |
1da177e4 LT |
131 | error2: |
132 | kfree(description); | |
133 | error: | |
134 | return ret; | |
135 | ||
136 | } /* end sys_add_key() */ | |
137 | ||
138 | /*****************************************************************************/ | |
139 | /* | |
140 | * search the process keyrings for a matching key | |
141 | * - nested keyrings may also be searched if they have Search permission | |
142 | * - if a key is found, it will be attached to the destination keyring if | |
143 | * there's one specified | |
144 | * - /sbin/request-key will be invoked if _callout_info is non-NULL | |
145 | * - the _callout_info string will be passed to /sbin/request-key | |
146 | * - if the _callout_info string is empty, it will be rendered as "-" | |
147 | * - implements request_key() | |
148 | */ | |
1e7bfb21 HC |
149 | SYSCALL_DEFINE4(request_key, const char __user *, _type, |
150 | const char __user *, _description, | |
151 | const char __user *, _callout_info, | |
152 | key_serial_t, destringid) | |
1da177e4 LT |
153 | { |
154 | struct key_type *ktype; | |
664cceb0 DH |
155 | struct key *key; |
156 | key_ref_t dest_ref; | |
4a38e122 | 157 | size_t callout_len; |
1da177e4 | 158 | char type[32], *description, *callout_info; |
0cb409d9 | 159 | long ret; |
1da177e4 LT |
160 | |
161 | /* pull the type into kernel space */ | |
0cb409d9 | 162 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
163 | if (ret < 0) |
164 | goto error; | |
1260f801 | 165 | |
1da177e4 | 166 | /* pull the description into kernel space */ |
0cb409d9 DA |
167 | description = strndup_user(_description, PAGE_SIZE); |
168 | if (IS_ERR(description)) { | |
169 | ret = PTR_ERR(description); | |
1da177e4 | 170 | goto error; |
0cb409d9 | 171 | } |
1da177e4 LT |
172 | |
173 | /* pull the callout info into kernel space */ | |
174 | callout_info = NULL; | |
4a38e122 | 175 | callout_len = 0; |
1da177e4 | 176 | if (_callout_info) { |
0cb409d9 DA |
177 | callout_info = strndup_user(_callout_info, PAGE_SIZE); |
178 | if (IS_ERR(callout_info)) { | |
179 | ret = PTR_ERR(callout_info); | |
1da177e4 | 180 | goto error2; |
0cb409d9 | 181 | } |
4a38e122 | 182 | callout_len = strlen(callout_info); |
1da177e4 LT |
183 | } |
184 | ||
185 | /* get the destination keyring if specified */ | |
664cceb0 | 186 | dest_ref = NULL; |
1da177e4 | 187 | if (destringid) { |
5593122e DH |
188 | dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, |
189 | KEY_WRITE); | |
664cceb0 DH |
190 | if (IS_ERR(dest_ref)) { |
191 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
192 | goto error3; |
193 | } | |
194 | } | |
195 | ||
196 | /* find the key type */ | |
197 | ktype = key_type_lookup(type); | |
198 | if (IS_ERR(ktype)) { | |
199 | ret = PTR_ERR(ktype); | |
200 | goto error4; | |
201 | } | |
202 | ||
203 | /* do the search */ | |
4a38e122 DH |
204 | key = request_key_and_link(ktype, description, callout_info, |
205 | callout_len, NULL, key_ref_to_ptr(dest_ref), | |
7e047ef5 | 206 | KEY_ALLOC_IN_QUOTA); |
1da177e4 LT |
207 | if (IS_ERR(key)) { |
208 | ret = PTR_ERR(key); | |
209 | goto error5; | |
210 | } | |
211 | ||
1da177e4 LT |
212 | ret = key->serial; |
213 | ||
3e30148c | 214 | key_put(key); |
c5b60b5e | 215 | error5: |
1da177e4 | 216 | key_type_put(ktype); |
c5b60b5e | 217 | error4: |
664cceb0 | 218 | key_ref_put(dest_ref); |
c5b60b5e | 219 | error3: |
1da177e4 | 220 | kfree(callout_info); |
c5b60b5e | 221 | error2: |
1da177e4 | 222 | kfree(description); |
c5b60b5e | 223 | error: |
1da177e4 LT |
224 | return ret; |
225 | ||
226 | } /* end sys_request_key() */ | |
227 | ||
228 | /*****************************************************************************/ | |
229 | /* | |
230 | * get the ID of the specified process keyring | |
231 | * - the keyring must have search permission to be found | |
232 | * - implements keyctl(KEYCTL_GET_KEYRING_ID) | |
233 | */ | |
234 | long keyctl_get_keyring_ID(key_serial_t id, int create) | |
235 | { | |
664cceb0 | 236 | key_ref_t key_ref; |
5593122e | 237 | unsigned long lflags; |
1da177e4 LT |
238 | long ret; |
239 | ||
5593122e DH |
240 | lflags = create ? KEY_LOOKUP_CREATE : 0; |
241 | key_ref = lookup_user_key(id, lflags, KEY_SEARCH); | |
664cceb0 DH |
242 | if (IS_ERR(key_ref)) { |
243 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
244 | goto error; |
245 | } | |
246 | ||
664cceb0 DH |
247 | ret = key_ref_to_ptr(key_ref)->serial; |
248 | key_ref_put(key_ref); | |
c5b60b5e | 249 | error: |
1da177e4 LT |
250 | return ret; |
251 | ||
252 | } /* end keyctl_get_keyring_ID() */ | |
253 | ||
254 | /*****************************************************************************/ | |
255 | /* | |
256 | * join the session keyring | |
257 | * - implements keyctl(KEYCTL_JOIN_SESSION_KEYRING) | |
258 | */ | |
259 | long keyctl_join_session_keyring(const char __user *_name) | |
260 | { | |
261 | char *name; | |
0cb409d9 | 262 | long ret; |
1da177e4 LT |
263 | |
264 | /* fetch the name from userspace */ | |
265 | name = NULL; | |
266 | if (_name) { | |
0cb409d9 DA |
267 | name = strndup_user(_name, PAGE_SIZE); |
268 | if (IS_ERR(name)) { | |
269 | ret = PTR_ERR(name); | |
1da177e4 | 270 | goto error; |
0cb409d9 | 271 | } |
1da177e4 LT |
272 | } |
273 | ||
274 | /* join the session */ | |
275 | ret = join_session_keyring(name); | |
0d54ee1c | 276 | kfree(name); |
1da177e4 | 277 | |
c5b60b5e | 278 | error: |
1da177e4 LT |
279 | return ret; |
280 | ||
281 | } /* end keyctl_join_session_keyring() */ | |
282 | ||
283 | /*****************************************************************************/ | |
284 | /* | |
285 | * update a key's data payload | |
286 | * - the key must be writable | |
287 | * - implements keyctl(KEYCTL_UPDATE) | |
