2 * AppArmor security module
4 * This file contains AppArmor policy attachment and domain transitions
6 * Copyright (C) 2002-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
15 #include <linux/errno.h>
16 #include <linux/fdtable.h>
17 #include <linux/file.h>
18 #include <linux/mount.h>
19 #include <linux/syscalls.h>
20 #include <linux/tracehook.h>
21 #include <linux/personality.h>
23 #include "include/audit.h"
24 #include "include/apparmorfs.h"
25 #include "include/context.h"
26 #include "include/domain.h"
27 #include "include/file.h"
28 #include "include/ipc.h"
29 #include "include/match.h"
30 #include "include/path.h"
31 #include "include/policy.h"
32 #include "include/policy_ns.h"
35 * aa_free_domain_entries - free entries in a domain table
36 * @domain: the domain table to free (MAYBE NULL)
38 void aa_free_domain_entries(struct aa_domain *domain)
45 for (i = 0; i < domain->size; i++)
46 kzfree(domain->table[i]);
47 kzfree(domain->table);
53 * may_change_ptraced_domain - check if can change profile on ptraced task
54 * @to_label: profile to change to (NOT NULL)
55 * @info: message if there is an error
57 * Check if current is ptraced and if so if the tracing task is allowed
58 * to trace the new domain
60 * Returns: %0 or error if change not allowed
62 static int may_change_ptraced_domain(struct aa_label *to_label,
65 struct task_struct *tracer;
66 struct aa_label *tracerl = NULL;
70 tracer = ptrace_parent(current);
73 tracerl = aa_get_task_label(tracer);
76 if (!tracer || unconfined(tracerl))
79 error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
83 aa_put_label(tracerl);
86 *info = "ptrace prevents transition";
90 /**** TODO: dedup to aa_label_match - needs perm and dfa, merging
91 * specifically this is an exact copy of aa_label_match except
92 * aa_compute_perms is replaced with aa_compute_fperms
93 * and policy.dfa with file.dfa
95 /* match a profile and its associated ns component if needed
96 * Assumes visibility test has already been done.
97 * If a subns profile is not to be matched should be prescreened with
100 static inline unsigned int match_component(struct aa_profile *profile,
101 struct aa_profile *tp,
102 bool stack, unsigned int state)
107 state = aa_dfa_match(profile->file.dfa, state, "&");
108 if (profile->ns == tp->ns)
109 return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
111 /* try matching with namespace name and then profile */
112 ns_name = aa_ns_name(profile->ns, tp->ns, true);
113 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
114 state = aa_dfa_match(profile->file.dfa, state, ns_name);
115 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
116 return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
120 * label_compound_match - find perms for full compound label
121 * @profile: profile to find perms for
122 * @label: label to check access permissions for
123 * @stack: whether this is a stacking request
124 * @start: state to start match in
125 * @subns: whether to do permission checks on components in a subns
126 * @request: permissions to request
127 * @perms: perms struct to set
129 * Returns: 0 on success else ERROR
131 * For the label A//&B//&C this does the perm match for A//&B//&C
132 * @perms should be preinitialized with allperms OR a previous permission
133 * check to be stacked.
135 static int label_compound_match(struct aa_profile *profile,
136 struct aa_label *label, bool stack,
137 unsigned int state, bool subns, u32 request,
138 struct aa_perms *perms)
140 struct aa_profile *tp;
142 struct path_cond cond = { };
144 /* find first subcomponent that is visible */
145 label_for_each(i, label, tp) {
146 if (!aa_ns_visible(profile->ns, tp->ns, subns))
148 state = match_component(profile, tp, stack, state);
154 /* no component visible */
159 label_for_each_cont(i, label, tp) {
160 if (!aa_ns_visible(profile->ns, tp->ns, subns))
162 state = aa_dfa_match(profile->file.dfa, state, "//&");
163 state = match_component(profile, tp, false, state);
167 *perms = aa_compute_fperms(profile->file.dfa, state, &cond);
168 aa_apply_modes_to_perms(profile, perms);
169 if ((perms->allow & request) != request)
180 * label_components_match - find perms for all subcomponents of a label
181 * @profile: profile to find perms for
182 * @label: label to check access permissions for
183 * @stack: whether this is a stacking request
184 * @start: state to start match in
185 * @subns: whether to do permission checks on components in a subns
186 * @request: permissions to request
187 * @perms: an initialized perms struct to add accumulation to
189 * Returns: 0 on success else ERROR
191 * For the label A//&B//&C this does the perm match for each of A and B and C
192 * @perms should be preinitialized with allperms OR a previous permission
193 * check to be stacked.
