aboutsummaryrefslogtreecommitdiff
path: root/security/apparmor/domain.c
blob: c825c6e0b636ee985283d3d4a077deaa24343808 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
/*
 * AppArmor security module
 *
 * This file contains AppArmor policy attachment and domain transitions
 *
 * Copyright (C) 2002-2008 Novell/SUSE
 * Copyright 2009-2010 Canonical Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2 of the
 * License.
 */

#include <linux/errno.h>
#include <linux/fdtable.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/syscalls.h>
#include <linux/tracehook.h>
#include <linux/personality.h>

#include "include/audit.h"
#include "include/apparmorfs.h"
#include "include/context.h"
#include "include/domain.h"
#include "include/file.h"
#include "include/ipc.h"
#include "include/match.h"
#include "include/path.h"
#include "include/policy.h"

/**
 * aa_free_domain_entries - free entries in a domain table
 * @domain: the domain table to free  (MAYBE NULL)
 */
void aa_free_domain_entries(struct aa_domain *domain)
{
	int i;
	if (domain) {
		if (!domain->table)
			return;

		for (i = 0; i < domain->size; i++)
			kzfree(domain->table[i]);
		kzfree(domain->table);
		domain->table = NULL;
	}
}

/**
 * may_change_ptraced_domain - check if can change profile on ptraced task
 * @task: task we want to change profile of   (NOT NULL)
 * @to_profile: profile to change to  (NOT NULL)
 *
 * Check if the task is ptraced and if so if the tracing task is allowed
 * to trace the new domain
 *
 * Returns: %0 or error if change not allowed
 */
static int may_change_ptraced_domain(struct task_struct *task,
				     struct aa_profile *to_profile)
{
	struct task_struct *tracer;
	const struct cred *cred = NULL;
	struct aa_profile *tracerp = NULL;
	int error = 0;

	rcu_read_lock();
	tracer = tracehook_tracer_task(task);
	if (tracer) {
		/* released below */
		cred = get_task_cred(tracer);
		tracerp = aa_cred_profile(cred);
	}
	rcu_read_unlock();

	/* not ptraced */
	if (!tracer || unconfined(tracerp))
		goto out;

	error = aa_may_ptrace(tracer, tracerp, to_profile, PTRACE_MODE_ATTACH);

out:
	if (cred)
		put_cred(cred);

	return error;
}

/**
 * change_profile_perms - find permissions for change_profile
 * @profile: the current profile  (NOT NULL)
 * @ns: the namespace being switched to  (NOT NULL)
 * @name: the name of the profile to change to  (NOT NULL)
 * @request: requested perms
 * @start: state to start matching in
 *
 * Returns: permission set
 */
static struct file_perms change_profile_perms(struct aa_profile *profile,
					      struct aa_namespace *ns,
					      const char *name, u32 request,
					      unsigned int start)
{
	struct file_perms perms;
	struct path_cond cond = { };
	unsigned int state;

	if (unconfined(profile)) {
		perms.allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
		perms.audit = perms.quiet = perms.kill = 0;
		return perms;
	} else if (!profile->file.dfa) {
		return nullperms;
	} else if ((ns == profile->ns)) {
		/* try matching against rules with out namespace prepended */
		aa_str_perms(profile->file.dfa, start, name, &cond, &perms);
		if (COMBINED_PERM_MASK(perms) & request)
			return perms;
	}

	/* try matching with namespace name and then profile */
	state = aa_dfa_match(profile->file.dfa, start, ns->base.name);
	state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
	aa_str_perms(profile->file.dfa, state, name, &cond, &perms);

	return perms;
}

/**
 * __attach_match_ - find an attachment match
 * @name - to match against  (NOT NULL)
 * @head - profile list to walk  (NOT NULL)
 *
 * Do a linear search on the profiles in the list.  There is a matching
 * preference where an exact match is preferred over a name which uses
 * expressions to match, and matching expressions with the greatest
 * xmatch_len are preferred.
 *
 * Requires: @head not be shared or have appropriate locks held
 *
 * Returns: profile or NULL if no match found
 */
static struct aa_profile *__attach_match(const char *name,
					 struct list_head *head)
{
	int len = 0;
	struct aa_profile *profile, *candidate = NULL;

