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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, NULL);
80 if (IS_ERR(uid_keyring)) {
81 ret = PTR_ERR(uid_keyring);
82 goto error;
83 }
84 }
85
86
87
88 sprintf(buf, "_uid_ses.%u", uid);
89
90 session_keyring = find_keyring_by_name(buf, true);
91 if (IS_ERR(session_keyring)) {
92 session_keyring =
93 keyring_alloc(buf, user->uid, INVALID_GID,
94 cred, user_keyring_perm,
95 KEY_ALLOC_IN_QUOTA, NULL);
96 if (IS_ERR(session_keyring)) {
97 ret = PTR_ERR(session_keyring);
98 goto error_release;
99 }
100
101
102
103 ret = key_link(session_keyring, uid_keyring);
104 if (ret < 0)
105 goto error_release_both;
106 }
107
108
109 user->uid_keyring = uid_keyring;
110 user->session_keyring = session_keyring;
111 }
112
113 mutex_unlock(&key_user_keyring_mutex);
114 kleave(" = 0");
115 return 0;
116
117error_release_both:
118 key_put(session_keyring);
119error_release:
120 key_put(uid_keyring);
121error:
122 mutex_unlock(&key_user_keyring_mutex);
123 kleave(" = %d", ret);
124 return ret;
125}
126
127
128
129
130
131int install_thread_keyring_to_cred(struct cred *new)
132{
133 struct key *keyring;
134
135 keyring = keyring_alloc("_tid", new->uid, new->gid, new,
136 KEY_POS_ALL | KEY_USR_VIEW,
137 KEY_ALLOC_QUOTA_OVERRUN, NULL);
138 if (IS_ERR(keyring))
139 return PTR_ERR(keyring);
140
141 new->thread_keyring = keyring;
142 return 0;
143}
144
145
146
147
148static int install_thread_keyring(void)
149{
150 struct cred *new;
151 int ret;
152
153 new = prepare_creds();
154 if (!new)
155 return -ENOMEM;
156
157 BUG_ON(new->thread_keyring);
158
159 ret = install_thread_keyring_to_cred(new);
160 if (ret < 0) {
161 abort_creds(new);
162 return ret;
163 }
164
165 return commit_creds(new);
166}
167
168
169
170
171
172
173
174int install_process_keyring_to_cred(struct cred *new)
175{
176 struct key *keyring;
177
178 if (new->process_keyring)
179 return -EEXIST;
180
181 keyring = keyring_alloc("_pid", new->uid, new->gid, new,
182 KEY_POS_ALL | KEY_USR_VIEW,
183 KEY_ALLOC_QUOTA_OVERRUN, NULL);
184 if (IS_ERR(keyring))
185 return PTR_ERR(keyring);
186
187 new->process_keyring = keyring;
188 return 0;
189}
190
191
192
193
194
195
196
197
198static int install_process_keyring(void)
199{
200 struct cred *new;
201 int ret;
202
203 new = prepare_creds();
204 if (!new)
205 return -ENOMEM;
206
207 ret = install_process_keyring_to_cred(new);
208 if (ret < 0) {
209 abort_creds(new);
210 return ret != -EEXIST ? ret : 0;
211 }
212
213 return commit_creds(new);
214}
215
216
217
218
219int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
220{
221 unsigned long flags;
222 struct key *old;
223
224 might_sleep();
225
226
227 if (!keyring) {
228 flags = KEY_ALLOC_QUOTA_OVERRUN;
229 if (cred->session_keyring)
230 flags = KEY_ALLOC_IN_QUOTA;
231
232 keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred,
233 KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
234 flags, NULL);
235 if (IS_ERR(keyring))
236 return PTR_ERR(keyring);
237 } else {
238 __key_get(keyring);
239 }
240
241
242 old = cred->session_keyring;
243 rcu_assign_pointer(cred->session_keyring, keyring);
244
245 if (old)
246 key_put(old);
247
248 return 0;
249}
250
251
252
253
254
255static int install_session_keyring(struct key *keyring)
256{
257 struct cred *new;
258 int ret;
259
260 new = prepare_creds();
261 if (!new)
262 return -ENOMEM;
263
264 ret = install_session_keyring_to_cred(new, keyring);
265 if (ret < 0) {
266 abort_creds(new);
267 return ret;
268 }
269
270 return commit_creds(new);
271}
272
273
274
275
276void key_fsuid_changed(struct task_struct *tsk)
277{
278
279 BUG_ON(!tsk->cred);
280 if (tsk->cred->thread_keyring) {
281 down_write(&tsk->cred->thread_keyring->sem);
282 tsk->cred->thread_keyring->uid = tsk->cred->fsuid;