195 static int label_components_match(struct aa_profile *profile,
196 struct aa_label *label, bool stack,
197 unsigned int start, bool subns, u32 request,
198 struct aa_perms *perms)
200 struct aa_profile *tp;
203 struct path_cond cond = { };
204 unsigned int state = 0;
206 /* find first subcomponent to test */
207 label_for_each(i, label, tp) {
208 if (!aa_ns_visible(profile->ns, tp->ns, subns))
210 state = match_component(profile, tp, stack, start);
216 /* no subcomponents visible - no change in perms */
220 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
221 aa_apply_modes_to_perms(profile, &tmp);
222 aa_perms_accum(perms, &tmp);
223 label_for_each_cont(i, label, tp) {
224 if (!aa_ns_visible(profile->ns, tp->ns, subns))
226 state = match_component(profile, tp, stack, start);
229 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
230 aa_apply_modes_to_perms(profile, &tmp);
231 aa_perms_accum(perms, &tmp);
234 if ((perms->allow & request) != request)
245 * label_match - do a multi-component label match
246 * @profile: profile to match against (NOT NULL)
247 * @label: label to match (NOT NULL)
248 * @stack: whether this is a stacking request
249 * @state: state to start in
250 * @subns: whether to match subns components
251 * @request: permission request
252 * @perms: Returns computed perms (NOT NULL)
254 * Returns: the state the match finished in, may be the none matching state
256 static int label_match(struct aa_profile *profile, struct aa_label *label,
257 bool stack, unsigned int state, bool subns, u32 request,
258 struct aa_perms *perms)
263 error = label_compound_match(profile, label, stack, state, subns,
269 return label_components_match(profile, label, stack, state, subns,
273 /******* end TODO: dedup *****/
276 * change_profile_perms - find permissions for change_profile
277 * @profile: the current profile (NOT NULL)
278 * @target: label to transition to (NOT NULL)
279 * @stack: whether this is a stacking request
280 * @request: requested perms
281 * @start: state to start matching in
284 * Returns: permission set
286 * currently only matches full label A//&B//&C or individual components A, B, C
287 * not arbitrary combinations. Eg. A//&B, C
289 static int change_profile_perms(struct aa_profile *profile,
290 struct aa_label *target, bool stack,
291 u32 request, unsigned int start,
292 struct aa_perms *perms)
294 if (profile_unconfined(profile)) {
295 perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
296 perms->audit = perms->quiet = perms->kill = 0;
300 /* TODO: add profile in ns screening */
301 return label_match(profile, target, stack, start, true, request, perms);
305 * __attach_match_ - find an attachment match
306 * @name - to match against (NOT NULL)
307 * @head - profile list to walk (NOT NULL)
308 * @info - info message if there was an error (NOT NULL)
310 * Do a linear search on the profiles in the list. There is a matching
311 * preference where an exact match is preferred over a name which uses
312 * expressions to match, and matching expressions with the greatest
313 * xmatch_len are preferred.
