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15#include <linux/errno.h>
16#include <linux/fdtable.h>
17#include <linux/file.h>
18#include <linux/mount.h>
19#include <linux/syscalls.h>
20#include <linux/tracehook.h>
21#include <linux/personality.h>
22
23#include "include/audit.h"
24#include "include/apparmorfs.h"
25#include "include/context.h"
26#include "include/domain.h"
27#include "include/file.h"
28#include "include/ipc.h"
29#include "include/match.h"
30#include "include/path.h"
31#include "include/policy.h"
32
33
34
35
36
37void aa_free_domain_entries(struct aa_domain *domain)
38{
39 int i;
40 if (domain) {
41 if (!domain->table)
42 return;
43
44 for (i = 0; i < domain->size; i++)
45 kzfree(domain->table[i]);
46 kzfree(domain->table);
47 domain->table = NULL;
48 }
49}
50
51
52
53
54
55
56
57
58
59
60
61static int may_change_ptraced_domain(struct task_struct *task,
62 struct aa_profile *to_profile)
63{
64 struct task_struct *tracer;
65 const struct cred *cred = NULL;
66 struct aa_profile *tracerp = NULL;
67 int error = 0;
68
69 rcu_read_lock();
70 tracer = ptrace_parent(task);
71 if (tracer) {
72
73 cred = get_task_cred(tracer);
74 tracerp = aa_cred_profile(cred);
75 }
76
77
78 if (!tracer || unconfined(tracerp))
79 goto out;
80
81 error = aa_may_ptrace(tracer, tracerp, to_profile, PTRACE_MODE_ATTACH);
82
83out:
84 rcu_read_unlock();
85 if (cred)
86 put_cred(cred);
87
88 return error;
89}
90
91
92
93
94
95
96
97
98
99
100
101static struct file_perms change_profile_perms(struct aa_profile *profile,
102 struct aa_namespace *ns,
103 const char *name, u32 request,
104 unsigned int start)
105{
106 struct file_perms perms;
107 struct path_cond cond = { };
108 unsigned int state;
109
110 if (unconfined(profile)) {
111 perms.allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
112 perms.audit = perms.quiet = perms.kill = 0;
113 return perms;
114 } else if (!profile->file.dfa) {
115 return nullperms;
116 } else if ((ns == profile->ns)) {
117
118 aa_str_perms(profile->file.dfa, start, name, &cond, &perms);
119 if (COMBINED_PERM_MASK(perms) & request)
120 return perms;
121 }
122
123
124 state = aa_dfa_match(profile->file.dfa, start, ns->base.name);
125 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
126 aa_str_perms(profile->file.dfa, state, name, &cond, &perms);
127
128 return perms;
129}
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145static struct aa_profile *__attach_match(const char *name,
146 struct list_head *head)
147{
148 int len = 0;
149 struct aa_profile *profile, *candidate = NULL;
150
151 list_for_each_entry(profile, head, base.list) {
152 if (profile->flags & PFLAG_NULL)
153 continue;
154 if (profile->xmatch && profile->xmatch_len > len) {
155 unsigned int state = aa_dfa_match(profile->xmatch,
156 DFA_START, name);
157 u32 perm = dfa_user_allow(profile->xmatch, state);
158
159 if (perm & MAY_EXEC) {
160 candidate = profile;
161 len = profile->xmatch_len;
162 }
163 } else if (!strcmp(profile->base.name, name))
164
165 return profile;
166 }
167
168 return candidate;
169}
170
171
172
173
174
175
176
177
178
179static struct aa_profile *find_attach(struct aa_namespace *ns,
180 struct list_head *list, const char *name)
181{
182 struct aa_profile *profile;
183
184 read_lock(&ns->lock);
185 profile = aa_get_profile(__attach_match(name, list));
186 read_unlock(&ns->lock);
187
188 return profile;
189}
190
191
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210
211
212static const char *separate_fqname(const char *fqname, const char **ns_name)
213{
214 const char *name;
215
216 if (fqname[0] == ':') {
217
218
219
220
221 *ns_name = fqname + 1;
222 name = *ns_name + strlen(*ns_name) + 1;
223 if (!*name)
224 name = NULL;
225 } else {
226 *ns_name = NULL;
227 name = fqname;
228 }
229
230 return name;
231}
232
233static const char *next_name(int xtype, const char *name)
