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[thirdparty/linux.git] / security / apparmor / domain.c
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b886d83c 1// SPDX-License-Identifier: GPL-2.0-only
898127c3
JJ
2/*
3 * AppArmor security module
4 *
5 * This file contains AppArmor policy attachment and domain transitions
6 *
7 * Copyright (C) 2002-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
898127c3
JJ
9 */
10
11#include <linux/errno.h>
12#include <linux/fdtable.h>
13#include <linux/file.h>
14#include <linux/mount.h>
15#include <linux/syscalls.h>
16#include <linux/tracehook.h>
17#include <linux/personality.h>
8e51f908 18#include <linux/xattr.h>
898127c3
JJ
19
20#include "include/audit.h"
21#include "include/apparmorfs.h"
d8889d49 22#include "include/cred.h"
898127c3
JJ
23#include "include/domain.h"
24#include "include/file.h"
25#include "include/ipc.h"
26#include "include/match.h"
27#include "include/path.h"
28#include "include/policy.h"
cff281f6 29#include "include/policy_ns.h"
898127c3
JJ
30
31/**
32 * aa_free_domain_entries - free entries in a domain table
33 * @domain: the domain table to free (MAYBE NULL)
34 */
35void aa_free_domain_entries(struct aa_domain *domain)
36{
37 int i;
38 if (domain) {
39 if (!domain->table)
40 return;
41
42 for (i = 0; i < domain->size; i++)
43 kzfree(domain->table[i]);
44 kzfree(domain->table);
45 domain->table = NULL;
46 }
47}
48
49/**
50 * may_change_ptraced_domain - check if can change profile on ptraced task
b2d09ae4
JJ
51 * @to_label: profile to change to (NOT NULL)
52 * @info: message if there is an error
898127c3 53 *
51775fe7 54 * Check if current is ptraced and if so if the tracing task is allowed
898127c3
JJ
55 * to trace the new domain
56 *
57 * Returns: %0 or error if change not allowed
58 */
b2d09ae4
JJ
59static int may_change_ptraced_domain(struct aa_label *to_label,
60 const char **info)
898127c3
JJ
61{
62 struct task_struct *tracer;
637f688d 63 struct aa_label *tracerl = NULL;
898127c3
JJ
64 int error = 0;
65
66 rcu_read_lock();
51775fe7 67 tracer = ptrace_parent(current);
3cfcc19e 68 if (tracer)
898127c3 69 /* released below */
637f688d 70 tracerl = aa_get_task_label(tracer);
898127c3
JJ
71
72 /* not ptraced */
637f688d 73 if (!tracer || unconfined(tracerl))
898127c3
JJ
74 goto out;
75
b2d09ae4 76 error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
898127c3
JJ
77
78out:
04fdc099 79 rcu_read_unlock();
637f688d 80 aa_put_label(tracerl);
898127c3 81
b2d09ae4
JJ
82 if (error)
83 *info = "ptrace prevents transition";
898127c3
JJ
84 return error;
85}
86
93c98a48
JJ
87/**** TODO: dedup to aa_label_match - needs perm and dfa, merging
88 * specifically this is an exact copy of aa_label_match except
89 * aa_compute_perms is replaced with aa_compute_fperms
90 * and policy.dfa with file.dfa
91 ****/
92/* match a profile and its associated ns component if needed
93 * Assumes visibility test has already been done.
94 * If a subns profile is not to be matched should be prescreened with
95 * visibility test.
96 */
97static inline unsigned int match_component(struct aa_profile *profile,
98 struct aa_profile *tp,
99 bool stack, unsigned int state)
100{
101 const char *ns_name;
102
103 if (stack)
104 state = aa_dfa_match(profile->file.dfa, state, "&");
105 if (profile->ns == tp->ns)
106 return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
107
108 /* try matching with namespace name and then profile */
109 ns_name = aa_ns_name(profile->ns, tp->ns, true);
110 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
111 state = aa_dfa_match(profile->file.dfa, state, ns_name);
112 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
113 return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
114}
115
116/**
117 * label_compound_match - find perms for full compound label
118 * @profile: profile to find perms for
119 * @label: label to check access permissions for
120 * @stack: whether this is a stacking request
121 * @start: state to start match in
122 * @subns: whether to do permission checks on components in a subns
123 * @request: permissions to request
124 * @perms: perms struct to set
125 *
126 * Returns: 0 on success else ERROR
127 *
128 * For the label A//&B//&C this does the perm match for A//&B//&C
129 * @perms should be preinitialized with allperms OR a previous permission
130 * check to be stacked.
131 */
132static int label_compound_match(struct aa_profile *profile,
133 struct aa_label *label, bool stack,
134 unsigned int state, bool subns, u32 request,
135 struct aa_perms *perms)
136{
137 struct aa_profile *tp;
138 struct label_it i;
139 struct path_cond cond = { };
140
141 /* find first subcomponent that is visible */
142 label_for_each(i, label, tp) {
143 if (!aa_ns_visible(profile->ns, tp->ns, subns))
144 continue;
145 state = match_component(profile, tp, stack, state);
146 if (!state)
147 goto fail;
148 goto next;
149 }
150
151 /* no component visible */
152 *perms = allperms;
153 return 0;
154
155next:
156 label_for_each_cont(i, label, tp) {
157 if (!aa_ns_visible(profile->ns, tp->ns, subns))
158 continue;
159 state = aa_dfa_match(profile->file.dfa, state, "//&");
160 state = match_component(profile, tp, false, state);
161 if (!state)
162 goto fail;
163 }
164 *perms = aa_compute_fperms(profile->file.dfa, state, &cond);
165 aa_apply_modes_to_perms(profile, perms);
166 if ((perms->allow & request) != request)
167 return -EACCES;
168
169 return 0;
170
171fail:
172 *perms = nullperms;
173 return -EACCES;
174}
175
176/**
177 * label_components_match - find perms for all subcomponents of a label
178 * @profile: profile to find perms for
179 * @label: label to check access permissions for
180 * @stack: whether this is a stacking request
181 * @start: state to start match in
182 * @subns: whether to do permission checks on components in a subns
183 * @request: permissions to request
184 * @perms: an initialized perms struct to add accumulation to
185 *
186 * Returns: 0 on success else ERROR
187 *
188 * For the label A//&B//&C this does the perm match for each of A and B and C
189 * @perms should be preinitialized with allperms OR a previous permission
190 * check to be stacked.