288 | */ | |
289 | long keyctl_update_key(key_serial_t id, | |
290 | const void __user *_payload, | |
291 | size_t plen) | |
292 | { | |
664cceb0 | 293 | key_ref_t key_ref; |
1da177e4 LT |
294 | void *payload; |
295 | long ret; | |
296 | ||
297 | ret = -EINVAL; | |
298 | if (plen > PAGE_SIZE) | |
299 | goto error; | |
300 | ||
301 | /* pull the payload in if one was supplied */ | |
302 | payload = NULL; | |
303 | if (_payload) { | |
304 | ret = -ENOMEM; | |
305 | payload = kmalloc(plen, GFP_KERNEL); | |
306 | if (!payload) | |
307 | goto error; | |
308 | ||
309 | ret = -EFAULT; | |
310 | if (copy_from_user(payload, _payload, plen) != 0) | |
311 | goto error2; | |
312 | } | |
313 | ||
314 | /* find the target key (which must be writable) */ | |
5593122e | 315 | key_ref = lookup_user_key(id, 0, KEY_WRITE); |
664cceb0 DH |
316 | if (IS_ERR(key_ref)) { |
317 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
318 | goto error2; |
319 | } | |
320 | ||
321 | /* update the key */ | |
664cceb0 | 322 | ret = key_update(key_ref, payload, plen); |
1da177e4 | 323 | |
664cceb0 | 324 | key_ref_put(key_ref); |
c5b60b5e | 325 | error2: |
1da177e4 | 326 | kfree(payload); |
c5b60b5e | 327 | error: |
1da177e4 LT |
328 | return ret; |
329 | ||
330 | } /* end keyctl_update_key() */ | |
331 | ||
332 | /*****************************************************************************/ | |
333 | /* | |
334 | * revoke a key | |
335 | * - the key must be writable | |
336 | * - implements keyctl(KEYCTL_REVOKE) | |
337 | */ | |
338 | long keyctl_revoke_key(key_serial_t id) | |
339 | { | |
664cceb0 | 340 | key_ref_t key_ref; |
1da177e4 LT |
341 | long ret; |
342 | ||
5593122e | 343 | key_ref = lookup_user_key(id, 0, KEY_WRITE); |
664cceb0 DH |
344 | if (IS_ERR(key_ref)) { |
345 | ret = PTR_ERR(key_ref); | |
0c2c9a3f DH |
346 | if (ret != -EACCES) |
347 | goto error; | |
348 | key_ref = lookup_user_key(id, 0, KEY_SETATTR); | |
349 | if (IS_ERR(key_ref)) { | |
350 | ret = PTR_ERR(key_ref); | |
351 | goto error; | |
352 | } | |
1da177e4 LT |
353 | } |
354 | ||
664cceb0 | 355 | key_revoke(key_ref_to_ptr(key_ref)); |
1da177e4 LT |
356 | ret = 0; |
357 | ||
664cceb0 | 358 | key_ref_put(key_ref); |
c5b60b5e | 359 | error: |
1260f801 | 360 | return ret; |
1da177e4 LT |
361 | |
362 | } /* end keyctl_revoke_key() */ | |
363 | ||
364 | /*****************************************************************************/ | |
365 | /* | |
366 | * clear the specified process keyring | |
367 | * - the keyring must be writable | |
368 | * - implements keyctl(KEYCTL_CLEAR) | |
369 | */ | |
370 | long keyctl_keyring_clear(key_serial_t ringid) | |
371 | { | |
664cceb0 | 372 | key_ref_t keyring_ref; |
1da177e4 LT |
373 | long ret; |
374 | ||
5593122e | 375 | keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); |
664cceb0 DH |
376 | if (IS_ERR(keyring_ref)) { |
377 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
378 | goto error; |
379 | } | |
380 | ||
664cceb0 | 381 | ret = keyring_clear(key_ref_to_ptr(keyring_ref)); |
1da177e4 | 382 | |
664cceb0 | 383 | key_ref_put(keyring_ref); |
c5b60b5e | 384 | error: |
1da177e4 LT |
385 | return ret; |
386 | ||
387 | } /* end keyctl_keyring_clear() */ | |
388 | ||
389 | /*****************************************************************************/ | |
390 | /* | |
391 | * link a key into a keyring | |
392 | * - the keyring must be writable | |
393 | * - the key must be linkable | |
394 | * - implements keyctl(KEYCTL_LINK) | |
395 | */ | |
396 | long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) | |
397 | { | |
664cceb0 | 398 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
399 | long ret; |
400 | ||
5593122e | 401 | keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); |
664cceb0 DH |
402 | if (IS_ERR(keyring_ref)) { |
403 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
404 | goto error; |
405 | } | |
406 | ||
5593122e | 407 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_LINK); |
664cceb0 DH |
408 | if (IS_ERR(key_ref)) { |
409 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
410 | goto error2; |
411 | } | |
412 | ||
664cceb0 | 413 | ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); |
1da177e4 | 414 | |
664cceb0 | 415 | key_ref_put(key_ref); |
c5b60b5e | 416 | error2: |
664cceb0 | 417 | key_ref_put(keyring_ref); |
c5b60b5e | 418 | error: |
1da177e4 LT |
419 | return ret; |
420 | ||
421 | } /* end keyctl_keyring_link() */ | |
422 | ||
423 | /*****************************************************************************/ | |
424 | /* | |
425 | * unlink the first attachment of a key from a keyring | |
426 | * - the keyring must be writable | |
427 | * - we don't need any permissions on the key | |
428 | * - implements keyctl(KEYCTL_UNLINK) | |
429 | */ | |
430 | long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) | |
431 | { | |
664cceb0 | 432 | key_ref_t keyring_ref, key_ref; |
1da177e4 LT |
433 | long ret; |
434 | ||
5593122e | 435 | keyring_ref = lookup_user_key(ringid, 0, KEY_WRITE); |
664cceb0 DH |
436 | if (IS_ERR(keyring_ref)) { |
437 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
438 | goto error; |
439 | } | |
440 | ||
5593122e | 441 | key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0); |
664cceb0 DH |
442 | if (IS_ERR(key_ref)) { |
443 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
444 | goto error2; |
445 | } | |
446 | ||
664cceb0 | 447 | ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); |
1da177e4 | 448 | |
664cceb0 | 449 | key_ref_put(key_ref); |
c5b60b5e | 450 | error2: |
664cceb0 | 451 | key_ref_put(keyring_ref); |
c5b60b5e | 452 | error: |
1da177e4 LT |
453 | return ret; |
454 | ||