315 * Requires: @head not be shared or have appropriate locks held
317 * Returns: profile or NULL if no match found
319 static struct aa_profile *__attach_match(const char *name,
320 struct list_head *head,
324 bool conflict = false;
325 struct aa_profile *profile, *candidate = NULL;
327 list_for_each_entry_rcu(profile, head, base.list) {
328 if (profile->label.flags & FLAG_NULL &&
329 &profile->label == ns_unconfined(profile->ns))
332 if (profile->xmatch) {
333 if (profile->xmatch_len >= len) {
337 state = aa_dfa_match(profile->xmatch,
339 perm = dfa_user_allow(profile->xmatch, state);
340 /* any accepting state means a valid match. */
341 if (perm & MAY_EXEC) {
342 if (profile->xmatch_len == len) {
347 len = profile->xmatch_len;
351 } else if (!strcmp(profile->base.name, name))
352 /* exact non-re match, no more searching required */
357 *info = "conflicting profile attachments";
365 * find_attach - do attachment search for unconfined processes
366 * @ns: the current namespace (NOT NULL)
367 * @list: list to search (NOT NULL)
368 * @name: the executable name to match against (NOT NULL)
369 * @info: info message if there was an error
371 * Returns: label or NULL if no match found
373 static struct aa_label *find_attach(struct aa_ns *ns, struct list_head *list,
374 const char *name, const char **info)
376 struct aa_profile *profile;
379 profile = aa_get_profile(__attach_match(name, list, info));
382 return profile ? &profile->label : NULL;
385 static const char *next_name(int xtype, const char *name)
391 * x_table_lookup - lookup an x transition name via transition table
392 * @profile: current profile (NOT NULL)
393 * @xindex: index into x transition table
394 * @name: returns: name tested to find label (NOT NULL)
396 * Returns: refcounted label, or NULL on failure (MAYBE NULL)
398 struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex,
401 struct aa_label *label = NULL;
402 u32 xtype = xindex & AA_X_TYPE_MASK;
403 int index = xindex & AA_X_INDEX_MASK;
407 /* index is guaranteed to be in range, validated at load time */
408 /* TODO: move lookup parsing to unpack time so this is a straight
409 * index into the resultant label
411 for (*name = profile->file.trans.table[index]; !label && *name;
412 *name = next_name(xtype, *name)) {
413 if (xindex & AA_X_CHILD) {
414 struct aa_profile *new_profile;
415 /* release by caller */
416 new_profile = aa_find_child(profile, *name);
418 label = &new_profile->label;
421 label = aa_label_parse(&profile->label, *name, GFP_ATOMIC,
427 /* released by caller */
433 * x_to_label - get target label for a given xindex
434 * @profile: current profile (NOT NULL)
435 * @name: name to lookup (NOT NULL)
436 * @xindex: index into x transition table
437 * @lookupname: returns: name used in lookup if one was specified (NOT NULL)
439 * find label for a transition index
441 * Returns: refcounted label or NULL if not found available
443 static struct aa_label *x_to_label(struct aa_profile *profile,
444 const char *name, u32 xindex,
445 const char **lookupname,
448 struct aa_label *new = NULL;
449 struct aa_ns *ns = profile->ns;
450 u32 xtype = xindex & AA_X_TYPE_MASK;
451 const char *stack = NULL;
455 /* fail exec unless ix || ux fallback - handled by caller */
459 /* TODO: fix when perm mapping done at unload */
460 stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK];
462 /* released by caller */
463 new = x_table_lookup(profile, xindex, lookupname);
467 /* fall through to X_NAME */
469 if (xindex & AA_X_CHILD)
470 /* released by caller */
471 new = find_attach(ns, &profile->base.profiles,
474 /* released by caller */
475 new = find_attach(ns, &ns->base.profiles,
482 if (xindex & AA_X_INHERIT) {
483 /* (p|c|n)ix - don't change profile but do
484 * use the newest version
486 *info = "ix fallback";
487 /* no profile && no error */
488 new = aa_get_newest_label(&profile->label);
489 } else if (xindex & AA_X_UNCONFINED) {
490 new = aa_get_newest_label(ns_unconfined(profile->ns));
491 *info = "ux fallback";