283 up_write(&tsk->cred->thread_keyring->sem);
284 }
285}
286
287
288
289
290void key_fsgid_changed(struct task_struct *tsk)
291{
292
293 BUG_ON(!tsk->cred);
294 if (tsk->cred->thread_keyring) {
295 down_write(&tsk->cred->thread_keyring->sem);
296 tsk->cred->thread_keyring->gid = tsk->cred->fsgid;
297 up_write(&tsk->cred->thread_keyring->sem);
298 }
299}
300
301
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320
321
322key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx)
323{
324 key_ref_t key_ref, ret, err;
325
326
327
328
329
330
331
332
333 key_ref = NULL;
334 ret = NULL;
335 err = ERR_PTR(-EAGAIN);
336
337
338 if (ctx->cred->thread_keyring) {
339 key_ref = keyring_search_aux(
340 make_key_ref(ctx->cred->thread_keyring, 1), ctx);
341 if (!IS_ERR(key_ref))
342 goto found;
343
344 switch (PTR_ERR(key_ref)) {
345 case -EAGAIN:
346 case -ENOKEY:
347 ret = key_ref;
348 break;
349 default:
350 err = key_ref;
351 break;
352 }
353 }
354
355
356 if (ctx->cred->process_keyring) {
357 key_ref = keyring_search_aux(
358 make_key_ref(ctx->cred->process_keyring, 1), ctx);
359 if (!IS_ERR(key_ref))
360 goto found;
361
362 switch (PTR_ERR(key_ref)) {
363 case -EAGAIN:
364 if (ret)
365 break;
366 case -ENOKEY:
367 ret = key_ref;
368 break;
369 default:
370 err = key_ref;
371 break;
372 }
373 }
374
375
376 if (ctx->cred->session_keyring) {
377 rcu_read_lock();
378 key_ref = keyring_search_aux(
379 make_key_ref(rcu_dereference(ctx->cred->session_keyring), 1),
380 ctx);
381 rcu_read_unlock();
382
383 if (!IS_ERR(key_ref))
384 goto found;
385
386 switch (PTR_ERR(key_ref)) {
387 case -EAGAIN:
388 if (ret)
389 break;
390 case -ENOKEY:
391 ret = key_ref;
392 break;
393 default:
394 err = key_ref;
395 break;
396 }
397 }
398
399 else if (ctx->cred->user->session_keyring) {
400 key_ref = keyring_search_aux(
401 make_key_ref(ctx->cred->user->session_keyring, 1),
402 ctx);
403 if (!IS_ERR(key_ref))
404 goto found;
405
406 switch (PTR_ERR(key_ref)) {
407 case -EAGAIN:
408 if (ret)
409 break;
410 case -ENOKEY:
411 ret = key_ref;
412 break;
413 default:
414 err = key_ref;
415 break;
416 }
417 }
418
419
420 key_ref = ret ? ret : err;
421
422found:
423 return key_ref;
424}
425
426
427
428
429
430
431
432
433
434key_ref_t search_process_keyrings(struct keyring_search_context *ctx)
435{
436 struct request_key_auth *rka;
437 key_ref_t key_ref, ret = ERR_PTR(-EACCES), err;
438
439 might_sleep();
440
441 key_ref = search_my_process_keyrings(ctx);
442 if (!IS_ERR(key_ref))
443 goto found;
444 err = key_ref;
445
446
447
448
449
450 if (ctx->cred->request_key_auth &&
451 ctx->cred == current_cred() &&
452 ctx->index_key.type != &key_type_request_key_auth
453 ) {
454 const struct cred *cred = ctx->cred;
455
456
457 down_read(&cred->request_key_auth->sem);
458
459 if (key_validate(ctx->cred->request_key_auth) == 0) {
460 rka = ctx->cred->request_key_auth->payload.data[0];
461
462 ctx->cred = rka->cred;
463 key_ref = search_process_keyrings(ctx);
464 ctx->cred = cred;
465
466 up_read(&cred->request_key_auth->sem);
467
468 if (!IS_ERR(key_ref))
469 goto found;
470
471 ret = key_ref;
472 } else {
473 up_read(&cred->request_key_auth->sem);
474 }
475 }
476
477
478 if (err == ERR_PTR(-ENOKEY) || ret == ERR_PTR(-ENOKEY))
479 key_ref = ERR_PTR(-ENOKEY);
480 else if (err == ERR_PTR(-EACCES))
481 key_ref = ret;
482 else
483 key_ref = err;
484
485found:
486 return key_ref;
487}
488
489
490
491
492bool lookup_user_key_possessed(const struct key *key,
493 const struct key_match_data *match_data)
494{
495 return key == match_data->raw_data;
496}
497
498
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512
513
514
515
516key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
517 key_perm_t perm)
518{