234{
235 return NULL;
236}
237
238
239
240
241
242
243
244
245static struct aa_profile *x_table_lookup(struct aa_profile *profile, u32 xindex)
246{
247 struct aa_profile *new_profile = NULL;
248 struct aa_namespace *ns = profile->ns;
249 u32 xtype = xindex & AA_X_TYPE_MASK;
250 int index = xindex & AA_X_INDEX_MASK;
251 const char *name;
252
253
254 for (name = profile->file.trans.table[index]; !new_profile && name;
255 name = next_name(xtype, name)) {
256 struct aa_namespace *new_ns;
257 const char *xname = NULL;
258
259 new_ns = NULL;
260 if (xindex & AA_X_CHILD) {
261
262 new_profile = aa_find_child(profile, name);
263 continue;
264 } else if (*name == ':') {
265
266 const char *ns_name;
267 xname = name = separate_fqname(name, &ns_name);
268 if (!xname)
269
270 xname = profile->base.hname;
271 if (*ns_name == '@') {
272
273 ;
274 }
275
276 new_ns = aa_find_namespace(ns, ns_name);
277 if (!new_ns)
278 continue;
279 } else if (*name == '@') {
280
281 continue;
282 } else {
283
284 xname = name;
285 }
286
287
288 new_profile = aa_lookup_profile(new_ns ? new_ns : ns, xname);
289 aa_put_namespace(new_ns);
290 }
291
292
293 return new_profile;
294}
295
296
297
298
299
300
301
302
303
304
305
306static struct aa_profile *x_to_profile(struct aa_profile *profile,
307 const char *name, u32 xindex)
308{
309 struct aa_profile *new_profile = NULL;
310 struct aa_namespace *ns = profile->ns;
311 u32 xtype = xindex & AA_X_TYPE_MASK;
312
313 switch (xtype) {
314 case AA_X_NONE:
315
316 return NULL;
317 case AA_X_NAME:
318 if (xindex & AA_X_CHILD)
319
320 new_profile = find_attach(ns, &profile->base.profiles,
321 name);
322 else
323
324 new_profile = find_attach(ns, &ns->base.profiles,
325 name);
326 break;
327 case AA_X_TABLE:
328
329 new_profile = x_table_lookup(profile, xindex);
330 break;
331 }
332
333
334 return new_profile;
335}
336
337
338
339
340
341
342
343int apparmor_bprm_set_creds(struct linux_binprm *bprm)
344{
345 struct aa_task_cxt *cxt;
346 struct aa_profile *profile, *new_profile = NULL;
347 struct aa_namespace *ns;
348 char *buffer = NULL;
349 unsigned int state;
350 struct file_perms perms = {};
351 struct path_cond cond = {
352 file_inode(bprm->file)->i_uid,
353 file_inode(bprm->file)->i_mode
354 };
355 const char *name = NULL, *target = NULL, *info = NULL;
356 int error = cap_bprm_set_creds(bprm);
357 if (error)
358 return error;
359
360 if (bprm->cred_prepared)
361 return 0;
362
363 cxt = bprm->cred->security;
364 BUG_ON(!cxt);
365
366 profile = aa_get_profile(aa_newest_version(cxt->profile));
367
368
369
370
371 ns = profile->ns;
372 state = profile->file.start;
373
374
375 error = aa_path_name(&bprm->file->f_path, profile->path_flags, &buffer,
376 &name, &info);
377 if (error) {
378 if (profile->flags &
379 (PFLAG_IX_ON_NAME_ERROR | PFLAG_UNCONFINED))
380 error = 0;
381 name = bprm->filename;
382 goto audit;
383 }
384
385
386
387
388 if (unconfined(profile)) {
389
390 if (cxt->onexec)
391
392 new_profile = aa_get_profile(cxt->onexec);
393 else
394 new_profile = find_attach(ns, &ns->base.profiles, name);
395 if (!new_profile)
396 goto cleanup;
397
398
399
400
401
402 goto apply;
403 }
404
405
406 state = aa_str_perms(profile->file.dfa, state, name, &cond, &perms);
407 if (cxt->onexec) {
408 struct file_perms cp;
409 info = "change_profile onexec";
410 if (!(perms.allow & AA_MAY_ONEXEC))
411 goto audit;
412
413
414
415
416
417 state = aa_dfa_null_transition(profile->file.dfa, state);
418 cp = change_profile_perms(profile, cxt->onexec->ns,
419 cxt->onexec->base.name,
420 AA_MAY_ONEXEC, state);
421
422 if (!(cp.allow & AA_MAY_ONEXEC))
423 goto audit;
424 new_profile = aa_get_profile(aa_newest_version(cxt->onexec));
425 goto apply;
426 }
427
428 if (perms.allow & MAY_EXEC) {
429
430 new_profile = x_to_profile(profile, name, perms.xindex);
431 if (!new_profile) {
