1 // SPDX-License-Identifier: GPL-2.0-only
3 * AppArmor security module
5 * This file contains AppArmor policy attachment and domain transitions
7 * Copyright (C) 2002-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
11 #include <linux/errno.h>
12 #include <linux/fdtable.h>
14 #include <linux/file.h>
15 #include <linux/mount.h>
16 #include <linux/syscalls.h>
17 #include <linux/personality.h>
18 #include <linux/xattr.h>
19 #include <linux/user_namespace.h>
21 #include "include/audit.h"
22 #include "include/apparmorfs.h"
23 #include "include/cred.h"
24 #include "include/domain.h"
25 #include "include/file.h"
26 #include "include/ipc.h"
27 #include "include/match.h"
28 #include "include/path.h"
29 #include "include/policy.h"
30 #include "include/policy_ns.h"
33 * aa_free_domain_entries - free entries in a domain table
34 * @domain: the domain table to free (MAYBE NULL)
36 void aa_free_domain_entries(struct aa_domain *domain)
43 for (i = 0; i < domain->size; i++)
44 kfree_sensitive(domain->table[i]);
45 kfree_sensitive(domain->table);
51 * may_change_ptraced_domain - check if can change profile on ptraced task
52 * @to_label: profile to change to (NOT NULL)
53 * @info: message if there is an error
55 * Check if current is ptraced and if so if the tracing task is allowed
56 * to trace the new domain
58 * Returns: %0 or error if change not allowed
60 static int may_change_ptraced_domain(struct aa_label *to_label,
63 struct task_struct *tracer;
64 struct aa_label *tracerl = NULL;
68 tracer = ptrace_parent(current);
71 tracerl = aa_get_task_label(tracer);
74 if (!tracer || unconfined(tracerl))
77 error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
81 aa_put_label(tracerl);
84 *info = "ptrace prevents transition";
88 /**** TODO: dedup to aa_label_match - needs perm and dfa, merging
89 * specifically this is an exact copy of aa_label_match except
90 * aa_compute_perms is replaced with aa_compute_fperms
91 * and policy.dfa with file.dfa
93 /* match a profile and its associated ns component if needed
94 * Assumes visibility test has already been done.
95 * If a subns profile is not to be matched should be prescreened with
98 static inline unsigned int match_component(struct aa_profile *profile,
99 struct aa_profile *tp,
100 bool stack, unsigned int state)
105 state = aa_dfa_match(profile->file.dfa, state, "&");
106 if (profile->ns == tp->ns)
107 return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
109 /* try matching with namespace name and then profile */
110 ns_name = aa_ns_name(profile->ns, tp->ns, true);
111 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
112 state = aa_dfa_match(profile->file.dfa, state, ns_name);
113 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
114 return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
118 * label_compound_match - find perms for full compound label
119 * @profile: profile to find perms for
120 * @label: label to check access permissions for
121 * @stack: whether this is a stacking request
122 * @state: state to start match in
123 * @subns: whether to do permission checks on components in a subns
124 * @request: permissions to request
125 * @perms: perms struct to set
127 * Returns: 0 on success else ERROR
129 * For the label A//&B//&C this does the perm match for A//&B//&C
130 * @perms should be preinitialized with allperms OR a previous permission
131 * check to be stacked.
133 static int label_compound_match(struct aa_profile *profile,
134 struct aa_label *label, bool stack,
135 unsigned int state, bool subns, u32 request,
136 struct aa_perms *perms)
138 struct aa_profile *tp;
140 struct path_cond cond = { };
142 /* find first subcomponent that is visible */
143 label_for_each(i, label, tp) {
144 if (!aa_ns_visible(profile->ns, tp->ns, subns))
146 state = match_component(profile, tp, stack, state);
152 /* no component visible */
157 label_for_each_cont(i, label, tp) {
158 if (!aa_ns_visible(profile->ns, tp->ns, subns))
160 state = aa_dfa_match(profile->file.dfa, state, "//&");
161 state = match_component(profile, tp, false, state);
165 *perms = aa_compute_fperms(profile->file.dfa, state, &cond);
166 aa_apply_modes_to_perms(profile, perms);
167 if ((perms->allow & request) != request)
178 * label_components_match - find perms for all subcomponents of a label
179 * @profile: profile to find perms for
180 * @label: label to check access permissions for
181 * @stack: whether this is a stacking request
182 * @start: state to start match in
183 * @subns: whether to do permission checks on components in a subns
184 * @request: permissions to request
185 * @perms: an initialized perms struct to add accumulation to
187 * Returns: 0 on success else ERROR
189 * For the label A//&B//&C this does the perm match for each of A and B and C
190 * @perms should be preinitialized with allperms OR a previous permission
191 * check to be stacked.
