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12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/sched.h>
15#include <linux/keyctl.h>
16#include <linux/fs.h>
17#include <linux/err.h>
18#include <linux/mutex.h>
19#include <linux/security.h>
20#include <linux/user_namespace.h>
21#include <asm/uaccess.h>
22#include "internal.h"
23
24
25static DEFINE_MUTEX(key_session_mutex);
26
27
28static DEFINE_MUTEX(key_user_keyring_mutex);
29
30
31struct key_user root_key_user = {
32 .usage = ATOMIC_INIT(3),
33 .cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock),
34 .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock),
35 .nkeys = ATOMIC_INIT(2),
36 .nikeys = ATOMIC_INIT(2),
37 .uid = GLOBAL_ROOT_UID,
38};
39
40
41
42
43int install_user_keyrings(void)
44{
45 struct user_struct *user;
46 const struct cred *cred;
47 struct key *uid_keyring, *session_keyring;
48 key_perm_t user_keyring_perm;
49 char buf[20];
50 int ret;
51 uid_t uid;
52
53 user_keyring_perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL;
54 cred = current_cred();
55 user = cred->user;
56 uid = from_kuid(cred->user_ns, user->uid);
57
58 kenter("%p{%u}", user, uid);
59
60 if (user->uid_keyring && user->session_keyring) {
61 kleave(" = 0 [exist]");
62 return 0;
63 }
64
65 mutex_lock(&key_user_keyring_mutex);
66 ret = 0;
67
68 if (!user->uid_keyring) {
69
70
71
72
73 sprintf(buf, "_uid.%u", uid);
74
75 uid_keyring = find_keyring_by_name(buf, true);
76 if (IS_ERR(uid_keyring)) {
77 uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID,
78 cred, user_keyring_perm,
79 KEY_ALLOC_IN_QUOTA,
80 NULL, NULL);
81 if (IS_ERR(uid_keyring)) {
82 ret = PTR_ERR(uid_keyring);
83 goto error;
84 }
85 }
86
87
88
89 sprintf(buf, "_uid_ses.%u", uid);
90
91 session_keyring = find_keyring_by_name(buf, true);
92 if (IS_ERR(session_keyring)) {
93 session_keyring =
94 keyring_alloc(buf, user->uid, INVALID_GID,
95 cred, user_keyring_perm,
96 KEY_ALLOC_IN_QUOTA,
97 NULL, NULL);
98 if (IS_ERR(session_keyring)) {
99 ret = PTR_ERR(session_keyring);
100 goto error_release;
101 }
102
103
104
105 ret = key_link(session_keyring, uid_keyring);
106 if (ret < 0)
107 goto error_release_both;
108 }
109
110
111 user->uid_keyring = uid_keyring;
112 user->session_keyring = session_keyring;
113 }
114
115 mutex_unlock(&key_user_keyring_mutex);
116 kleave(" = 0");
117 return 0;
118
119error_release_both:
120 key_put(session_keyring);
121error_release:
122 key_put(uid_keyring);
123error:
124 mutex_unlock(&key_user_keyring_mutex);
125 kleave(" = %d", ret);
126 return ret;
127}
128
129
130
131
132
133int install_thread_keyring_to_cred(struct cred *new)
134{
135 struct key *keyring;
136
137 keyring = keyring_alloc("_tid", new->uid, new->gid, new,
138 KEY_POS_ALL | KEY_USR_VIEW,
139 KEY_ALLOC_QUOTA_OVERRUN,
140 NULL, NULL);
141 if (IS_ERR(keyring))
142 return PTR_ERR(keyring);
143
144 new->thread_keyring = keyring;
145 return 0;
146}
147
148
149
150
151static int install_thread_keyring(void)
152{
153 struct cred *new;
154 int ret;
155
156 new = prepare_creds();
157 if (!new)
158 return -ENOMEM;
159
160 BUG_ON(new->thread_keyring);
161
162 ret = install_thread_keyring_to_cred(new);
163 if (ret < 0) {
164 abort_creds(new);
165 return ret;
166 }
167
168 return commit_creds(new);
169}
170
171
172
173
174
175
176
177int install_process_keyring_to_cred(struct cred *new)
