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Linux/security/apparmor/domain.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  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.
  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>
 18 #include <linux/xattr.h>
 19 
 20 #include "include/audit.h"
 21 #include "include/apparmorfs.h"
 22 #include "include/cred.h"
 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"
 29 #include "include/policy_ns.h"
 30 
 31 /**
 32  * aa_free_domain_entries - free entries in a domain table
 33  * @domain: the domain table to free  (MAYBE NULL)
 34  */
 35 void 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
 51  * @to_label: profile to change to  (NOT NULL)
 52  * @info: message if there is an error
 53  *
 54  * Check if current is ptraced and if so if the tracing task is allowed
 55  * to trace the new domain
 56  *
 57  * Returns: %0 or error if change not allowed
 58  */
 59 static int may_change_ptraced_domain(struct aa_label *to_label,
 60                                      const char **info)
 61 {
 62         struct task_struct *tracer;
 63         struct aa_label *tracerl = NULL;
 64         int error = 0;
 65 
 66         rcu_read_lock();
 67         tracer = ptrace_parent(current);
 68         if (tracer)
 69                 /* released below */
 70                 tracerl = aa_get_task_label(tracer);
 71 
 72         /* not ptraced */
 73         if (!tracer || unconfined(tracerl))
 74                 goto out;
 75 
 76         error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
 77 
 78 out:
 79         rcu_read_unlock();
 80         aa_put_label(tracerl);
 81 
 82         if (error)
 83                 *info = "ptrace prevents transition";
 84         return error;
 85 }
 86 
 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  */
 97 static 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  */
132 static 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 
155 next:
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 
171 fail:
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  */
192 static 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 
216 next:
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 
236 fail:
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  */
253 static 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 
272 /**
273  * change_profile_perms - find permissions for change_profile
274  * @profile: the current profile  (NOT NULL)
275  * @target: label to transition to (NOT NULL)
276  * @stack: whether this is a stacking request
277  * @request: requested perms
278  * @start: state to start matching in
279  *
280  *
281  * Returns: permission set
282  *
283  * currently only matches full label A//&B//&C or individual components A, B, C
284  * not arbitrary combinations. Eg. A//&B, C
285  */
286 static 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 
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)
305  * @state: state to start match in
306  *
307  * Returns: number of extended attributes that matched, or < 0 on error
308  */
309 static int aa_xattrs_match(const struct linux_binprm *bprm,
310                            struct aa_profile *profile, unsigned int state)
311 {
312         int i;
313         ssize_t size;
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;
320 
321         /* transition from exec match to xattr set */
322         state = aa_dfa_null_transition(profile->xmatch, state);
323 
324         d = bprm->file->f_path.dentry;
325 
326         for (i = 0; i < profile->xattr_count; i++) {
327                 size = vfs_getxattr_alloc(d, profile->xattrs[i], &value,
328                                           value_size, GFP_KERNEL);
329                 if (size >= 0) {
330                         u32 perm;
331 
332                         /* Check the xattr value, not just presence */
333                         state = aa_dfa_match_len(profile->xmatch, state, value,
334                                                  size);
335                         perm = dfa_user_allow(profile->xmatch, state);
336                         if (!(perm & MAY_EXEC)) {
337                                 ret = -EINVAL;
338                                 goto out;
339                         }
340                 }
341                 /* transition to next element */
342                 state = aa_dfa_null_transition(profile->xmatch, state);
343                 if (size < 0) {
344                         /*
345                          * No xattr match, so verify if transition to
346                          * next element was valid. IFF so the xattr
347                          * was optional.
348                          */
349                         if (!state) {
350                                 ret = -EINVAL;
351                                 goto out;
352                         }
353                         /* don't count missing optional xattr as matched */
354                         ret--;
355                 }
356         }
357 
358 out:
359         kfree(value);
360         return ret;
361 }
362 
363 /**
364  * __attach_match_ - find an attachment match
365  * @bprm - binprm structure of transitioning task
366  * @name - to match against  (NOT NULL)
367  * @head - profile list to walk  (NOT NULL)
368  * @info - info message if there was an error (NOT NULL)
369  *
370  * Do a linear search on the profiles in the list.  There is a matching
371  * preference where an exact match is preferred over a name which uses
372  * expressions to match, and matching expressions with the greatest
373  * xmatch_len are preferred.
374  *
375  * Requires: @head not be shared or have appropriate locks held
376  *
377  * Returns: profile or NULL if no match found
378  */
379 static struct aa_profile *__attach_match(const struct linux_binprm *bprm,
380                                          const char *name,
381                                          struct list_head *head,
382                                          const char **info)
383 {
384         int candidate_len = 0, candidate_xattrs = 0;
385         bool conflict = false;
386         struct aa_profile *profile, *candidate = NULL;
387 
388         AA_BUG(!name);
389         AA_BUG(!head);
390 
391         list_for_each_entry_rcu(profile, head, base.list) {
392                 if (profile->label.flags & FLAG_NULL &&
393                     &profile->label == ns_unconfined(profile->ns))
394                         continue;
395 
396                 /* Find the "best" matching profile. Profiles must
397                  * match the path and extended attributes (if any)
398                  * associated with the file. A more specific path
399                  * match will be preferred over a less specific one,
400                  * and a match with more matching extended attributes
401                  * will be preferred over one with fewer. If the best
402                  * match has both the same level of path specificity
403                  * and the same number of matching extended attributes
404                  * as another profile, signal a conflict and refuse to
405                  * match.