193 static int label_components_match(struct aa_profile *profile,
194 struct aa_label *label, bool stack,
195 unsigned int start, bool subns, u32 request,
196 struct aa_perms *perms)
198 struct aa_profile *tp;
201 struct path_cond cond = { };
202 unsigned int state = 0;
204 /* find first subcomponent to test */
205 label_for_each(i, label, tp) {
206 if (!aa_ns_visible(profile->ns, tp->ns, subns))
208 state = match_component(profile, tp, stack, start);
214 /* no subcomponents visible - no change in perms */
218 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
219 aa_apply_modes_to_perms(profile, &tmp);
220 aa_perms_accum(perms, &tmp);
221 label_for_each_cont(i, label, tp) {
222 if (!aa_ns_visible(profile->ns, tp->ns, subns))
224 state = match_component(profile, tp, stack, start);
227 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
228 aa_apply_modes_to_perms(profile, &tmp);
229 aa_perms_accum(perms, &tmp);
232 if ((perms->allow & request) != request)
243 * label_match - do a multi-component label match
244 * @profile: profile to match against (NOT NULL)
245 * @label: label to match (NOT NULL)
246 * @stack: whether this is a stacking request
247 * @state: state to start in
248 * @subns: whether to match subns components
249 * @request: permission request
250 * @perms: Returns computed perms (NOT NULL)
252 * Returns: the state the match finished in, may be the none matching state
254 static int label_match(struct aa_profile *profile, struct aa_label *label,
255 bool stack, unsigned int state, bool subns, u32 request,
256 struct aa_perms *perms)
261 error = label_compound_match(profile, label, stack, state, subns,
267 return label_components_match(profile, label, stack, state, subns,
271 /******* end TODO: dedup *****/
274 * change_profile_perms - find permissions for change_profile
275 * @profile: the current profile (NOT NULL)
276 * @target: label to transition to (NOT NULL)
277 * @stack: whether this is a stacking request
278 * @request: requested perms
279 * @start: state to start matching in
282 * Returns: permission set
284 * currently only matches full label A//&B//&C or individual components A, B, C
285 * not arbitrary combinations. Eg. A//&B, C
287 static int change_profile_perms(struct aa_profile *profile,
288 struct aa_label *target, bool stack,
289 u32 request, unsigned int start,
290 struct aa_perms *perms)
292 if (profile_unconfined(profile)) {
293 perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
294 perms->audit = perms->quiet = perms->kill = 0;
298 /* TODO: add profile in ns screening */
299 return label_match(profile, target, stack, start, true, request, perms);
303 * aa_xattrs_match - check whether a file matches the xattrs defined in profile
304 * @bprm: binprm struct for the process to validate
305 * @profile: profile to match against (NOT NULL)
306 * @state: state to start match in
308 * Returns: number of extended attributes that matched, or < 0 on error
310 static int aa_xattrs_match(const struct linux_binprm *bprm,
311 struct aa_profile *profile, unsigned int state)
316 int size, value_size = 0, ret = profile->xattr_count;
318 if (!bprm || !profile->xattr_count)
322 /* transition from exec match to xattr set */
323 state = aa_dfa_outofband_transition(profile->xmatch, state);
324 d = bprm->file->f_path.dentry;
326 for (i = 0; i < profile->xattr_count; i++) {
327 size = vfs_getxattr_alloc(&init_user_ns, d, profile->xattrs[i],
328 &value, value_size, GFP_KERNEL);
333 * Check the xattr presence before value. This ensure
334 * that not present xattr can be distinguished from a 0
335 * length value or rule that matches any value
337 state = aa_dfa_null_transition(profile->xmatch, state);
338 /* Check xattr value */
339 state = aa_dfa_match_len(profile->xmatch, state, value,
341 perm = dfa_user_allow(profile->xmatch, state);
342 if (!(perm & MAY_EXEC)) {
347 /* transition to next element */
348 state = aa_dfa_outofband_transition(profile->xmatch, state);
351 * No xattr match, so verify if transition to
352 * next element was valid. IFF so the xattr
359 /* don't count missing optional xattr as matched */
370 * find_attach - do attachment search for unconfined processes
371 * @bprm - binprm structure of transitioning task
372 * @ns: the current namespace (NOT NULL)
373 * @head - profile list to walk (NOT NULL)
374 * @name - to match against (NOT NULL)
375 * @info - info message if there was an error (NOT NULL)
377 * Do a linear search on the profiles in the list. There is a matching
378 * preference where an exact match is preferred over a name which uses
379 * expressions to match, and matching expressions with the greatest
380 * xmatch_len are preferred.
