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>
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>
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"
32 * aa_free_domain_entries - free entries in a domain table
33 * @domain: the domain table to free (MAYBE NULL)
35 void aa_free_domain_entries(struct aa_domain *domain)
42 for (i = 0; i < domain->size; i++)
43 kzfree(domain->table[i]);
44 kzfree(domain->table);
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
54 * Check if current is ptraced and if so if the tracing task is allowed
55 * to trace the new domain
57 * Returns: %0 or error if change not allowed
59 static int may_change_ptraced_domain(struct aa_label *to_label,
62 struct task_struct *tracer;
63 struct aa_label *tracerl = NULL;
67 tracer = ptrace_parent(current);
70 tracerl = aa_get_task_label(tracer);
73 if (!tracer || unconfined(tracerl))
76 error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
80 aa_put_label(tracerl);
83 *info = "ptrace prevents transition";
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
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
97 static inline unsigned int match_component(struct aa_profile *profile,
98 struct aa_profile *tp,
99 bool stack, unsigned int state)
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);
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);
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
126 * Returns: 0 on success else ERROR
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.
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)
137 struct aa_profile *tp;
139 struct path_cond cond = { };
141 /* find first subcomponent that is visible */
142 label_for_each(i, label, tp) {
143 if (!aa_ns_visible(profile->ns, tp->ns, subns))
145 state = match_component(profile, tp, stack, state);
151 /* no component visible */
156 label_for_each_cont(i, label, tp) {
157 if (!aa_ns_visible(profile->ns, tp->ns, subns))
159 state = aa_dfa_match(profile->file.dfa, state, "//&");
160 state = match_component(profile, tp, false, state);
164 *perms = aa_compute_fperms(profile->file.dfa, state, &cond);
165 aa_apply_modes_to_perms(profile, perms);
166 if ((perms->allow & request) != request)
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
186 * Returns: 0 on success else ERROR
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.
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)
197 struct aa_profile *tp;
200 struct path_cond cond = { };
201 unsigned int state = 0;
203 /* find first subcomponent to test */
204 label_for_each(i, label, tp) {
205 if (!aa_ns_visible(profile->ns, tp->ns, subns))
207 state = match_component(profile, tp, stack, start);
213 /* no subcomponents visible - no change in perms */
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))
223 state = match_component(profile, tp, stack, start);
226 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
227 aa_apply_modes_to_perms(profile, &tmp);
228 aa_perms_accum(perms, &tmp);
231 if ((perms->allow & request) != request)
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)
251 * Returns: the state the match finished in, may be the none matching state
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)
260 error = label_compound_match(profile, label, stack, state, subns,
266 return label_components_match(profile, label, stack, state, subns,
270 /******* end TODO: dedup *****/
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
281 * Returns: permission set
283 * currently only matches full label A//&B//&C or individual components A, B, C
284 * not arbitrary combinations. Eg. A//&B, C
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)
291 if (profile_unconfined(profile)) {
292 perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
293 perms->audit = perms->quiet = perms->kill = 0;
297 /* TODO: add profile in ns screening */
298 return label_match(profile, target, stack, start, true, request, perms);
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
307 * Returns: number of extended attributes that matched, or < 0 on error
309 static int aa_xattrs_match(const struct linux_binprm *bprm,
310 struct aa_profile *profile, unsigned int state)
316 int value_size = 0, ret = profile->xattr_count;
318 if (!bprm || !profile->xattr_count)
321 /* transition from exec match to xattr set */
322 state = aa_dfa_null_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(d, profile->xattrs[i], &value,
328 value_size, GFP_KERNEL);
332 /* Check the xattr value, not just presence */
333 state = aa_dfa_match_len(profile->xmatch, state, value,
335 perm = dfa_user_allow(profile->xmatch, state);
336 if (!(perm & MAY_EXEC)) {
341 /* transition to next element */
342 state = aa_dfa_null_transition(profile->xmatch, state);
345 * No xattr match, so verify if transition to
346 * next element was valid. IFF so the xattr
353 /* don't count missing optional xattr as matched */
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)
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.
