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14#include <linux/module.h>
15#include <linux/sched.h>
16#include <linux/kmod.h>
17#include <linux/err.h>
18#include <linux/keyctl.h>
19#include <linux/slab.h>
20#include "internal.h"
21
22#define key_negative_timeout 60
23
24
25
26
27
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31
32
33void complete_request_key(struct key_construction *cons, int error)
34{
35 kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error);
36
37 if (error < 0)
38 key_negate_and_link(cons->key, key_negative_timeout, NULL,
39 cons->authkey);
40 else
41 key_revoke(cons->authkey);
42
43 key_put(cons->key);
44 key_put(cons->authkey);
45 kfree(cons);
46}
47EXPORT_SYMBOL(complete_request_key);
48
49
50
51
52
53
54
55
56static int umh_keys_init(struct subprocess_info *info, struct cred *cred)
57{
58 struct key *keyring = info->data;
59
60 return install_session_keyring_to_cred(cred, keyring);
61}
62
63
64
65
66static void umh_keys_cleanup(struct subprocess_info *info)
67{
68 struct key *keyring = info->data;
69 key_put(keyring);
70}
71
72
73
74
75static int call_usermodehelper_keys(const char *path, char **argv, char **envp,
76 struct key *session_keyring, int wait)
77{
78 struct subprocess_info *info;
79
80 info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL,
81 umh_keys_init, umh_keys_cleanup,
82 session_keyring);
83 if (!info)
84 return -ENOMEM;
85
86 key_get(session_keyring);
87 return call_usermodehelper_exec(info, wait);
88}
89
90
91
92
93
94static int call_sbin_request_key(struct key_construction *cons,
95 const char *op,
96 void *aux)
97{
98 static char const request_key[] = "/sbin/request-key";
99 const struct cred *cred = current_cred();
100 key_serial_t prkey, sskey;
101 struct key *key = cons->key, *authkey = cons->authkey, *keyring,
102 *session;
103 char *argv[9], *envp[3], uid_str[12], gid_str[12];
104 char key_str[12], keyring_str[3][12];
105 char desc[20];
106 int ret, i;
107
108 kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
109
110 ret = install_user_keyrings();
111 if (ret < 0)
112 goto error_alloc;
113
114
115 sprintf(desc, "_req.%u", key->serial);
116
117 cred = get_current_cred();
118 keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
119 KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
120 KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL);
121 put_cred(cred);
122 if (IS_ERR(keyring)) {
123 ret = PTR_ERR(keyring);
124 goto error_alloc;
125 }
126
127
128 ret = key_link(keyring, authkey);
129 if (ret < 0)
130 goto error_link;
131
132
133 sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid));
134 sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid));
135
136
137 sprintf(key_str, "%d", key->serial);
138
139
140 sprintf(keyring_str[0], "%d",
141 cred->thread_keyring ? cred->thread_keyring->serial : 0);
142
143 prkey = 0;
144 if (cred->process_keyring)
145 prkey = cred->process_keyring->serial;
146 sprintf(keyring_str[1], "%d", prkey);
147
148 rcu_read_lock();
149 session = rcu_dereference(cred->session_keyring);
150 if (!session)
151 session = cred->user->session_keyring;
152 sskey = session->serial;
153 rcu_read_unlock();
154
155 sprintf(keyring_str[2], "%d", sskey);
156
157
158 i = 0;
159 envp[i++] = "HOME=/";
160 envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
161 envp[i] = NULL;
162
163
164 i = 0;
165 argv[i++] = (char *)request_key;
166 argv[i++] = (char *) op;
167 argv[i++] = key_str;
168 argv[i++] = uid_str;
169 argv[i++] = gid_str;
170 argv[i++] = keyring_str[0];
171 argv[i++] = keyring_str[1];
172 argv[i++] = keyring_str[2];
173 argv[i] = NULL;
174
175
176 ret = call_usermodehelper_keys(request_key, argv, envp, keyring,
177 UMH_WAIT_PROC);
178 kdebug("usermode -> 0x%x", ret);