519 struct keyring_search_context ctx = {
520 .match_data.cmp = lookup_user_key_possessed,
521 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
522 .flags = KEYRING_SEARCH_NO_STATE_CHECK,
523 };
524 struct request_key_auth *rka;
525 struct key *key;
526 key_ref_t key_ref, skey_ref;
527 int ret;
528
529try_again:
530 ctx.cred = get_current_cred();
531 key_ref = ERR_PTR(-ENOKEY);
532
533 switch (id) {
534 case KEY_SPEC_THREAD_KEYRING:
535 if (!ctx.cred->thread_keyring) {
536 if (!(lflags & KEY_LOOKUP_CREATE))
537 goto error;
538
539 ret = install_thread_keyring();
540 if (ret < 0) {
541 key_ref = ERR_PTR(ret);
542 goto error;
543 }
544 goto reget_creds;
545 }
546
547 key = ctx.cred->thread_keyring;
548 __key_get(key);
549 key_ref = make_key_ref(key, 1);
550 break;
551
552 case KEY_SPEC_PROCESS_KEYRING:
553 if (!ctx.cred->process_keyring) {
554 if (!(lflags & KEY_LOOKUP_CREATE))
555 goto error;
556
557 ret = install_process_keyring();
558 if (ret < 0) {
559 key_ref = ERR_PTR(ret);
560 goto error;
561 }
562 goto reget_creds;
563 }
564
565 key = ctx.cred->process_keyring;
566 __key_get(key);
567 key_ref = make_key_ref(key, 1);
568 break;
569
570 case KEY_SPEC_SESSION_KEYRING:
571 if (!ctx.cred->session_keyring) {
572
573
574 ret = install_user_keyrings();
575 if (ret < 0)
576 goto error;
577 if (lflags & KEY_LOOKUP_CREATE)
578 ret = join_session_keyring(NULL);
579 else
580 ret = install_session_keyring(
581 ctx.cred->user->session_keyring);
582
583 if (ret < 0)
584 goto error;
585 goto reget_creds;
586 } else if (ctx.cred->session_keyring ==
587 ctx.cred->user->session_keyring &&
588 lflags & KEY_LOOKUP_CREATE) {
589 ret = join_session_keyring(NULL);
590 if (ret < 0)
591 goto error;
592 goto reget_creds;
593 }
594
595 rcu_read_lock();
596 key = rcu_dereference(ctx.cred->session_keyring);
597 __key_get(key);
598 rcu_read_unlock();
599 key_ref = make_key_ref(key, 1);
600 break;
601
602 case KEY_SPEC_USER_KEYRING:
603 if (!ctx.cred->user->uid_keyring) {
604 ret = install_user_keyrings();
605 if (ret < 0)
606 goto error;
607 }
608
609 key = ctx.cred->user->uid_keyring;
610 __key_get(key);
611 key_ref = make_key_ref(key, 1);
612 break;
613
614 case KEY_SPEC_USER_SESSION_KEYRING:
615 if (!ctx.cred->user->session_keyring) {
616 ret = install_user_keyrings();
617 if (ret < 0)
618 goto error;
619 }
620
621 key = ctx.cred->user->session_keyring;
622 __key_get(key);
623 key_ref = make_key_ref(key, 1);
624 break;
625
626 case KEY_SPEC_GROUP_KEYRING:
627
628 key_ref = ERR_PTR(-EINVAL);
629 goto error;
630
631 case KEY_SPEC_REQKEY_AUTH_KEY:
632 key = ctx.cred->request_key_auth;
633 if (!key)
634 goto error;
635
636 __key_get(key);
637 key_ref = make_key_ref(key, 1);
638 break;
639
640 case KEY_SPEC_REQUESTOR_KEYRING:
641 if (!ctx.cred->request_key_auth)
642 goto error;
643
644 down_read(&ctx.cred->request_key_auth->sem);
645 if (test_bit(KEY_FLAG_REVOKED,
646 &ctx.cred->request_key_auth->flags)) {
647 key_ref = ERR_PTR(-EKEYREVOKED);
648 key = NULL;
649 } else {
650 rka = ctx.cred->request_key_auth->payload.data[0];
651 key = rka->dest_keyring;
652 __key_get(key);
653 }
654 up_read(&ctx.cred->request_key_auth->sem);
655 if (!key)
656 goto error;
657 key_ref = make_key_ref(key, 1);
658 break;
659
660 default:
661 key_ref = ERR_PTR(-EINVAL);
662 if (id < 1)
663 goto error;
664
665 key = key_lookup(id);
666 if (IS_ERR(key)) {
667 key_ref = ERR_CAST(key);
668 goto error;
669 }
670
671 key_ref = make_key_ref(key, 0);
672
673
674 ctx.index_key.type = key->type;
675 ctx.index_key.description = key->description;
676 ctx.index_key.desc_len = strlen(key->description);
677 ctx.match_data.raw_data = key;
678 kdebug("check possessed");
679 skey_ref = search_process_keyrings(&ctx);
680 kdebug("possessed=%p", skey_ref);
681
682 if (!IS_ERR(skey_ref)) {