	list_for_each_entry(profile, head, base.list) {
		if (profile->flags & PFLAG_NULL)
			continue;
		if (profile->xmatch && profile->xmatch_len > len) {
			unsigned int state = aa_dfa_match(profile->xmatch,
							  DFA_START, name);
			u32 perm = dfa_user_allow(profile->xmatch, state);
			/* any accepting state means a valid match. */
			if (perm & MAY_EXEC) {
				candidate = profile;
				len = profile->xmatch_len;
			}
		} else if (!strcmp(profile->base.name, name))
			/* exact non-re match, no more searching required */
			return profile;
	}

	return candidate;
}

/**
 * find_attach - do attachment search for unconfined processes
 * @ns: the current namespace  (NOT NULL)
 * @list: list to search  (NOT NULL)
 * @name: the executable name to match against  (NOT NULL)
 *
 * Returns: profile or NULL if no match found
 */
static struct aa_profile *find_attach(struct aa_namespace *ns,
				      struct list_head *list, const char *name)
{
	struct aa_profile *profile;

	read_lock(&ns->lock);
	profile = aa_get_profile(__attach_match(name, list));
	read_unlock(&ns->lock);

	return profile;
}

/**
 * separate_fqname - separate the namespace and profile names
 * @fqname: the fqname name to split  (NOT NULL)
 * @ns_name: the namespace name if it exists  (NOT NULL)
 *
 * This is the xtable equivalent routine of aa_split_fqname.  It finds the
 * split in an xtable fqname which contains an embedded \0 instead of a :
 * if a namespace is specified.  This is done so the xtable is constant and
 * isn't re-split on every lookup.
 *
 * Either the profile or namespace name may be optional but if the namespace
 * is specified the profile name termination must be present.  This results
 * in the following possible encodings:
 * profile_name\0
 * :ns_name\0profile_name\0
 * :ns_name\0\0
 *
 * NOTE: the xtable fqname is pre-validated at load time in unpack_trans_table
 *
 * Returns: profile name if it is specified else NULL
 */
static const char *separate_fqname(const char *fqname, const char **ns_name)
{
	const char *name;

	if (fqname[0] == ':') {
		/* In this case there is guaranteed to be two \0 terminators
		 * in the string.  They are verified at load time by
		 * by unpack_trans_table
		 */
		*ns_name = fqname + 1;		/* skip : */
		name = *ns_name + strlen(*ns_name) + 1;
		if (!*name)
			name = NULL;
	} else {
		*ns_name = NULL;
		name = fqname;
	}

	return name;
}

static const char *next_name(int xtype, const char *name)
{
	return NULL;
}

/**
 * x_table_lookup - lookup an x transition name via transition table
 * @profile: current profile (NOT NULL)
 * @xindex: index into x transition table
 *
 * Returns: refcounted profile, or NULL on failure (MAYBE NULL)
 */
static struct aa_profile *x_table_lookup(struct aa_profile *profile, u32 xindex)
{
	struct aa_profile *new_profile = NULL;
	struct aa_namespace *ns = profile->ns;
	u32 xtype = xindex & AA_X_TYPE_MASK;
	int index = xindex & AA_X_INDEX_MASK;
	const char *name;

	/* index is guaranteed to be in range, validated at load time */
	for (name = profile->file.trans.table[index]; !new_profile && name;
	     name = next_name(xtype, name)) {
		struct aa_namespace *new_ns;
		const char *xname = NULL;

		new_ns = NULL;
		if (xindex & AA_X_CHILD) {
			/* release by caller */
			new_profile = aa_find_child(profile, name);
			continue;
		} else if (*name == ':') {
			/* switching namespace */
			const char *ns_name;
			xname = name = separate_fqname(name, &ns_name);
			if (!xname)
				/* no name so use profile name */
				xname = profile->base.hname;
			if (*ns_name == '@') {
				/* TODO: variable support */
				;
			}
			/* released below */
			new_ns = aa_find_namespace(ns, ns_name);
			if (!new_ns)
				continue;
		} else if (*name == '@') {
			/* TODO: variable support */
			continue;
		} else {
			/* basic namespace lookup */
			xname = name;
		}