191 */
192static int label_components_match(struct aa_profile *profile,
193 struct aa_label *label, bool stack,
194 unsigned int start, bool subns, u32 request,
195 struct aa_perms *perms)
196{
197 struct aa_profile *tp;
198 struct label_it i;
199 struct aa_perms tmp;
200 struct path_cond cond = { };
201 unsigned int state = 0;
202
203 /* find first subcomponent to test */
204 label_for_each(i, label, tp) {
205 if (!aa_ns_visible(profile->ns, tp->ns, subns))
206 continue;
207 state = match_component(profile, tp, stack, start);
208 if (!state)
209 goto fail;
210 goto next;
211 }
212
213 /* no subcomponents visible - no change in perms */
214 return 0;
215
216next:
217 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
218 aa_apply_modes_to_perms(profile, &tmp);
219 aa_perms_accum(perms, &tmp);
220 label_for_each_cont(i, label, tp) {
221 if (!aa_ns_visible(profile->ns, tp->ns, subns))
222 continue;
223 state = match_component(profile, tp, stack, start);
224 if (!state)
225 goto fail;
226 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
227 aa_apply_modes_to_perms(profile, &tmp);
228 aa_perms_accum(perms, &tmp);
229 }
230
231 if ((perms->allow & request) != request)
232 return -EACCES;
233
234 return 0;
235
236fail:
237 *perms = nullperms;
238 return -EACCES;
239}
240
241/**
242 * label_match - do a multi-component label match
243 * @profile: profile to match against (NOT NULL)
244 * @label: label to match (NOT NULL)
245 * @stack: whether this is a stacking request
246 * @state: state to start in
247 * @subns: whether to match subns components
248 * @request: permission request
249 * @perms: Returns computed perms (NOT NULL)
250 *
251 * Returns: the state the match finished in, may be the none matching state
252 */
253static int label_match(struct aa_profile *profile, struct aa_label *label,
254 bool stack, unsigned int state, bool subns, u32 request,
255 struct aa_perms *perms)
256{
257 int error;
258
259 *perms = nullperms;
260 error = label_compound_match(profile, label, stack, state, subns,
261 request, perms);
262 if (!error)
263 return error;
264
265 *perms = allperms;
266 return label_components_match(profile, label, stack, state, subns,
267 request, perms);
268}
269
270/******* end TODO: dedup *****/
271
898127c3
JJ
272/**
273 * change_profile_perms - find permissions for change_profile
274 * @profile: the current profile (NOT NULL)
93c98a48
JJ
275 * @target: label to transition to (NOT NULL)
276 * @stack: whether this is a stacking request
898127c3
JJ
277 * @request: requested perms
278 * @start: state to start matching in
279 *
93c98a48 280 *
898127c3 281 * Returns: permission set
93c98a48
JJ
282 *
283 * currently only matches full label A//&B//&C or individual components A, B, C
284 * not arbitrary combinations. Eg. A//&B, C
898127c3 285 */
93c98a48
JJ
286static int change_profile_perms(struct aa_profile *profile,
287 struct aa_label *target, bool stack,
288 u32 request, unsigned int start,
289 struct aa_perms *perms)
290{
291 if (profile_unconfined(profile)) {
292 perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
293 perms->audit = perms->quiet = perms->kill = 0;
294 return 0;
295 }
296
297 /* TODO: add profile in ns screening */
298 return label_match(profile, target, stack, start, true, request, perms);
299}
300
8e51f908
MG
301/**
302 * aa_xattrs_match - check whether a file matches the xattrs defined in profile
303 * @bprm: binprm struct for the process to validate
304 * @profile: profile to match against (NOT NULL)
73f488cd 305 * @state: state to start match in
8e51f908
MG
306 *
307 * Returns: number of extended attributes that matched, or < 0 on error
308 */
309static int aa_xattrs_match(const struct linux_binprm *bprm,
73f488cd 310 struct aa_profile *profile, unsigned int state)
8e51f908
MG
311{
312 int i;
a61ecd32 313 ssize_t size;
8e51f908
MG
314 struct dentry *d;
315 char *value = NULL;
316 int value_size = 0, ret = profile->xattr_count;
317
318 if (!bprm || !profile->xattr_count)
319 return 0;
8c62ed27 320 might_sleep();
8e51f908 321
73f488cd
JJ
322 /* transition from exec match to xattr set */
323 state = aa_dfa_null_transition(profile->xmatch, state);
324
8e51f908
MG
325 d = bprm->file->f_path.dentry;
326
327 for (i = 0; i < profile->xattr_count; i++) {
328 size = vfs_getxattr_alloc(d, profile->xattrs[i], &value,
329 value_size, GFP_KERNEL);
73f488cd
JJ
330 if (size >= 0) {
331 u32 perm;
8e51f908 332
73f488cd
JJ
333 /* Check the xattr value, not just presence */
334 state = aa_dfa_match_len(profile->xmatch, state, value,
335 size);
336 perm = dfa_user_allow(profile->xmatch, state);
337 if (!(perm & MAY_EXEC)) {
8e51f908
MG
338 ret = -EINVAL;
339 goto out;
340 }
73f488cd
JJ
341 }
342 /* transition to next element */
343 state = aa_dfa_null_transition(profile->xmatch, state);
344 if (size < 0) {
345 /*
346 * No xattr match, so verify if transition to
347 * next element was valid. IFF so the xattr
348 * was optional.
349 */
350 if (!state) {
8e51f908
MG
351 ret = -EINVAL;
352 goto out;
353 }
73f488cd
JJ
354 /* don't count missing optional xattr as matched */
355 ret--;
8e51f908
MG
356 }
357 }
358
359out:
360 kfree(value);
361 return ret;
362}
363
898127c3 364/**
8c62ed27 365 * find_attach - do attachment search for unconfined processes
8e51f908 366 * @bprm - binprm structure of transitioning task
8c62ed27 367 * @ns: the current namespace (NOT NULL)
898127c3 368 * @head - profile list to walk (NOT NULL)
8c62ed27 369 * @name - to match against (NOT NULL)
844b8292 370 * @info - info message if there was an error (NOT NULL)
898127c3
JJ
371 *
372 * Do a linear search on the profiles in the list. There is a matching
373 * preference where an exact match is preferred over a name which uses
374 * expressions to match, and matching expressions with the greatest
375 * xmatch_len are preferred.