382 * Requires: @head not be shared or have appropriate locks held
384 * Returns: label or NULL if no match found
386 static struct aa_label *find_attach(const struct linux_binprm *bprm,
387 struct aa_ns *ns, struct list_head *head,
388 const char *name, const char **info)
390 int candidate_len = 0, candidate_xattrs = 0;
391 bool conflict = false;
392 struct aa_profile *profile, *candidate = NULL;
399 list_for_each_entry_rcu(profile, head, base.list) {
400 if (profile->label.flags & FLAG_NULL &&
401 &profile->label == ns_unconfined(profile->ns))
404 /* Find the "best" matching profile. Profiles must
405 * match the path and extended attributes (if any)
406 * associated with the file. A more specific path
407 * match will be preferred over a less specific one,
408 * and a match with more matching extended attributes
409 * will be preferred over one with fewer. If the best
410 * match has both the same level of path specificity
411 * and the same number of matching extended attributes
412 * as another profile, signal a conflict and refuse to
415 if (profile->xmatch) {
416 unsigned int state, count;
419 state = aa_dfa_leftmatch(profile->xmatch, DFA_START,
421 perm = dfa_user_allow(profile->xmatch, state);
422 /* any accepting state means a valid match. */
423 if (perm & MAY_EXEC) {
426 if (count < candidate_len)
429 if (bprm && profile->xattr_count) {
430 long rev = READ_ONCE(ns->revision);
432 if (!aa_get_profile_not0(profile))
435 ret = aa_xattrs_match(bprm, profile,
438 aa_put_profile(profile);
440 READ_ONCE(ns->revision))
444 * Fail matching if the xattrs don't
451 * TODO: allow for more flexible best match
453 * The new match isn't more specific
454 * than the current best match
456 if (count == candidate_len &&
457 ret <= candidate_xattrs) {
458 /* Match is equivalent, so conflict */
459 if (ret == candidate_xattrs)
464 /* Either the same length with more matching
465 * xattrs, or a longer match
468 candidate_len = max(count, profile->xmatch_len);
469 candidate_xattrs = ret;
472 } else if (!strcmp(profile->base.name, name)) {
474 * old exact non-re match, without conditionals such
475 * as xattrs. no more searching required
482 if (!candidate || conflict) {
484 *info = "conflicting profile attachments";
490 candidate = aa_get_newest_profile(candidate);
493 return &candidate->label;
496 static const char *next_name(int xtype, const char *name)
502 * x_table_lookup - lookup an x transition name via transition table
503 * @profile: current profile (NOT NULL)
504 * @xindex: index into x transition table
505 * @name: returns: name tested to find label (NOT NULL)
507 * Returns: refcounted label, or NULL on failure (MAYBE NULL)
509 struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex,
512 struct aa_label *label = NULL;
513 u32 xtype = xindex & AA_X_TYPE_MASK;
514 int index = xindex & AA_X_INDEX_MASK;
518 /* index is guaranteed to be in range, validated at load time */
519 /* TODO: move lookup parsing to unpack time so this is a straight
520 * index into the resultant label
522 for (*name = profile->file.trans.table[index]; !label && *name;
523 *name = next_name(xtype, *name)) {
524 if (xindex & AA_X_CHILD) {
525 struct aa_profile *new_profile;
526 /* release by caller */
527 new_profile = aa_find_child(profile, *name);
529 label = &new_profile->label;
532 label = aa_label_parse(&profile->label, *name, GFP_KERNEL,
538 /* released by caller */
544 * x_to_label - get target label for a given xindex
545 * @profile: current profile (NOT NULL)
546 * @bprm: binprm structure of transitioning task
547 * @name: name to lookup (NOT NULL)
548 * @xindex: index into x transition table
549 * @lookupname: returns: name used in lookup if one was specified (NOT NULL)
551 * find label for a transition index
553 * Returns: refcounted label or NULL if not found available
555 static struct aa_label *x_to_label(struct aa_profile *profile,