455 | } /* end keyctl_keyring_unlink() */ | |
456 | ||
457 | /*****************************************************************************/ | |
458 | /* | |
459 | * describe a user key | |
460 | * - the key must have view permission | |
461 | * - if there's a buffer, we place up to buflen bytes of data into it | |
462 | * - unless there's an error, we return the amount of description available, | |
463 | * irrespective of how much we may have copied | |
464 | * - the description is formatted thus: | |
465 | * type;uid;gid;perm;description<NUL> | |
466 | * - implements keyctl(KEYCTL_DESCRIBE) | |
467 | */ | |
468 | long keyctl_describe_key(key_serial_t keyid, | |
469 | char __user *buffer, | |
470 | size_t buflen) | |
471 | { | |
3e30148c | 472 | struct key *key, *instkey; |
664cceb0 | 473 | key_ref_t key_ref; |
1da177e4 LT |
474 | char *tmpbuf; |
475 | long ret; | |
476 | ||
5593122e | 477 | key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW); |
664cceb0 | 478 | if (IS_ERR(key_ref)) { |
3e30148c DH |
479 | /* viewing a key under construction is permitted if we have the |
480 | * authorisation token handy */ | |
664cceb0 | 481 | if (PTR_ERR(key_ref) == -EACCES) { |
3e30148c DH |
482 | instkey = key_get_instantiation_authkey(keyid); |
483 | if (!IS_ERR(instkey)) { | |
484 | key_put(instkey); | |
8bbf4976 | 485 | key_ref = lookup_user_key(keyid, |
5593122e DH |
486 | KEY_LOOKUP_PARTIAL, |
487 | 0); | |
664cceb0 | 488 | if (!IS_ERR(key_ref)) |
3e30148c DH |
489 | goto okay; |
490 | } | |
491 | } | |
492 | ||
664cceb0 | 493 | ret = PTR_ERR(key_ref); |
1da177e4 LT |
494 | goto error; |
495 | } | |
496 | ||
3e30148c | 497 | okay: |
1da177e4 LT |
498 | /* calculate how much description we're going to return */ |
499 | ret = -ENOMEM; | |
500 | tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
501 | if (!tmpbuf) | |
502 | goto error2; | |
503 | ||
664cceb0 DH |
504 | key = key_ref_to_ptr(key_ref); |
505 | ||
1da177e4 | 506 | ret = snprintf(tmpbuf, PAGE_SIZE - 1, |
664cceb0 DH |
507 | "%s;%d;%d;%08x;%s", |
508 | key_ref_to_ptr(key_ref)->type->name, | |
509 | key_ref_to_ptr(key_ref)->uid, | |
510 | key_ref_to_ptr(key_ref)->gid, | |
511 | key_ref_to_ptr(key_ref)->perm, | |
512 | key_ref_to_ptr(key_ref)->description ? | |
513 | key_ref_to_ptr(key_ref)->description : "" | |
1da177e4 LT |
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); | |
c5b60b5e | 532 | error2: |
664cceb0 | 533 | key_ref_put(key_ref); |
c5b60b5e | 534 | error: |
1da177e4 LT |
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; | |
664cceb0 | 555 | key_ref_t keyring_ref, key_ref, dest_ref; |
1da177e4 | 556 | char type[32], *description; |
0cb409d9 | 557 | long ret; |
1da177e4 LT |
558 | |
559 | /* pull the type and description into kernel space */ | |
0cb409d9 | 560 | ret = key_get_type_from_user(type, _type, sizeof(type)); |
1da177e4 LT |
561 | if (ret < 0) |
562 | goto error; | |
1da177e4 | 563 | |
0cb409d9 DA |
564 | description = strndup_user(_description, PAGE_SIZE); |
565 | if (IS_ERR(description)) { | |
566 | ret = PTR_ERR(description); | |
1da177e4 | 567 | goto error; |
0cb409d9 | 568 | } |
1da177e4 LT |
569 | |
570 | /* get the keyring at which to begin the search */ | |
5593122e | 571 | keyring_ref = lookup_user_key(ringid, 0, KEY_SEARCH); |
664cceb0 DH |
572 | if (IS_ERR(keyring_ref)) { |
573 | ret = PTR_ERR(keyring_ref); | |
1da177e4 LT |
574 | goto error2; |
575 | } | |
576 | ||
577 | /* get the destination keyring if specified */ | |
664cceb0 | 578 | dest_ref = NULL; |
1da177e4 | 579 | if (destringid) { |
5593122e DH |
580 | dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, |
581 | KEY_WRITE); | |
664cceb0 DH |
582 | if (IS_ERR(dest_ref)) { |
583 | ret = PTR_ERR(dest_ref); | |
1da177e4 LT |
584 | goto error3; |
585 | } | |
586 | } | |
587 | ||
588 | /* find the key type */ | |
589 | ktype = key_type_lookup(type); | |
590 | if (IS_ERR(ktype)) { | |
591 | ret = PTR_ERR(ktype); | |
592 | goto error4; | |
593 | } | |
594 | ||
595 | /* do the search */ | |
664cceb0 DH |
596 | key_ref = keyring_search(keyring_ref, ktype, description); |
597 | if (IS_ERR(key_ref)) { | |
598 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
599 | |
600 | /* treat lack or presence of a negative key the same */ | |
601 | if (ret == -EAGAIN) | |
602 | ret = -ENOKEY; | |
603 | goto error5; | |
604 | } | |
605 | ||
606 | /* link the resulting key to the destination keyring if we can */ | |
664cceb0 | 607 | if (dest_ref) { |
29db9190 DH |
608 | ret = key_permission(key_ref, KEY_LINK); |
609 | if (ret < 0) | |
1da177e4 LT |
610 | goto error6; |
611 | ||
664cceb0 | 612 | ret = key_link(key_ref_to_ptr(dest_ref), key_ref_to_ptr(key_ref)); |
1da177e4 LT |
613 | if (ret < 0) |
614 | goto error6; | |
615 | } | |
616 | ||
664cceb0 | 617 | ret = key_ref_to_ptr(key_ref)->serial; |
1da177e4 | 618 | |
c5b60b5e | 619 | error6: |
664cceb0 | 620 | key_ref_put(key_ref); |
c5b60b5e | 621 | error5: |
1da177e4 | 622 | key_type_put(ktype); |
c5b60b5e | 623 | error4: |
664cceb0 | 624 | key_ref_put(dest_ref); |
c5b60b5e | 625 | error3: |
664cceb0 | 626 | key_ref_put(keyring_ref); |
c5b60b5e | 627 | error2: |
1da177e4 | 628 | kfree(description); |
c5b60b5e | 629 | error: |
1da177e4 LT |
630 | return ret; |
631 | ||
632 | } /* end keyctl_keyring_search() */ | |
633 | ||
1da177e4 LT |
634 | /*****************************************************************************/ |
635 | /* | |
636 | * read a user key's payload | |
637 | * - the keyring must be readable or the key must be searchable from the | |
638 | * process's keyrings | |
639 | * - if there's a buffer, we place up to buflen bytes of data into it | |