376 *
377 * Requires: @head not be shared or have appropriate locks held
378 *
8c62ed27 379 * Returns: label or NULL if no match found
898127c3 380 */
8c62ed27
JJ
381static struct aa_label *find_attach(const struct linux_binprm *bprm,
382 struct aa_ns *ns, struct list_head *head,
383 const char *name, const char **info)
898127c3 384{
21f60661 385 int candidate_len = 0, candidate_xattrs = 0;
844b8292 386 bool conflict = false;
898127c3
JJ
387 struct aa_profile *profile, *candidate = NULL;
388
21f60661
JJ
389 AA_BUG(!name);
390 AA_BUG(!head);
391
8c62ed27
JJ
392 rcu_read_lock();
393restart:
01e2b670 394 list_for_each_entry_rcu(profile, head, base.list) {
06d426d1
JJ
395 if (profile->label.flags & FLAG_NULL &&
396 &profile->label == ns_unconfined(profile->ns))
898127c3 397 continue;
06d426d1 398
8e51f908
MG
399 /* Find the "best" matching profile. Profiles must
400 * match the path and extended attributes (if any)
401 * associated with the file. A more specific path
402 * match will be preferred over a less specific one,
403 * and a match with more matching extended attributes
404 * will be preferred over one with fewer. If the best
405 * match has both the same level of path specificity
406 * and the same number of matching extended attributes
407 * as another profile, signal a conflict and refuse to
408 * match.
409 */
844b8292 410 if (profile->xmatch) {
21f60661 411 unsigned int state, count;
8e51f908
MG
412 u32 perm;
413
21f60661
JJ
414 state = aa_dfa_leftmatch(profile->xmatch, DFA_START,
415 name, &count);
8e51f908
MG
416 perm = dfa_user_allow(profile->xmatch, state);
417 /* any accepting state means a valid match. */
418 if (perm & MAY_EXEC) {
8c62ed27 419 int ret = 0;
21f60661
JJ
420
421 if (count < candidate_len)
422 continue;
8e51f908 423
8c62ed27
JJ
424 if (bprm && profile->xattr_count) {
425 long rev = READ_ONCE(ns->revision);
426
427 if (!aa_get_profile_not0(profile))
428 goto restart;
429 rcu_read_unlock();
430 ret = aa_xattrs_match(bprm, profile,
431 state);
432 rcu_read_lock();
433 aa_put_profile(profile);
434 if (rev !=
435 READ_ONCE(ns->revision))
436 /* policy changed */
437 goto restart;
438 /*
439 * Fail matching if the xattrs don't
440 * match
441 */
442 if (ret < 0)
443 continue;
444 }
73f488cd
JJ
445 /*
446 * TODO: allow for more flexible best match
447 *
448 * The new match isn't more specific
8e51f908
MG
449 * than the current best match
450 */
21f60661
JJ
451 if (count == candidate_len &&
452 ret <= candidate_xattrs) {
8e51f908 453 /* Match is equivalent, so conflict */
21f60661 454 if (ret == candidate_xattrs)
1a3881d3 455 conflict = true;
8e51f908 456 continue;
844b8292 457 }
8e51f908
MG
458
459 /* Either the same length with more matching
460 * xattrs, or a longer match
461 */
462 candidate = profile;
21f60661
JJ
463 candidate_len = profile->xmatch_len;
464 candidate_xattrs = ret;
8e51f908 465 conflict = false;
898127c3 466 }
8c62ed27 467 } else if (!strcmp(profile->base.name, name)) {
73f488cd
JJ
468 /*
469 * old exact non-re match, without conditionals such
470 * as xattrs. no more searching required
471 */
8c62ed27
JJ
472 candidate = profile;
473 goto out;
474 }
898127c3
JJ
475 }
476
8c62ed27
JJ
477 if (!candidate || conflict) {
478 if (conflict)
479 *info = "conflicting profile attachments";
480 rcu_read_unlock();
844b8292
JJ
481 return NULL;
482 }
483
8c62ed27
JJ
484out:
485 candidate = aa_get_newest_profile(candidate);
01e2b670 486 rcu_read_unlock();
898127c3 487
8c62ed27 488 return &candidate->label;
898127c3
JJ
489}
490
491static const char *next_name(int xtype, const char *name)
492{
493 return NULL;
494}
495
496/**
497 * x_table_lookup - lookup an x transition name via transition table
498 * @profile: current profile (NOT NULL)
499 * @xindex: index into x transition table
93c98a48 500 * @name: returns: name tested to find label (NOT NULL)
898127c3 501 *
93c98a48 502 * Returns: refcounted label, or NULL on failure (MAYBE NULL)
898127c3 503 */
2ea3ffb7
JJ
504struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex,
505 const char **name)
898127c3 506{
93c98a48 507 struct aa_label *label = NULL;
898127c3
JJ
508 u32 xtype = xindex & AA_X_TYPE_MASK;
509 int index = xindex & AA_X_INDEX_MASK;
898127c3 510
93c98a48 511 AA_BUG(!name);
898127c3 512
93c98a48
JJ
513 /* index is guaranteed to be in range, validated at load time */
514 /* TODO: move lookup parsing to unpack time so this is a straight
515 * index into the resultant label
516 */
517 for (*name = profile->file.trans.table[index]; !label && *name;
518 *name = next_name(xtype, *name)) {
898127c3 519 if (xindex & AA_X_CHILD) {
93c98a48 520 struct aa_profile *new_profile;
898127c3 521 /* release by caller */
93c98a48
JJ
522 new_profile = aa_find_child(profile, *name);
523 if (new_profile)
524 label = &new_profile->label;
898127c3 525 continue;
898127c3 526 }
8ac2ca32 527 label = aa_label_parse(&profile->label, *name, GFP_KERNEL,
93c98a48
JJ
528 true, false);
529 if (IS_ERR(label))
530 label = NULL;
898127c3
JJ
531 }
532
533 /* released by caller */
93c98a48
JJ
534
535 return label;
898127c3
JJ
536}
537
538/**
93c98a48 539 * x_to_label - get target label for a given xindex
898127c3 540 * @profile: current profile (NOT NULL)
8e51f908 541 * @bprm: binprm structure of transitioning task
898127c3
JJ
542 * @name: name to lookup (NOT NULL)
543 * @xindex: index into x transition table
93c98a48 544 * @lookupname: returns: name used in lookup if one was specified (NOT NULL)
898127c3 545 *
93c98a48 546 * find label for a transition index
898127c3 547 *
93c98a48 548 * Returns: refcounted label or NULL if not found available
898127c3 549 */
93c98a48 550static struct aa_label *x_to_label(struct aa_profile *profile,
8e51f908 551 const struct linux_binprm *bprm,
93c98a48
JJ
552 const char *name, u32 xindex,
553 const char **lookupname,
554 const char **info)
898127c3 555{
93c98a48 556 struct aa_label *new = NULL;
98849dff 557 struct aa_ns *ns = profile->ns;
898127c3 558 u32 xtype = xindex & AA_X_TYPE_MASK;