556 const struct linux_binprm *bprm,
557 const char *name, u32 xindex,
558 const char **lookupname,
561 struct aa_label *new = NULL;
562 struct aa_ns *ns = profile->ns;
563 u32 xtype = xindex & AA_X_TYPE_MASK;
564 const char *stack = NULL;
568 /* fail exec unless ix || ux fallback - handled by caller */
572 /* TODO: fix when perm mapping done at unload */
573 stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK];
575 /* released by caller */
576 new = x_table_lookup(profile, xindex, lookupname);
580 fallthrough; /* to X_NAME */
582 if (xindex & AA_X_CHILD)
583 /* released by caller */
584 new = find_attach(bprm, ns, &profile->base.profiles,
587 /* released by caller */
588 new = find_attach(bprm, ns, &ns->base.profiles,
595 if (xindex & AA_X_INHERIT) {
596 /* (p|c|n)ix - don't change profile but do
597 * use the newest version
599 *info = "ix fallback";
600 /* no profile && no error */
601 new = aa_get_newest_label(&profile->label);
602 } else if (xindex & AA_X_UNCONFINED) {
603 new = aa_get_newest_label(ns_unconfined(profile->ns));
604 *info = "ux fallback";
609 /* base the stack on post domain transition */
610 struct aa_label *base = new;
612 new = aa_label_parse(base, stack, GFP_KERNEL, true, false);
618 /* released by caller */
622 static struct aa_label *profile_transition(struct aa_profile *profile,
623 const struct linux_binprm *bprm,
624 char *buffer, struct path_cond *cond,
627 struct aa_label *new = NULL;
628 const char *info = NULL, *name = NULL, *target = NULL;
629 unsigned int state = profile->file.start;
630 struct aa_perms perms = {};
631 bool nonewprivs = false;
638 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
639 &name, &info, profile->disconnected);
641 if (profile_unconfined(profile) ||
642 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
643 AA_DEBUG("name lookup ix on error");
645 new = aa_get_newest_label(&profile->label);
647 name = bprm->filename;
651 if (profile_unconfined(profile)) {
652 new = find_attach(bprm, profile->ns,
653 &profile->ns->base.profiles, name, &info);
655 AA_DEBUG("unconfined attached to new label");
658 AA_DEBUG("unconfined exec no attachment");
659 return aa_get_newest_label(&profile->label);
662 /* find exec permissions for name */
663 state = aa_str_perms(profile->file.dfa, state, name, cond, &perms);
664 if (perms.allow & MAY_EXEC) {
665 /* exec permission determine how to transition */
666 new = x_to_label(profile, bprm, name, perms.xindex, &target,
668 if (new && new->proxy == profile->label.proxy && info) {
669 /* hack ix fallback - improve how this is detected */
673 info = "profile transition not found";
674 /* remove MAY_EXEC to audit as failure */
675 perms.allow &= ~MAY_EXEC;
677 } else if (COMPLAIN_MODE(profile)) {
678 /* no exec permission - learning mode */
679 struct aa_profile *new_profile = NULL;
681 new_profile = aa_new_null_profile(profile, false, name,
685 info = "could not create null profile";
688 new = &new_profile->label;
690 perms.xindex |= AA_X_UNSAFE;
699 if (!(perms.xindex & AA_X_UNSAFE)) {
701 dbg_printk("apparmor: scrubbing environment variables"
702 " for %s profile=", name);
703 aa_label_printk(new, GFP_KERNEL);
710 aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new,
711 cond->uid, info, error);
712 if (!new || nonewprivs) {
714 return ERR_PTR(error);
720 static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec,
721 bool stack, const struct linux_binprm *bprm,
722 char *buffer, struct path_cond *cond,
725 unsigned int state = profile->file.start;
726 struct aa_perms perms = {};
727 const char *xname = NULL, *info = "change_profile onexec";
735 if (profile_unconfined(profile)) {
736 /* change_profile on exec already granted */
738 * NOTE: Domain transitions from unconfined are allowed
739 * even when no_new_privs is set because this aways results
740 * in a further reduction of permissions.