406                  */
407                 if (profile->xmatch) {
408                         unsigned int state, count;
409                         u32 perm;
410 
411                         state = aa_dfa_leftmatch(profile->xmatch, DFA_START,
412                                                  name, &count);
413                         perm = dfa_user_allow(profile->xmatch, state);
414                         /* any accepting state means a valid match. */
415                         if (perm & MAY_EXEC) {
416                                 int ret;
417 
418                                 if (count < candidate_len)
419                                         continue;
420 
421                                 ret = aa_xattrs_match(bprm, profile, state);
422                                 /* Fail matching if the xattrs don't match */
423                                 if (ret < 0)
424                                         continue;
425 
426                                 /*
427                                  * TODO: allow for more flexible best match
428                                  *
429                                  * The new match isn't more specific
430                                  * than the current best match
431                                  */
432                                 if (count == candidate_len &&
433                                     ret <= candidate_xattrs) {
434                                         /* Match is equivalent, so conflict */
435                                         if (ret == candidate_xattrs)
436                                                 conflict = true;
437                                         continue;
438                                 }
439 
440                                 /* Either the same length with more matching
441                                  * xattrs, or a longer match
442                                  */
443                                 candidate = profile;
444                                 candidate_len = profile->xmatch_len;
445                                 candidate_xattrs = ret;
446                                 conflict = false;
447                         }
448                 } else if (!strcmp(profile->base.name, name))
449                         /*
450                          * old exact non-re match, without conditionals such
451                          * as xattrs. no more searching required
452                          */
453                         return profile;
454         }
455 
456         if (conflict) {
457                 *info = "conflicting profile attachments";
458                 return NULL;
459         }
460 
461         return candidate;
462 }
463 
464 /**
465  * find_attach - do attachment search for unconfined processes
466  * @bprm - binprm structure of transitioning task
467  * @ns: the current namespace  (NOT NULL)
468  * @list: list to search  (NOT NULL)
469  * @name: the executable name to match against  (NOT NULL)
470  * @info: info message if there was an error
471  *
472  * Returns: label or NULL if no match found
473  */
474 static struct aa_label *find_attach(const struct linux_binprm *bprm,
475                                     struct aa_ns *ns, struct list_head *list,
476                                     const char *name, const char **info)
477 {
478         struct aa_profile *profile;
479 
480         rcu_read_lock();
481         profile = aa_get_profile(__attach_match(bprm, name, list, info));
482         rcu_read_unlock();
483 
484         return profile ? &profile->label : NULL;
485 }
486 
487 static const char *next_name(int xtype, const char *name)
488 {
489         return NULL;
490 }
491 
492 /**
493  * x_table_lookup - lookup an x transition name via transition table
494  * @profile: current profile (NOT NULL)
495  * @xindex: index into x transition table
496  * @name: returns: name tested to find label (NOT NULL)
497  *
498  * Returns: refcounted label, or NULL on failure (MAYBE NULL)
499  */
500 struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex,
501                                 const char **name)
502 {
503         struct aa_label *label = NULL;
504         u32 xtype = xindex & AA_X_TYPE_MASK;
505         int index = xindex & AA_X_INDEX_MASK;
506 
507         AA_BUG(!name);
508 
509         /* index is guaranteed to be in range, validated at load time */
510         /* TODO: move lookup parsing to unpack time so this is a straight
511          *       index into the resultant label
512          */
513         for (*name = profile->file.trans.table[index]; !label && *name;
514              *name = next_name(xtype, *name)) {
515                 if (xindex & AA_X_CHILD) {
516                         struct aa_profile *new_profile;
517                         /* release by caller */
518                         new_profile = aa_find_child(profile, *name);
519                         if (new_profile)
520                                 label = &new_profile->label;
521                         continue;
522                 }
523                 label = aa_label_parse(&profile->label, *name, GFP_ATOMIC,
524                                        true, false);
525                 if (IS_ERR(label))
526                         label = NULL;
527         }
528 
529         /* released by caller */
530 
531         return label;
532 }
533 
534 /**
535  * x_to_label - get target label for a given xindex
536  * @profile: current profile  (NOT NULL)
537  * @bprm: binprm structure of transitioning task
538  * @name: name to lookup (NOT NULL)
539  * @xindex: index into x transition table
540  * @lookupname: returns: name used in lookup if one was specified (NOT NULL)
541  *
542  * find label for a transition index
543  *
544  * Returns: refcounted label or NULL if not found available
545  */
546 static struct aa_label *x_to_label(struct aa_profile *profile,
547                                    const struct linux_binprm *bprm,
548                                    const char *name, u32 xindex,
549                                    const char **lookupname,
550                                    const char **info)
551 {
552         struct aa_label *new = NULL;
553         struct aa_ns *ns = profile->ns;
554         u32 xtype = xindex & AA_X_TYPE_MASK;
555         const char *stack = NULL;
556 
557         switch (xtype) {
558         case AA_X_NONE:
559                 /* fail exec unless ix || ux fallback - handled by caller */
560                 *lookupname = NULL;
561                 break;
562         case AA_X_TABLE:
563                 /* TODO: fix when perm mapping done at unload */
564                 stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK];
565                 if (*stack != '&') {
566                         /* released by caller */
567                         new = x_table_lookup(profile, xindex, lookupname);
568                         stack = NULL;
569                         break;
570                 }
571                 /* fall through - to X_NAME */
572         case AA_X_NAME:
573                 if (xindex & AA_X_CHILD)
574                         /* released by caller */
575                         new = find_attach(bprm, ns, &profile->base.profiles,
576                                           name, info);
577                 else
578                         /* released by caller */
579                         new = find_attach(bprm, ns, &ns->base.profiles,
580                                           name, info);
581                 *lookupname = name;
582                 break;
583         }
584 
585         if (!new) {