640 | * - unless there's an error, we return the amount of data in the key, | |
641 | * irrespective of how much we may have copied | |
642 | * - implements keyctl(KEYCTL_READ) | |
643 | */ | |
644 | long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) | |
645 | { | |
664cceb0 DH |
646 | struct key *key; |
647 | key_ref_t key_ref; | |
1da177e4 LT |
648 | long ret; |
649 | ||
650 | /* find the key first */ | |
5593122e | 651 | key_ref = lookup_user_key(keyid, 0, 0); |
664cceb0 DH |
652 | if (IS_ERR(key_ref)) { |
653 | ret = -ENOKEY; | |
654 | goto error; | |
1da177e4 LT |
655 | } |
656 | ||
664cceb0 DH |
657 | key = key_ref_to_ptr(key_ref); |
658 | ||
659 | /* see if we can read it directly */ | |
29db9190 DH |
660 | ret = key_permission(key_ref, KEY_READ); |
661 | if (ret == 0) | |
664cceb0 | 662 | goto can_read_key; |
29db9190 DH |
663 | if (ret != -EACCES) |
664 | goto error; | |
664cceb0 DH |
665 | |
666 | /* we can't; see if it's searchable from this process's keyrings | |
667 | * - we automatically take account of the fact that it may be | |
668 | * dangling off an instantiation key | |
669 | */ | |
670 | if (!is_key_possessed(key_ref)) { | |
671 | ret = -EACCES; | |
672 | goto error2; | |
673 | } | |
1da177e4 LT |
674 | |
675 | /* the key is probably readable - now try to read it */ | |
c5b60b5e | 676 | can_read_key: |
1da177e4 LT |
677 | ret = key_validate(key); |
678 | if (ret == 0) { | |
679 | ret = -EOPNOTSUPP; | |
680 | if (key->type->read) { | |
681 | /* read the data with the semaphore held (since we | |
682 | * might sleep) */ | |
683 | down_read(&key->sem); | |
684 | ret = key->type->read(key, buffer, buflen); | |
685 | up_read(&key->sem); | |
686 | } | |
687 | } | |
688 | ||
c5b60b5e | 689 | error2: |
1da177e4 | 690 | key_put(key); |
c5b60b5e | 691 | error: |
1da177e4 LT |
692 | return ret; |
693 | ||
694 | } /* end keyctl_read_key() */ | |
695 | ||
696 | /*****************************************************************************/ | |
697 | /* | |
698 | * change the ownership of a key | |
699 | * - the keyring owned by the changer | |
700 | * - if the uid or gid is -1, then that parameter is not changed | |
701 | * - implements keyctl(KEYCTL_CHOWN) | |
702 | */ | |
703 | long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) | |
704 | { | |
5801649d | 705 | struct key_user *newowner, *zapowner = NULL; |
1da177e4 | 706 | struct key *key; |
664cceb0 | 707 | key_ref_t key_ref; |
1da177e4 LT |
708 | long ret; |
709 | ||
710 | ret = 0; | |
711 | if (uid == (uid_t) -1 && gid == (gid_t) -1) | |
712 | goto error; | |
713 | ||
5593122e DH |
714 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
715 | KEY_SETATTR); | |
664cceb0 DH |
716 | if (IS_ERR(key_ref)) { |
717 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
718 | goto error; |
719 | } | |
720 | ||
664cceb0 DH |
721 | key = key_ref_to_ptr(key_ref); |
722 | ||
1da177e4 LT |
723 | /* make the changes with the locks held to prevent chown/chown races */ |
724 | ret = -EACCES; | |
725 | down_write(&key->sem); | |
1da177e4 LT |
726 | |
727 | if (!capable(CAP_SYS_ADMIN)) { | |
728 | /* only the sysadmin can chown a key to some other UID */ | |
729 | if (uid != (uid_t) -1 && key->uid != uid) | |
5801649d | 730 | goto error_put; |
1da177e4 LT |
731 | |
732 | /* only the sysadmin can set the key's GID to a group other | |
733 | * than one of those that the current process subscribes to */ | |
734 | if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid)) | |
5801649d | 735 | goto error_put; |
1da177e4 LT |
736 | } |
737 | ||
5801649d | 738 | /* change the UID */ |
1da177e4 | 739 | if (uid != (uid_t) -1 && uid != key->uid) { |
5801649d | 740 | ret = -ENOMEM; |
1d1e9756 | 741 | newowner = key_user_lookup(uid, current_user_ns()); |
5801649d FT |
742 | if (!newowner) |
743 | goto error_put; | |
744 | ||
745 | /* transfer the quota burden to the new user */ | |
746 | if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { | |
0b77f5bf DH |
747 | unsigned maxkeys = (uid == 0) ? |
748 | key_quota_root_maxkeys : key_quota_maxkeys; | |
749 | unsigned maxbytes = (uid == 0) ? | |
750 | key_quota_root_maxbytes : key_quota_maxbytes; | |
751 | ||
5801649d | 752 | spin_lock(&newowner->lock); |
0b77f5bf DH |
753 | if (newowner->qnkeys + 1 >= maxkeys || |
754 | newowner->qnbytes + key->quotalen >= maxbytes || | |
755 | newowner->qnbytes + key->quotalen < | |
756 | newowner->qnbytes) | |
5801649d FT |
757 | goto quota_overrun; |
758 | ||
759 | newowner->qnkeys++; | |
760 | newowner->qnbytes += key->quotalen; | |
761 | spin_unlock(&newowner->lock); | |
762 | ||
763 | spin_lock(&key->user->lock); | |
764 | key->user->qnkeys--; | |
765 | key->user->qnbytes -= key->quotalen; | |
766 | spin_unlock(&key->user->lock); | |
767 | } | |
768 | ||
769 | atomic_dec(&key->user->nkeys); | |
770 | atomic_inc(&newowner->nkeys); | |
771 | ||
772 | if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { | |
773 | atomic_dec(&key->user->nikeys); | |
774 | atomic_inc(&newowner->nikeys); | |
775 | } | |
776 | ||
777 | zapowner = key->user; | |
778 | key->user = newowner; | |
779 | key->uid = uid; | |
1da177e4 LT |
780 | } |
781 | ||
782 | /* change the GID */ | |
783 | if (gid != (gid_t) -1) | |
784 | key->gid = gid; | |
785 | ||
786 | ret = 0; | |
787 | ||
5801649d | 788 | error_put: |
1da177e4 LT |
789 | up_write(&key->sem); |
790 | key_put(key); | |
5801649d FT |
791 | if (zapowner) |
792 | key_user_put(zapowner); | |
793 | error: | |
1da177e4 LT |
794 | return ret; |
795 | ||
5801649d FT |
796 | quota_overrun: |
797 | spin_unlock(&newowner->lock); | |
798 | zapowner = newowner; | |
799 | ret = -EDQUOT; | |
800 | goto error_put; | |
801 | ||
1da177e4 LT |