745 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
746 &xname, &info, profile->disconnected);
748 if (profile_unconfined(profile) ||
749 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
750 AA_DEBUG("name lookup ix on error");
753 xname = bprm->filename;
757 /* find exec permissions for name */
758 state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms);
759 if (!(perms.allow & AA_MAY_ONEXEC)) {
760 info = "no change_onexec valid for executable";
763 /* test if this exec can be paired with change_profile onexec.
764 * onexec permission is linked to exec with a standard pairing
765 * exec\0change_profile
767 state = aa_dfa_null_transition(profile->file.dfa, state);
768 error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC,
771 perms.allow &= ~AA_MAY_ONEXEC;
775 if (!(perms.xindex & AA_X_UNSAFE)) {
777 dbg_printk("apparmor: scrubbing environment "
778 "variables for %s label=", xname);
779 aa_label_printk(onexec, GFP_KERNEL);
786 return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname,
787 NULL, onexec, cond->uid, info, error);
790 /* ensure none ns domain transitions are correctly applied with onexec */
792 static struct aa_label *handle_onexec(struct aa_label *label,
793 struct aa_label *onexec, bool stack,
794 const struct linux_binprm *bprm,
795 char *buffer, struct path_cond *cond,
798 struct aa_profile *profile;
799 struct aa_label *new;
808 error = fn_for_each_in_ns(label, profile,
809 profile_onexec(profile, onexec, stack,
810 bprm, buffer, cond, unsafe));
812 return ERR_PTR(error);
813 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
814 aa_get_newest_label(onexec),
815 profile_transition(profile, bprm, buffer,
819 /* TODO: determine how much we want to loosen this */
820 error = fn_for_each_in_ns(label, profile,
821 profile_onexec(profile, onexec, stack, bprm,
822 buffer, cond, unsafe));
824 return ERR_PTR(error);
825 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
826 aa_label_merge(&profile->label, onexec,
828 profile_transition(profile, bprm, buffer,
835 /* TODO: get rid of GLOBAL_ROOT_UID */
836 error = fn_for_each_in_ns(label, profile,
837 aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC,
838 AA_MAY_ONEXEC, bprm->filename, NULL,
839 onexec, GLOBAL_ROOT_UID,
840 "failed to build target label", -ENOMEM));
841 return ERR_PTR(error);
845 * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct
846 * @bprm: binprm for the exec (NOT NULL)
848 * Returns: %0 or error on failure
850 * TODO: once the other paths are done see if we can't refactor into a fn
852 int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm)
854 struct aa_task_ctx *ctx;
855 struct aa_label *label, *new = NULL;
856 struct aa_profile *profile;
858 const char *info = NULL;
861 kuid_t i_uid = i_uid_into_mnt(file_mnt_user_ns(bprm->file),
862 file_inode(bprm->file));
863 struct path_cond cond = {
865 file_inode(bprm->file)->i_mode
868 ctx = task_ctx(current);
869 AA_BUG(!cred_label(bprm->cred));
872 label = aa_get_newest_label(cred_label(bprm->cred));
875 * Detect no new privs being set, and store the label it
876 * occurred under. Ideally this would happen when nnp
877 * is set but there isn't a good way to do that yet.
879 * Testing for unconfined must be done before the subset test
881 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) &&
883 ctx->nnp = aa_get_label(label);
885 /* buffer freed below, name is pointer into buffer */
886 buffer = aa_get_buffer(false);
892 /* Test for onexec first as onexec override other x transitions. */
894 new = handle_onexec(label, ctx->onexec, ctx->token,
895 bprm, buffer, &cond, &unsafe);
897 new = fn_label_build(label, profile, GFP_KERNEL,
898 profile_transition(profile, bprm, buffer,
903 error = PTR_ERR(new);
910 /* Policy has specified a domain transitions. If no_new_privs and
911 * confined ensure the transition is to confinement that is subset
912 * of the confinement when the task entered no new privs.
914 * NOTE: Domain transitions from unconfined and to stacked
915 * subsets are allowed even when no_new_privs is set because this
916 * aways results in a further reduction of permissions.