586                 if (xindex & AA_X_INHERIT) {
587                         /* (p|c|n)ix - don't change profile but do
588                          * use the newest version
589                          */
590                         *info = "ix fallback";
591                         /* no profile && no error */
592                         new = aa_get_newest_label(&profile->label);
593                 } else if (xindex & AA_X_UNCONFINED) {
594                         new = aa_get_newest_label(ns_unconfined(profile->ns));
595                         *info = "ux fallback";
596                 }
597         }
598 
599         if (new && stack) {
600                 /* base the stack on post domain transition */
601                 struct aa_label *base = new;
602 
603                 new = aa_label_parse(base, stack, GFP_ATOMIC, true, false);
604                 if (IS_ERR(new))
605                         new = NULL;
606                 aa_put_label(base);
607         }
608 
609         /* released by caller */
610         return new;
611 }
612 
613 static struct aa_label *profile_transition(struct aa_profile *profile,
614                                            const struct linux_binprm *bprm,
615                                            char *buffer, struct path_cond *cond,
616                                            bool *secure_exec)
617 {
618         struct aa_label *new = NULL;
619         struct aa_profile *component;
620         struct label_it i;
621         const char *info = NULL, *name = NULL, *target = NULL;
622         unsigned int state = profile->file.start;
623         struct aa_perms perms = {};
624         bool nonewprivs = false;
625         int error = 0;
626 
627         AA_BUG(!profile);
628         AA_BUG(!bprm);
629         AA_BUG(!buffer);
630 
631         error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
632                              &name, &info, profile->disconnected);
633         if (error) {
634                 if (profile_unconfined(profile) ||
635                     (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
636                         AA_DEBUG("name lookup ix on error");
637                         error = 0;
638                         new = aa_get_newest_label(&profile->label);
639                 }
640                 name = bprm->filename;
641                 goto audit;
642         }
643 
644         if (profile_unconfined(profile)) {
645                 new = find_attach(bprm, profile->ns,
646                                   &profile->ns->base.profiles, name, &info);
647                 if (new) {
648                         AA_DEBUG("unconfined attached to new label");
649                         return new;
650                 }
651                 AA_DEBUG("unconfined exec no attachment");
652                 return aa_get_newest_label(&profile->label);
653         }
654 
655         /* find exec permissions for name */
656         state = aa_str_perms(profile->file.dfa, state, name, cond, &perms);
657         if (perms.allow & MAY_EXEC) {
658                 /* exec permission determine how to transition */
659                 new = x_to_label(profile, bprm, name, perms.xindex, &target,
660                                  &info);
661                 if (new && new->proxy == profile->label.proxy && info) {
662                         /* hack ix fallback - improve how this is detected */
663                         goto audit;
664                 } else if (!new) {
665                         error = -EACCES;
666                         info = "profile transition not found";
667                         /* remove MAY_EXEC to audit as failure */
668                         perms.allow &= ~MAY_EXEC;
669                 } else {
670                         /* verify that each component's xattr requirements are
671                          * met, and fail execution otherwise
672                          */
673                         label_for_each(i, new, component) {
674                                 if (aa_xattrs_match(bprm, component, state) <
675                                     0) {
676                                         error = -EACCES;
677                                         info = "required xattrs not present";
678                                         perms.allow &= ~MAY_EXEC;
679                                         aa_put_label(new);
680                                         new = NULL;
681                                         goto audit;
682                                 }
683                         }
684                 }
685         } else if (COMPLAIN_MODE(profile)) {
686                 /* no exec permission - learning mode */
687                 struct aa_profile *new_profile = NULL;
688                 char *n = kstrdup(name, GFP_ATOMIC);
689 
690                 if (n) {
691                         /* name is ptr into buffer */
692                         long pos = name - buffer;
693                         /* break per cpu buffer hold */
694                         put_buffers(buffer);
695                         new_profile = aa_new_null_profile(profile, false, n,
696                                                           GFP_KERNEL);
697                         get_buffers(buffer);
698                         name = buffer + pos;
699                         strcpy((char *)name, n);
700                         kfree(n);
701                 }
702                 if (!new_profile) {
703                         error = -ENOMEM;
704                         info = "could not create null profile";
705                 } else {
706                         error = -EACCES;
707                         new = &new_profile->label;
708                 }
709                 perms.xindex |= AA_X_UNSAFE;
710         } else
711                 /* fail exec */
712                 error = -EACCES;
713 
714         if (!new)
715                 goto audit;
716 
717 
718         if (!(perms.xindex & AA_X_UNSAFE)) {
719                 if (DEBUG_ON) {
720                         dbg_printk("apparmor: scrubbing environment variables"
721                                    " for %s profile=", name);
722                         aa_label_printk(new, GFP_ATOMIC);
723                         dbg_printk("\n");
724                 }
725                 *secure_exec = true;
726         }
727 
728 audit:
729         aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new,
730                       cond->uid, info, error);
731         if (!new || nonewprivs) {
732                 aa_put_label(new);
733                 return ERR_PTR(error);
734         }
735 
736         return new;
737 }
738 
739 static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec,
740                           bool stack, const struct linux_binprm *bprm,
741                           char *buffer, struct path_cond *cond,
742                           bool *secure_exec)
743 {
744         unsigned int state = profile->file.start;
745         struct aa_perms perms = {};
746         const char *xname = NULL, *info = "change_profile onexec";
747         int error = -EACCES;
748 
749         AA_BUG(!profile);
750         AA_BUG(!onexec);
751         AA_BUG(!bprm);
752         AA_BUG(!buffer);
753 
754         if (profile_unconfined(profile)) {
755                 /* change_profile on exec already granted */
756                 /*
757                  * NOTE: Domain transitions from unconfined are allowed
758                  * even when no_new_privs is set because this aways results
759                  * in a further reduction of permissions.
