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>
22 #include <linux/xattr.h>
24 #include "include/audit.h"
25 #include "include/apparmorfs.h"
26 #include "include/cred.h"
27 #include "include/domain.h"
28 #include "include/file.h"
29 #include "include/ipc.h"
30 #include "include/match.h"
31 #include "include/path.h"
32 #include "include/policy.h"
33 #include "include/policy_ns.h"
36 * aa_free_domain_entries - free entries in a domain table
37 * @domain: the domain table to free (MAYBE NULL)
39 void aa_free_domain_entries(struct aa_domain *domain)
46 for (i = 0; i < domain->size; i++)
47 kzfree(domain->table[i]);
48 kzfree(domain->table);
54 * may_change_ptraced_domain - check if can change profile on ptraced task
55 * @to_label: profile to change to (NOT NULL)
56 * @info: message if there is an error
58 * Check if current is ptraced and if so if the tracing task is allowed
59 * to trace the new domain
61 * Returns: %0 or error if change not allowed
63 static int may_change_ptraced_domain(struct aa_label *to_label,
66 struct task_struct *tracer;
67 struct aa_label *tracerl = NULL;
71 tracer = ptrace_parent(current);
74 tracerl = aa_get_task_label(tracer);
77 if (!tracer || unconfined(tracerl))
80 error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH);
84 aa_put_label(tracerl);
87 *info = "ptrace prevents transition";
91 /**** TODO: dedup to aa_label_match - needs perm and dfa, merging
92 * specifically this is an exact copy of aa_label_match except
93 * aa_compute_perms is replaced with aa_compute_fperms
94 * and policy.dfa with file.dfa
96 /* match a profile and its associated ns component if needed
97 * Assumes visibility test has already been done.
98 * If a subns profile is not to be matched should be prescreened with
101 static inline unsigned int match_component(struct aa_profile *profile,
102 struct aa_profile *tp,
103 bool stack, unsigned int state)
108 state = aa_dfa_match(profile->file.dfa, state, "&");
109 if (profile->ns == tp->ns)
110 return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
112 /* try matching with namespace name and then profile */
113 ns_name = aa_ns_name(profile->ns, tp->ns, true);
114 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
115 state = aa_dfa_match(profile->file.dfa, state, ns_name);
116 state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
117 return aa_dfa_match(profile->file.dfa, state, tp->base.hname);
121 * label_compound_match - find perms for full compound label
122 * @profile: profile to find perms for
123 * @label: label to check access permissions for
124 * @stack: whether this is a stacking request
125 * @start: state to start match in
126 * @subns: whether to do permission checks on components in a subns
127 * @request: permissions to request
128 * @perms: perms struct to set
130 * Returns: 0 on success else ERROR
132 * For the label A//&B//&C this does the perm match for A//&B//&C
133 * @perms should be preinitialized with allperms OR a previous permission
134 * check to be stacked.
136 static int label_compound_match(struct aa_profile *profile,
137 struct aa_label *label, bool stack,
138 unsigned int state, bool subns, u32 request,
139 struct aa_perms *perms)
141 struct aa_profile *tp;
143 struct path_cond cond = { };
145 /* find first subcomponent that is visible */
146 label_for_each(i, label, tp) {
147 if (!aa_ns_visible(profile->ns, tp->ns, subns))
149 state = match_component(profile, tp, stack, state);
155 /* no component visible */
160 label_for_each_cont(i, label, tp) {
161 if (!aa_ns_visible(profile->ns, tp->ns, subns))
163 state = aa_dfa_match(profile->file.dfa, state, "//&");
164 state = match_component(profile, tp, false, state);
168 *perms = aa_compute_fperms(profile->file.dfa, state, &cond);
169 aa_apply_modes_to_perms(profile, perms);
170 if ((perms->allow & request) != request)
181 * label_components_match - find perms for all subcomponents of a label
182 * @profile: profile to find perms for
183 * @label: label to check access permissions for
184 * @stack: whether this is a stacking request
185 * @start: state to start match in
186 * @subns: whether to do permission checks on components in a subns
187 * @request: permissions to request
188 * @perms: an initialized perms struct to add accumulation to
190 * Returns: 0 on success else ERROR
192 * For the label A//&B//&C this does the perm match for each of A and B and C
193 * @perms should be preinitialized with allperms OR a previous permission
194 * check to be stacked.