93c98a48 559 const char *stack = NULL;
898127c3
JJ
560
561 switch (xtype) {
562 case AA_X_NONE:
563 /* fail exec unless ix || ux fallback - handled by caller */
93c98a48
JJ
564 *lookupname = NULL;
565 break;
566 case AA_X_TABLE:
567 /* TODO: fix when perm mapping done at unload */
568 stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK];
569 if (*stack != '&') {
570 /* released by caller */
571 new = x_table_lookup(profile, xindex, lookupname);
572 stack = NULL;
573 break;
574 }
09186e50 575 /* fall through - to X_NAME */
898127c3
JJ
576 case AA_X_NAME:
577 if (xindex & AA_X_CHILD)
578 /* released by caller */
8e51f908 579 new = find_attach(bprm, ns, &profile->base.profiles,
844b8292 580 name, info);
898127c3
JJ
581 else
582 /* released by caller */
8e51f908 583 new = find_attach(bprm, ns, &ns->base.profiles,
844b8292 584 name, info);
93c98a48 585 *lookupname = name;
898127c3
JJ
586 break;
587 }
588
93c98a48
JJ
589 if (!new) {
590 if (xindex & AA_X_INHERIT) {
591 /* (p|c|n)ix - don't change profile but do
592 * use the newest version
593 */
594 *info = "ix fallback";
595 /* no profile && no error */
596 new = aa_get_newest_label(&profile->label);
597 } else if (xindex & AA_X_UNCONFINED) {
598 new = aa_get_newest_label(ns_unconfined(profile->ns));
599 *info = "ux fallback";
600 }
601 }
602
603 if (new && stack) {
604 /* base the stack on post domain transition */
605 struct aa_label *base = new;
606
8ac2ca32 607 new = aa_label_parse(base, stack, GFP_KERNEL, true, false);
93c98a48
JJ
608 if (IS_ERR(new))
609 new = NULL;
610 aa_put_label(base);
611 }
612
898127c3 613 /* released by caller */
93c98a48 614 return new;
898127c3
JJ
615}
616
93c98a48
JJ
617static struct aa_label *profile_transition(struct aa_profile *profile,
618 const struct linux_binprm *bprm,
619 char *buffer, struct path_cond *cond,
620 bool *secure_exec)
898127c3 621{
93c98a48 622 struct aa_label *new = NULL;
8e51f908
MG
623 struct aa_profile *component;
624 struct label_it i;
93c98a48
JJ
625 const char *info = NULL, *name = NULL, *target = NULL;
626 unsigned int state = profile->file.start;
2d679f3c 627 struct aa_perms perms = {};
93c98a48 628 bool nonewprivs = false;
b1d9e6b0 629 int error = 0;
898127c3 630
93c98a48
JJ
631 AA_BUG(!profile);
632 AA_BUG(!bprm);
633 AA_BUG(!buffer);
898127c3 634
4227c333 635 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
72c8a768 636 &name, &info, profile->disconnected);
898127c3 637 if (error) {
637f688d 638 if (profile_unconfined(profile) ||
93c98a48
JJ
639 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
640 AA_DEBUG("name lookup ix on error");
898127c3 641 error = 0;
93c98a48
JJ
642 new = aa_get_newest_label(&profile->label);
643 }
898127c3
JJ
644 name = bprm->filename;
645 goto audit;
646 }
647
637f688d 648 if (profile_unconfined(profile)) {
8e51f908
MG
649 new = find_attach(bprm, profile->ns,
650 &profile->ns->base.profiles, name, &info);
93c98a48
JJ
651 if (new) {
652 AA_DEBUG("unconfined attached to new label");
653 return new;
654 }
655 AA_DEBUG("unconfined exec no attachment");
656 return aa_get_newest_label(&profile->label);
898127c3
JJ
657 }
658
659 /* find exec permissions for name */
93c98a48 660 state = aa_str_perms(profile->file.dfa, state, name, cond, &perms);
898127c3
JJ
661 if (perms.allow & MAY_EXEC) {
662 /* exec permission determine how to transition */
8e51f908
MG
663 new = x_to_label(profile, bprm, name, perms.xindex, &target,
664 &info);
93c98a48
JJ
665 if (new && new->proxy == profile->label.proxy && info) {
666 /* hack ix fallback - improve how this is detected */
667 goto audit;
668 } else if (!new) {
669 error = -EACCES;
670 info = "profile transition not found";
671 /* remove MAY_EXEC to audit as failure */
672 perms.allow &= ~MAY_EXEC;
8e51f908
MG
673 } else {
674 /* verify that each component's xattr requirements are
675 * met, and fail execution otherwise
676 */
677 label_for_each(i, new, component) {
73f488cd
JJ
678 if (aa_xattrs_match(bprm, component, state) <
679 0) {
8e51f908
MG
680 error = -EACCES;
681 info = "required xattrs not present";
682 perms.allow &= ~MAY_EXEC;
683 aa_put_label(new);
684 new = NULL;
685 goto audit;
686 }
687 }
898127c3
JJ
688 }
689 } else if (COMPLAIN_MODE(profile)) {
93c98a48 690 /* no exec permission - learning mode */
5d7c44ef 691 struct aa_profile *new_profile = NULL;
df323337
SAS
692
693 new_profile = aa_new_null_profile(profile, false, name,
694 GFP_KERNEL);
898127c3
JJ
695 if (!new_profile) {
696 error = -ENOMEM;
697 info = "could not create null profile";
93c98a48 698 } else {
898127c3 699 error = -EACCES;
93c98a48
JJ
700 new = &new_profile->label;
701 }
898127c3
JJ
702 perms.xindex |= AA_X_UNSAFE;
703 } else
704 /* fail exec */
705 error = -EACCES;
706
93c98a48
JJ
707 if (!new)
708 goto audit;
709
93c98a48
JJ
710
711 if (!(perms.xindex & AA_X_UNSAFE)) {
712 if (DEBUG_ON) {
713 dbg_printk("apparmor: scrubbing environment variables"
714 " for %s profile=", name);
8ac2ca32 715 aa_label_printk(new, GFP_KERNEL);
93c98a48
JJ
716 dbg_printk("\n");
717 }
718 *secure_exec = true;
c29bceb3
JJ
719 }
720
93c98a48
JJ
721audit:
722 aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new,
723 cond->uid, info, error);
724 if (!new || nonewprivs) {
725 aa_put_label(new);
726 return ERR_PTR(error);
727 }
728
729 return new;
730}
731
732static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec,
733 bool stack, const struct linux_binprm *bprm,
734 char *buffer, struct path_cond *cond,
735 bool *secure_exec)
736{
737 unsigned int state = profile->file.start;
738 struct aa_perms perms = {};
739 const char *xname = NULL, *info = "change_profile onexec";
740 int error = -EACCES;
741
742 AA_BUG(!profile);
743 AA_BUG(!onexec);
744 AA_BUG(!bprm);
745 AA_BUG(!buffer);
746
747 if (profile_unconfined(profile)) {
748 /* change_profile on exec already granted */
749 /*
750 * NOTE: Domain transitions from unconfined are allowed
751 * even when no_new_privs is set because this aways results
752 * in a further reduction of permissions.