802 | } /* end keyctl_chown_key() */ |
803 | ||
804 | /*****************************************************************************/ | |
805 | /* | |
806 | * change the permission mask on a key | |
807 | * - the keyring owned by the changer | |
808 | * - implements keyctl(KEYCTL_SETPERM) | |
809 | */ | |
810 | long keyctl_setperm_key(key_serial_t id, key_perm_t perm) | |
811 | { | |
812 | struct key *key; | |
664cceb0 | 813 | key_ref_t key_ref; |
1da177e4 LT |
814 | long ret; |
815 | ||
816 | ret = -EINVAL; | |
664cceb0 | 817 | if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) |
1da177e4 LT |
818 | goto error; |
819 | ||
5593122e DH |
820 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
821 | KEY_SETATTR); | |
664cceb0 DH |
822 | if (IS_ERR(key_ref)) { |
823 | ret = PTR_ERR(key_ref); | |
1da177e4 LT |
824 | goto error; |
825 | } | |
826 | ||
664cceb0 DH |
827 | key = key_ref_to_ptr(key_ref); |
828 | ||
76d8aeab | 829 | /* make the changes with the locks held to prevent chown/chmod races */ |
1da177e4 LT |
830 | ret = -EACCES; |
831 | down_write(&key->sem); | |
1da177e4 | 832 | |
76d8aeab | 833 | /* if we're not the sysadmin, we can only change a key that we own */ |
47d804bf | 834 | if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) { |
76d8aeab DH |
835 | key->perm = perm; |
836 | ret = 0; | |
837 | } | |
1da177e4 | 838 | |
1da177e4 LT |
839 | up_write(&key->sem); |
840 | key_put(key); | |
76d8aeab | 841 | error: |
1da177e4 LT |
842 | return ret; |
843 | ||
844 | } /* end keyctl_setperm_key() */ | |
845 | ||
8bbf4976 DH |
846 | /* |
847 | * get the destination keyring for instantiation | |
848 | */ | |
849 | static long get_instantiation_keyring(key_serial_t ringid, | |
850 | struct request_key_auth *rka, | |
851 | struct key **_dest_keyring) | |
852 | { | |
853 | key_ref_t dkref; | |
854 | ||
eca1bf5b DH |
855 | *_dest_keyring = NULL; |
856 | ||
8bbf4976 | 857 | /* just return a NULL pointer if we weren't asked to make a link */ |
eca1bf5b | 858 | if (ringid == 0) |
8bbf4976 | 859 | return 0; |
8bbf4976 DH |
860 | |
861 | /* if a specific keyring is nominated by ID, then use that */ | |
862 | if (ringid > 0) { | |
5593122e | 863 | dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_WRITE); |
8bbf4976 DH |
864 | if (IS_ERR(dkref)) |
865 | return PTR_ERR(dkref); | |
866 | *_dest_keyring = key_ref_to_ptr(dkref); | |
867 | return 0; | |
868 | } | |
869 | ||
870 | if (ringid == KEY_SPEC_REQKEY_AUTH_KEY) | |
871 | return -EINVAL; | |
872 | ||
873 | /* otherwise specify the destination keyring recorded in the | |
874 | * authorisation key (any KEY_SPEC_*_KEYRING) */ | |
875 | if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) { | |
21279cfa | 876 | *_dest_keyring = key_get(rka->dest_keyring); |
8bbf4976 DH |
877 | return 0; |
878 | } | |
879 | ||
880 | return -ENOKEY; | |
881 | } | |
882 | ||
d84f4f99 DH |
883 | /* |
884 | * change the request_key authorisation key on the current process | |
885 | */ | |
886 | static int keyctl_change_reqkey_auth(struct key *key) | |
887 | { | |
888 | struct cred *new; | |
889 | ||
890 | new = prepare_creds(); | |
891 | if (!new) | |
892 | return -ENOMEM; | |
893 | ||
894 | key_put(new->request_key_auth); | |
895 | new->request_key_auth = key_get(key); | |
896 | ||
897 | return commit_creds(new); | |
898 | } | |
899 | ||
1da177e4 LT |
900 | /*****************************************************************************/ |
901 | /* | |
902 | * instantiate the key with the specified payload, and, if one is given, link | |
903 | * the key into the keyring | |
904 | */ | |
905 | long keyctl_instantiate_key(key_serial_t id, | |
906 | const void __user *_payload, | |
907 | size_t plen, | |
908 | key_serial_t ringid) | |
909 | { | |
d84f4f99 | 910 | const struct cred *cred = current_cred(); |
3e30148c | 911 | struct request_key_auth *rka; |
8bbf4976 | 912 | struct key *instkey, *dest_keyring; |
1da177e4 LT |
913 | void *payload; |
914 | long ret; | |
38bbca6b | 915 | bool vm = false; |
1da177e4 | 916 | |
d84f4f99 DH |
917 | kenter("%d,,%zu,%d", id, plen, ringid); |
918 | ||
1da177e4 | 919 | ret = -EINVAL; |
38bbca6b | 920 | if (plen > 1024 * 1024 - 1) |
1da177e4 LT |
921 | goto error; |
922 | ||
b5f545c8 DH |
923 | /* the appropriate instantiation authorisation key must have been |
924 | * assumed before calling this */ | |
925 | ret = -EPERM; | |
d84f4f99 | 926 | instkey = cred->request_key_auth; |
b5f545c8 DH |
927 | if (!instkey) |
928 | goto error; | |
929 | ||
930 | rka = instkey->payload.data; | |
931 | if (rka->target_key->serial != id) | |
932 | goto error; | |
933 | ||
1da177e4 LT |
934 | /* pull the payload in if one was supplied */ |
935 | payload = NULL; | |
936 | ||
937 | if (_payload) { | |
938 | ret = -ENOMEM; | |
939 | payload = kmalloc(plen, GFP_KERNEL); | |
38bbca6b DH |
940 | if (!payload) { |
941 | if (plen <= PAGE_SIZE) | |
942 | goto error; | |
943 | vm = true; | |
944 | payload = vmalloc(plen); | |
945 | if (!payload) | |
946 | goto error; | |
947 | } | |
1da177e4 LT |
948 | |
949 | ret = -EFAULT; | |
950 | if (copy_from_user(payload, _payload, plen) != 0) | |
951 | goto error2; | |
952 | } | |
953 | ||
3e30148c DH |
954 | /* find the destination keyring amongst those belonging to the |
955 | * requesting task */ | |
8bbf4976 DH |
956 | ret = get_instantiation_keyring(ringid, rka, &dest_keyring); |
957 | if (ret < 0) | |
958 | goto error2; | |
1da177e4 LT |
959 | |
960 | /* instantiate the key and link it into a keyring */ | |
3e30148c | 961 | ret = key_instantiate_and_link(rka->target_key, payload, plen, |
8bbf4976 | 962 | dest_keyring, instkey); |
1da177e4 | 963 | |
8bbf4976 | 964 | key_put(dest_keyring); |