		/* released by caller */
		new_profile = aa_lookup_profile(new_ns ? new_ns : ns, xname);
		aa_put_namespace(new_ns);
	}

	/* released by caller */
	return new_profile;
}

/**
 * x_to_profile - get target profile for a given xindex
 * @profile: current profile  (NOT NULL)
 * @name: name to lookup (NOT NULL)
 * @xindex: index into x transition table
 *
 * find profile for a transition index
 *
 * Returns: refcounted profile or NULL if not found available
 */
static struct aa_profile *x_to_profile(struct aa_profile *profile,
				       const char *name, u32 xindex)
{
	struct aa_profile *new_profile = NULL;
	struct aa_namespace *ns = profile->ns;
	u32 xtype = xindex & AA_X_TYPE_MASK;

	switch (xtype) {
	case AA_X_NONE:
		/* fail exec unless ix || ux fallback - handled by caller */
		return NULL;
	case AA_X_NAME:
		if (xindex & AA_X_CHILD)
			/* released by caller */
			new_profile = find_attach(ns, &profile->base.profiles,
						  name);
		else
			/* released by caller */
			new_profile = find_attach(ns, &ns->base.profiles,
						  name);
		break;
	case AA_X_TABLE:
		/* released by caller */
		new_profile = x_table_lookup(profile, xindex);
		break;
	}

	/* released by caller */
	return new_profile;
}

/**
 * apparmor_bprm_set_creds - set the new creds on the bprm struct
 * @bprm: binprm for the exec  (NOT NULL)
 *
 * Returns: %0 or error on failure
 */
int apparmor_bprm_set_creds(struct linux_binprm *bprm)
{
	struct aa_task_cxt *cxt;
	struct aa_profile *profile, *new_profile = NULL;
	struct aa_namespace *ns;
	char *buffer = NULL;
	unsigned int state;
	struct file_perms perms = {};
	struct path_cond cond = {
		bprm->file->f_path.dentry->d_inode->i_uid,
		bprm->file->f_path.dentry->d_inode->i_mode
	};
	const char *name = NULL, *target = NULL, *info = NULL;
	int error = cap_bprm_set_creds(bprm);
	if (error)
		return error;

	if (bprm->cred_prepared)
		return 0;

	cxt = bprm->cred->security;
	BUG_ON(!cxt);

	profile = aa_get_profile(aa_newest_version(cxt->profile));
	/*
	 * get the namespace from the replacement profile as replacement
	 * can change the namespace
	 */
	ns = profile->ns;
	state = profile->file.start;

	/* buffer freed below, name is pointer into buffer */
	error = aa_get_name(&bprm->file->f_path, profile->path_flags, &buffer,
			    &name);
	if (error) {
		if (profile->flags &
		    (PFLAG_IX_ON_NAME_ERROR | PFLAG_UNCONFINED))
			error = 0;
		info = "Exec failed name resolution";
		name = bprm->filename;
		goto audit;
	}

	/* Test for onexec first as onexec directives override other
	 * x transitions.
	 */
	if (unconfined(profile)) {
		/* unconfined task */
		if (cxt->onexec)
			/* change_profile on exec already been granted */
			new_profile = aa_get_profile(cxt->onexec);
		else
			new_profile = find_attach(ns, &ns->base.profiles, name);
		if (!new_profile)
			goto cleanup;
		goto apply;
	}

	/* find exec permissions for name */
	state = aa_str_perms(profile->file.dfa, state, name, &cond, &perms);
	if (cxt->onexec) {
		struct file_perms cp;
		info = "change_profile onexec";
		if (!(perms.allow & AA_MAY_ONEXEC))
			goto audit;