496 /* base the stack on post domain transition */
497 struct aa_label *base = new;
499 new = aa_label_parse(base, stack, GFP_ATOMIC, true, false);
505 /* released by caller */
509 static struct aa_label *profile_transition(struct aa_profile *profile,
510 const struct linux_binprm *bprm,
511 char *buffer, struct path_cond *cond,
514 struct aa_label *new = NULL;
515 const char *info = NULL, *name = NULL, *target = NULL;
516 unsigned int state = profile->file.start;
517 struct aa_perms perms = {};
518 bool nonewprivs = false;
525 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
526 &name, &info, profile->disconnected);
528 if (profile_unconfined(profile) ||
529 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
530 AA_DEBUG("name lookup ix on error");
532 new = aa_get_newest_label(&profile->label);
534 name = bprm->filename;
538 if (profile_unconfined(profile)) {
539 new = find_attach(profile->ns, &profile->ns->base.profiles,
542 AA_DEBUG("unconfined attached to new label");
545 AA_DEBUG("unconfined exec no attachment");
546 return aa_get_newest_label(&profile->label);
549 /* find exec permissions for name */
550 state = aa_str_perms(profile->file.dfa, state, name, cond, &perms);
551 if (perms.allow & MAY_EXEC) {
552 /* exec permission determine how to transition */
553 new = x_to_label(profile, name, perms.xindex, &target, &info);
554 if (new && new->proxy == profile->label.proxy && info) {
555 /* hack ix fallback - improve how this is detected */
559 info = "profile transition not found";
560 /* remove MAY_EXEC to audit as failure */
561 perms.allow &= ~MAY_EXEC;
563 } else if (COMPLAIN_MODE(profile)) {
564 /* no exec permission - learning mode */
565 struct aa_profile *new_profile = NULL;
566 char *n = kstrdup(name, GFP_ATOMIC);
569 /* name is ptr into buffer */
570 long pos = name - buffer;
571 /* break per cpu buffer hold */
573 new_profile = aa_new_null_profile(profile, false, n,
577 strcpy((char *)name, n);
582 info = "could not create null profile";
585 new = &new_profile->label;
587 perms.xindex |= AA_X_UNSAFE;
595 /* Policy has specified a domain transitions. if no_new_privs and
596 * confined and not transitioning to the current domain fail.
598 * NOTE: Domain transitions from unconfined and to stritly stacked
599 * subsets are allowed even when no_new_privs is set because this
600 * aways results in a further reduction of permissions.
602 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
603 !profile_unconfined(profile) &&
604 !aa_label_is_subset(new, &profile->label)) {
606 info = "no new privs";
608 perms.allow &= ~MAY_EXEC;
612 if (!(perms.xindex & AA_X_UNSAFE)) {
614 dbg_printk("apparmor: scrubbing environment variables"
615 " for %s profile=", name);
616 aa_label_printk(new, GFP_ATOMIC);
623 aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new,
624 cond->uid, info, error);
625 if (!new || nonewprivs) {
627 return ERR_PTR(error);
633 static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec,
634 bool stack, const struct linux_binprm *bprm,
635 char *buffer, struct path_cond *cond,
638 unsigned int state = profile->file.start;
639 struct aa_perms perms = {};
640 const char *xname = NULL, *info = "change_profile onexec";
648 if (profile_unconfined(profile)) {
649 /* change_profile on exec already granted */
651 * NOTE: Domain transitions from unconfined are allowed
652 * even when no_new_privs is set because this aways results
653 * in a further reduction of permissions.
658 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
659 &xname, &info, profile->disconnected);
661 if (profile_unconfined(profile) ||
662 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
663 AA_DEBUG("name lookup ix on error");
666 xname = bprm->filename;
670 /* find exec permissions for name */
671 state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms);
672 if (!(perms.allow & AA_MAY_ONEXEC)) {
673 info = "no change_onexec valid for executable";
676 /* test if this exec can be paired with change_profile onexec.