760                  */
761                 return 0;
762         }
763 
764         error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
765                              &xname, &info, profile->disconnected);
766         if (error) {
767                 if (profile_unconfined(profile) ||
768                     (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
769                         AA_DEBUG("name lookup ix on error");
770                         error = 0;
771                 }
772                 xname = bprm->filename;
773                 goto audit;
774         }
775 
776         /* find exec permissions for name */
777         state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms);
778         if (!(perms.allow & AA_MAY_ONEXEC)) {
779                 info = "no change_onexec valid for executable";
780                 goto audit;
781         }
782         /* test if this exec can be paired with change_profile onexec.
783          * onexec permission is linked to exec with a standard pairing
784          * exec\0change_profile
785          */
786         state = aa_dfa_null_transition(profile->file.dfa, state);
787         error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC,
788                                      state, &perms);
789         if (error) {
790                 perms.allow &= ~AA_MAY_ONEXEC;
791                 goto audit;
792         }
793 
794         if (!(perms.xindex & AA_X_UNSAFE)) {
795                 if (DEBUG_ON) {
796                         dbg_printk("apparmor: scrubbing environment "
797                                    "variables for %s label=", xname);
798                         aa_label_printk(onexec, GFP_ATOMIC);
799                         dbg_printk("\n");
800                 }
801                 *secure_exec = true;
802         }
803 
804 audit:
805         return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname,
806                              NULL, onexec, cond->uid, info, error);
807 }
808 
809 /* ensure none ns domain transitions are correctly applied with onexec */
810 
811 static struct aa_label *handle_onexec(struct aa_label *label,
812                                       struct aa_label *onexec, bool stack,
813                                       const struct linux_binprm *bprm,
814                                       char *buffer, struct path_cond *cond,
815                                       bool *unsafe)
816 {
817         struct aa_profile *profile;
818         struct aa_label *new;
819         int error;
820 
821         AA_BUG(!label);
822         AA_BUG(!onexec);
823         AA_BUG(!bprm);
824         AA_BUG(!buffer);
825 
826         if (!stack) {
827                 error = fn_for_each_in_ns(label, profile,
828                                 profile_onexec(profile, onexec, stack,
829                                                bprm, buffer, cond, unsafe));
830                 if (error)
831                         return ERR_PTR(error);
832                 new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
833                                 aa_get_newest_label(onexec),
834                                 profile_transition(profile, bprm, buffer,
835                                                    cond, unsafe));
836 
837         } else {
838                 /* TODO: determine how much we want to loosen this */
839                 error = fn_for_each_in_ns(label, profile,
840                                 profile_onexec(profile, onexec, stack, bprm,
841                                                buffer, cond, unsafe));
842                 if (error)
843                         return ERR_PTR(error);
844                 new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
845                                 aa_label_merge(&profile->label, onexec,
846                                                GFP_ATOMIC),
847                                 profile_transition(profile, bprm, buffer,
848                                                    cond, unsafe));
849         }
850 
851         if (new)
852                 return new;
853 
854         /* TODO: get rid of GLOBAL_ROOT_UID */
855         error = fn_for_each_in_ns(label, profile,
856                         aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC,
857                                       AA_MAY_ONEXEC, bprm->filename, NULL,
858                                       onexec, GLOBAL_ROOT_UID,
859                                       "failed to build target label", -ENOMEM));
860         return ERR_PTR(error);
861 }
862 
863 /**
864  * apparmor_bprm_set_creds - set the new creds on the bprm struct
865  * @bprm: binprm for the exec  (NOT NULL)
866  *
867  * Returns: %0 or error on failure
868  *
869  * TODO: once the other paths are done see if we can't refactor into a fn
870  */
871 int apparmor_bprm_set_creds(struct linux_binprm *bprm)
872 {
873         struct aa_task_ctx *ctx;
874         struct aa_label *label, *new = NULL;
875         struct aa_profile *profile;
876         char *buffer = NULL;
877         const char *info = NULL;
878         int error = 0;
879         bool unsafe = false;
880         struct path_cond cond = {
881                 file_inode(bprm->file)->i_uid,
882                 file_inode(bprm->file)->i_mode
883         };
884 
885         if (bprm->called_set_creds)
886                 return 0;
887 
888         ctx = task_ctx(current);
889         AA_BUG(!cred_label(bprm->cred));
890         AA_BUG(!ctx);
891 
892         label = aa_get_newest_label(cred_label(bprm->cred));
893 
894         /*
895          * Detect no new privs being set, and store the label it
896          * occurred under. Ideally this would happen when nnp
897          * is set but there isn't a good way to do that yet.