753 */
754 return 0;
755 }
756
757 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
758 &xname, &info, profile->disconnected);
759 if (error) {
760 if (profile_unconfined(profile) ||
761 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
762 AA_DEBUG("name lookup ix on error");
763 error = 0;
764 }
765 xname = bprm->filename;
898127c3 766 goto audit;
93c98a48
JJ
767 }
768
769 /* find exec permissions for name */
770 state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms);
771 if (!(perms.allow & AA_MAY_ONEXEC)) {
772 info = "no change_onexec valid for executable";
773 goto audit;
774 }
775 /* test if this exec can be paired with change_profile onexec.
776 * onexec permission is linked to exec with a standard pairing
777 * exec\0change_profile
778 */
779 state = aa_dfa_null_transition(profile->file.dfa, state);
780 error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC,
781 state, &perms);
782 if (error) {
783 perms.allow &= ~AA_MAY_ONEXEC;
784 goto audit;
785 }
93c98a48
JJ
786
787 if (!(perms.xindex & AA_X_UNSAFE)) {
788 if (DEBUG_ON) {
789 dbg_printk("apparmor: scrubbing environment "
790 "variables for %s label=", xname);
8ac2ca32 791 aa_label_printk(onexec, GFP_KERNEL);
93c98a48
JJ
792 dbg_printk("\n");
793 }
794 *secure_exec = true;
795 }
796
797audit:
798 return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname,
799 NULL, onexec, cond->uid, info, error);
800}
801
802/* ensure none ns domain transitions are correctly applied with onexec */
803
804static struct aa_label *handle_onexec(struct aa_label *label,
805 struct aa_label *onexec, bool stack,
806 const struct linux_binprm *bprm,
807 char *buffer, struct path_cond *cond,
808 bool *unsafe)
809{
810 struct aa_profile *profile;
811 struct aa_label *new;
812 int error;
813
814 AA_BUG(!label);
815 AA_BUG(!onexec);
816 AA_BUG(!bprm);
817 AA_BUG(!buffer);
818
819 if (!stack) {
820 error = fn_for_each_in_ns(label, profile,
821 profile_onexec(profile, onexec, stack,
822 bprm, buffer, cond, unsafe));
823 if (error)
824 return ERR_PTR(error);
8ac2ca32 825 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
93c98a48
JJ
826 aa_get_newest_label(onexec),
827 profile_transition(profile, bprm, buffer,
828 cond, unsafe));
829
830 } else {
b2c2086c 831 /* TODO: determine how much we want to loosen this */
93c98a48
JJ
832 error = fn_for_each_in_ns(label, profile,
833 profile_onexec(profile, onexec, stack, bprm,
834 buffer, cond, unsafe));
835 if (error)
836 return ERR_PTR(error);
8ac2ca32 837 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
93c98a48 838 aa_label_merge(&profile->label, onexec,
8ac2ca32 839 GFP_KERNEL),
93c98a48
JJ
840 profile_transition(profile, bprm, buffer,
841 cond, unsafe));
842 }
843
844 if (new)
845 return new;
846
847 /* TODO: get rid of GLOBAL_ROOT_UID */
848 error = fn_for_each_in_ns(label, profile,
849 aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC,
850 AA_MAY_ONEXEC, bprm->filename, NULL,
851 onexec, GLOBAL_ROOT_UID,
852 "failed to build target label", -ENOMEM));
853 return ERR_PTR(error);
854}
855
856/**
857 * apparmor_bprm_set_creds - set the new creds on the bprm struct
858 * @bprm: binprm for the exec (NOT NULL)
859 *
860 * Returns: %0 or error on failure
861 *
862 * TODO: once the other paths are done see if we can't refactor into a fn
863 */
864int apparmor_bprm_set_creds(struct linux_binprm *bprm)
865{
f175221a 866 struct aa_task_ctx *ctx;
93c98a48
JJ
867 struct aa_label *label, *new = NULL;
868 struct aa_profile *profile;
869 char *buffer = NULL;
870 const char *info = NULL;
871 int error = 0;
872 bool unsafe = false;
873 struct path_cond cond = {
874 file_inode(bprm->file)->i_uid,
875 file_inode(bprm->file)->i_mode
876 };
877
ddb4a144 878 if (bprm->called_set_creds)
93c98a48
JJ
879 return 0;
880
de62de59 881 ctx = task_ctx(current);
d9087c49 882 AA_BUG(!cred_label(bprm->cred));
f175221a 883 AA_BUG(!ctx);
93c98a48 884
d9087c49 885 label = aa_get_newest_label(cred_label(bprm->cred));
93c98a48 886
9fcf78cc
JJ
887 /*
888 * Detect no new privs being set, and store the label it
889 * occurred under. Ideally this would happen when nnp
890 * is set but there isn't a good way to do that yet.
891 *
892 * Testing for unconfined must be done before the subset test
893 */
894 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) &&
895 !ctx->nnp)
896 ctx->nnp = aa_get_label(label);
897
93c98a48 898 /* buffer freed below, name is pointer into buffer */
341c1fda 899 buffer = aa_get_buffer(false);
df323337
SAS
900 if (!buffer) {
901 error = -ENOMEM;
902 goto done;
903 }
904
93c98a48 905 /* Test for onexec first as onexec override other x transitions. */
f175221a
JJ
906 if (ctx->onexec)
907 new = handle_onexec(label, ctx->onexec, ctx->token,
93c98a48
JJ
908 bprm, buffer, &cond, &unsafe);
909 else
8ac2ca32 910 new = fn_label_build(label, profile, GFP_KERNEL,
93c98a48
JJ
911 profile_transition(profile, bprm, buffer,
912 &cond, &unsafe));
913
914 AA_BUG(!new);
915 if (IS_ERR(new)) {
916 error = PTR_ERR(new);
917 goto done;
918 } else if (!new) {
919 error = -ENOMEM;
920 goto done;
921 }
922
9fcf78cc
JJ
923 /* Policy has specified a domain transitions. If no_new_privs and
924 * confined ensure the transition is to confinement that is subset
925 * of the confinement when the task entered no new privs.
926 *
927 * NOTE: Domain transitions from unconfined and to stacked
928 * subsets are allowed even when no_new_privs is set because this
929 * aways results in a further reduction of permissions.