677 * onexec permission is linked to exec with a standard pairing
678 * exec\0change_profile
680 state = aa_dfa_null_transition(profile->file.dfa, state);
681 error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC,
684 perms.allow &= ~AA_MAY_ONEXEC;
687 /* Policy has specified a domain transitions. if no_new_privs and
688 * confined and not transitioning to the current domain fail.
690 * NOTE: Domain transitions from unconfined and to stritly stacked
691 * subsets are allowed even when no_new_privs is set because this
692 * aways results in a further reduction of permissions.
694 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
695 !profile_unconfined(profile) &&
696 !aa_label_is_subset(onexec, &profile->label)) {
698 info = "no new privs";
699 perms.allow &= ~AA_MAY_ONEXEC;
703 if (!(perms.xindex & AA_X_UNSAFE)) {
705 dbg_printk("apparmor: scrubbing environment "
706 "variables for %s label=", xname);
707 aa_label_printk(onexec, GFP_ATOMIC);
714 return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname,
715 NULL, onexec, cond->uid, info, error);
718 /* ensure none ns domain transitions are correctly applied with onexec */
720 static struct aa_label *handle_onexec(struct aa_label *label,
721 struct aa_label *onexec, bool stack,
722 const struct linux_binprm *bprm,
723 char *buffer, struct path_cond *cond,
726 struct aa_profile *profile;
727 struct aa_label *new;
736 error = fn_for_each_in_ns(label, profile,
737 profile_onexec(profile, onexec, stack,
738 bprm, buffer, cond, unsafe));
740 return ERR_PTR(error);
741 new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
742 aa_get_newest_label(onexec),
743 profile_transition(profile, bprm, buffer,
747 /* TODO: determine how much we want to losen this */
748 error = fn_for_each_in_ns(label, profile,
749 profile_onexec(profile, onexec, stack, bprm,
750 buffer, cond, unsafe));
752 return ERR_PTR(error);
753 new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
754 aa_label_merge(&profile->label, onexec,
756 profile_transition(profile, bprm, buffer,
763 /* TODO: get rid of GLOBAL_ROOT_UID */
764 error = fn_for_each_in_ns(label, profile,
765 aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC,
766 AA_MAY_ONEXEC, bprm->filename, NULL,
767 onexec, GLOBAL_ROOT_UID,
768 "failed to build target label", -ENOMEM));
769 return ERR_PTR(error);
773 * apparmor_bprm_set_creds - set the new creds on the bprm struct
774 * @bprm: binprm for the exec (NOT NULL)
776 * Returns: %0 or error on failure
778 * TODO: once the other paths are done see if we can't refactor into a fn
780 int apparmor_bprm_set_creds(struct linux_binprm *bprm)
782 struct aa_task_ctx *ctx;
783 struct aa_label *label, *new = NULL;
784 struct aa_profile *profile;
786 const char *info = NULL;
789 struct path_cond cond = {
790 file_inode(bprm->file)->i_uid,
791 file_inode(bprm->file)->i_mode
794 if (bprm->called_set_creds)
797 ctx = cred_ctx(bprm->cred);
800 label = aa_get_newest_label(ctx->label);
802 /* buffer freed below, name is pointer into buffer */
804 /* Test for onexec first as onexec override other x transitions. */
806 new = handle_onexec(label, ctx->onexec, ctx->token,
807 bprm, buffer, &cond, &unsafe);
809 new = fn_label_build(label, profile, GFP_ATOMIC,
810 profile_transition(profile, bprm, buffer,
815 error = PTR_ERR(new);
822 /* TODO: Add ns level no_new_privs subset test */
824 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
825 /* FIXME: currently don't mediate shared state */
829 if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) {
830 /* TODO: test needs to be profile of label to new */
831 error = may_change_ptraced_domain(new, &info);
838 dbg_printk("scrubbing environment variables for %s "
839 "label=", bprm->filename);
840 aa_label_printk(new, GFP_ATOMIC);
843 bprm->secureexec = 1;
846 if (label->proxy != new->proxy) {
847 /* when transitioning clear unsafe personality bits */
849 dbg_printk("apparmor: clearing unsafe personality "
850 "bits. %s label=", bprm->filename);