898          *
899          * Testing for unconfined must be done before the subset test
900          */
901         if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) &&
902             !ctx->nnp)
903                 ctx->nnp = aa_get_label(label);
904 
905         /* buffer freed below, name is pointer into buffer */
906         get_buffers(buffer);
907         /* Test for onexec first as onexec override other x transitions. */
908         if (ctx->onexec)
909                 new = handle_onexec(label, ctx->onexec, ctx->token,
910                                     bprm, buffer, &cond, &unsafe);
911         else
912                 new = fn_label_build(label, profile, GFP_ATOMIC,
913                                 profile_transition(profile, bprm, buffer,
914                                                    &cond, &unsafe));
915 
916         AA_BUG(!new);
917         if (IS_ERR(new)) {
918                 error = PTR_ERR(new);
919                 goto done;
920         } else if (!new) {
921                 error = -ENOMEM;
922                 goto done;
923         }
924 
925         /* Policy has specified a domain transitions. If no_new_privs and
926          * confined ensure the transition is to confinement that is subset
927          * of the confinement when the task entered no new privs.
928          *
929          * NOTE: Domain transitions from unconfined and to stacked
930          * subsets are allowed even when no_new_privs is set because this
931          * aways results in a further reduction of permissions.
932          */
933         if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
934             !unconfined(label) && !aa_label_is_subset(new, ctx->nnp)) {
935                 error = -EPERM;
936                 info = "no new privs";
937                 goto audit;
938         }
939 
940         if (bprm->unsafe & LSM_UNSAFE_SHARE) {
941                 /* FIXME: currently don't mediate shared state */
942                 ;
943         }
944 
945         if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) {
946                 /* TODO: test needs to be profile of label to new */
947                 error = may_change_ptraced_domain(new, &info);
948                 if (error)
949                         goto audit;
950         }
951 
952         if (unsafe) {
953                 if (DEBUG_ON) {
954                         dbg_printk("scrubbing environment variables for %s "
955                                    "label=", bprm->filename);
956                         aa_label_printk(new, GFP_ATOMIC);
957                         dbg_printk("\n");
958                 }
959                 bprm->secureexec = 1;
960         }
961 
962         if (label->proxy != new->proxy) {
963                 /* when transitioning clear unsafe personality bits */
964                 if (DEBUG_ON) {
965                         dbg_printk("apparmor: clearing unsafe personality "
966                                    "bits. %s label=", bprm->filename);
967                         aa_label_printk(new, GFP_ATOMIC);
968                         dbg_printk("\n");
969                 }
970                 bprm->per_clear |= PER_CLEAR_ON_SETID;
971         }
972         aa_put_label(cred_label(bprm->cred));
973         /* transfer reference, released when cred is freed */
974         set_cred_label(bprm->cred, new);
975 
976 done:
977         aa_put_label(label);
978         put_buffers(buffer);
979 
980         return error;
981 
982 audit:
983         error = fn_for_each(label, profile,
984                         aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC,
985                                       bprm->filename, NULL, new,
986                                       file_inode(bprm->file)->i_uid, info,
987                                       error));
988         aa_put_label(new);
989         goto done;
990 }
991 
992 /*
993  * Functions for self directed profile change
994  */
995 
996 
997 /* helper fn for change_hat
998  *
999  * Returns: label for hat transition OR ERR_PTR.  Does NOT return NULL
1000  */
1001 static struct aa_label *build_change_hat(struct aa_profile *profile,
1002                                          const char *name, bool sibling)
1003 {
1004         struct aa_profile *root, *hat = NULL;
1005         const char *info = NULL;
1006         int error = 0;
1007 
1008         if (sibling && PROFILE_IS_HAT(profile)) {
1009                 root = aa_get_profile_rcu(&profile->parent);
1010         } else if (!sibling && !PROFILE_IS_HAT(profile)) {
1011                 root = aa_get_profile(profile);
1012         } else {
1013                 info = "conflicting target types";
1014                 error = -EPERM;
1015                 goto audit;
1016         }
1017 
1018         hat = aa_find_child(root, name);
1019         if (!hat) {
1020                 error = -ENOENT;
1021                 if (COMPLAIN_MODE(profile)) {
1022                         hat = aa_new_null_profile(profile, true, name,
1023                                                   GFP_KERNEL);
1024                         if (!hat) {
1025                                 info = "failed null profile create";
1026                                 error = -ENOMEM;
1027                         }
1028                 }
1029         }
1030         aa_put_profile(root);
1031 
1032 audit:
1033         aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT,
1034                       name, hat ? hat->base.hname : NULL,
1035                       hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info,
1036                       error);
1037         if (!hat || (error && error != -ENOENT))
1038                 return ERR_PTR(error);
1039         /* if hat && error - complain mode, already audited and we adjust for
1040          * complain mode allow by returning hat->label
1041          */
1042         return &hat->label;
1043 }
1044 
1045 /* helper fn for changing into a hat