b5f545c8 DH |
965 | |
966 | /* discard the assumed authority if it's just been disabled by | |
967 | * instantiation of the key */ | |
d84f4f99 DH |
968 | if (ret == 0) |
969 | keyctl_change_reqkey_auth(NULL); | |
b5f545c8 DH |
970 | |
971 | error2: | |
38bbca6b DH |
972 | if (!vm) |
973 | kfree(payload); | |
974 | else | |
975 | vfree(payload); | |
b5f545c8 | 976 | error: |
1da177e4 LT |
977 | return ret; |
978 | ||
979 | } /* end keyctl_instantiate_key() */ | |
980 | ||
981 | /*****************************************************************************/ | |
982 | /* | |
983 | * negatively instantiate the key with the given timeout (in seconds), and, if | |
984 | * one is given, link the key into the keyring | |
985 | */ | |
986 | long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) | |
987 | { | |
d84f4f99 | 988 | const struct cred *cred = current_cred(); |
3e30148c | 989 | struct request_key_auth *rka; |
8bbf4976 | 990 | struct key *instkey, *dest_keyring; |
1da177e4 LT |
991 | long ret; |
992 | ||
d84f4f99 DH |
993 | kenter("%d,%u,%d", id, timeout, ringid); |
994 | ||
b5f545c8 DH |
995 | /* the appropriate instantiation authorisation key must have been |
996 | * assumed before calling this */ | |
997 | ret = -EPERM; | |
d84f4f99 | 998 | instkey = cred->request_key_auth; |
b5f545c8 | 999 | if (!instkey) |
1da177e4 | 1000 | goto error; |
1da177e4 | 1001 | |
3e30148c | 1002 | rka = instkey->payload.data; |
b5f545c8 DH |
1003 | if (rka->target_key->serial != id) |
1004 | goto error; | |
3e30148c | 1005 | |
1da177e4 LT |
1006 | /* find the destination keyring if present (which must also be |
1007 | * writable) */ | |
8bbf4976 DH |
1008 | ret = get_instantiation_keyring(ringid, rka, &dest_keyring); |
1009 | if (ret < 0) | |
1010 | goto error; | |
1da177e4 LT |
1011 | |
1012 | /* instantiate the key and link it into a keyring */ | |
664cceb0 | 1013 | ret = key_negate_and_link(rka->target_key, timeout, |
8bbf4976 | 1014 | dest_keyring, instkey); |
1da177e4 | 1015 | |
8bbf4976 | 1016 | key_put(dest_keyring); |
b5f545c8 DH |
1017 | |
1018 | /* discard the assumed authority if it's just been disabled by | |
1019 | * instantiation of the key */ | |
d84f4f99 DH |
1020 | if (ret == 0) |
1021 | keyctl_change_reqkey_auth(NULL); | |
b5f545c8 DH |
1022 | |
1023 | error: | |
1da177e4 LT |
1024 | return ret; |
1025 | ||
1026 | } /* end keyctl_negate_key() */ | |
1027 | ||
3e30148c DH |
1028 | /*****************************************************************************/ |
1029 | /* | |
1030 | * set the default keyring in which request_key() will cache keys | |
1031 | * - return the old setting | |
1032 | */ | |
1033 | long keyctl_set_reqkey_keyring(int reqkey_defl) | |
1034 | { | |
d84f4f99 DH |
1035 | struct cred *new; |
1036 | int ret, old_setting; | |
1037 | ||
1038 | old_setting = current_cred_xxx(jit_keyring); | |
1039 | ||
1040 | if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE) | |
1041 | return old_setting; | |
1042 | ||
1043 | new = prepare_creds(); | |
1044 | if (!new) | |
1045 | return -ENOMEM; | |
3e30148c DH |
1046 | |
1047 | switch (reqkey_defl) { | |
1048 | case KEY_REQKEY_DEFL_THREAD_KEYRING: | |
d84f4f99 | 1049 | ret = install_thread_keyring_to_cred(new); |
3e30148c | 1050 | if (ret < 0) |
d84f4f99 | 1051 | goto error; |
3e30148c DH |
1052 | goto set; |
1053 | ||
1054 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: | |
d84f4f99 DH |
1055 | ret = install_process_keyring_to_cred(new); |
1056 | if (ret < 0) { | |
1057 | if (ret != -EEXIST) | |
1058 | goto error; | |
1059 | ret = 0; | |
1060 | } | |
1061 | goto set; | |
3e30148c DH |
1062 | |
1063 | case KEY_REQKEY_DEFL_DEFAULT: | |
1064 | case KEY_REQKEY_DEFL_SESSION_KEYRING: | |
1065 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
1066 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: | |
d84f4f99 DH |
1067 | case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: |
1068 | goto set; | |
3e30148c DH |
1069 | |
1070 | case KEY_REQKEY_DEFL_NO_CHANGE: | |
3e30148c DH |
1071 | case KEY_REQKEY_DEFL_GROUP_KEYRING: |
1072 | default: | |
d84f4f99 DH |
1073 | ret = -EINVAL; |
1074 | goto error; | |
3e30148c DH |
1075 | } |
1076 | ||
d84f4f99 DH |
1077 | set: |
1078 | new->jit_keyring = reqkey_defl; | |
1079 | commit_creds(new); | |
1080 | return old_setting; | |
1081 | error: | |
1082 | abort_creds(new); | |
4303ef19 | 1083 | return ret; |
d84f4f99 | 1084 | |
3e30148c DH |
1085 | } /* end keyctl_set_reqkey_keyring() */ |
1086 | ||
017679c4 DH |
1087 | /*****************************************************************************/ |
1088 | /* | |
1089 | * set or clear the timeout for a key | |
1090 | */ | |
1091 | long keyctl_set_timeout(key_serial_t id, unsigned timeout) | |
1092 | { | |
1093 | struct timespec now; | |
9156235b | 1094 | struct key *key, *instkey; |
017679c4 DH |
1095 | key_ref_t key_ref; |
1096 | time_t expiry; | |
1097 | long ret; | |
1098 | ||
5593122e DH |
1099 | key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, |
1100 | KEY_SETATTR); | |
017679c4 | 1101 | if (IS_ERR(key_ref)) { |
9156235b DH |
1102 | /* setting the timeout on a key under construction is permitted |
1103 | * if we have the authorisation token handy */ | |
1104 | if (PTR_ERR(key_ref) == -EACCES) { | |
1105 | instkey = key_get_instantiation_authkey(id); | |
1106 | if (!IS_ERR(instkey)) { | |
1107 | key_put(instkey); | |
1108 | key_ref = lookup_user_key(id, | |
1109 | KEY_LOOKUP_PARTIAL, | |
1110 | 0); | |
1111 | if (!IS_ERR(key_ref)) | |
1112 | goto okay; | |
1113 | } | |
1114 | } | |
1115 | ||
017679c4 DH |
1116 | ret = PTR_ERR(key_ref); |
1117 | goto error; | |
1118 | } | |
1119 | ||
9156235b | 1120 | okay: |