178{
179 struct key *keyring;
180
181 if (new->process_keyring)
182 return -EEXIST;
183
184 keyring = keyring_alloc("_pid", new->uid, new->gid, new,
185 KEY_POS_ALL | KEY_USR_VIEW,
186 KEY_ALLOC_QUOTA_OVERRUN,
187 NULL, NULL);
188 if (IS_ERR(keyring))
189 return PTR_ERR(keyring);
190
191 new->process_keyring = keyring;
192 return 0;
193}
194
195
196
197
198
199
200
201
202static int install_process_keyring(void)
203{
204 struct cred *new;
205 int ret;
206
207 new = prepare_creds();
208 if (!new)
209 return -ENOMEM;
210
211 ret = install_process_keyring_to_cred(new);
212 if (ret < 0) {
213 abort_creds(new);
214 return ret != -EEXIST ? ret : 0;
215 }
216
217 return commit_creds(new);
218}
219
220
221
222
223int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
224{
225 unsigned long flags;
226 struct key *old;
227
228 might_sleep();
229
230
231 if (!keyring) {
232 flags = KEY_ALLOC_QUOTA_OVERRUN;
233 if (cred->session_keyring)
234 flags = KEY_ALLOC_IN_QUOTA;
235
236 keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred,
237 KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
238 flags, NULL, NULL);
239 if (IS_ERR(keyring))
240 return PTR_ERR(keyring);
241 } else {
242 __key_get(keyring);
243 }
244
245
246 old = cred->session_keyring;
247 rcu_assign_pointer(cred->session_keyring, keyring);
248
249 if (old)
250 key_put(old);
251
252 return 0;
253}
254
255
256
257
258
259static int install_session_keyring(struct key *keyring)
260{
261 struct cred *new;
262 int ret;
263
264 new = prepare_creds();
265 if (!new)
266 return -ENOMEM;
267
268 ret = install_session_keyring_to_cred(new, keyring);
269 if (ret < 0) {
270 abort_creds(new);
271 return ret;
272 }
273
274 return commit_creds(new);
275}
276
277
278
279
280void key_fsuid_changed(struct task_struct *tsk)
281{
282
283 BUG_ON(!tsk->cred);
284 if (tsk->cred->thread_keyring) {
285 down_write(&tsk->cred->thread_keyring->sem);
286 tsk->cred->thread_keyring->uid = tsk->cred->fsuid;
287 up_write(&tsk->cred->thread_keyring->sem);
288 }
289}
290
291
292
293
294void key_fsgid_changed(struct task_struct *tsk)
295{
296
297 BUG_ON(!tsk->cred);
298 if (tsk->cred->thread_keyring) {
299 down_write(&tsk->cred->thread_keyring->sem);
300 tsk->cred->thread_keyring->gid = tsk->cred->fsgid;
301 up_write(&tsk->cred->thread_keyring->sem);
302 }
303}
304
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312
313
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324
325
326key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx)
327{
328 key_ref_t key_ref, ret, err;
329
330
331
332
333
334
335
336
337 key_ref = NULL;
338 ret = NULL;
339 err = ERR_PTR(-EAGAIN);
340
341
342 if (ctx->cred->thread_keyring) {
343 key_ref = keyring_search_aux(
344 make_key_ref(ctx->cred->thread_keyring, 1), ctx);
345 if (!IS_ERR(key_ref))
346 goto found;
347
348 switch (PTR_ERR(key_ref)) {
349 case -EAGAIN:
350 case -ENOKEY:
351 ret = key_ref;
352 break;
353 default:
354 err = key_ref;
355 break;
356 }
357 }
358
359
360 if (ctx->cred->process_keyring) {
361 key_ref = keyring_search_aux(
362 make_key_ref(ctx->cred->process_keyring, 1), ctx);
363 if (!IS_ERR(key_ref))
364 goto found;
365
366 switch (PTR_ERR(key_ref)) {
367 case -EAGAIN:
368 if (ret)
369 break;
370 case -ENOKEY:
371 ret = key_ref;
372 break;
373 default:
374 err = key_ref;
375 break;
376 }
377 }
378
379