1046  *
1047  * Returns: label for hat transition or ERR_PTR. Does not return NULL
1048  */
1049 static struct aa_label *change_hat(struct aa_label *label, const char *hats[],
1050                                    int count, int flags)
1051 {
1052         struct aa_profile *profile, *root, *hat = NULL;
1053         struct aa_label *new;
1054         struct label_it it;
1055         bool sibling = false;
1056         const char *name, *info = NULL;
1057         int i, error;
1058 
1059         AA_BUG(!label);
1060         AA_BUG(!hats);
1061         AA_BUG(count < 1);
1062 
1063         if (PROFILE_IS_HAT(labels_profile(label)))
1064                 sibling = true;
1065 
1066         /*find first matching hat */
1067         for (i = 0; i < count && !hat; i++) {
1068                 name = hats[i];
1069                 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1070                         if (sibling && PROFILE_IS_HAT(profile)) {
1071                                 root = aa_get_profile_rcu(&profile->parent);
1072                         } else if (!sibling && !PROFILE_IS_HAT(profile)) {
1073                                 root = aa_get_profile(profile);
1074                         } else {        /* conflicting change type */
1075                                 info = "conflicting targets types";
1076                                 error = -EPERM;
1077                                 goto fail;
1078                         }
1079                         hat = aa_find_child(root, name);
1080                         aa_put_profile(root);
1081                         if (!hat) {
1082                                 if (!COMPLAIN_MODE(profile))
1083                                         goto outer_continue;
1084                                 /* complain mode succeed as if hat */
1085                         } else if (!PROFILE_IS_HAT(hat)) {
1086                                 info = "target not hat";
1087                                 error = -EPERM;
1088                                 aa_put_profile(hat);
1089                                 goto fail;
1090                         }
1091                         aa_put_profile(hat);
1092                 }
1093                 /* found a hat for all profiles in ns */
1094                 goto build;
1095 outer_continue:
1096         ;
1097         }
1098         /* no hats that match, find appropriate error
1099          *
1100          * In complain mode audit of the failure is based off of the first
1101          * hat supplied.  This is done due how userspace interacts with
1102          * change_hat.
1103          */
1104         name = NULL;
1105         label_for_each_in_ns(it, labels_ns(label), label, profile) {
1106                 if (!list_empty(&profile->base.profiles)) {
1107                         info = "hat not found";
1108                         error = -ENOENT;
1109                         goto fail;
1110                 }
1111         }
1112         info = "no hats defined";
1113         error = -ECHILD;
1114 
1115 fail:
1116         label_for_each_in_ns(it, labels_ns(label), label, profile) {
1117                 /*
1118                  * no target as it has failed to be found or built
1119                  *
1120                  * change_hat uses probing and should not log failures
1121                  * related to missing hats
1122                  */
1123                 /* TODO: get rid of GLOBAL_ROOT_UID */
1124                 if (count > 1 || COMPLAIN_MODE(profile)) {
1125                         aa_audit_file(profile, &nullperms, OP_CHANGE_HAT,
1126                                       AA_MAY_CHANGEHAT, name, NULL, NULL,
1127                                       GLOBAL_ROOT_UID, info, error);
1128                 }
1129         }
1130         return ERR_PTR(error);
1131 
1132 build:
1133         new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1134                                    build_change_hat(profile, name, sibling),
1135                                    aa_get_label(&profile->label));
1136         if (!new) {
1137                 info = "label build failed";
1138                 error = -ENOMEM;
1139                 goto fail;
1140         } /* else if (IS_ERR) build_change_hat has logged error so return new */
1141 
1142         return new;
1143 }
1144 
1145 /**
1146  * aa_change_hat - change hat to/from subprofile
1147  * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
1148  * @count: number of hat names in @hats
1149  * @token: magic value to validate the hat change
1150  * @flags: flags affecting behavior of the change
1151  *
1152  * Returns %0 on success, error otherwise.
1153  *
1154  * Change to the first profile specified in @hats that exists, and store
1155  * the @hat_magic in the current task context.  If the count == 0 and the
1156  * @token matches that stored in the current task context, return to the
1157  * top level profile.
1158  *
1159  * change_hat only applies to profiles in the current ns, and each profile
1160  * in the ns must make the same transition otherwise change_hat will fail.
1161  */
1162 int aa_change_hat(const char *hats[], int count, u64 token, int flags)
1163 {
1164         const struct cred *cred;
1165         struct aa_task_ctx *ctx = task_ctx(current);
1166         struct aa_label *label, *previous, *new = NULL, *target = NULL;
1167         struct aa_profile *profile;
1168         struct aa_perms perms = {};
1169         const char *info = NULL;
1170         int error = 0;
1171 
1172         /* released below */
1173         cred = get_current_cred();
1174         label = aa_get_newest_cred_label(cred);
1175         previous = aa_get_newest_label(ctx->previous);
1176 
1177         /*
1178          * Detect no new privs being set, and store the label it
1179          * occurred under. Ideally this would happen when nnp
1180          * is set but there isn't a good way to do that yet.