196 static int label_components_match(struct aa_profile *profile,
197 struct aa_label *label, bool stack,
198 unsigned int start, bool subns, u32 request,
199 struct aa_perms *perms)
201 struct aa_profile *tp;
204 struct path_cond cond = { };
205 unsigned int state = 0;
207 /* find first subcomponent to test */
208 label_for_each(i, label, tp) {
209 if (!aa_ns_visible(profile->ns, tp->ns, subns))
211 state = match_component(profile, tp, stack, start);
217 /* no subcomponents visible - no change in perms */
221 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
222 aa_apply_modes_to_perms(profile, &tmp);
223 aa_perms_accum(perms, &tmp);
224 label_for_each_cont(i, label, tp) {
225 if (!aa_ns_visible(profile->ns, tp->ns, subns))
227 state = match_component(profile, tp, stack, start);
230 tmp = aa_compute_fperms(profile->file.dfa, state, &cond);
231 aa_apply_modes_to_perms(profile, &tmp);
232 aa_perms_accum(perms, &tmp);
235 if ((perms->allow & request) != request)
246 * label_match - do a multi-component label match
247 * @profile: profile to match against (NOT NULL)
248 * @label: label to match (NOT NULL)
249 * @stack: whether this is a stacking request
250 * @state: state to start in
251 * @subns: whether to match subns components
252 * @request: permission request
253 * @perms: Returns computed perms (NOT NULL)
255 * Returns: the state the match finished in, may be the none matching state
257 static int label_match(struct aa_profile *profile, struct aa_label *label,
258 bool stack, unsigned int state, bool subns, u32 request,
259 struct aa_perms *perms)
264 error = label_compound_match(profile, label, stack, state, subns,
270 return label_components_match(profile, label, stack, state, subns,
274 /******* end TODO: dedup *****/
277 * change_profile_perms - find permissions for change_profile
278 * @profile: the current profile (NOT NULL)
279 * @target: label to transition to (NOT NULL)
280 * @stack: whether this is a stacking request
281 * @request: requested perms
282 * @start: state to start matching in
285 * Returns: permission set
287 * currently only matches full label A//&B//&C or individual components A, B, C
288 * not arbitrary combinations. Eg. A//&B, C
290 static int change_profile_perms(struct aa_profile *profile,
291 struct aa_label *target, bool stack,
292 u32 request, unsigned int start,
293 struct aa_perms *perms)
295 if (profile_unconfined(profile)) {
296 perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
297 perms->audit = perms->quiet = perms->kill = 0;
301 /* TODO: add profile in ns screening */
302 return label_match(profile, target, stack, start, true, request, perms);
306 * aa_xattrs_match - check whether a file matches the xattrs defined in profile
307 * @bprm: binprm struct for the process to validate
308 * @profile: profile to match against (NOT NULL)
309 * @state: state to start match in
311 * Returns: number of extended attributes that matched, or < 0 on error
313 static int aa_xattrs_match(const struct linux_binprm *bprm,
314 struct aa_profile *profile, unsigned int state)
320 int value_size = 0, ret = profile->xattr_count;
322 if (!bprm || !profile->xattr_count)
326 /* transition from exec match to xattr set */
327 state = aa_dfa_null_transition(profile->xmatch, state);
329 d = bprm->file->f_path.dentry;
331 for (i = 0; i < profile->xattr_count; i++) {
332 size = vfs_getxattr_alloc(d, profile->xattrs[i], &value,
333 value_size, GFP_KERNEL);
337 /* Check the xattr value, not just presence */
338 state = aa_dfa_match_len(profile->xmatch, state, value,
340 perm = dfa_user_allow(profile->xmatch, state);
341 if (!(perm & MAY_EXEC)) {
346 /* transition to next element */
347 state = aa_dfa_null_transition(profile->xmatch, state);
350 * No xattr match, so verify if transition to
351 * next element was valid. IFF so the xattr
358 /* don't count missing optional xattr as matched */
369 * find_attach - do attachment search for unconfined processes
370 * @bprm - binprm structure of transitioning task
371 * @ns: the current namespace (NOT NULL)
372 * @head - profile list to walk (NOT NULL)
373 * @name - to match against (NOT NULL)
374 * @info - info message if there was an error (NOT NULL)
376 * Do a linear search on the profiles in the list. There is a matching
377 * preference where an exact match is preferred over a name which uses
378 * expressions to match, and matching expressions with the greatest
379 * xmatch_len are preferred.