375 * Requires: @head not be shared or have appropriate locks held
377 * Returns: profile or NULL if no match found
379 static struct aa_profile *__attach_match(const struct linux_binprm *bprm,
381 struct list_head *head,
384 int candidate_len = 0, candidate_xattrs = 0;
385 bool conflict = false;
386 struct aa_profile *profile, *candidate = NULL;
391 list_for_each_entry_rcu(profile, head, base.list) {
392 if (profile->label.flags & FLAG_NULL &&
393 &profile->label == ns_unconfined(profile->ns))
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
407 if (profile->xmatch) {
408 unsigned int state, count;
411 state = aa_dfa_leftmatch(profile->xmatch, DFA_START,
413 perm = dfa_user_allow(profile->xmatch, state);
414 /* any accepting state means a valid match. */
415 if (perm & MAY_EXEC) {
418 if (count < candidate_len)
421 ret = aa_xattrs_match(bprm, profile, state);
422 /* Fail matching if the xattrs don't match */
427 * TODO: allow for more flexible best match
429 * The new match isn't more specific
430 * than the current best match
432 if (count == candidate_len &&
433 ret <= candidate_xattrs) {
434 /* Match is equivalent, so conflict */
435 if (ret == candidate_xattrs)
440 /* Either the same length with more matching
441 * xattrs, or a longer match
444 candidate_len = profile->xmatch_len;
445 candidate_xattrs = ret;
448 } else if (!strcmp(profile->base.name, name))
450 * old exact non-re match, without conditionals such
451 * as xattrs. no more searching required
457 *info = "conflicting profile attachments";
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
472 * Returns: label or NULL if no match found
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)
478 struct aa_profile *profile;
481 profile = aa_get_profile(__attach_match(bprm, name, list, info));
484 return profile ? &profile->label : NULL;
487 static const char *next_name(int xtype, const char *name)
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)
498 * Returns: refcounted label, or NULL on failure (MAYBE NULL)
500 struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex,
503 struct aa_label *label = NULL;
504 u32 xtype = xindex & AA_X_TYPE_MASK;
505 int index = xindex & AA_X_INDEX_MASK;
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
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);
520 label = &new_profile->label;
523 label = aa_label_parse(&profile->label, *name, GFP_ATOMIC,
529 /* released by caller */
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)
542 * find label for a transition index
544 * Returns: refcounted label or NULL if not found available
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,
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;
559 /* fail exec unless ix || ux fallback - handled by caller */
563 /* TODO: fix when perm mapping done at unload */
564 stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK];
566 /* released by caller */
567 new = x_table_lookup(profile, xindex, lookupname);
571 /* fall through - to X_NAME */
573 if (xindex & AA_X_CHILD)
574 /* released by caller */
575 new = find_attach(bprm, ns, &profile->base.profiles,
578 /* released by caller */
579 new = find_attach(bprm, ns, &ns->base.profiles,
586 if (xindex & AA_X_INHERIT) {
587 /* (p|c|n)ix - don't change profile but do
588 * use the newest version
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";
600 /* base the stack on post domain transition */
601 struct aa_label *base = new;
603 new = aa_label_parse(base, stack, GFP_ATOMIC, true, false);
609 /* released by caller */
613 static struct aa_label *profile_transition(struct aa_profile *profile,
614 const struct linux_binprm *bprm,
615 char *buffer, struct path_cond *cond,
618 struct aa_label *new = NULL;
619 struct aa_profile *component;
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;
631 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
632 &name, &info, profile->disconnected);
634 if (profile_unconfined(profile) ||
635 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
636 AA_DEBUG("name lookup ix on error");
638 new = aa_get_newest_label(&profile->label);
640 name = bprm->filename;
644 if (profile_unconfined(profile)) {
645 new = find_attach(bprm, profile->ns,
646 &profile->ns->base.profiles, name, &info);
648 AA_DEBUG("unconfined attached to new label");
651 AA_DEBUG("unconfined exec no attachment");
652 return aa_get_newest_label(&profile->label);
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,
661 if (new && new->proxy == profile->label.proxy && info) {
662 /* hack ix fallback - improve how this is detected */
666 info = "profile transition not found";
667 /* remove MAY_EXEC to audit as failure */
668 perms.allow &= ~MAY_EXEC;
670 /* verify that each component's xattr requirements are
671 * met, and fail execution otherwise
673 label_for_each(i, new, component) {
674 if (aa_xattrs_match(bprm, component, state) <
677 info = "required xattrs not present";
678 perms.allow &= ~MAY_EXEC;
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);
691 /* name is ptr into buffer */
692 long pos = name - buffer;
693 /* break per cpu buffer hold */
695 new_profile = aa_new_null_profile(profile, false, n,
699 strcpy((char *)name, n);
704 info = "could not create null profile";
707 new = &new_profile->label;
709 perms.xindex |= AA_X_UNSAFE;
718 if (!(perms.xindex & AA_X_UNSAFE)) {
720 dbg_printk("apparmor: scrubbing environment variables"
721 " for %s profile=", name);
722 aa_label_printk(new, GFP_ATOMIC);
729 aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new,
730 cond->uid, info, error);
731 if (!new || nonewprivs) {
733 return ERR_PTR(error);
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,
744 unsigned int state = profile->file.start;
745 struct aa_perms perms = {};
746 const char *xname = NULL, *info = "change_profile onexec";
754 if (profile_unconfined(profile)) {
755 /* change_profile on exec already granted */
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.