		/* test if this exec can be paired with change_profile onexec.
		 * onexec permission is linked to exec with a standard pairing
		 * exec\0change_profile
		 */
		state = aa_dfa_null_transition(profile->file.dfa, state);
		cp = change_profile_perms(profile, cxt->onexec->ns, name,
					  AA_MAY_ONEXEC, state);

		if (!(cp.allow & AA_MAY_ONEXEC))
			goto audit;
		new_profile = aa_get_profile(aa_newest_version(cxt->onexec));
		goto apply;
	}

	if (perms.allow & MAY_EXEC) {
		/* exec permission determine how to transition */
		new_profile = x_to_profile(profile, name, perms.xindex);
		if (!new_profile) {
			if (perms.xindex & AA_X_INHERIT) {
				/* (p|c|n)ix - don't change profile but do
				 * use the newest version, which was picked
				 * up above when getting profile
				 */
				info = "ix fallback";
				new_profile = aa_get_profile(profile);
				goto x_clear;
			} else if (perms.xindex & AA_X_UNCONFINED) {
				new_profile = aa_get_profile(ns->unconfined);
				info = "ux fallback";
			} else {
				error = -ENOENT;
				info = "profile not found";
			}
		}
	} else if (COMPLAIN_MODE(profile)) {
		/* no exec permission - are we in learning mode */
		new_profile = aa_new_null_profile(profile, 0);
		if (!new_profile) {
			error = -ENOMEM;
			info = "could not create null profile";
		} else {
			error = -EACCES;
			target = new_profile->base.hname;
		}
		perms.xindex |= AA_X_UNSAFE;
	} else
		/* fail exec */
		error = -EACCES;

	if (!new_profile)
		goto audit;

	if (bprm->unsafe & LSM_UNSAFE_SHARE) {
		/* FIXME: currently don't mediate shared state */
		;
	}

	if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
		error = may_change_ptraced_domain(current, new_profile);
		if (error) {
			aa_put_profile(new_profile);
			goto audit;
		}
	}

	/* Determine if secure exec is needed.
	 * Can be at this point for the following reasons:
	 * 1. unconfined switching to confined
	 * 2. confined switching to different confinement
	 * 3. confined switching to unconfined
	 *
	 * Cases 2 and 3 are marked as requiring secure exec
	 * (unless policy specified "unsafe exec")
	 *
	 * bprm->unsafe is used to cache the AA_X_UNSAFE permission
	 * to avoid having to recompute in secureexec
	 */
	if (!(perms.xindex & AA_X_UNSAFE)) {
		AA_DEBUG("scrubbing environment variables for %s profile=%s\n",
			 name, new_profile->base.hname);
		bprm->unsafe |= AA_SECURE_X_NEEDED;
	}
apply:
	target = new_profile->base.hname;
	/* when transitioning profiles clear unsafe personality bits */
	bprm->per_clear |= PER_CLEAR_ON_SETID;

x_clear:
	aa_put_profile(cxt->profile);
	/* transfer new profile reference will be released when cxt is freed */
	cxt->profile = new_profile;

	/* clear out all temporary/transitional state from the context */
	aa_put_profile(cxt->previous);
	aa_put_profile(cxt->onexec);
	cxt->previous = NULL;
	cxt->onexec = NULL;
	cxt->token = 0;

audit:
	error = aa_audit_file(profile, &perms, GFP_KERNEL, OP_EXEC, MAY_EXEC,
			      name, target, cond.uid, info, error);

cleanup:
	aa_put_profile(profile);
	kfree(buffer);

	return error;
}

/**
 * apparmor_bprm_secureexec - determine if secureexec is needed
 * @bprm: binprm for exec  (NOT NULL)
 *
 * Returns: %1 if secureexec is needed else %0
 */
int apparmor_bprm_secureexec(struct linux_binprm *bprm)
{
	int ret = cap_bprm_secureexec(bprm);