380 if (ctx->cred->session_keyring) {
381 rcu_read_lock();
382 key_ref = keyring_search_aux(
383 make_key_ref(rcu_dereference(ctx->cred->session_keyring), 1),
384 ctx);
385 rcu_read_unlock();
386
387 if (!IS_ERR(key_ref))
388 goto found;
389
390 switch (PTR_ERR(key_ref)) {
391 case -EAGAIN:
392 if (ret)
393 break;
394 case -ENOKEY:
395 ret = key_ref;
396 break;
397 default:
398 err = key_ref;
399 break;
400 }
401 }
402
403 else if (ctx->cred->user->session_keyring) {
404 key_ref = keyring_search_aux(
405 make_key_ref(ctx->cred->user->session_keyring, 1),
406 ctx);
407 if (!IS_ERR(key_ref))
408 goto found;
409
410 switch (PTR_ERR(key_ref)) {
411 case -EAGAIN:
412 if (ret)
413 break;
414 case -ENOKEY:
415 ret = key_ref;
416 break;
417 default:
418 err = key_ref;
419 break;
420 }
421 }
422
423
424 key_ref = ret ? ret : err;
425
426found:
427 return key_ref;
428}
429
430
431
432
433
434
435
436
437
438key_ref_t search_process_keyrings(struct keyring_search_context *ctx)
439{
440 struct request_key_auth *rka;
441 key_ref_t key_ref, ret = ERR_PTR(-EACCES), err;
442
443 might_sleep();
444
445 key_ref = search_my_process_keyrings(ctx);
446 if (!IS_ERR(key_ref))
447 goto found;
448 err = key_ref;
449
450
451
452
453
454 if (ctx->cred->request_key_auth &&
455 ctx->cred == current_cred() &&
456 ctx->index_key.type != &key_type_request_key_auth
457 ) {
458 const struct cred *cred = ctx->cred;
459
460
461 down_read(&cred->request_key_auth->sem);
462
463 if (key_validate(ctx->cred->request_key_auth) == 0) {
464 rka = ctx->cred->request_key_auth->payload.data[0];
465
466 ctx->cred = rka->cred;
467 key_ref = search_process_keyrings(ctx);
468 ctx->cred = cred;
469
470 up_read(&cred->request_key_auth->sem);
471
472 if (!IS_ERR(key_ref))
473 goto found;
474
475 ret = key_ref;
476 } else {
477 up_read(&cred->request_key_auth->sem);
478 }
479 }
480
481
482 if (err == ERR_PTR(-ENOKEY) || ret == ERR_PTR(-ENOKEY))
483 key_ref = ERR_PTR(-ENOKEY);
484 else if (err == ERR_PTR(-EACCES))
485 key_ref = ret;
486 else
487 key_ref = err;
488
489found:
490 return key_ref;
491}
492
493
494
495
496bool lookup_user_key_possessed(const struct key *key,
497 const struct key_match_data *match_data)
498{
499 return key == match_data->raw_data;
500}
501
502
503
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505
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515
516
517
518
519
520key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
521 key_perm_t perm)
522{
523 struct keyring_search_context ctx = {
524 .match_data.cmp = lookup_user_key_possessed,
525 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
526 .flags = KEYRING_SEARCH_NO_STATE_CHECK,
527 };
528 struct request_key_auth *rka;
529 struct key *key;
530 key_ref_t key_ref, skey_ref;
531 int ret;
532
533try_again:
534 ctx.cred = get_current_cred();
535 key_ref = ERR_PTR(-ENOKEY);
536
537 switch (id) {
538 case KEY_SPEC_THREAD_KEYRING:
539 if (!ctx.cred->thread_keyring) {
540 if (!(lflags & KEY_LOOKUP_CREATE))
541 goto error;
542
543 ret = install_thread_keyring();
544 if (ret < 0) {
545 key_ref = ERR_PTR(ret);
546 goto error;
547 }
548 goto reget_creds;
549 }
550
551 key = ctx.cred->thread_keyring;
552 __key_get(key);
553 key_ref = make_key_ref(key, 1);
554 break;
555
556 case KEY_SPEC_PROCESS_KEYRING:
557 if (!ctx.cred->process_keyring) {