179 if (ret >= 0) {
180
181 if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) ||
182 key_validate(key) < 0)
183 ret = -ENOKEY;
184 else
185
186
187 ret = 0;
188 }
189
190error_link:
191 key_put(keyring);
192
193error_alloc:
194 complete_request_key(cons, ret);
195 kleave(" = %d", ret);
196 return ret;
197}
198
199
200
201
202
203
204static int construct_key(struct key *key, const void *callout_info,
205 size_t callout_len, void *aux,
206 struct key *dest_keyring)
207{
208 struct key_construction *cons;
209 request_key_actor_t actor;
210 struct key *authkey;
211 int ret;
212
213 kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
214
215 cons = kmalloc(sizeof(*cons), GFP_KERNEL);
216 if (!cons)
217 return -ENOMEM;
218
219
220 authkey = request_key_auth_new(key, callout_info, callout_len,
221 dest_keyring);
222 if (IS_ERR(authkey)) {
223 kfree(cons);
224 ret = PTR_ERR(authkey);
225 authkey = NULL;
226 } else {
227 cons->authkey = key_get(authkey);
228 cons->key = key_get(key);
229
230
231 actor = call_sbin_request_key;
232 if (key->type->request_key)
233 actor = key->type->request_key;
234
235 ret = actor(cons, "create", aux);
236
237
238
239 WARN_ON(ret < 0 &&
240 !test_bit(KEY_FLAG_REVOKED, &authkey->flags));
241 key_put(authkey);
242 }
243
244 kleave(" = %d", ret);
245 return ret;
246}
247
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252
253
254static int construct_get_dest_keyring(struct key **_dest_keyring)
255{
256 struct request_key_auth *rka;
257 const struct cred *cred = current_cred();
258 struct key *dest_keyring = *_dest_keyring, *authkey;
259 int ret;
260
261 kenter("%p", dest_keyring);
262
263
264 if (dest_keyring) {
265
266 key_get(dest_keyring);
267 } else {
268 bool do_perm_check = true;
269
270
271
272 switch (cred->jit_keyring) {
273 case KEY_REQKEY_DEFL_DEFAULT:
274 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
275 if (cred->request_key_auth) {
276 authkey = cred->request_key_auth;
277 down_read(&authkey->sem);
278 rka = authkey->payload.data[0];
279 if (!test_bit(KEY_FLAG_REVOKED,
280 &authkey->flags))
281 dest_keyring =
282 key_get(rka->dest_keyring);
283 up_read(&authkey->sem);
284 if (dest_keyring) {
285 do_perm_check = false;
286 break;
287 }
288 }
289
290 case KEY_REQKEY_DEFL_THREAD_KEYRING:
291 dest_keyring = key_get(cred->thread_keyring);
292 if (dest_keyring)
293 break;
294
295 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
296 dest_keyring = key_get(cred->process_keyring);
297 if (dest_keyring)
298 break;
299
300 case KEY_REQKEY_DEFL_SESSION_KEYRING:
301 rcu_read_lock();
302 dest_keyring = key_get(
303 rcu_dereference(cred->session_keyring));
304 rcu_read_unlock();
305
306 if (dest_keyring)
307 break;
308
309 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
310 dest_keyring =
311 key_get(cred->user->session_keyring);
312 break;
313
314 case KEY_REQKEY_DEFL_USER_KEYRING:
315 dest_keyring = key_get(cred->user->uid_keyring);
316 break;
317
318 case KEY_REQKEY_DEFL_GROUP_KEYRING:
319 default:
320 BUG();
321 }
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332 if (dest_keyring && do_perm_check) {
333 ret = key_permission(make_key_ref(dest_keyring, 1),
334 KEY_NEED_WRITE);
335 if (ret) {
336 key_put(dest_keyring);
337 return ret;
338 }
339 }
340 }
341
342 *_dest_keyring = dest_keyring;
343 kleave(" [dk %d]", key_serial(dest_keyring));
344 return 0;
345}
346
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352
353
354static int construct_alloc_key(struct keyring_search_context *ctx,
355 struct key *dest_keyring,
356 unsigned long flags,
357 struct key_user *user,
358 struct key **_key)
359{
360 struct assoc_array_edit *edit;
361 struct key *key;
362 key_perm_t perm;
363 key_ref_t key_ref;
364 int ret;
365
366 kenter("%s,%s,,,",