432 if (perms.xindex & AA_X_INHERIT) {
433
434
435
436
437 info = "ix fallback";
438 new_profile = aa_get_profile(profile);
439 goto x_clear;
440 } else if (perms.xindex & AA_X_UNCONFINED) {
441 new_profile = aa_get_profile(ns->unconfined);
442 info = "ux fallback";
443 } else {
444 error = -ENOENT;
445 info = "profile not found";
446 }
447 }
448 } else if (COMPLAIN_MODE(profile)) {
449
450 new_profile = aa_new_null_profile(profile, 0);
451 if (!new_profile) {
452 error = -ENOMEM;
453 info = "could not create null profile";
454 } else {
455 error = -EACCES;
456 target = new_profile->base.hname;
457 }
458 perms.xindex |= AA_X_UNSAFE;
459 } else
460
461 error = -EACCES;
462
463
464
465
466
467 if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) {
468 aa_put_profile(new_profile);
469 error = -EPERM;
470 goto cleanup;
471 }
472
473 if (!new_profile)
474 goto audit;
475
476 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
477
478 ;
479 }
480
481 if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
482 error = may_change_ptraced_domain(current, new_profile);
483 if (error) {
484 aa_put_profile(new_profile);
485 goto audit;
486 }
487 }
488
489
490
491
492
493
494
495
496
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498
499
500
501 if (!(perms.xindex & AA_X_UNSAFE)) {
502 AA_DEBUG("scrubbing environment variables for %s profile=%s\n",
503 name, new_profile->base.hname);
504 bprm->unsafe |= AA_SECURE_X_NEEDED;
505 }
506apply:
507 target = new_profile->base.hname;
508
509 bprm->per_clear |= PER_CLEAR_ON_SETID;
510
511x_clear:
512 aa_put_profile(cxt->profile);
513
514 cxt->profile = new_profile;
515
516
517 aa_put_profile(cxt->previous);
518 aa_put_profile(cxt->onexec);
519 cxt->previous = NULL;
520 cxt->onexec = NULL;
521 cxt->token = 0;
522
523audit:
524 error = aa_audit_file(profile, &perms, GFP_KERNEL, OP_EXEC, MAY_EXEC,
525 name, target, cond.uid, info, error);
526
527cleanup:
528 aa_put_profile(profile);
529 kfree(buffer);
530
531 return error;
532}
533
534
535
536
537
538
539
540int apparmor_bprm_secureexec(struct linux_binprm *bprm)
541{
542 int ret = cap_bprm_secureexec(bprm);
543
544
545
546
547 if (!ret && (bprm->unsafe & AA_SECURE_X_NEEDED))
548 ret = 1;
549
550 return ret;
551}
552
553
554
555
556
557void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
558{
559 struct aa_profile *profile = __aa_current_profile();
560 struct aa_task_cxt *new_cxt = bprm->cred->security;
561
562
563 if ((new_cxt->profile == profile) ||
564 (unconfined(new_cxt->profile)))
565 return;
566
567 current->pdeath_signal = 0;
568
569
570 __aa_transition_rlimits(profile, new_cxt->profile);
571}
572
573
574
575
576
577void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
578{
579
580 return;
581}
582
583
584
585
586
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588
589
590
591
592
593
594static char *new_compound_name(const char *n1, const char *n2)
595{
596 char *name = kmalloc(strlen(n1) + strlen(n2) + 3, GFP_KERNEL);
597 if (name)
598 sprintf(name, "%s//%s", n1, n2);
599 return name;
600}
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
617{
618 const struct cred *cred;
619 struct aa_task_cxt *cxt;
620 struct aa_profile *profile, *previous_profile, *hat = NULL;
621 char *name = NULL;
622 int i;
623 struct file_perms perms = {};
624 const char *target = NULL, *info = NULL;
625 int error = 0;
626
627
628
629
630
631
632 if (current->no_new_privs)
633 return -EPERM;
634
635
636 cred = get_current_cred();
637 cxt = cred->security;
638 profile = aa_cred_profile(cred);
639 previous_profile = cxt->previous;
640
641 if (unconfined(profile)) {
642 info = "unconfined";
643 error = -EPERM;
644 goto audit;
645 }
646
647 if (count) {
648
649 struct aa_profile *root;
650 root = PROFILE_IS_HAT(profile) ? profile->parent : profile;
651
652
653 for (i = 0; i < count && !hat; i++)
654