558 if (!(lflags & KEY_LOOKUP_CREATE))
559 goto error;
560
561 ret = install_process_keyring();
562 if (ret < 0) {
563 key_ref = ERR_PTR(ret);
564 goto error;
565 }
566 goto reget_creds;
567 }
568
569 key = ctx.cred->process_keyring;
570 __key_get(key);
571 key_ref = make_key_ref(key, 1);
572 break;
573
574 case KEY_SPEC_SESSION_KEYRING:
575 if (!ctx.cred->session_keyring) {
576
577
578 ret = install_user_keyrings();
579 if (ret < 0)
580 goto error;
581 if (lflags & KEY_LOOKUP_CREATE)
582 ret = join_session_keyring(NULL);
583 else
584 ret = install_session_keyring(
585 ctx.cred->user->session_keyring);
586
587 if (ret < 0)
588 goto error;
589 goto reget_creds;
590 } else if (ctx.cred->session_keyring ==
591 ctx.cred->user->session_keyring &&
592 lflags & KEY_LOOKUP_CREATE) {
593 ret = join_session_keyring(NULL);
594 if (ret < 0)
595 goto error;
596 goto reget_creds;
597 }
598
599 rcu_read_lock();
600 key = rcu_dereference(ctx.cred->session_keyring);
601 __key_get(key);
602 rcu_read_unlock();
603 key_ref = make_key_ref(key, 1);
604 break;
605
606 case KEY_SPEC_USER_KEYRING:
607 if (!ctx.cred->user->uid_keyring) {
608 ret = install_user_keyrings();
609 if (ret < 0)
610 goto error;
611 }
612
613 key = ctx.cred->user->uid_keyring;
614 __key_get(key);
615 key_ref = make_key_ref(key, 1);
616 break;
617
618 case KEY_SPEC_USER_SESSION_KEYRING:
619 if (!ctx.cred->user->session_keyring) {
620 ret = install_user_keyrings();
621 if (ret < 0)
622 goto error;
623 }
624
625 key = ctx.cred->user->session_keyring;
626 __key_get(key);
627 key_ref = make_key_ref(key, 1);
628 break;
629
630 case KEY_SPEC_GROUP_KEYRING:
631
632 key_ref = ERR_PTR(-EINVAL);
633 goto error;
634
635 case KEY_SPEC_REQKEY_AUTH_KEY:
636 key = ctx.cred->request_key_auth;
637 if (!key)
638 goto error;
639
640 __key_get(key);
641 key_ref = make_key_ref(key, 1);
642 break;
643
644 case KEY_SPEC_REQUESTOR_KEYRING:
645 if (!ctx.cred->request_key_auth)
646 goto error;
647
648 down_read(&ctx.cred->request_key_auth->sem);
649 if (test_bit(KEY_FLAG_REVOKED,
650 &ctx.cred->request_key_auth->flags)) {
651 key_ref = ERR_PTR(-EKEYREVOKED);
652 key = NULL;
653 } else {
654 rka = ctx.cred->request_key_auth->payload.data[0];
655 key = rka->dest_keyring;
656 __key_get(key);
657 }
658 up_read(&ctx.cred->request_key_auth->sem);
659 if (!key)
660 goto error;
661 key_ref = make_key_ref(key, 1);
662 break;
663
664 default:
665 key_ref = ERR_PTR(-EINVAL);
666 if (id < 1)
667 goto error;
668
669 key = key_lookup(id);
670 if (IS_ERR(key)) {
671 key_ref = ERR_CAST(key);
672 goto error;
673 }
674
675 key_ref = make_key_ref(key, 0);
676
677
678 ctx.index_key.type = key->type;
679 ctx.index_key.description = key->description;
680 ctx.index_key.desc_len = strlen(key->description);
681 ctx.match_data.raw_data = key;
682 kdebug("check possessed");
683 skey_ref = search_process_keyrings(&ctx);
684 kdebug("possessed=%p", skey_ref);
685
686 if (!IS_ERR(skey_ref)) {
687 key_put(key);
688 key_ref = skey_ref;
689 }
690
691 break;
692 }
693
694
695
696 if (lflags & KEY_LOOKUP_FOR_UNLINK) {
697 ret = 0;
698 goto error;
699 }
700
701 if (!(lflags & KEY_LOOKUP_PARTIAL)) {
702 ret = wait_for_key_construction(key, true);
703 switch (ret) {
704 case -ERESTARTSYS:
705 goto invalid_key;
706 default:
707 if (perm)
708 goto invalid_key;
709 case 0:
710 break;
711 }
712 } else if (perm) {