930 */
931 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
932 !unconfined(label) && !aa_label_is_subset(new, ctx->nnp)) {
933 error = -EPERM;
934 info = "no new privs";
935 goto audit;
936 }
898127c3
JJ
937
938 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
939 /* FIXME: currently don't mediate shared state */
940 ;
941 }
942
93c98a48
JJ
943 if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) {
944 /* TODO: test needs to be profile of label to new */
945 error = may_change_ptraced_domain(new, &info);
f7da2de0 946 if (error)
898127c3 947 goto audit;
898127c3
JJ
948 }
949
93c98a48
JJ
950 if (unsafe) {
951 if (DEBUG_ON) {
952 dbg_printk("scrubbing environment variables for %s "
953 "label=", bprm->filename);
8ac2ca32 954 aa_label_printk(new, GFP_KERNEL);
93c98a48
JJ
955 dbg_printk("\n");
956 }
993b3ab0 957 bprm->secureexec = 1;
898127c3 958 }
898127c3 959
93c98a48
JJ
960 if (label->proxy != new->proxy) {
961 /* when transitioning clear unsafe personality bits */
962 if (DEBUG_ON) {
963 dbg_printk("apparmor: clearing unsafe personality "
964 "bits. %s label=", bprm->filename);
8ac2ca32 965 aa_label_printk(new, GFP_KERNEL);
93c98a48
JJ
966 dbg_printk("\n");
967 }
968 bprm->per_clear |= PER_CLEAR_ON_SETID;
969 }
d9087c49
JJ
970 aa_put_label(cred_label(bprm->cred));
971 /* transfer reference, released when cred is freed */
69b5a44a 972 set_cred_label(bprm->cred, new);
898127c3 973
93c98a48 974done:
637f688d 975 aa_put_label(label);
df323337 976 aa_put_buffer(buffer);
898127c3
JJ
977
978 return error;
93c98a48
JJ
979
980audit:
981 error = fn_for_each(label, profile,
982 aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC,
983 bprm->filename, NULL, new,
984 file_inode(bprm->file)->i_uid, info,
985 error));
986 aa_put_label(new);
987 goto done;
898127c3
JJ
988}
989
898127c3
JJ
990/*
991 * Functions for self directed profile change
992 */
993
89dbf196
JJ
994
995/* helper fn for change_hat
898127c3 996 *
89dbf196 997 * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL
898127c3 998 */
89dbf196
JJ
999static struct aa_label *build_change_hat(struct aa_profile *profile,
1000 const char *name, bool sibling)
898127c3 1001{
89dbf196
JJ
1002 struct aa_profile *root, *hat = NULL;
1003 const char *info = NULL;
1004 int error = 0;
1005
1006 if (sibling && PROFILE_IS_HAT(profile)) {
1007 root = aa_get_profile_rcu(&profile->parent);
1008 } else if (!sibling && !PROFILE_IS_HAT(profile)) {
1009 root = aa_get_profile(profile);
1010 } else {
1011 info = "conflicting target types";
1012 error = -EPERM;
1013 goto audit;
1014 }
1015
1016 hat = aa_find_child(root, name);
1017 if (!hat) {
1018 error = -ENOENT;
1019 if (COMPLAIN_MODE(profile)) {
1020 hat = aa_new_null_profile(profile, true, name,
1021 GFP_KERNEL);
1022 if (!hat) {
1023 info = "failed null profile create";
1024 error = -ENOMEM;
1025 }
1026 }
1027 }
1028 aa_put_profile(root);
1029
1030audit:
1031 aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT,
1032 name, hat ? hat->base.hname : NULL,
24b87a16 1033 hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info,
89dbf196
JJ
1034 error);
1035 if (!hat || (error && error != -ENOENT))
1036 return ERR_PTR(error);
1037 /* if hat && error - complain mode, already audited and we adjust for
1038 * complain mode allow by returning hat->label
1039 */
1040 return &hat->label;
1041}
1042
1043/* helper fn for changing into a hat
1044 *
1045 * Returns: label for hat transition or ERR_PTR. Does not return NULL
1046 */
1047static struct aa_label *change_hat(struct aa_label *label, const char *hats[],
1048 int count, int flags)
1049{
1050 struct aa_profile *profile, *root, *hat = NULL;
1051 struct aa_label *new;
1052 struct label_it it;
1053 bool sibling = false;
1054 const char *name, *info = NULL;
1055 int i, error;
1056
1057 AA_BUG(!label);
1058 AA_BUG(!hats);
1059 AA_BUG(count < 1);
1060
1061 if (PROFILE_IS_HAT(labels_profile(label)))
1062 sibling = true;
1063
1064 /*find first matching hat */
1065 for (i = 0; i < count && !hat; i++) {
1066 name = hats[i];
1067 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1068 if (sibling && PROFILE_IS_HAT(profile)) {
1069 root = aa_get_profile_rcu(&profile->parent);
1070 } else if (!sibling && !PROFILE_IS_HAT(profile)) {
1071 root = aa_get_profile(profile);
1072 } else { /* conflicting change type */
1073 info = "conflicting targets types";
1074 error = -EPERM;
1075 goto fail;
1076 }
1077 hat = aa_find_child(root, name);
1078 aa_put_profile(root);
1079 if (!hat) {
1080 if (!COMPLAIN_MODE(profile))
1081 goto outer_continue;
1082 /* complain mode succeed as if hat */
1083 } else if (!PROFILE_IS_HAT(hat)) {
1084 info = "target not hat";
1085 error = -EPERM;
1086 aa_put_profile(hat);
1087 goto fail;
1088 }
1089 aa_put_profile(hat);
1090 }
1091 /* found a hat for all profiles in ns */
1092 goto build;
1093outer_continue:
1094 ;
1095 }
1096 /* no hats that match, find appropriate error
1097 *
1098 * In complain mode audit of the failure is based off of the first
1099 * hat supplied. This is done due how userspace interacts with
1100 * change_hat.
1101 */
1102 name = NULL;
1103 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1104 if (!list_empty(&profile->base.profiles)) {
1105 info = "hat not found";
1106 error = -ENOENT;
1107 goto fail;
1108 }
1109 }
1110 info = "no hats defined";
1111 error = -ECHILD;
1112
1113fail:
1114 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1115 /*
1116 * no target as it has failed to be found or built
1117 *
1118 * change_hat uses probing and should not log failures
1119 * related to missing hats
1120 */
1121 /* TODO: get rid of GLOBAL_ROOT_UID */
1122 if (count > 1 || COMPLAIN_MODE(profile)) {
1123 aa_audit_file(profile, &nullperms, OP_CHANGE_HAT,
1124 AA_MAY_CHANGEHAT, name, NULL, NULL,
1125 GLOBAL_ROOT_UID, info, error);
1126 }
1127 }
1128 return ERR_PTR(error);
1129
1130build:
1131 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1132 build_change_hat(profile, name, sibling),
1133 aa_get_label(&profile->label));
1134 if (!new) {
1135 info = "label build failed";
1136 error = -ENOMEM;
1137 goto fail;
1138 } /* else if (IS_ERR) build_change_hat has logged error so return new */
1139
1140 return new;
898127c3
JJ
1141}
1142
1143/**
1144 * aa_change_hat - change hat to/from subprofile
1145 * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
1146 * @count: number of hat names in @hats
1147 * @token: magic value to validate the hat change
df8073c6 1148 * @flags: flags affecting behavior of the change
898127c3 1149 *
89dbf196
JJ
1150 * Returns %0 on success, error otherwise.