1181          *
1182          * Testing for unconfined must be done before the subset test
1183          */
1184         if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1185                 ctx->nnp = aa_get_label(label);
1186 
1187         if (unconfined(label)) {
1188                 info = "unconfined can not change_hat";
1189                 error = -EPERM;
1190                 goto fail;
1191         }
1192 
1193         if (count) {
1194                 new = change_hat(label, hats, count, flags);
1195                 AA_BUG(!new);
1196                 if (IS_ERR(new)) {
1197                         error = PTR_ERR(new);
1198                         new = NULL;
1199                         /* already audited */
1200                         goto out;
1201                 }
1202 
1203                 error = may_change_ptraced_domain(new, &info);
1204                 if (error)
1205                         goto fail;
1206 
1207                 /*
1208                  * no new privs prevents domain transitions that would
1209                  * reduce restrictions.
1210                  */
1211                 if (task_no_new_privs(current) && !unconfined(label) &&
1212                     !aa_label_is_subset(new, ctx->nnp)) {
1213                         /* not an apparmor denial per se, so don't log it */
1214                         AA_DEBUG("no_new_privs - change_hat denied");
1215                         error = -EPERM;
1216                         goto out;
1217                 }
1218 
1219                 if (flags & AA_CHANGE_TEST)
1220                         goto out;
1221 
1222                 target = new;
1223                 error = aa_set_current_hat(new, token);
1224                 if (error == -EACCES)
1225                         /* kill task in case of brute force attacks */
1226                         goto kill;
1227         } else if (previous && !(flags & AA_CHANGE_TEST)) {
1228                 /*
1229                  * no new privs prevents domain transitions that would
1230                  * reduce restrictions.
1231                  */
1232                 if (task_no_new_privs(current) && !unconfined(label) &&
1233                     !aa_label_is_subset(previous, ctx->nnp)) {
1234                         /* not an apparmor denial per se, so don't log it */
1235                         AA_DEBUG("no_new_privs - change_hat denied");
1236                         error = -EPERM;
1237                         goto out;
1238                 }
1239 
1240                 /* Return to saved label.  Kill task if restore fails
1241                  * to avoid brute force attacks
1242                  */
1243                 target = previous;
1244                 error = aa_restore_previous_label(token);
1245                 if (error) {
1246                         if (error == -EACCES)
1247                                 goto kill;
1248                         goto fail;
1249                 }
1250         } /* else ignore @flags && restores when there is no saved profile */
1251 
1252 out:
1253         aa_put_label(new);
1254         aa_put_label(previous);
1255         aa_put_label(label);
1256         put_cred(cred);
1257 
1258         return error;
1259 
1260 kill:
1261         info = "failed token match";
1262         perms.kill = AA_MAY_CHANGEHAT;
1263 
1264 fail:
1265         fn_for_each_in_ns(label, profile,
1266                 aa_audit_file(profile, &perms, OP_CHANGE_HAT,
1267                               AA_MAY_CHANGEHAT, NULL, NULL, target,
1268                               GLOBAL_ROOT_UID, info, error));
1269 
1270         goto out;
1271 }
1272 
1273 
1274 static int change_profile_perms_wrapper(const char *op, const char *name,
1275                                         struct aa_profile *profile,
1276                                         struct aa_label *target, bool stack,
1277                                         u32 request, struct aa_perms *perms)
1278 {
1279         const char *info = NULL;
1280         int error = 0;
1281 
1282         if (!error)
1283                 error = change_profile_perms(profile, target, stack, request,
1284                                              profile->file.start, perms);
1285         if (error)
1286                 error = aa_audit_file(profile, perms, op, request, name,
1287                                       NULL, target, GLOBAL_ROOT_UID, info,
1288                                       error);
1289 
1290         return error;
1291 }
1292 
1293 /**
1294  * aa_change_profile - perform a one-way profile transition
1295  * @fqname: name of profile may include namespace (NOT NULL)
1296  * @onexec: whether this transition is to take place immediately or at exec
1297  * @flags: flags affecting change behavior
1298  *
1299  * Change to new profile @name.  Unlike with hats, there is no way
1300  * to change back.  If @name isn't specified the current profile name is
1301  * used.
1302  * If @onexec then the transition is delayed until
1303  * the next exec.
1304  *
1305  * Returns %0 on success, error otherwise.
1306  */
1307 int aa_change_profile(const char *fqname, int flags)
1308 {
1309         struct aa_label *label, *new = NULL, *target = NULL;
1310         struct aa_profile *profile;
1311         struct aa_perms perms = {};
1312         const char *info = NULL;
1313         const char *auditname = fqname;         /* retain leading & if stack */
1314         bool stack = flags & AA_CHANGE_STACK;
1315         struct aa_task_ctx *ctx = task_ctx(current);
1316         int error = 0;
1317         char *op;
1318         u32 request;
1319 
1320         label = aa_get_current_label();
1321 
1322         /*
1323          * Detect no new privs being set, and store the label it
1324          * occurred under. Ideally this would happen when nnp
1325          * is set but there isn't a good way to do that yet.