918 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
919 !unconfined(label) &&
920 !aa_label_is_unconfined_subset(new, ctx->nnp)) {
922 info = "no new privs";
926 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
927 /* FIXME: currently don't mediate shared state */
931 if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) {
932 /* TODO: test needs to be profile of label to new */
933 error = may_change_ptraced_domain(new, &info);
940 dbg_printk("scrubbing environment variables for %s "
941 "label=", bprm->filename);
942 aa_label_printk(new, GFP_KERNEL);
945 bprm->secureexec = 1;
948 if (label->proxy != new->proxy) {
949 /* when transitioning clear unsafe personality bits */
951 dbg_printk("apparmor: clearing unsafe personality "
952 "bits. %s label=", bprm->filename);
953 aa_label_printk(new, GFP_KERNEL);
956 bprm->per_clear |= PER_CLEAR_ON_SETID;
958 aa_put_label(cred_label(bprm->cred));
959 /* transfer reference, released when cred is freed */
960 set_cred_label(bprm->cred, new);
964 aa_put_buffer(buffer);
969 error = fn_for_each(label, profile,
970 aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC,
971 bprm->filename, NULL, new,
972 i_uid, info, error));
978 * Functions for self directed profile change
982 /* helper fn for change_hat
984 * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL
986 static struct aa_label *build_change_hat(struct aa_profile *profile,
987 const char *name, bool sibling)
989 struct aa_profile *root, *hat = NULL;
990 const char *info = NULL;
993 if (sibling && PROFILE_IS_HAT(profile)) {
994 root = aa_get_profile_rcu(&profile->parent);
995 } else if (!sibling && !PROFILE_IS_HAT(profile)) {
996 root = aa_get_profile(profile);
998 info = "conflicting target types";
1003 hat = aa_find_child(root, name);
1006 if (COMPLAIN_MODE(profile)) {
1007 hat = aa_new_null_profile(profile, true, name,
1010 info = "failed null profile create";
1015 aa_put_profile(root);
1018 aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT,
1019 name, hat ? hat->base.hname : NULL,
1020 hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info,
1022 if (!hat || (error && error != -ENOENT))
1023 return ERR_PTR(error);
1024 /* if hat && error - complain mode, already audited and we adjust for
1025 * complain mode allow by returning hat->label
1030 /* helper fn for changing into a hat
1032 * Returns: label for hat transition or ERR_PTR. Does not return NULL
1034 static struct aa_label *change_hat(struct aa_label *label, const char *hats[],
1035 int count, int flags)
1037 struct aa_profile *profile, *root, *hat = NULL;
1038 struct aa_label *new;
1040 bool sibling = false;
1041 const char *name, *info = NULL;
1048 if (PROFILE_IS_HAT(labels_profile(label)))
1051 /*find first matching hat */
1052 for (i = 0; i < count && !hat; i++) {
1054 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1055 if (sibling && PROFILE_IS_HAT(profile)) {
1056 root = aa_get_profile_rcu(&profile->parent);
1057 } else if (!sibling && !PROFILE_IS_HAT(profile)) {
1058 root = aa_get_profile(profile);
1059 } else { /* conflicting change type */
1060 info = "conflicting targets types";
1064 hat = aa_find_child(root, name);
1065 aa_put_profile(root);
1067 if (!COMPLAIN_MODE(profile))
1068 goto outer_continue;
1069 /* complain mode succeed as if hat */
1070 } else if (!PROFILE_IS_HAT(hat)) {
1071 info = "target not hat";
1073 aa_put_profile(hat);
1076 aa_put_profile(hat);
1078 /* found a hat for all profiles in ns */
1083 /* no hats that match, find appropriate error
1085 * In complain mode audit of the failure is based off of the first
1086 * hat supplied. This is done due how userspace interacts with
1090 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1091 if (!list_empty(&profile->base.profiles)) {
1092 info = "hat not found";
1097 info = "no hats defined";
1101 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1103 * no target as it has failed to be found or built
1105 * change_hat uses probing and should not log failures
1106 * related to missing hats
1108 /* TODO: get rid of GLOBAL_ROOT_UID */
1109 if (count > 1 || COMPLAIN_MODE(profile)) {
1110 aa_audit_file(profile, &nullperms, OP_CHANGE_HAT,
1111 AA_MAY_CHANGEHAT, name, NULL, NULL,
1112 GLOBAL_ROOT_UID, info, error);
1115 return ERR_PTR(error);
1118 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1119 build_change_hat(profile, name, sibling),
1120 aa_get_label(&profile->label));
1122 info = "label build failed";
1125 } /* else if (IS_ERR) build_change_hat has logged error so return new */
1131 * aa_change_hat - change hat to/from subprofile
1132 * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
1133 * @count: number of hat names in @hats
1134 * @token: magic value to validate the hat change
1135 * @flags: flags affecting behavior of the change
1137 * Returns %0 on success, error otherwise.