017679c4 DH |
1121 | key = key_ref_to_ptr(key_ref); |
1122 | ||
1123 | /* make the changes with the locks held to prevent races */ | |
1124 | down_write(&key->sem); | |
1125 | ||
1126 | expiry = 0; | |
1127 | if (timeout > 0) { | |
1128 | now = current_kernel_time(); | |
1129 | expiry = now.tv_sec + timeout; | |
1130 | } | |
1131 | ||
1132 | key->expiry = expiry; | |
c08ef808 | 1133 | key_schedule_gc(key->expiry + key_gc_delay); |
017679c4 DH |
1134 | |
1135 | up_write(&key->sem); | |
1136 | key_put(key); | |
1137 | ||
1138 | ret = 0; | |
1139 | error: | |
1140 | return ret; | |
1141 | ||
1142 | } /* end keyctl_set_timeout() */ | |
1143 | ||
b5f545c8 DH |
1144 | /*****************************************************************************/ |
1145 | /* | |
1146 | * assume the authority to instantiate the specified key | |
1147 | */ | |
1148 | long keyctl_assume_authority(key_serial_t id) | |
1149 | { | |
1150 | struct key *authkey; | |
1151 | long ret; | |
1152 | ||
1153 | /* special key IDs aren't permitted */ | |
1154 | ret = -EINVAL; | |
1155 | if (id < 0) | |
1156 | goto error; | |
1157 | ||
1158 | /* we divest ourselves of authority if given an ID of 0 */ | |
1159 | if (id == 0) { | |
d84f4f99 | 1160 | ret = keyctl_change_reqkey_auth(NULL); |
b5f545c8 DH |
1161 | goto error; |
1162 | } | |
1163 | ||
1164 | /* attempt to assume the authority temporarily granted to us whilst we | |
1165 | * instantiate the specified key | |
1166 | * - the authorisation key must be in the current task's keyrings | |
1167 | * somewhere | |
1168 | */ | |
1169 | authkey = key_get_instantiation_authkey(id); | |
1170 | if (IS_ERR(authkey)) { | |
1171 | ret = PTR_ERR(authkey); | |
1172 | goto error; | |
1173 | } | |
1174 | ||
d84f4f99 DH |
1175 | ret = keyctl_change_reqkey_auth(authkey); |
1176 | if (ret < 0) | |
1177 | goto error; | |
1178 | key_put(authkey); | |
b5f545c8 | 1179 | |
d84f4f99 | 1180 | ret = authkey->serial; |
b5f545c8 DH |
1181 | error: |
1182 | return ret; | |
1183 | ||
1184 | } /* end keyctl_assume_authority() */ | |
1185 | ||
70a5bb72 DH |
1186 | /* |
1187 | * get the security label of a key | |
1188 | * - the key must grant us view permission | |
1189 | * - if there's a buffer, we place up to buflen bytes of data into it | |
1190 | * - unless there's an error, we return the amount of information available, | |
1191 | * irrespective of how much we may have copied (including the terminal NUL) | |
1192 | * - implements keyctl(KEYCTL_GET_SECURITY) | |
1193 | */ | |
1194 | long keyctl_get_security(key_serial_t keyid, | |
1195 | char __user *buffer, | |
1196 | size_t buflen) | |
1197 | { | |
1198 | struct key *key, *instkey; | |
1199 | key_ref_t key_ref; | |
1200 | char *context; | |
1201 | long ret; | |
1202 | ||
5593122e | 1203 | key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_VIEW); |
70a5bb72 DH |
1204 | if (IS_ERR(key_ref)) { |
1205 | if (PTR_ERR(key_ref) != -EACCES) | |
1206 | return PTR_ERR(key_ref); | |
1207 | ||
1208 | /* viewing a key under construction is also permitted if we | |
1209 | * have the authorisation token handy */ | |
1210 | instkey = key_get_instantiation_authkey(keyid); | |
1211 | if (IS_ERR(instkey)) | |
fa1cc7b5 | 1212 | return PTR_ERR(instkey); |
70a5bb72 DH |
1213 | key_put(instkey); |
1214 | ||
5593122e | 1215 | key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0); |
70a5bb72 DH |
1216 | if (IS_ERR(key_ref)) |
1217 | return PTR_ERR(key_ref); | |
1218 | } | |
1219 | ||
1220 | key = key_ref_to_ptr(key_ref); | |
1221 | ret = security_key_getsecurity(key, &context); | |
1222 | if (ret == 0) { | |
1223 | /* if no information was returned, give userspace an empty | |
1224 | * string */ | |
1225 | ret = 1; | |
1226 | if (buffer && buflen > 0 && | |
1227 | copy_to_user(buffer, "", 1) != 0) | |
1228 | ret = -EFAULT; | |
1229 | } else if (ret > 0) { | |
1230 | /* return as much data as there's room for */ | |
1231 | if (buffer && buflen > 0) { | |
1232 | if (buflen > ret) | |
1233 | buflen = ret; | |
1234 | ||
1235 | if (copy_to_user(buffer, context, buflen) != 0) | |
1236 | ret = -EFAULT; | |
1237 | } | |
1238 | ||
1239 | kfree(context); | |
1240 | } | |
1241 | ||
1242 | key_ref_put(key_ref); | |
1243 | return ret; | |
1244 | } | |
1245 | ||
ee18d64c DH |
1246 | /* |
1247 | * attempt to install the calling process's session keyring on the process's | |
1248 | * parent process | |
1249 | * - the keyring must exist and must grant us LINK permission | |
1250 | * - implements keyctl(KEYCTL_SESSION_TO_PARENT) | |
1251 | */ | |
1252 | long keyctl_session_to_parent(void) | |
1253 | { | |
a00ae4d2 | 1254 | #ifdef TIF_NOTIFY_RESUME |
ee18d64c DH |
1255 | struct task_struct *me, *parent; |
1256 | const struct cred *mycred, *pcred; | |
1257 | struct cred *cred, *oldcred; | |
1258 | key_ref_t keyring_r; | |
1259 | int ret; | |
1260 | ||
1261 | keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK); | |
1262 | if (IS_ERR(keyring_r)) | |
1263 | return PTR_ERR(keyring_r); | |
1264 | ||
1265 | /* our parent is going to need a new cred struct, a new tgcred struct | |
1266 | * and new security data, so we allocate them here to prevent ENOMEM in | |
1267 | * our parent */ | |
1268 | ret = -ENOMEM; | |
1269 | cred = cred_alloc_blank(); | |
1270 | if (!cred) | |
1271 | goto error_keyring; | |
1272 | ||
1273 | cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r); | |
1274 | keyring_r = NULL; | |
1275 | ||
1276 | me = current; | |
1277 | write_lock_irq(&tasklist_lock); | |
1278 | ||
1279 | parent = me->real_parent; | |
1280 | ret = -EPERM; | |
1281 | ||
1282 | /* the parent mustn't be init and mustn't be a kernel thread */ | |
1283 | if (parent->pid <= 1 || !parent->mm) | |