1151 *
898127c3
JJ
1152 * Change to the first profile specified in @hats that exists, and store
1153 * the @hat_magic in the current task context. If the count == 0 and the
1154 * @token matches that stored in the current task context, return to the
1155 * top level profile.
1156 *
89dbf196
JJ
1157 * change_hat only applies to profiles in the current ns, and each profile
1158 * in the ns must make the same transition otherwise change_hat will fail.
898127c3 1159 */
df8073c6 1160int aa_change_hat(const char *hats[], int count, u64 token, int flags)
898127c3
JJ
1161{
1162 const struct cred *cred;
9fcf78cc 1163 struct aa_task_ctx *ctx = task_ctx(current);
89dbf196
JJ
1164 struct aa_label *label, *previous, *new = NULL, *target = NULL;
1165 struct aa_profile *profile;
2d679f3c 1166 struct aa_perms perms = {};
89dbf196 1167 const char *info = NULL;
898127c3
JJ
1168 int error = 0;
1169
1170 /* released below */
1171 cred = get_current_cred();
637f688d 1172 label = aa_get_newest_cred_label(cred);
f175221a 1173 previous = aa_get_newest_label(ctx->previous);
898127c3 1174
9fcf78cc
JJ
1175 /*
1176 * Detect no new privs being set, and store the label it
1177 * occurred under. Ideally this would happen when nnp
1178 * is set but there isn't a good way to do that yet.
1179 *
1180 * Testing for unconfined must be done before the subset test
1181 */
1182 if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1183 ctx->nnp = aa_get_label(label);
1184
637f688d 1185 if (unconfined(label)) {
89dbf196 1186 info = "unconfined can not change_hat";
898127c3 1187 error = -EPERM;
89dbf196 1188 goto fail;
898127c3
JJ
1189 }
1190
1191 if (count) {
89dbf196
JJ
1192 new = change_hat(label, hats, count, flags);
1193 AA_BUG(!new);
1194 if (IS_ERR(new)) {
1195 error = PTR_ERR(new);
1196 new = NULL;
1197 /* already audited */
1198 goto out;
898127c3
JJ
1199 }
1200
89dbf196
JJ
1201 error = may_change_ptraced_domain(new, &info);
1202 if (error)
1203 goto fail;
898127c3 1204
9fcf78cc
JJ
1205 /*
1206 * no new privs prevents domain transitions that would
1207 * reduce restrictions.
1208 */
1209 if (task_no_new_privs(current) && !unconfined(label) &&
1210 !aa_label_is_subset(new, ctx->nnp)) {
1211 /* not an apparmor denial per se, so don't log it */
1212 AA_DEBUG("no_new_privs - change_hat denied");
1213 error = -EPERM;
1214 goto out;
1215 }
1216
89dbf196
JJ
1217 if (flags & AA_CHANGE_TEST)
1218 goto out;
1219
1220 target = new;
1221 error = aa_set_current_hat(new, token);
1222 if (error == -EACCES)
1223 /* kill task in case of brute force attacks */
1224 goto kill;
1225 } else if (previous && !(flags & AA_CHANGE_TEST)) {
9fcf78cc
JJ
1226 /*
1227 * no new privs prevents domain transitions that would
1228 * reduce restrictions.
1229 */
1230 if (task_no_new_privs(current) && !unconfined(label) &&
1231 !aa_label_is_subset(previous, ctx->nnp)) {
1232 /* not an apparmor denial per se, so don't log it */
1233 AA_DEBUG("no_new_privs - change_hat denied");
1234 error = -EPERM;
1235 goto out;
1236 }
1237
89dbf196 1238 /* Return to saved label. Kill task if restore fails
898127c3
JJ
1239 * to avoid brute force attacks
1240 */
89dbf196 1241 target = previous;
637f688d 1242 error = aa_restore_previous_label(token);
89dbf196
JJ
1243 if (error) {
1244 if (error == -EACCES)
1245 goto kill;
1246 goto fail;
1247 }
1248 } /* else ignore @flags && restores when there is no saved profile */
898127c3
JJ
1249
1250out:
89dbf196
JJ
1251 aa_put_label(new);
1252 aa_put_label(previous);
637f688d 1253 aa_put_label(label);
898127c3
JJ
1254 put_cred(cred);
1255
1256 return error;
89dbf196
JJ
1257
1258kill:
1259 info = "failed token match";
1260 perms.kill = AA_MAY_CHANGEHAT;
1261
1262fail:
1263 fn_for_each_in_ns(label, profile,
1264 aa_audit_file(profile, &perms, OP_CHANGE_HAT,
1265 AA_MAY_CHANGEHAT, NULL, NULL, target,
1266 GLOBAL_ROOT_UID, info, error));
1267
1268 goto out;
898127c3
JJ
1269}
1270
89dbf196 1271
e00b02bb
JJ
1272static int change_profile_perms_wrapper(const char *op, const char *name,
1273 struct aa_profile *profile,
1274 struct aa_label *target, bool stack,
1275 u32 request, struct aa_perms *perms)
1276{
1277 const char *info = NULL;
1278 int error = 0;
1279
e00b02bb
JJ
1280 if (!error)
1281 error = change_profile_perms(profile, target, stack, request,
1282 profile->file.start, perms);
1283 if (error)
1284 error = aa_audit_file(profile, perms, op, request, name,
1285 NULL, target, GLOBAL_ROOT_UID, info,
1286 error);
1287
1288 return error;
1289}
89dbf196 1290
898127c3
JJ
1291/**
1292 * aa_change_profile - perform a one-way profile transition
aa9a39ad 1293 * @fqname: name of profile may include namespace (NOT NULL)
898127c3 1294 * @onexec: whether this transition is to take place immediately or at exec
df8073c6 1295 * @flags: flags affecting change behavior
898127c3
JJ
1296 *
1297 * Change to new profile @name. Unlike with hats, there is no way
1298 * to change back. If @name isn't specified the current profile name is
1299 * used.
1300 * If @onexec then the transition is delayed until
1301 * the next exec.
1302 *
1303 * Returns %0 on success, error otherwise.