851 aa_label_printk(new, GFP_ATOMIC);
854 bprm->per_clear |= PER_CLEAR_ON_SETID;
856 aa_put_label(ctx->label);
857 /* transfer reference, released when ctx is freed */
861 /* clear out temporary/transitional state from the context */
862 aa_clear_task_ctx_trans(ctx);
870 error = fn_for_each(label, profile,
871 aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC,
872 bprm->filename, NULL, new,
873 file_inode(bprm->file)->i_uid, info,
880 * Functions for self directed profile change
884 /* helper fn for change_hat
886 * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL
888 static struct aa_label *build_change_hat(struct aa_profile *profile,
889 const char *name, bool sibling)
891 struct aa_profile *root, *hat = NULL;
892 const char *info = NULL;
895 if (sibling && PROFILE_IS_HAT(profile)) {
896 root = aa_get_profile_rcu(&profile->parent);
897 } else if (!sibling && !PROFILE_IS_HAT(profile)) {
898 root = aa_get_profile(profile);
900 info = "conflicting target types";
905 hat = aa_find_child(root, name);
908 if (COMPLAIN_MODE(profile)) {
909 hat = aa_new_null_profile(profile, true, name,
912 info = "failed null profile create";
917 aa_put_profile(root);
920 aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT,
921 name, hat ? hat->base.hname : NULL,
922 hat ? &hat->label : NULL, GLOBAL_ROOT_UID, NULL,
924 if (!hat || (error && error != -ENOENT))
925 return ERR_PTR(error);
926 /* if hat && error - complain mode, already audited and we adjust for
927 * complain mode allow by returning hat->label
932 /* helper fn for changing into a hat
934 * Returns: label for hat transition or ERR_PTR. Does not return NULL
936 static struct aa_label *change_hat(struct aa_label *label, const char *hats[],
937 int count, int flags)
939 struct aa_profile *profile, *root, *hat = NULL;
940 struct aa_label *new;
942 bool sibling = false;
943 const char *name, *info = NULL;
950 if (PROFILE_IS_HAT(labels_profile(label)))
953 /*find first matching hat */
954 for (i = 0; i < count && !hat; i++) {
956 label_for_each_in_ns(it, labels_ns(label), label, profile) {
957 if (sibling && PROFILE_IS_HAT(profile)) {
958 root = aa_get_profile_rcu(&profile->parent);
959 } else if (!sibling && !PROFILE_IS_HAT(profile)) {
960 root = aa_get_profile(profile);
961 } else { /* conflicting change type */
962 info = "conflicting targets types";
966 hat = aa_find_child(root, name);
967 aa_put_profile(root);
969 if (!COMPLAIN_MODE(profile))
971 /* complain mode succeed as if hat */
972 } else if (!PROFILE_IS_HAT(hat)) {
973 info = "target not hat";
980 /* found a hat for all profiles in ns */
985 /* no hats that match, find appropriate error
987 * In complain mode audit of the failure is based off of the first
988 * hat supplied. This is done due how userspace interacts with
992 label_for_each_in_ns(it, labels_ns(label), label, profile) {
993 if (!list_empty(&profile->base.profiles)) {
994 info = "hat not found";
999 info = "no hats defined";
1003 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1005 * no target as it has failed to be found or built
1007 * change_hat uses probing and should not log failures
1008 * related to missing hats
1010 /* TODO: get rid of GLOBAL_ROOT_UID */
1011 if (count > 1 || COMPLAIN_MODE(profile)) {
1012 aa_audit_file(profile, &nullperms, OP_CHANGE_HAT,
1013 AA_MAY_CHANGEHAT, name, NULL, NULL,
1014 GLOBAL_ROOT_UID, info, error);
1017 return ERR_PTR(error);
1020 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1021 build_change_hat(profile, name, sibling),
1022 aa_get_label(&profile->label));
1024 info = "label build failed";
1027 } /* else if (IS_ERR) build_change_hat has logged error so return new */
1033 * aa_change_hat - change hat to/from subprofile
1034 * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
1035 * @count: number of hat names in @hats
1036 * @token: magic value to validate the hat change
1037 * @flags: flags affecting behavior of the change
1039 * Returns %0 on success, error otherwise.