	/* the decision to use secure exec is computed in set_creds
	 * and stored in bprm->unsafe.
	 */
	if (!ret && (bprm->unsafe & AA_SECURE_X_NEEDED))
		ret = 1;

	return ret;
}

/**
 * apparmor_bprm_committing_creds - do task cleanup on committing new creds
 * @bprm: binprm for the exec  (NOT NULL)
 */
void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
{
	struct aa_profile *profile = __aa_current_profile();
	struct aa_task_cxt *new_cxt = bprm->cred->security;

	/* bail out if unconfined or not changing profile */
	if ((new_cxt->profile == profile) ||
	    (unconfined(new_cxt->profile)))
		return;

	current->pdeath_signal = 0;

	/* reset soft limits and set hard limits for the new profile */
	__aa_transition_rlimits(profile, new_cxt->profile);
}

/**
 * apparmor_bprm_commited_cred - do cleanup after new creds committed
 * @bprm: binprm for the exec  (NOT NULL)
 */
void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
{
	/* TODO: cleanup signals - ipc mediation */
	return;
}

/*
 * Functions for self directed profile change
 */

/**
 * new_compound_name - create an hname with @n2 appended to @n1
 * @n1: base of hname  (NOT NULL)
 * @n2: name to append (NOT NULL)
 *
 * Returns: new name or NULL on error
 */
static char *new_compound_name(const char *n1, const char *n2)
{
	char *name = kmalloc(strlen(n1) + strlen(n2) + 3, GFP_KERNEL);
	if (name)
		sprintf(name, "%s//%s", n1, n2);
	return name;
}

/**
 * aa_change_hat - change hat to/from subprofile
 * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
 * @count: number of hat names in @hats
 * @token: magic value to validate the hat change
 * @permtest: true if this is just a permission test
 *
 * Change to the first profile specified in @hats that exists, and store
 * the @hat_magic in the current task context.  If the count == 0 and the
 * @token matches that stored in the current task context, return to the
 * top level profile.
 *
 * Returns %0 on success, error otherwise.
 */
int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
{
	const struct cred *cred;
	struct aa_task_cxt *cxt;
	struct aa_profile *profile, *previous_profile, *hat = NULL;
	char *name = NULL;
	int i;
	struct file_perms perms = {};
	const char *target = NULL, *info = NULL;
	int error = 0;

	/* released below */
	cred = get_current_cred();
	cxt = cred->security;
	profile = aa_cred_profile(cred);
	previous_profile = cxt->previous;

	if (unconfined(profile)) {
		info = "unconfined";
		error = -EPERM;
		goto audit;
	}

	if (count) {
		/* attempting to change into a new hat or switch to a sibling */
		struct aa_profile *root;
		root = PROFILE_IS_HAT(profile) ? profile->parent : profile;

		/* find first matching hat */
		for (i = 0; i < count && !hat; i++)
			/* released below */
			hat = aa_find_child(root, hats[i]);
		if (!hat) {
			if (!COMPLAIN_MODE(root) || permtest) {
				if (list_empty(&root->base.profiles))
					error = -ECHILD;
				else
					error = -ENOENT;
				goto out;
			}

			/*
			 * In complain mode and failed to match any hats.
			 * Audit the failure is based off of the first hat
			 * supplied.  This is done due how userspace
			 * interacts with change_hat.
			 *
			 * TODO: Add logging of all failed hats
			 */

			/* freed below */
			name = new_compound_name(root->base.hname, hats[0]);
			target = name;
			/* released below */
			hat = aa_new_null_profile(profile, 1);
			if (!hat) {
				info = "failed null profile create";
				error = -ENOMEM;
				goto audit;
			}
		} else {
			target = hat->base.hname;
			if (!PROFILE_IS_HAT(hat)) {
				info = "target not hat";
				error = -EPERM;
				goto audit;
			}
		}

		error = may_change_ptraced_domain(current, hat);
		if (error) {
			info = "ptraced";
			error = -EPERM;
			goto audit;
		}