764 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
765 &xname, &info, profile->disconnected);
767 if (profile_unconfined(profile) ||
768 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
769 AA_DEBUG("name lookup ix on error");
772 xname = bprm->filename;
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";
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
786 state = aa_dfa_null_transition(profile->file.dfa, state);
787 error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC,
790 perms.allow &= ~AA_MAY_ONEXEC;
794 if (!(perms.xindex & AA_X_UNSAFE)) {
796 dbg_printk("apparmor: scrubbing environment "
797 "variables for %s label=", xname);
798 aa_label_printk(onexec, GFP_ATOMIC);
805 return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname,
806 NULL, onexec, cond->uid, info, error);
809 /* ensure none ns domain transitions are correctly applied with onexec */
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,
817 struct aa_profile *profile;
818 struct aa_label *new;
827 error = fn_for_each_in_ns(label, profile,
828 profile_onexec(profile, onexec, stack,
829 bprm, buffer, cond, unsafe));
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,
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));
843 return ERR_PTR(error);
844 new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
845 aa_label_merge(&profile->label, onexec,
847 profile_transition(profile, bprm, buffer,
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);
864 * apparmor_bprm_set_creds - set the new creds on the bprm struct
865 * @bprm: binprm for the exec (NOT NULL)
867 * Returns: %0 or error on failure
869 * TODO: once the other paths are done see if we can't refactor into a fn
871 int apparmor_bprm_set_creds(struct linux_binprm *bprm)
873 struct aa_task_ctx *ctx;
874 struct aa_label *label, *new = NULL;
875 struct aa_profile *profile;
877 const char *info = NULL;
880 struct path_cond cond = {
881 file_inode(bprm->file)->i_uid,
882 file_inode(bprm->file)->i_mode
885 if (bprm->called_set_creds)
888 ctx = task_ctx(current);
889 AA_BUG(!cred_label(bprm->cred));
892 label = aa_get_newest_label(cred_label(bprm->cred));
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.
899 * Testing for unconfined must be done before the subset test
901 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) &&
903 ctx->nnp = aa_get_label(label);
905 /* buffer freed below, name is pointer into buffer */
907 /* Test for onexec first as onexec override other x transitions. */
909 new = handle_onexec(label, ctx->onexec, ctx->token,
910 bprm, buffer, &cond, &unsafe);
912 new = fn_label_build(label, profile, GFP_ATOMIC,
913 profile_transition(profile, bprm, buffer,
918 error = PTR_ERR(new);
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.
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.
933 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
934 !unconfined(label) && !aa_label_is_subset(new, ctx->nnp)) {
936 info = "no new privs";
940 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
941 /* FIXME: currently don't mediate shared state */
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);
954 dbg_printk("scrubbing environment variables for %s "
955 "label=", bprm->filename);
956 aa_label_printk(new, GFP_ATOMIC);
959 bprm->secureexec = 1;
962 if (label->proxy != new->proxy) {
963 /* when transitioning clear unsafe personality bits */
965 dbg_printk("apparmor: clearing unsafe personality "
966 "bits. %s label=", bprm->filename);
967 aa_label_printk(new, GFP_ATOMIC);
970 bprm->per_clear |= PER_CLEAR_ON_SETID;
972 aa_put_label(cred_label(bprm->cred));
973 /* transfer reference, released when cred is freed */
974 set_cred_label(bprm->cred, new);
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,
993 * Functions for self directed profile change
997 /* helper fn for change_hat
999 * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL
1001 static struct aa_label *build_change_hat(struct aa_profile *profile,
1002 const char *name, bool sibling)
1004 struct aa_profile *root, *hat = NULL;
1005 const char *info = NULL;
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);
1013 info = "conflicting target types";
1018 hat = aa_find_child(root, name);
1021 if (COMPLAIN_MODE(profile)) {
1022 hat = aa_new_null_profile(profile, true, name,
1025 info = "failed null profile create";
1030 aa_put_profile(root);
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,
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
1045 /* helper fn for changing into a hat
1047 * Returns: label for hat transition or ERR_PTR. Does not return NULL
1049 static struct aa_label *change_hat(struct aa_label *label, const char *hats[],
1050 int count, int flags)
1052 struct aa_profile *profile, *root, *hat = NULL;
1053 struct aa_label *new;
1055 bool sibling = false;
1056 const char *name, *info = NULL;
1063 if (PROFILE_IS_HAT(labels_profile(label)))
1066 /*find first matching hat */
1067 for (i = 0; i < count && !hat; 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";
1079 hat = aa_find_child(root, name);
1080 aa_put_profile(root);
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";
1088 aa_put_profile(hat);
1091 aa_put_profile(hat);
1093 /* found a hat for all profiles in ns */
1098 /* no hats that match, find appropriate error
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
1105 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1106 if (!list_empty(&profile->base.profiles)) {
1107 info = "hat not found";
1112 info = "no hats defined";
1116 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1118 * no target as it has failed to be found or built
1120 * change_hat uses probing and should not log failures
1121 * related to missing hats
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);
1130 return ERR_PTR(error);
1133 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1134 build_change_hat(profile, name, sibling),
1135 aa_get_label(&profile->label));
1137 info = "label build failed";
1140 } /* else if (IS_ERR) build_change_hat has logged error so return new */
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
1152 * Returns %0 on success, error otherwise.