1041 * Change to the first profile specified in @hats that exists, and store
1042 * the @hat_magic in the current task context. If the count == 0 and the
1043 * @token matches that stored in the current task context, return to the
1044 * top level profile.
1046 * change_hat only applies to profiles in the current ns, and each profile
1047 * in the ns must make the same transition otherwise change_hat will fail.
1049 int aa_change_hat(const char *hats[], int count, u64 token, int flags)
1051 const struct cred *cred;
1052 struct aa_task_ctx *ctx;
1053 struct aa_label *label, *previous, *new = NULL, *target = NULL;
1054 struct aa_profile *profile;
1055 struct aa_perms perms = {};
1056 const char *info = NULL;
1060 * Fail explicitly requested domain transitions if no_new_privs.
1061 * There is no exception for unconfined as change_hat is not
1064 if (task_no_new_privs(current)) {
1065 /* not an apparmor denial per se, so don't log it */
1066 AA_DEBUG("no_new_privs - change_hat denied");
1070 /* released below */
1071 cred = get_current_cred();
1072 ctx = cred_ctx(cred);
1073 label = aa_get_newest_cred_label(cred);
1074 previous = aa_get_newest_label(ctx->previous);
1076 if (unconfined(label)) {
1077 info = "unconfined can not change_hat";
1083 new = change_hat(label, hats, count, flags);
1086 error = PTR_ERR(new);
1088 /* already audited */
1092 error = may_change_ptraced_domain(new, &info);
1096 if (flags & AA_CHANGE_TEST)
1100 error = aa_set_current_hat(new, token);
1101 if (error == -EACCES)
1102 /* kill task in case of brute force attacks */
1104 } else if (previous && !(flags & AA_CHANGE_TEST)) {
1105 /* Return to saved label. Kill task if restore fails
1106 * to avoid brute force attacks
1109 error = aa_restore_previous_label(token);
1111 if (error == -EACCES)
1115 } /* else ignore @flags && restores when there is no saved profile */
1119 aa_put_label(previous);
1120 aa_put_label(label);
1126 info = "failed token match";
1127 perms.kill = AA_MAY_CHANGEHAT;
1130 fn_for_each_in_ns(label, profile,
1131 aa_audit_file(profile, &perms, OP_CHANGE_HAT,
1132 AA_MAY_CHANGEHAT, NULL, NULL, target,
1133 GLOBAL_ROOT_UID, info, error));
1139 static int change_profile_perms_wrapper(const char *op, const char *name,
1140 struct aa_profile *profile,
1141 struct aa_label *target, bool stack,
1142 u32 request, struct aa_perms *perms)
1144 const char *info = NULL;
1148 * Fail explicitly requested domain transitions when no_new_privs
1149 * and not unconfined OR the transition results in a stack on
1150 * the current label.
1151 * Stacking domain transitions and transitions from unconfined are
1152 * allowed even when no_new_privs is set because this aways results
1153 * in a reduction of permissions.