367 ctx->index_key.type->name, ctx->index_key.description);
368
369 *_key = NULL;
370 mutex_lock(&user->cons_lock);
371
372 perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
373 perm |= KEY_USR_VIEW;
374 if (ctx->index_key.type->read)
375 perm |= KEY_POS_READ;
376 if (ctx->index_key.type == &key_type_keyring ||
377 ctx->index_key.type->update)
378 perm |= KEY_POS_WRITE;
379
380 key = key_alloc(ctx->index_key.type, ctx->index_key.description,
381 ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred,
382 perm, flags, NULL);
383 if (IS_ERR(key))
384 goto alloc_failed;
385
386 set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
387
388 if (dest_keyring) {
389 ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit);
390 if (ret < 0)
391 goto link_prealloc_failed;
392 }
393
394
395
396
397 mutex_lock(&key_construction_mutex);
398
399 key_ref = search_process_keyrings(ctx);
400 if (!IS_ERR(key_ref))
401 goto key_already_present;
402
403 if (dest_keyring)
404 __key_link(key, &edit);
405
406 mutex_unlock(&key_construction_mutex);
407 if (dest_keyring)
408 __key_link_end(dest_keyring, &ctx->index_key, edit);
409 mutex_unlock(&user->cons_lock);
410 *_key = key;
411 kleave(" = 0 [%d]", key_serial(key));
412 return 0;
413
414
415
416key_already_present:
417 key_put(key);
418 mutex_unlock(&key_construction_mutex);
419 key = key_ref_to_ptr(key_ref);
420 if (dest_keyring) {
421 ret = __key_link_check_live_key(dest_keyring, key);
422 if (ret == 0)
423 __key_link(key, &edit);
424 __key_link_end(dest_keyring, &ctx->index_key, edit);
425 if (ret < 0)
426 goto link_check_failed;
427 }
428 mutex_unlock(&user->cons_lock);
429 *_key = key;
430 kleave(" = -EINPROGRESS [%d]", key_serial(key));
431 return -EINPROGRESS;
432
433link_check_failed:
434 mutex_unlock(&user->cons_lock);
435 key_put(key);
436 kleave(" = %d [linkcheck]", ret);
437 return ret;
438
439link_prealloc_failed:
440 mutex_unlock(&user->cons_lock);
441 key_put(key);
442 kleave(" = %d [prelink]", ret);
443 return ret;
444
445alloc_failed:
446 mutex_unlock(&user->cons_lock);
447 kleave(" = %ld", PTR_ERR(key));
448 return PTR_ERR(key);
449}
450
451
452
453
454static struct key *construct_key_and_link(struct keyring_search_context *ctx,
455 const char *callout_info,
456 size_t callout_len,
457 void *aux,
458 struct key *dest_keyring,
459 unsigned long flags)
460{
461 struct key_user *user;
462 struct key *key;
463 int ret;
464
465 kenter("");
466
467 if (ctx->index_key.type == &key_type_keyring)
468 return ERR_PTR(-EPERM);
469
470 ret = construct_get_dest_keyring(&dest_keyring);
471 if (ret)
472 goto error;
473
474 user = key_user_lookup(current_fsuid());
475 if (!user) {
476 ret = -ENOMEM;
477 goto error_put_dest_keyring;
478 }
479
480 ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
481 key_user_put(user);
482
483 if (ret == 0) {
484 ret = construct_key(key, callout_info, callout_len, aux,
485 dest_keyring);
486 if (ret < 0) {
487 kdebug("cons failed");
488 goto construction_failed;
489 }
490 } else if (ret == -EINPROGRESS) {
491 ret = 0;
492 } else {
493 goto error_put_dest_keyring;
494 }
495
496 key_put(dest_keyring);
497 kleave(" = key %d", key_serial(key));
498 return key;
499
500construction_failed:
501 key_negate_and_link(key, key_negative_timeout, NULL, NULL);
502 key_put(key);
503error_put_dest_keyring:
504 key_put(dest_keyring);
505error:
506 kleave(" = %d", ret);
507 return ERR_PTR(ret);
508}
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537struct key *request_key_and_link(struct key_type *type,
538 const char *description,
539 const void *callout_info,
540 size_t callout_len,
541 void *aux,
542 struct key *dest_keyring,
543 unsigned long flags)
544{
545 struct keyring_search_context ctx = {
546 .index_key.type = type,