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.
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.
1162 int aa_change_hat(const char *hats[], int count, u64 token, int flags)
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;
1172 /* released below */
1173 cred = get_current_cred();
1174 label = aa_get_newest_cred_label(cred);
1175 previous = aa_get_newest_label(ctx->previous);
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.
1182 * Testing for unconfined must be done before the subset test
1184 if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1185 ctx->nnp = aa_get_label(label);
1187 if (unconfined(label)) {
1188 info = "unconfined can not change_hat";
1194 new = change_hat(label, hats, count, flags);
1197 error = PTR_ERR(new);
1199 /* already audited */
1203 error = may_change_ptraced_domain(new, &info);
1208 * no new privs prevents domain transitions that would
1209 * reduce restrictions.
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");
1219 if (flags & AA_CHANGE_TEST)
1223 error = aa_set_current_hat(new, token);
1224 if (error == -EACCES)
1225 /* kill task in case of brute force attacks */
1227 } else if (previous && !(flags & AA_CHANGE_TEST)) {
1229 * no new privs prevents domain transitions that would
1230 * reduce restrictions.
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");
1240 /* Return to saved label. Kill task if restore fails
1241 * to avoid brute force attacks
1244 error = aa_restore_previous_label(token);
1246 if (error == -EACCES)
1250 } /* else ignore @flags && restores when there is no saved profile */
1254 aa_put_label(previous);
1255 aa_put_label(label);
1261 info = "failed token match";
1262 perms.kill = AA_MAY_CHANGEHAT;
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));
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)
1279 const char *info = NULL;
1283 error = change_profile_perms(profile, target, stack, request,
1284 profile->file.start, perms);
1286 error = aa_audit_file(profile, perms, op, request, name,
1287 NULL, target, GLOBAL_ROOT_UID, info,
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
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
1302 * If @onexec then the transition is delayed until
1305 * Returns %0 on success, error otherwise.
1307 int aa_change_profile(const char *fqname, int flags)
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);
1320 label = aa_get_current_label();
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.
1327 * Testing for unconfined must be done before the subset test
1329 if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1330 ctx->nnp = aa_get_label(label);
1332 if (!fqname || !*fqname) {
1333 AA_DEBUG("no profile name");
1337 if (flags & AA_CHANGE_ONEXEC) {
1338 request = AA_MAY_ONEXEC;
1340 op = OP_STACK_ONEXEC;
1342 op = OP_CHANGE_ONEXEC;
1344 request = AA_MAY_CHANGE_PROFILE;
1348 op = OP_CHANGE_PROFILE;
1351 label = aa_get_current_label();
1353 if (*fqname == '&') {
1355 /* don't have label_parse() do stacking */
1358 target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
1359 if (IS_ERR(target)) {
1360 struct aa_profile *tprofile;
1362 info = "label not found";
1363 error = PTR_ERR(target);
1366 * TODO: fixme using labels_profile is not right - do profile
1367 * per complain profile
1369 if ((flags & AA_CHANGE_TEST) ||
1370 !COMPLAIN_MODE(labels_profile(label)))
1372 /* released below */
1373 tprofile = aa_new_null_profile(labels_profile(label), false,
1374 fqname, GFP_KERNEL);
1376 info = "failed null profile create";
1380 target = &tprofile->label;
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
1392 error = fn_for_each_in_ns(label, profile,
1393 change_profile_perms_wrapper(op, auditname,
1394 profile, target, stack,
1397 /* auditing done in change_profile_perms_wrapper */
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)))
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";
1416 if (flags & AA_CHANGE_TEST)
1419 /* stacking is always a subset, so only check the nonstack case */
1421 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1422 aa_get_label(target),
1423 aa_get_label(&profile->label));
1425 * no new privs prevents domain transitions that would
1426 * reduce restrictions.
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");
1437 if (!(flags & AA_CHANGE_ONEXEC)) {
1438 /* only transition profiles in the current ns */
1440 new = aa_label_merge(label, target, GFP_KERNEL);
1441 if (IS_ERR_OR_NULL(new)) {
1442 info = "failed to build target label";
1446 error = PTR_ERR(new);
1451 error = aa_replace_current_label(new);
1458 /* full transition will be built in exec path */
1459 error = aa_set_current_onexec(target, stack);
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));
1470 aa_put_label(target);
1471 aa_put_label(label);