1155 if (task_no_new_privs(current) && !stack &&
1156 !profile_unconfined(profile) &&
1157 !aa_label_is_subset(target, &profile->label)) {
1158 info = "no new privs";
1163 error = change_profile_perms(profile, target, stack, request,
1164 profile->file.start, perms);
1166 error = aa_audit_file(profile, perms, op, request, name,
1167 NULL, target, GLOBAL_ROOT_UID, info,
1174 * aa_change_profile - perform a one-way profile transition
1175 * @fqname: name of profile may include namespace (NOT NULL)
1176 * @onexec: whether this transition is to take place immediately or at exec
1177 * @flags: flags affecting change behavior
1179 * Change to new profile @name. Unlike with hats, there is no way
1180 * to change back. If @name isn't specified the current profile name is
1182 * If @onexec then the transition is delayed until
1185 * Returns %0 on success, error otherwise.
1187 int aa_change_profile(const char *fqname, int flags)
1189 struct aa_label *label, *new = NULL, *target = NULL;
1190 struct aa_profile *profile;
1191 struct aa_perms perms = {};
1192 const char *info = NULL;
1193 const char *auditname = fqname; /* retain leading & if stack */
1194 bool stack = flags & AA_CHANGE_STACK;
1199 if (!fqname || !*fqname) {
1200 AA_DEBUG("no profile name");
1204 if (flags & AA_CHANGE_ONEXEC) {
1205 request = AA_MAY_ONEXEC;
1207 op = OP_STACK_ONEXEC;
1209 op = OP_CHANGE_ONEXEC;
1211 request = AA_MAY_CHANGE_PROFILE;
1215 op = OP_CHANGE_PROFILE;
1218 label = aa_get_current_label();
1220 if (*fqname == '&') {
1222 /* don't have label_parse() do stacking */
1225 target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
1226 if (IS_ERR(target)) {
1227 struct aa_profile *tprofile;
1229 info = "label not found";
1230 error = PTR_ERR(target);
1233 * TODO: fixme using labels_profile is not right - do profile
1234 * per complain profile
1236 if ((flags & AA_CHANGE_TEST) ||
1237 !COMPLAIN_MODE(labels_profile(label)))
1239 /* released below */
1240 tprofile = aa_new_null_profile(labels_profile(label), false,
1241 fqname, GFP_KERNEL);
1243 info = "failed null profile create";
1247 target = &tprofile->label;
1252 * self directed transitions only apply to current policy ns
1253 * TODO: currently requiring perms for stacking and straight change
1254 * stacking doesn't strictly need this. Determine how much
1255 * we want to loosen this restriction for stacking
1259 error = fn_for_each_in_ns(label, profile,
1260 change_profile_perms_wrapper(op, auditname,
1261 profile, target, stack,
1264 /* auditing done in change_profile_perms_wrapper */
1270 /* check if tracing task is allowed to trace target domain */
1271 error = may_change_ptraced_domain(target, &info);
1272 if (error && !fn_for_each_in_ns(label, profile,
1273 COMPLAIN_MODE(profile)))
1276 /* TODO: add permission check to allow this
1277 * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
1278 * info = "not a single threaded task";
1283 if (flags & AA_CHANGE_TEST)
1286 if (!(flags & AA_CHANGE_ONEXEC)) {
1287 /* only transition profiles in the current ns */
1289 new = aa_label_merge(label, target, GFP_KERNEL);
1291 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1292 aa_get_label(target),
1293 aa_get_label(&profile->label));
1294 if (IS_ERR_OR_NULL(new)) {
1295 info = "failed to build target label";
1296 error = PTR_ERR(new);
1301 error = aa_replace_current_label(new);
1303 /* full transition will be built in exec path */
1304 error = aa_set_current_onexec(target, stack);
1307 error = fn_for_each_in_ns(label, profile,
1308 aa_audit_file(profile, &perms, op, request, auditname,
1309 NULL, new ? new : target,
1310 GLOBAL_ROOT_UID, info, error));
1314 aa_put_label(target);
1315 aa_put_label(label);