1284 | goto not_permitted; | |
1285 | ||
1286 | /* the parent must be single threaded */ | |
dd98acf7 | 1287 | if (!thread_group_empty(parent)) |
ee18d64c DH |
1288 | goto not_permitted; |
1289 | ||
1290 | /* the parent and the child must have different session keyrings or | |
1291 | * there's no point */ | |
1292 | mycred = current_cred(); | |
1293 | pcred = __task_cred(parent); | |
1294 | if (mycred == pcred || | |
1295 | mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) | |
1296 | goto already_same; | |
1297 | ||
1298 | /* the parent must have the same effective ownership and mustn't be | |
1299 | * SUID/SGID */ | |
c5b60b5e | 1300 | if (pcred->uid != mycred->euid || |
ee18d64c DH |
1301 | pcred->euid != mycred->euid || |
1302 | pcred->suid != mycred->euid || | |
c5b60b5e | 1303 | pcred->gid != mycred->egid || |
ee18d64c DH |
1304 | pcred->egid != mycred->egid || |
1305 | pcred->sgid != mycred->egid) | |
1306 | goto not_permitted; | |
1307 | ||
1308 | /* the keyrings must have the same UID */ | |
c5b60b5e | 1309 | if (pcred->tgcred->session_keyring->uid != mycred->euid || |
ee18d64c DH |
1310 | mycred->tgcred->session_keyring->uid != mycred->euid) |
1311 | goto not_permitted; | |
1312 | ||
ee18d64c DH |
1313 | /* if there's an already pending keyring replacement, then we replace |
1314 | * that */ | |
1315 | oldcred = parent->replacement_session_keyring; | |
1316 | ||
1317 | /* the replacement session keyring is applied just prior to userspace | |
1318 | * restarting */ | |
1319 | parent->replacement_session_keyring = cred; | |
1320 | cred = NULL; | |
1321 | set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME); | |
1322 | ||
1323 | write_unlock_irq(&tasklist_lock); | |
1324 | if (oldcred) | |
1325 | put_cred(oldcred); | |
1326 | return 0; | |
1327 | ||
1328 | already_same: | |
1329 | ret = 0; | |
1330 | not_permitted: | |
5c84342a | 1331 | write_unlock_irq(&tasklist_lock); |
ee18d64c DH |
1332 | put_cred(cred); |
1333 | return ret; | |
1334 | ||
1335 | error_keyring: | |
1336 | key_ref_put(keyring_r); | |
1337 | return ret; | |
a00ae4d2 GU |
1338 | |
1339 | #else /* !TIF_NOTIFY_RESUME */ | |
1340 | /* | |
1341 | * To be removed when TIF_NOTIFY_RESUME has been implemented on | |
1342 | * m68k/xtensa | |
1343 | */ | |
1344 | #warning TIF_NOTIFY_RESUME not implemented | |
1345 | return -EOPNOTSUPP; | |
1346 | #endif /* !TIF_NOTIFY_RESUME */ | |
ee18d64c DH |
1347 | } |
1348 | ||
1da177e4 LT |
1349 | /*****************************************************************************/ |
1350 | /* | |
1351 | * the key control system call | |
1352 | */ | |
938bb9f5 HC |
1353 | SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, |
1354 | unsigned long, arg4, unsigned long, arg5) | |
1da177e4 LT |
1355 | { |
1356 | switch (option) { | |
1357 | case KEYCTL_GET_KEYRING_ID: | |
1358 | return keyctl_get_keyring_ID((key_serial_t) arg2, | |
1359 | (int) arg3); | |
1360 | ||
1361 | case KEYCTL_JOIN_SESSION_KEYRING: | |
1362 | return keyctl_join_session_keyring((const char __user *) arg2); | |
1363 | ||
1364 | case KEYCTL_UPDATE: | |
1365 | return keyctl_update_key((key_serial_t) arg2, | |
1366 | (const void __user *) arg3, | |
1367 | (size_t) arg4); | |
1368 | ||
1369 | case KEYCTL_REVOKE: | |
1370 | return keyctl_revoke_key((key_serial_t) arg2); | |
1371 | ||
1372 | case KEYCTL_DESCRIBE: | |
1373 | return keyctl_describe_key((key_serial_t) arg2, | |
1374 | (char __user *) arg3, | |
1375 | (unsigned) arg4); | |
1376 | ||
1377 | case KEYCTL_CLEAR: | |
1378 | return keyctl_keyring_clear((key_serial_t) arg2); | |
1379 | ||
1380 | case KEYCTL_LINK: | |
1381 | return keyctl_keyring_link((key_serial_t) arg2, | |
1382 | (key_serial_t) arg3); | |
1383 | ||
1384 | case KEYCTL_UNLINK: | |
1385 | return keyctl_keyring_unlink((key_serial_t) arg2, | |
1386 | (key_serial_t) arg3); | |
1387 | ||
1388 | case KEYCTL_SEARCH: | |
1389 | return keyctl_keyring_search((key_serial_t) arg2, | |
1390 | (const char __user *) arg3, | |
1391 | (const char __user *) arg4, | |
1392 | (key_serial_t) arg5); | |
1393 | ||
1394 | case KEYCTL_READ: | |
1395 | return keyctl_read_key((key_serial_t) arg2, | |
1396 | (char __user *) arg3, | |
1397 | (size_t) arg4); | |
1398 | ||
1399 | case KEYCTL_CHOWN: | |
1400 | return keyctl_chown_key((key_serial_t) arg2, | |
1401 | (uid_t) arg3, | |
1402 | (gid_t) arg4); | |
1403 | ||
1404 | case KEYCTL_SETPERM: | |
1405 | return keyctl_setperm_key((key_serial_t) arg2, | |
1406 | (key_perm_t) arg3); | |
1407 | ||
1408 | case KEYCTL_INSTANTIATE: | |
1409 | return keyctl_instantiate_key((key_serial_t) arg2, | |
1410 | (const void __user *) arg3, | |
1411 | (size_t) arg4, | |
1412 | (key_serial_t) arg5); | |
1413 | ||
1414 | case KEYCTL_NEGATE: | |
1415 | return keyctl_negate_key((key_serial_t) arg2, | |
1416 | (unsigned) arg3, | |
1417 | (key_serial_t) arg4); | |
1418 | ||
3e30148c DH |
1419 | case KEYCTL_SET_REQKEY_KEYRING: |
1420 | return keyctl_set_reqkey_keyring(arg2); | |
1421 | ||
017679c4 DH |
1422 | case KEYCTL_SET_TIMEOUT: |
1423 | return keyctl_set_timeout((key_serial_t) arg2, | |
1424 | (unsigned) arg3); | |
1425 | ||
b5f545c8 DH |
1426 | case KEYCTL_ASSUME_AUTHORITY: |
1427 | return keyctl_assume_authority((key_serial_t) arg2); | |
1428 | ||
70a5bb72 DH |
1429 | case KEYCTL_GET_SECURITY: |
1430 | return keyctl_get_security((key_serial_t) arg2, | |
90bd49ab | 1431 | (char __user *) arg3, |
70a5bb72 DH |
1432 | (size_t) arg4); |
1433 | ||
ee18d64c DH |
1434 | case KEYCTL_SESSION_TO_PARENT: |
1435 | return keyctl_session_to_parent(); | |
1436 | ||
1da177e4 LT |
1437 | default: |
1438 | return -EOPNOTSUPP; | |
1439 | } | |
1440 | ||
1441 | } /* end sys_keyctl() */ |