1326          *
1327          * Testing for unconfined must be done before the subset test
1328          */
1329         if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1330                 ctx->nnp = aa_get_label(label);
1331 
1332         if (!fqname || !*fqname) {
1333                 AA_DEBUG("no profile name");
1334                 return -EINVAL;
1335         }
1336 
1337         if (flags & AA_CHANGE_ONEXEC) {
1338                 request = AA_MAY_ONEXEC;
1339                 if (stack)
1340                         op = OP_STACK_ONEXEC;
1341                 else
1342                         op = OP_CHANGE_ONEXEC;
1343         } else {
1344                 request = AA_MAY_CHANGE_PROFILE;
1345                 if (stack)
1346                         op = OP_STACK;
1347                 else
1348                         op = OP_CHANGE_PROFILE;
1349         }
1350 
1351         label = aa_get_current_label();
1352 
1353         if (*fqname == '&') {
1354                 stack = true;
1355                 /* don't have label_parse() do stacking */
1356                 fqname++;
1357         }
1358         target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
1359         if (IS_ERR(target)) {
1360                 struct aa_profile *tprofile;
1361 
1362                 info = "label not found";
1363                 error = PTR_ERR(target);
1364                 target = NULL;
1365                 /*
1366                  * TODO: fixme using labels_profile is not right - do profile
1367                  * per complain profile
1368                  */
1369                 if ((flags & AA_CHANGE_TEST) ||
1370                     !COMPLAIN_MODE(labels_profile(label)))
1371                         goto audit;
1372                 /* released below */
1373                 tprofile = aa_new_null_profile(labels_profile(label), false,
1374                                                fqname, GFP_KERNEL);
1375                 if (!tprofile) {
1376                         info = "failed null profile create";
1377                         error = -ENOMEM;
1378                         goto audit;
1379                 }
1380                 target = &tprofile->label;
1381                 goto check;
1382         }
1383 
1384         /*
1385          * self directed transitions only apply to current policy ns
1386          * TODO: currently requiring perms for stacking and straight change
1387          *       stacking doesn't strictly need this. Determine how much
1388          *       we want to loosen this restriction for stacking
1389          *
1390          * if (!stack) {
1391          */
1392         error = fn_for_each_in_ns(label, profile,
1393                         change_profile_perms_wrapper(op, auditname,
1394                                                      profile, target, stack,
1395                                                      request, &perms));
1396         if (error)
1397                 /* auditing done in change_profile_perms_wrapper */
1398                 goto out;
1399 
1400         /* } */
1401 
1402 check:
1403         /* check if tracing task is allowed to trace target domain */
1404         error = may_change_ptraced_domain(target, &info);
1405         if (error && !fn_for_each_in_ns(label, profile,
1406                                         COMPLAIN_MODE(profile)))
1407                 goto audit;
1408 
1409         /* TODO: add permission check to allow this
1410          * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
1411          *      info = "not a single threaded task";
1412          *      error = -EACCES;
1413          *      goto audit;
1414          * }
1415          */
1416         if (flags & AA_CHANGE_TEST)
1417                 goto out;
1418 
1419         /* stacking is always a subset, so only check the nonstack case */
1420         if (!stack) {
1421                 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1422                                            aa_get_label(target),
1423                                            aa_get_label(&profile->label));
1424                 /*
1425                  * no new privs prevents domain transitions that would
1426                  * reduce restrictions.
1427                  */
1428                 if (task_no_new_privs(current) && !unconfined(label) &&
1429                     !aa_label_is_subset(new, ctx->nnp)) {
1430                         /* not an apparmor denial per se, so don't log it */
1431                         AA_DEBUG("no_new_privs - change_hat denied");
1432                         error = -EPERM;
1433                         goto out;
1434                 }
1435         }
1436 
1437         if (!(flags & AA_CHANGE_ONEXEC)) {
1438                 /* only transition profiles in the current ns */
1439                 if (stack)
1440                         new = aa_label_merge(label, target, GFP_KERNEL);
1441                 if (IS_ERR_OR_NULL(new)) {
1442                         info = "failed to build target label";
1443                         if (!new)
1444                                 error = -ENOMEM;
1445                         else
1446                                 error = PTR_ERR(new);
1447                         new = NULL;
1448                         perms.allow = 0;
1449                         goto audit;
1450                 }
1451                 error = aa_replace_current_label(new);
1452         } else {
1453                 if (new) {
1454                         aa_put_label(new);
1455                         new = NULL;
1456                 }
1457 
1458                 /* full transition will be built in exec path */
1459                 error = aa_set_current_onexec(target, stack);
1460         }
1461 
1462 audit:
1463         error = fn_for_each_in_ns(label, profile,
1464                         aa_audit_file(profile, &perms, op, request, auditname,
1465                                       NULL, new ? new : target,
1466                                       GLOBAL_ROOT_UID, info, error));
1467 
1468 out:
1469         aa_put_label(new);
1470         aa_put_label(target);
1471         aa_put_label(label);
1472 
1473         return error;
1474 }
1475 

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