1139 * Change to the first profile specified in @hats that exists, and store
1140 * the @hat_magic in the current task context. If the count == 0 and the
1141 * @token matches that stored in the current task context, return to the
1142 * top level profile.
1144 * change_hat only applies to profiles in the current ns, and each profile
1145 * in the ns must make the same transition otherwise change_hat will fail.
1147 int aa_change_hat(const char *hats[], int count, u64 token, int flags)
1149 const struct cred *cred;
1150 struct aa_task_ctx *ctx = task_ctx(current);
1151 struct aa_label *label, *previous, *new = NULL, *target = NULL;
1152 struct aa_profile *profile;
1153 struct aa_perms perms = {};
1154 const char *info = NULL;
1157 /* released below */
1158 cred = get_current_cred();
1159 label = aa_get_newest_cred_label(cred);
1160 previous = aa_get_newest_label(ctx->previous);
1163 * Detect no new privs being set, and store the label it
1164 * occurred under. Ideally this would happen when nnp
1165 * is set but there isn't a good way to do that yet.
1167 * Testing for unconfined must be done before the subset test
1169 if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1170 ctx->nnp = aa_get_label(label);
1172 if (unconfined(label)) {
1173 info = "unconfined can not change_hat";
1179 new = change_hat(label, hats, count, flags);
1182 error = PTR_ERR(new);
1184 /* already audited */
1188 error = may_change_ptraced_domain(new, &info);
1193 * no new privs prevents domain transitions that would
1194 * reduce restrictions.
1196 if (task_no_new_privs(current) && !unconfined(label) &&
1197 !aa_label_is_unconfined_subset(new, ctx->nnp)) {
1198 /* not an apparmor denial per se, so don't log it */
1199 AA_DEBUG("no_new_privs - change_hat denied");
1204 if (flags & AA_CHANGE_TEST)
1208 error = aa_set_current_hat(new, token);
1209 if (error == -EACCES)
1210 /* kill task in case of brute force attacks */
1212 } else if (previous && !(flags & AA_CHANGE_TEST)) {
1214 * no new privs prevents domain transitions that would
1215 * reduce restrictions.
1217 if (task_no_new_privs(current) && !unconfined(label) &&
1218 !aa_label_is_unconfined_subset(previous, ctx->nnp)) {
1219 /* not an apparmor denial per se, so don't log it */
1220 AA_DEBUG("no_new_privs - change_hat denied");
1225 /* Return to saved label. Kill task if restore fails
1226 * to avoid brute force attacks
1229 error = aa_restore_previous_label(token);
1231 if (error == -EACCES)
1235 } /* else ignore @flags && restores when there is no saved profile */
1239 aa_put_label(previous);
1240 aa_put_label(label);
1246 info = "failed token match";
1247 perms.kill = AA_MAY_CHANGEHAT;
1250 fn_for_each_in_ns(label, profile,
1251 aa_audit_file(profile, &perms, OP_CHANGE_HAT,
1252 AA_MAY_CHANGEHAT, NULL, NULL, target,
1253 GLOBAL_ROOT_UID, info, error));
1259 static int change_profile_perms_wrapper(const char *op, const char *name,
1260 struct aa_profile *profile,
1261 struct aa_label *target, bool stack,
1262 u32 request, struct aa_perms *perms)
1264 const char *info = NULL;
1268 error = change_profile_perms(profile, target, stack, request,
1269 profile->file.start, perms);
1271 error = aa_audit_file(profile, perms, op, request, name,
1272 NULL, target, GLOBAL_ROOT_UID, info,
1279 * aa_change_profile - perform a one-way profile transition
1280 * @fqname: name of profile may include namespace (NOT NULL)
1281 * @flags: flags affecting change behavior
1283 * Change to new profile @name. Unlike with hats, there is no way
1284 * to change back. If @name isn't specified the current profile name is
1286 * If @onexec then the transition is delayed until
1289 * Returns %0 on success, error otherwise.