1304 */
df8073c6 1305int aa_change_profile(const char *fqname, int flags)
898127c3 1306{
e00b02bb
JJ
1307 struct aa_label *label, *new = NULL, *target = NULL;
1308 struct aa_profile *profile;
2d679f3c 1309 struct aa_perms perms = {};
e00b02bb
JJ
1310 const char *info = NULL;
1311 const char *auditname = fqname; /* retain leading & if stack */
1312 bool stack = flags & AA_CHANGE_STACK;
9fcf78cc 1313 struct aa_task_ctx *ctx = task_ctx(current);
47f6e5cc 1314 int error = 0;
e00b02bb 1315 char *op;
898127c3
JJ
1316 u32 request;
1317
9fcf78cc
JJ
1318 label = aa_get_current_label();
1319
1320 /*
1321 * Detect no new privs being set, and store the label it
1322 * occurred under. Ideally this would happen when nnp
1323 * is set but there isn't a good way to do that yet.
1324 *
1325 * Testing for unconfined must be done before the subset test
1326 */
1327 if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1328 ctx->nnp = aa_get_label(label);
1329
aa9a39ad 1330 if (!fqname || !*fqname) {
a0b845ff 1331 aa_put_label(label);
aa9a39ad 1332 AA_DEBUG("no profile name");
898127c3 1333 return -EINVAL;
aa9a39ad 1334 }
898127c3 1335
df8073c6 1336 if (flags & AA_CHANGE_ONEXEC) {
898127c3 1337 request = AA_MAY_ONEXEC;
e00b02bb
JJ
1338 if (stack)
1339 op = OP_STACK_ONEXEC;
1340 else
1341 op = OP_CHANGE_ONEXEC;
898127c3
JJ
1342 } else {
1343 request = AA_MAY_CHANGE_PROFILE;
e00b02bb
JJ
1344 if (stack)
1345 op = OP_STACK;
1346 else
1347 op = OP_CHANGE_PROFILE;
898127c3
JJ
1348 }
1349
e00b02bb
JJ
1350 if (*fqname == '&') {
1351 stack = true;
1352 /* don't have label_parse() do stacking */
1353 fqname++;
c29bceb3 1354 }
e00b02bb
JJ
1355 target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
1356 if (IS_ERR(target)) {
1357 struct aa_profile *tprofile;
c29bceb3 1358
e00b02bb
JJ
1359 info = "label not found";
1360 error = PTR_ERR(target);
1361 target = NULL;
1362 /*
1363 * TODO: fixme using labels_profile is not right - do profile
1364 * per complain profile
1365 */
df8073c6 1366 if ((flags & AA_CHANGE_TEST) ||
e00b02bb 1367 !COMPLAIN_MODE(labels_profile(label)))
898127c3
JJ
1368 goto audit;
1369 /* released below */
e00b02bb
JJ
1370 tprofile = aa_new_null_profile(labels_profile(label), false,
1371 fqname, GFP_KERNEL);
1372 if (!tprofile) {
898127c3
JJ
1373 info = "failed null profile create";
1374 error = -ENOMEM;
1375 goto audit;
1376 }
e00b02bb
JJ
1377 target = &tprofile->label;
1378 goto check;
898127c3
JJ
1379 }
1380
e00b02bb
JJ
1381 /*
1382 * self directed transitions only apply to current policy ns
1383 * TODO: currently requiring perms for stacking and straight change
1384 * stacking doesn't strictly need this. Determine how much
1385 * we want to loosen this restriction for stacking
1386 *
1387 * if (!stack) {
1388 */
1389 error = fn_for_each_in_ns(label, profile,
1390 change_profile_perms_wrapper(op, auditname,
1391 profile, target, stack,
1392 request, &perms));
1393 if (error)
1394 /* auditing done in change_profile_perms_wrapper */
1395 goto out;
aa9a39ad 1396
e00b02bb
JJ
1397 /* } */
1398
1399check:
898127c3 1400 /* check if tracing task is allowed to trace target domain */
e00b02bb
JJ
1401 error = may_change_ptraced_domain(target, &info);
1402 if (error && !fn_for_each_in_ns(label, profile,
1403 COMPLAIN_MODE(profile)))
898127c3 1404 goto audit;
898127c3 1405
e00b02bb
JJ
1406 /* TODO: add permission check to allow this
1407 * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
1408 * info = "not a single threaded task";
1409 * error = -EACCES;
1410 * goto audit;
1411 * }
1412 */
df8073c6 1413 if (flags & AA_CHANGE_TEST)
e00b02bb 1414 goto out;
898127c3 1415
9fcf78cc
JJ
1416 /* stacking is always a subset, so only check the nonstack case */
1417 if (!stack) {
1418 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1419 aa_get_label(target),
1420 aa_get_label(&profile->label));
1421 /*
1422 * no new privs prevents domain transitions that would
1423 * reduce restrictions.
1424 */
1425 if (task_no_new_privs(current) && !unconfined(label) &&
1426 !aa_label_is_subset(new, ctx->nnp)) {
1427 /* not an apparmor denial per se, so don't log it */
1428 AA_DEBUG("no_new_privs - change_hat denied");
1429 error = -EPERM;
1430 goto out;
1431 }
1432 }
1433
e00b02bb
JJ
1434 if (!(flags & AA_CHANGE_ONEXEC)) {
1435 /* only transition profiles in the current ns */
1436 if (stack)
1437 new = aa_label_merge(label, target, GFP_KERNEL);
e00b02bb
JJ
1438 if (IS_ERR_OR_NULL(new)) {
1439 info = "failed to build target label";
d6d478ae
JJ
1440 if (!new)
1441 error = -ENOMEM;
1442 else
1443 error = PTR_ERR(new);
e00b02bb
JJ
1444 new = NULL;
1445 perms.allow = 0;
1446 goto audit;
1447 }
1448 error = aa_replace_current_label(new);
9fcf78cc
JJ
1449 } else {
1450 if (new) {
1451 aa_put_label(new);
1452 new = NULL;
1453 }
1454
e00b02bb
JJ
1455 /* full transition will be built in exec path */
1456 error = aa_set_current_onexec(target, stack);
9fcf78cc 1457 }
898127c3
JJ
1458
1459audit:
e00b02bb
JJ
1460 error = fn_for_each_in_ns(label, profile,
1461 aa_audit_file(profile, &perms, op, request, auditname,
1462 NULL, new ? new : target,
1463 GLOBAL_ROOT_UID, info, error));
898127c3 1464
e00b02bb
JJ
1465out:
1466 aa_put_label(new);
1467 aa_put_label(target);
637f688d 1468 aa_put_label(label);
898127c3
JJ
1469
1470 return error;
1471}