683 key_put(key);
684 key_ref = skey_ref;
685 }
686
687 break;
688 }
689
690
691
692 if (lflags & KEY_LOOKUP_FOR_UNLINK) {
693 ret = 0;
694 goto error;
695 }
696
697 if (!(lflags & KEY_LOOKUP_PARTIAL)) {
698 ret = wait_for_key_construction(key, true);
699 switch (ret) {
700 case -ERESTARTSYS:
701 goto invalid_key;
702 default:
703 if (perm)
704 goto invalid_key;
705 case 0:
706 break;
707 }
708 } else if (perm) {
709 ret = key_validate(key);
710 if (ret < 0)
711 goto invalid_key;
712 }
713
714 ret = -EIO;
715 if (!(lflags & KEY_LOOKUP_PARTIAL) &&
716 !test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
717 goto invalid_key;
718
719
720 ret = key_task_permission(key_ref, ctx.cred, perm);
721 if (ret < 0)
722 goto invalid_key;
723
724 key->last_used_at = current_kernel_time().tv_sec;
725
726error:
727 put_cred(ctx.cred);
728 return key_ref;
729
730invalid_key:
731 key_ref_put(key_ref);
732 key_ref = ERR_PTR(ret);
733 goto error;
734
735
736
737reget_creds:
738 put_cred(ctx.cred);
739 goto try_again;
740}
741
742
743
744
745
746
747
748
749
750
751
752
753long join_session_keyring(const char *name)
754{
755 const struct cred *old;
756 struct cred *new;
757 struct key *keyring;
758 long ret, serial;
759
760 new = prepare_creds();
761 if (!new)
762 return -ENOMEM;
763 old = current_cred();
764
765
766 if (!name) {
767 ret = install_session_keyring_to_cred(new, NULL);
768 if (ret < 0)
769 goto error;
770
771 serial = new->session_keyring->serial;
772 ret = commit_creds(new);
773 if (ret == 0)
774 ret = serial;
775 goto okay;
776 }
777
778
779 mutex_lock(&key_session_mutex);
780
781
782 keyring = find_keyring_by_name(name, false);
783 if (PTR_ERR(keyring) == -ENOKEY) {
784
785 keyring = keyring_alloc(
786 name, old->uid, old->gid, old,
787 KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK,
788 KEY_ALLOC_IN_QUOTA, NULL);
789 if (IS_ERR(keyring)) {
790 ret = PTR_ERR(keyring);
791 goto error2;
792 }
793 } else if (IS_ERR(keyring)) {
794 ret = PTR_ERR(keyring);
795 goto error2;
796 } else if (keyring == new->session_keyring) {
797 key_put(keyring);
798 ret = 0;
799 goto error2;
800 }
801
802
803 ret = install_session_keyring_to_cred(new, keyring);
804 if (ret < 0)
805 goto error2;
806
807 commit_creds(new);
808 mutex_unlock(&key_session_mutex);
809
810 ret = keyring->serial;
811 key_put(keyring);
812okay:
813 return ret;
814
815error2:
816 mutex_unlock(&key_session_mutex);
817error:
818 abort_creds(new);
819 return ret;
820}
821
822
823
824
825
826void key_change_session_keyring(struct callback_head *twork)
827{
828 const struct cred *old = current_cred();
829 struct cred *new = container_of(twork, struct cred, rcu);
830
831 if (unlikely(current->flags & PF_EXITING)) {
832 put_cred(new);
833 return;
834 }
835
836 new-> uid = old-> uid;
837 new-> euid = old-> euid;
838 new-> suid = old-> suid;
839 new->fsuid = old->fsuid;
840 new-> gid = old-> gid;
841 new-> egid = old-> egid;
842 new-> sgid = old-> sgid;
843 new->fsgid = old->fsgid;
844 new->user = get_uid(old->user);
845 new->user_ns = get_user_ns(old->user_ns);
846 new->group_info = get_group_info(old->group_info);
847
848 new->securebits = old->securebits;
849 new->cap_inheritable = old->cap_inheritable;
850 new->cap_permitted = old->cap_permitted;
851 new->cap_effective = old->cap_effective;
852 new->cap_ambient = old->cap_ambient;
853 new->cap_bset = old->cap_bset;
854
855 new->jit_keyring = old->jit_keyring;
856 new->thread_keyring = key_get(old->thread_keyring);
857 new->process_keyring = key_get(old->process_keyring);
858
859 security_transfer_creds(new, old);
860
861 commit_creds(new);
862}
863
864
865
866
867static int __init init_root_keyring(void)
868{
869 return install_user_keyrings();
870}
871
872late_initcall(init_root_keyring);
873