		if (!permtest) {
			error = aa_set_current_hat(hat, token);
			if (error == -EACCES)
				/* kill task in case of brute force attacks */
				perms.kill = AA_MAY_CHANGEHAT;
			else if (name && !error)
				/* reset error for learning of new hats */
				error = -ENOENT;
		}
	} else if (previous_profile) {
		/* Return to saved profile.  Kill task if restore fails
		 * to avoid brute force attacks
		 */
		target = previous_profile->base.hname;
		error = aa_restore_previous_profile(token);
		perms.kill = AA_MAY_CHANGEHAT;
	} else
		/* ignore restores when there is no saved profile */
		goto out;

audit:
	if (!permtest)
		error = aa_audit_file(profile, &perms, GFP_KERNEL,
				      OP_CHANGE_HAT, AA_MAY_CHANGEHAT, NULL,
				      target, 0, info, error);

out:
	aa_put_profile(hat);
	kfree(name);
	put_cred(cred);

	return error;
}

/**
 * aa_change_profile - perform a one-way profile transition
 * @ns_name: name of the profile namespace to change to (MAYBE NULL)
 * @hname: name of profile to change to (MAYBE NULL)
 * @onexec: whether this transition is to take place immediately or at exec
 * @permtest: true if this is just a permission test
 *
 * Change to new profile @name.  Unlike with hats, there is no way
 * to change back.  If @name isn't specified the current profile name is
 * used.
 * If @onexec then the transition is delayed until
 * the next exec.
 *
 * Returns %0 on success, error otherwise.
 */
int aa_change_profile(const char *ns_name, const char *hname, bool onexec,
		      bool permtest)
{
	const struct cred *cred;
	struct aa_task_cxt *cxt;
	struct aa_profile *profile, *target = NULL;
	struct aa_namespace *ns = NULL;
	struct file_perms perms = {};
	const char *name = NULL, *info = NULL;
	int op, error = 0;
	u32 request;

	if (!hname && !ns_name)
		return -EINVAL;

	if (onexec) {
		request = AA_MAY_ONEXEC;
		op = OP_CHANGE_ONEXEC;
	} else {
		request = AA_MAY_CHANGE_PROFILE;
		op = OP_CHANGE_PROFILE;
	}

	cred = get_current_cred();
	cxt = cred->security;
	profile = aa_cred_profile(cred);

	if (ns_name) {
		/* released below */
		ns = aa_find_namespace(profile->ns, ns_name);
		if (!ns) {
			/* we don't create new namespace in complain mode */
			name = ns_name;
			info = "namespace not found";
			error = -ENOENT;
			goto audit;
		}
	} else
		/* released below */
		ns = aa_get_namespace(profile->ns);

	/* if the name was not specified, use the name of the current profile */
	if (!hname) {
		if (unconfined(profile))
			hname = ns->unconfined->base.hname;
		else
			hname = profile->base.hname;
	}

	perms = change_profile_perms(profile, ns, hname, request,
				     profile->file.start);
	if (!(perms.allow & request)) {
		error = -EACCES;
		goto audit;
	}

	/* released below */
	target = aa_lookup_profile(ns, hname);
	if (!target) {
		info = "profile not found";
		error = -ENOENT;
		if (permtest || !COMPLAIN_MODE(profile))
			goto audit;
		/* released below */
		target = aa_new_null_profile(profile, 0);
		if (!target) {
			info = "failed null profile create";
			error = -ENOMEM;
			goto audit;
		}
	}

	/* check if tracing task is allowed to trace target domain */
	error = may_change_ptraced_domain(current, target);
	if (error) {
		info = "ptrace prevents transition";
		goto audit;
	}

	if (permtest)
		goto audit;

	if (onexec)
		error = aa_set_current_onexec(target);
	else
		error = aa_replace_current_profile(target);

audit:
	if (!permtest)
		error = aa_audit_file(profile, &perms, GFP_KERNEL, op, request,
				      name, hname, 0, info, error);

	aa_put_namespace(ns);
	aa_put_profile(target);
	put_cred(cred);

	return error;
}