381 * Requires: @head not be shared or have appropriate locks held
383 * Returns: label or NULL if no match found
385 static struct aa_label *find_attach(const struct linux_binprm *bprm,
386 struct aa_ns *ns, struct list_head *head,
387 const char *name, const char **info)
389 int candidate_len = 0, candidate_xattrs = 0;
390 bool conflict = false;
391 struct aa_profile *profile, *candidate = NULL;
398 list_for_each_entry_rcu(profile, head, base.list) {
399 if (profile->label.flags & FLAG_NULL &&
400 &profile->label == ns_unconfined(profile->ns))
403 /* Find the "best" matching profile. Profiles must
404 * match the path and extended attributes (if any)
405 * associated with the file. A more specific path
406 * match will be preferred over a less specific one,
407 * and a match with more matching extended attributes
408 * will be preferred over one with fewer. If the best
409 * match has both the same level of path specificity
410 * and the same number of matching extended attributes
411 * as another profile, signal a conflict and refuse to
414 if (profile->xmatch) {
415 unsigned int state, count;
418 state = aa_dfa_leftmatch(profile->xmatch, DFA_START,
420 perm = dfa_user_allow(profile->xmatch, state);
421 /* any accepting state means a valid match. */
422 if (perm & MAY_EXEC) {
425 if (count < candidate_len)
428 if (bprm && profile->xattr_count) {
429 long rev = READ_ONCE(ns->revision);
431 if (!aa_get_profile_not0(profile))
434 ret = aa_xattrs_match(bprm, profile,
437 aa_put_profile(profile);
439 READ_ONCE(ns->revision))
443 * Fail matching if the xattrs don't
450 * TODO: allow for more flexible best match
452 * The new match isn't more specific
453 * than the current best match
455 if (count == candidate_len &&
456 ret <= candidate_xattrs) {
457 /* Match is equivalent, so conflict */
458 if (ret == candidate_xattrs)
463 /* Either the same length with more matching
464 * xattrs, or a longer match
467 candidate_len = profile->xmatch_len;
468 candidate_xattrs = ret;
471 } else if (!strcmp(profile->base.name, name)) {
473 * old exact non-re match, without conditionals such
474 * as xattrs. no more searching required
481 if (!candidate || conflict) {
483 *info = "conflicting profile attachments";
489 candidate = aa_get_newest_profile(candidate);
492 return &candidate->label;
495 static const char *next_name(int xtype, const char *name)
501 * x_table_lookup - lookup an x transition name via transition table
502 * @profile: current profile (NOT NULL)
503 * @xindex: index into x transition table
504 * @name: returns: name tested to find label (NOT NULL)
506 * Returns: refcounted label, or NULL on failure (MAYBE NULL)
508 struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex,
511 struct aa_label *label = NULL;
512 u32 xtype = xindex & AA_X_TYPE_MASK;
513 int index = xindex & AA_X_INDEX_MASK;
517 /* index is guaranteed to be in range, validated at load time */
518 /* TODO: move lookup parsing to unpack time so this is a straight
519 * index into the resultant label
521 for (*name = profile->file.trans.table[index]; !label && *name;
522 *name = next_name(xtype, *name)) {
523 if (xindex & AA_X_CHILD) {
524 struct aa_profile *new_profile;
525 /* release by caller */
526 new_profile = aa_find_child(profile, *name);
528 label = &new_profile->label;
531 label = aa_label_parse(&profile->label, *name, GFP_ATOMIC,
537 /* released by caller */
543 * x_to_label - get target label for a given xindex
544 * @profile: current profile (NOT NULL)
545 * @bprm: binprm structure of transitioning task
546 * @name: name to lookup (NOT NULL)
547 * @xindex: index into x transition table
548 * @lookupname: returns: name used in lookup if one was specified (NOT NULL)
550 * find label for a transition index
552 * Returns: refcounted label or NULL if not found available
554 static struct aa_label *x_to_label(struct aa_profile *profile,
555 const struct linux_binprm *bprm,
556 const char *name, u32 xindex,
557 const char **lookupname,
560 struct aa_label *new = NULL;
561 struct aa_ns *ns = profile->ns;
562 u32 xtype = xindex & AA_X_TYPE_MASK;
563 const char *stack = NULL;