655 hat = aa_find_child(root, hats[i]);
656 if (!hat) {
657 if (!COMPLAIN_MODE(root) || permtest) {
658 if (list_empty(&root->base.profiles))
659 error = -ECHILD;
660 else
661 error = -ENOENT;
662 goto out;
663 }
664
665
666
667
668
669
670
671
672
673
674
675 name = new_compound_name(root->base.hname, hats[0]);
676 target = name;
677
678 hat = aa_new_null_profile(profile, 1);
679 if (!hat) {
680 info = "failed null profile create";
681 error = -ENOMEM;
682 goto audit;
683 }
684 } else {
685 target = hat->base.hname;
686 if (!PROFILE_IS_HAT(hat)) {
687 info = "target not hat";
688 error = -EPERM;
689 goto audit;
690 }
691 }
692
693 error = may_change_ptraced_domain(current, hat);
694 if (error) {
695 info = "ptraced";
696 error = -EPERM;
697 goto audit;
698 }
699
700 if (!permtest) {
701 error = aa_set_current_hat(hat, token);
702 if (error == -EACCES)
703
704 perms.kill = AA_MAY_CHANGEHAT;
705 else if (name && !error)
706
707 error = -ENOENT;
708 }
709 } else if (previous_profile) {
710
711
712
713 target = previous_profile->base.hname;
714 error = aa_restore_previous_profile(token);
715 perms.kill = AA_MAY_CHANGEHAT;
716 } else
717
718 goto out;
719
720audit:
721 if (!permtest)
722 error = aa_audit_file(profile, &perms, GFP_KERNEL,
723 OP_CHANGE_HAT, AA_MAY_CHANGEHAT, NULL,
724 target, GLOBAL_ROOT_UID, info, error);
725
726out:
727 aa_put_profile(hat);
728 kfree(name);
729 put_cred(cred);
730
731 return error;
732}
733
734
735
736
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739
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741
742
743
744
745
746
747
748
749int aa_change_profile(const char *ns_name, const char *hname, bool onexec,
750 bool permtest)
751{
752 const struct cred *cred;
753 struct aa_task_cxt *cxt;
754 struct aa_profile *profile, *target = NULL;
755 struct aa_namespace *ns = NULL;
756 struct file_perms perms = {};
757 const char *name = NULL, *info = NULL;
758 int op, error = 0;
759 u32 request;
760
761 if (!hname && !ns_name)
762 return -EINVAL;
763
764 if (onexec) {
765 request = AA_MAY_ONEXEC;
766 op = OP_CHANGE_ONEXEC;
767 } else {
768 request = AA_MAY_CHANGE_PROFILE;
769 op = OP_CHANGE_PROFILE;
770 }
771
772 cred = get_current_cred();
773 cxt = cred->security;
774 profile = aa_cred_profile(cred);
775
776
777
778
779
780
781
782
783 if (current->no_new_privs && !unconfined(profile)) {
784 put_cred(cred);
785 return -EPERM;
786 }
787
788 if (ns_name) {
789
790 ns = aa_find_namespace(profile->ns, ns_name);
791 if (!ns) {
792
793 name = ns_name;
794 info = "namespace not found";
795 error = -ENOENT;
796 goto audit;
797 }
798 } else
799
800 ns = aa_get_namespace(profile->ns);
801
802
803 if (!hname) {
804 if (unconfined(profile))
805 hname = ns->unconfined->base.hname;
806 else
807 hname = profile->base.hname;
808 }
809
810 perms = change_profile_perms(profile, ns, hname, request,
811 profile->file.start);
812 if (!(perms.allow & request)) {
813 error = -EACCES;
814 goto audit;
815 }
816
817
818 target = aa_lookup_profile(ns, hname);
819 if (!target) {
820 info = "profile not found";
821 error = -ENOENT;
822 if (permtest || !COMPLAIN_MODE(profile))
823 goto audit;
824
825 target = aa_new_null_profile(profile, 0);
826 if (!target) {
827 info = "failed null profile create";
828 error = -ENOMEM;
829 goto audit;
830 }
831 }
832
833
834 error = may_change_ptraced_domain(current, target);
835 if (error) {
836 info = "ptrace prevents transition";
837 goto audit;
838 }
839
840 if (permtest)
841 goto audit;
842
843 if (onexec)
844 error = aa_set_current_onexec(target);
845 else
846 error = aa_replace_current_profile(target);
847
848audit:
849 if (!permtest)
850 error = aa_audit_file(profile, &perms, GFP_KERNEL, op, request,
851 name, hname, GLOBAL_ROOT_UID, info, error);
852
853 aa_put_namespace(ns);
854 aa_put_profile(target);
855 put_cred(cred);
856
857 return error;
858}
859