547 .index_key.description = description,
548 .cred = current_cred(),
549 .match_data.cmp = key_default_cmp,
550 .match_data.raw_data = description,
551 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
552 .flags = (KEYRING_SEARCH_DO_STATE_CHECK |
553 KEYRING_SEARCH_SKIP_EXPIRED),
554 };
555 struct key *key;
556 key_ref_t key_ref;
557 int ret;
558
559 kenter("%s,%s,%p,%zu,%p,%p,%lx",
560 ctx.index_key.type->name, ctx.index_key.description,
561 callout_info, callout_len, aux, dest_keyring, flags);
562
563 if (type->match_preparse) {
564 ret = type->match_preparse(&ctx.match_data);
565 if (ret < 0) {
566 key = ERR_PTR(ret);
567 goto error;
568 }
569 }
570
571
572 key_ref = search_process_keyrings(&ctx);
573
574 if (!IS_ERR(key_ref)) {
575 key = key_ref_to_ptr(key_ref);
576 if (dest_keyring) {
577 ret = key_link(dest_keyring, key);
578 if (ret < 0) {
579 key_put(key);
580 key = ERR_PTR(ret);
581 goto error_free;
582 }
583 }
584 } else if (PTR_ERR(key_ref) != -EAGAIN) {
585 key = ERR_CAST(key_ref);
586 } else {
587
588
589 key = ERR_PTR(-ENOKEY);
590 if (!callout_info)
591 goto error_free;
592
593 key = construct_key_and_link(&ctx, callout_info, callout_len,
594 aux, dest_keyring, flags);
595 }
596
597error_free:
598 if (type->match_free)
599 type->match_free(&ctx.match_data);
600error:
601 kleave(" = %p", key);
602 return key;
603}
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615
616int wait_for_key_construction(struct key *key, bool intr)
617{
618 int ret;
619
620 ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT,
621 intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
622 if (ret)
623 return -ERESTARTSYS;
624 ret = key_read_state(key);
625 if (ret < 0)
626 return ret;
627 return key_validate(key);
628}
629EXPORT_SYMBOL(wait_for_key_construction);
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645struct key *request_key(struct key_type *type,
646 const char *description,
647 const char *callout_info)
648{
649 struct key *key;
650 size_t callout_len = 0;
651 int ret;
652
653 if (callout_info)
654 callout_len = strlen(callout_info);
655 key = request_key_and_link(type, description, callout_info, callout_len,
656 NULL, NULL, KEY_ALLOC_IN_QUOTA);
657 if (!IS_ERR(key)) {
658 ret = wait_for_key_construction(key, false);
659 if (ret < 0) {
660 key_put(key);
661 return ERR_PTR(ret);
662 }
663 }
664 return key;
665}
666EXPORT_SYMBOL(request_key);
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682struct key *request_key_with_auxdata(struct key_type *type,
683 const char *description,
684 const void *callout_info,
685 size_t callout_len,
686 void *aux)
687{
688 struct key *key;
689 int ret;
690
691 key = request_key_and_link(type, description, callout_info, callout_len,
692 aux, NULL, KEY_ALLOC_IN_QUOTA);
693 if (!IS_ERR(key)) {
694 ret = wait_for_key_construction(key, false);
695 if (ret < 0) {
696 key_put(key);
697 return ERR_PTR(ret);
698 }
699 }
700 return key;
701}
702EXPORT_SYMBOL(request_key_with_auxdata);
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718struct key *request_key_async(struct key_type *type,
719 const char *description,
720 const void *callout_info,
721 size_t callout_len)
722{
723 return request_key_and_link(type, description, callout_info,
724 callout_len, NULL, NULL,
725 KEY_ALLOC_IN_QUOTA);
726}
727EXPORT_SYMBOL(request_key_async);
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743struct key *request_key_async_with_auxdata(struct key_type *type,
744 const char *description,
745 const void *callout_info,
746 size_t callout_len,
747 void *aux)
748{
749 return request_key_and_link(type, description, callout_info,
750 callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA);
751}
752EXPORT_SYMBOL(request_key_async_with_auxdata);
753