567 /* fail exec unless ix || ux fallback - handled by caller */
571 /* TODO: fix when perm mapping done at unload */
572 stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK];
574 /* released by caller */
575 new = x_table_lookup(profile, xindex, lookupname);
579 /* fall through to X_NAME */
581 if (xindex & AA_X_CHILD)
582 /* released by caller */
583 new = find_attach(bprm, ns, &profile->base.profiles,
586 /* released by caller */
587 new = find_attach(bprm, ns, &ns->base.profiles,
594 if (xindex & AA_X_INHERIT) {
595 /* (p|c|n)ix - don't change profile but do
596 * use the newest version
598 *info = "ix fallback";
599 /* no profile && no error */
600 new = aa_get_newest_label(&profile->label);
601 } else if (xindex & AA_X_UNCONFINED) {
602 new = aa_get_newest_label(ns_unconfined(profile->ns));
603 *info = "ux fallback";
608 /* base the stack on post domain transition */
609 struct aa_label *base = new;
611 new = aa_label_parse(base, stack, GFP_ATOMIC, true, false);
617 /* released by caller */
621 static struct aa_label *profile_transition(struct aa_profile *profile,
622 const struct linux_binprm *bprm,
623 char *buffer, struct path_cond *cond,
626 struct aa_label *new = NULL;
627 struct aa_profile *component;
629 const char *info = NULL, *name = NULL, *target = NULL;
630 unsigned int state = profile->file.start;
631 struct aa_perms perms = {};
632 bool nonewprivs = false;
639 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
640 &name, &info, profile->disconnected);
642 if (profile_unconfined(profile) ||
643 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
644 AA_DEBUG("name lookup ix on error");
646 new = aa_get_newest_label(&profile->label);
648 name = bprm->filename;
652 if (profile_unconfined(profile)) {
653 new = find_attach(bprm, profile->ns,
654 &profile->ns->base.profiles, name, &info);
656 AA_DEBUG("unconfined attached to new label");
659 AA_DEBUG("unconfined exec no attachment");
660 return aa_get_newest_label(&profile->label);
663 /* find exec permissions for name */
664 state = aa_str_perms(profile->file.dfa, state, name, cond, &perms);
665 if (perms.allow & MAY_EXEC) {
666 /* exec permission determine how to transition */
667 new = x_to_label(profile, bprm, name, perms.xindex, &target,
669 if (new && new->proxy == profile->label.proxy && info) {
670 /* hack ix fallback - improve how this is detected */
674 info = "profile transition not found";
675 /* remove MAY_EXEC to audit as failure */
676 perms.allow &= ~MAY_EXEC;
678 /* verify that each component's xattr requirements are
679 * met, and fail execution otherwise
681 label_for_each(i, new, component) {
682 if (aa_xattrs_match(bprm, component, state) <
685 info = "required xattrs not present";
686 perms.allow &= ~MAY_EXEC;
693 } else if (COMPLAIN_MODE(profile)) {
694 /* no exec permission - learning mode */
695 struct aa_profile *new_profile = NULL;
696 char *n = kstrdup(name, GFP_ATOMIC);
699 /* name is ptr into buffer */
700 long pos = name - buffer;
701 /* break per cpu buffer hold */
703 new_profile = aa_new_null_profile(profile, false, n,
707 strcpy((char *)name, n);
712 info = "could not create null profile";
715 new = &new_profile->label;
717 perms.xindex |= AA_X_UNSAFE;
726 if (!(perms.xindex & AA_X_UNSAFE)) {
728 dbg_printk("apparmor: scrubbing environment variables"
729 " for %s profile=", name);
730 aa_label_printk(new, GFP_ATOMIC);
737 aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new,
738 cond->uid, info, error);
739 if (!new || nonewprivs) {
741 return ERR_PTR(error);
747 static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec,
748 bool stack, const struct linux_binprm *bprm,
749 char *buffer, struct path_cond *cond,
752 unsigned int state = profile->file.start;
753 struct aa_perms perms = {};
754 const char *xname = NULL, *info = "change_profile onexec";
762 if (profile_unconfined(profile)) {
763 /* change_profile on exec already granted */
765 * NOTE: Domain transitions from unconfined are allowed
766 * even when no_new_privs is set because this aways results
767 * in a further reduction of permissions.