713 ret = key_validate(key);
714 if (ret < 0)
715 goto invalid_key;
716 }
717
718 ret = -EIO;
719 if (!(lflags & KEY_LOOKUP_PARTIAL) &&
720 !test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
721 goto invalid_key;
722
723
724 ret = key_task_permission(key_ref, ctx.cred, perm);
725 if (ret < 0)
726 goto invalid_key;
727
728 key->last_used_at = current_kernel_time().tv_sec;
729
730error:
731 put_cred(ctx.cred);
732 return key_ref;
733
734invalid_key:
735 key_ref_put(key_ref);
736 key_ref = ERR_PTR(ret);
737 goto error;
738
739
740
741reget_creds:
742 put_cred(ctx.cred);
743 goto try_again;
744}
745
746
747
748
749
750
751
752
753
754
755
756
757long join_session_keyring(const char *name)
758{
759 const struct cred *old;
760 struct cred *new;
761 struct key *keyring;
762 long ret, serial;
763
764 new = prepare_creds();
765 if (!new)
766 return -ENOMEM;
767 old = current_cred();
768
769
770 if (!name) {
771 ret = install_session_keyring_to_cred(new, NULL);
772 if (ret < 0)
773 goto error;
774
775 serial = new->session_keyring->serial;
776 ret = commit_creds(new);
777 if (ret == 0)
778 ret = serial;
779 goto okay;
780 }
781
782
783 mutex_lock(&key_session_mutex);
784
785
786 keyring = find_keyring_by_name(name, false);
787 if (PTR_ERR(keyring) == -ENOKEY) {
788
789 keyring = keyring_alloc(
790 name, old->uid, old->gid, old,
791 KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK,
792 KEY_ALLOC_IN_QUOTA, NULL, NULL);
793 if (IS_ERR(keyring)) {
794 ret = PTR_ERR(keyring);
795 goto error2;
796 }
797 } else if (IS_ERR(keyring)) {
798 ret = PTR_ERR(keyring);
799 goto error2;
800 } else if (keyring == new->session_keyring) {
801 key_put(keyring);
802 ret = 0;
803 goto error2;
804 }
805
806
807 ret = install_session_keyring_to_cred(new, keyring);
808 if (ret < 0)
809 goto error2;
810
811 commit_creds(new);
812 mutex_unlock(&key_session_mutex);
813
814 ret = keyring->serial;
815 key_put(keyring);
816okay:
817 return ret;
818
819error2:
820 mutex_unlock(&key_session_mutex);
821error:
822 abort_creds(new);
823 return ret;
824}
825
826
827
828
829
830void key_change_session_keyring(struct callback_head *twork)
831{
832 const struct cred *old = current_cred();
833 struct cred *new = container_of(twork, struct cred, rcu);
834
835 if (unlikely(current->flags & PF_EXITING)) {
836 put_cred(new);
837 return;
838 }
839
840 new-> uid = old-> uid;
841 new-> euid = old-> euid;
842 new-> suid = old-> suid;
843 new->fsuid = old->fsuid;
844 new-> gid = old-> gid;
845 new-> egid = old-> egid;
846 new-> sgid = old-> sgid;
847 new->fsgid = old->fsgid;
848 new->user = get_uid(old->user);
849 new->user_ns = get_user_ns(old->user_ns);
850 new->group_info = get_group_info(old->group_info);
851
852 new->securebits = old->securebits;
853 new->cap_inheritable = old->cap_inheritable;
854 new->cap_permitted = old->cap_permitted;
855 new->cap_effective = old->cap_effective;
856 new->cap_ambient = old->cap_ambient;
857 new->cap_bset = old->cap_bset;
858
859 new->jit_keyring = old->jit_keyring;
860 new->thread_keyring = key_get(old->thread_keyring);
861 new->process_keyring = key_get(old->process_keyring);
862
863 security_transfer_creds(new, old);
864
865 commit_creds(new);
866}
867
868
869
870
871static int __init init_root_keyring(void)
872{
873 return install_user_keyrings();
874}
875
876late_initcall(init_root_keyring);
877