1291 int aa_change_profile(const char *fqname, int flags)
1293 struct aa_label *label, *new = NULL, *target = NULL;
1294 struct aa_profile *profile;
1295 struct aa_perms perms = {};
1296 const char *info = NULL;
1297 const char *auditname = fqname; /* retain leading & if stack */
1298 bool stack = flags & AA_CHANGE_STACK;
1299 struct aa_task_ctx *ctx = task_ctx(current);
1304 label = aa_get_current_label();
1307 * Detect no new privs being set, and store the label it
1308 * occurred under. Ideally this would happen when nnp
1309 * is set but there isn't a good way to do that yet.
1311 * Testing for unconfined must be done before the subset test
1313 if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1314 ctx->nnp = aa_get_label(label);
1316 if (!fqname || !*fqname) {
1317 aa_put_label(label);
1318 AA_DEBUG("no profile name");
1322 if (flags & AA_CHANGE_ONEXEC) {
1323 request = AA_MAY_ONEXEC;
1325 op = OP_STACK_ONEXEC;
1327 op = OP_CHANGE_ONEXEC;
1329 request = AA_MAY_CHANGE_PROFILE;
1333 op = OP_CHANGE_PROFILE;
1336 if (*fqname == '&') {
1338 /* don't have label_parse() do stacking */
1341 target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
1342 if (IS_ERR(target)) {
1343 struct aa_profile *tprofile;
1345 info = "label not found";
1346 error = PTR_ERR(target);
1349 * TODO: fixme using labels_profile is not right - do profile
1350 * per complain profile
1352 if ((flags & AA_CHANGE_TEST) ||
1353 !COMPLAIN_MODE(labels_profile(label)))
1355 /* released below */
1356 tprofile = aa_new_null_profile(labels_profile(label), false,
1357 fqname, GFP_KERNEL);
1359 info = "failed null profile create";
1363 target = &tprofile->label;
1368 * self directed transitions only apply to current policy ns
1369 * TODO: currently requiring perms for stacking and straight change
1370 * stacking doesn't strictly need this. Determine how much
1371 * we want to loosen this restriction for stacking
1375 error = fn_for_each_in_ns(label, profile,
1376 change_profile_perms_wrapper(op, auditname,
1377 profile, target, stack,
1380 /* auditing done in change_profile_perms_wrapper */
1386 /* check if tracing task is allowed to trace target domain */
1387 error = may_change_ptraced_domain(target, &info);
1388 if (error && !fn_for_each_in_ns(label, profile,
1389 COMPLAIN_MODE(profile)))
1392 /* TODO: add permission check to allow this
1393 * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
1394 * info = "not a single threaded task";
1399 if (flags & AA_CHANGE_TEST)
1402 /* stacking is always a subset, so only check the nonstack case */
1404 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1405 aa_get_label(target),
1406 aa_get_label(&profile->label));
1408 * no new privs prevents domain transitions that would
1409 * reduce restrictions.
1411 if (task_no_new_privs(current) && !unconfined(label) &&
1412 !aa_label_is_unconfined_subset(new, ctx->nnp)) {
1413 /* not an apparmor denial per se, so don't log it */
1414 AA_DEBUG("no_new_privs - change_hat denied");
1420 if (!(flags & AA_CHANGE_ONEXEC)) {
1421 /* only transition profiles in the current ns */
1423 new = aa_label_merge(label, target, GFP_KERNEL);
1424 if (IS_ERR_OR_NULL(new)) {
1425 info = "failed to build target label";
1429 error = PTR_ERR(new);
1434 error = aa_replace_current_label(new);
1441 /* full transition will be built in exec path */
1442 error = aa_set_current_onexec(target, stack);
1446 error = fn_for_each_in_ns(label, profile,
1447 aa_audit_file(profile, &perms, op, request, auditname,
1448 NULL, new ? new : target,
1449 GLOBAL_ROOT_UID, info, error));
1453 aa_put_label(target);
1454 aa_put_label(label);