772 error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer,
773 &xname, &info, profile->disconnected);
775 if (profile_unconfined(profile) ||
776 (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) {
777 AA_DEBUG("name lookup ix on error");
780 xname = bprm->filename;
784 /* find exec permissions for name */
785 state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms);
786 if (!(perms.allow & AA_MAY_ONEXEC)) {
787 info = "no change_onexec valid for executable";
790 /* test if this exec can be paired with change_profile onexec.
791 * onexec permission is linked to exec with a standard pairing
792 * exec\0change_profile
794 state = aa_dfa_null_transition(profile->file.dfa, state);
795 error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC,
798 perms.allow &= ~AA_MAY_ONEXEC;
802 if (!(perms.xindex & AA_X_UNSAFE)) {
804 dbg_printk("apparmor: scrubbing environment "
805 "variables for %s label=", xname);
806 aa_label_printk(onexec, GFP_ATOMIC);
813 return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname,
814 NULL, onexec, cond->uid, info, error);
817 /* ensure none ns domain transitions are correctly applied with onexec */
819 static struct aa_label *handle_onexec(struct aa_label *label,
820 struct aa_label *onexec, bool stack,
821 const struct linux_binprm *bprm,
822 char *buffer, struct path_cond *cond,
825 struct aa_profile *profile;
826 struct aa_label *new;
835 error = fn_for_each_in_ns(label, profile,
836 profile_onexec(profile, onexec, stack,
837 bprm, buffer, cond, unsafe));
839 return ERR_PTR(error);
840 new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
841 aa_get_newest_label(onexec),
842 profile_transition(profile, bprm, buffer,
846 /* TODO: determine how much we want to loosen this */
847 error = fn_for_each_in_ns(label, profile,
848 profile_onexec(profile, onexec, stack, bprm,
849 buffer, cond, unsafe));
851 return ERR_PTR(error);
852 new = fn_label_build_in_ns(label, profile, GFP_ATOMIC,
853 aa_label_merge(&profile->label, onexec,
855 profile_transition(profile, bprm, buffer,
862 /* TODO: get rid of GLOBAL_ROOT_UID */
863 error = fn_for_each_in_ns(label, profile,
864 aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC,
865 AA_MAY_ONEXEC, bprm->filename, NULL,
866 onexec, GLOBAL_ROOT_UID,
867 "failed to build target label", -ENOMEM));
868 return ERR_PTR(error);
872 * apparmor_bprm_set_creds - set the new creds on the bprm struct
873 * @bprm: binprm for the exec (NOT NULL)
875 * Returns: %0 or error on failure
877 * TODO: once the other paths are done see if we can't refactor into a fn
879 int apparmor_bprm_set_creds(struct linux_binprm *bprm)
881 struct aa_task_ctx *ctx;
882 struct aa_label *label, *new = NULL;
883 struct aa_profile *profile;
885 const char *info = NULL;
888 struct path_cond cond = {
889 file_inode(bprm->file)->i_uid,
890 file_inode(bprm->file)->i_mode
893 if (bprm->called_set_creds)
896 ctx = task_ctx(current);
897 AA_BUG(!cred_label(bprm->cred));
900 label = aa_get_newest_label(cred_label(bprm->cred));
903 * Detect no new privs being set, and store the label it
904 * occurred under. Ideally this would happen when nnp
905 * is set but there isn't a good way to do that yet.
907 * Testing for unconfined must be done before the subset test
909 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) &&
911 ctx->nnp = aa_get_label(label);
913 /* buffer freed below, name is pointer into buffer */
915 /* Test for onexec first as onexec override other x transitions. */
917 new = handle_onexec(label, ctx->onexec, ctx->token,
918 bprm, buffer, &cond, &unsafe);
920 new = fn_label_build(label, profile, GFP_ATOMIC,
921 profile_transition(profile, bprm, buffer,
926 error = PTR_ERR(new);
933 /* Policy has specified a domain transitions. If no_new_privs and
934 * confined ensure the transition is to confinement that is subset
935 * of the confinement when the task entered no new privs.
937 * NOTE: Domain transitions from unconfined and to stacked
938 * subsets are allowed even when no_new_privs is set because this
939 * aways results in a further reduction of permissions.
941 if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) &&
942 !unconfined(label) &&
943 !aa_label_is_unconfined_subset(new, ctx->nnp)) {
945 info = "no new privs";
949 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
950 /* FIXME: currently don't mediate shared state */
954 if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) {
955 /* TODO: test needs to be profile of label to new */
956 error = may_change_ptraced_domain(new, &info);
963 dbg_printk("scrubbing environment variables for %s "
964 "label=", bprm->filename);
965 aa_label_printk(new, GFP_ATOMIC);
968 bprm->secureexec = 1;
971 if (label->proxy != new->proxy) {
972 /* when transitioning clear unsafe personality bits */
974 dbg_printk("apparmor: clearing unsafe personality "
975 "bits. %s label=", bprm->filename);
976 aa_label_printk(new, GFP_ATOMIC);
979 bprm->per_clear |= PER_CLEAR_ON_SETID;
981 aa_put_label(cred_label(bprm->cred));
982 /* transfer reference, released when cred is freed */
983 cred_label(bprm->cred) = new;
992 error = fn_for_each(label, profile,
993 aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC,
994 bprm->filename, NULL, new,
995 file_inode(bprm->file)->i_uid, info,
1002 * Functions for self directed profile change
1006 /* helper fn for change_hat
1008 * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL
1010 static struct aa_label *build_change_hat(struct aa_profile *profile,
1011 const char *name, bool sibling)
1013 struct aa_profile *root, *hat = NULL;
1014 const char *info = NULL;
1017 if (sibling && PROFILE_IS_HAT(profile)) {
1018 root = aa_get_profile_rcu(&profile->parent);
1019 } else if (!sibling && !PROFILE_IS_HAT(profile)) {
1020 root = aa_get_profile(profile);
1022 info = "conflicting target types";
1027 hat = aa_find_child(root, name);
1030 if (COMPLAIN_MODE(profile)) {
1031 hat = aa_new_null_profile(profile, true, name,
1034 info = "failed null profile create";
1039 aa_put_profile(root);
1042 aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT,
1043 name, hat ? hat->base.hname : NULL,
1044 hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info,
1046 if (!hat || (error && error != -ENOENT))
1047 return ERR_PTR(error);
1048 /* if hat && error - complain mode, already audited and we adjust for
1049 * complain mode allow by returning hat->label
1054 /* helper fn for changing into a hat
1056 * Returns: label for hat transition or ERR_PTR. Does not return NULL
1058 static struct aa_label *change_hat(struct aa_label *label, const char *hats[],
1059 int count, int flags)
1061 struct aa_profile *profile, *root, *hat = NULL;
1062 struct aa_label *new;
1064 bool sibling = false;
1065 const char *name, *info = NULL;
1072 if (PROFILE_IS_HAT(labels_profile(label)))
1075 /*find first matching hat */
1076 for (i = 0; i < count && !hat; i++) {
1078 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1079 if (sibling && PROFILE_IS_HAT(profile)) {
1080 root = aa_get_profile_rcu(&profile->parent);
1081 } else if (!sibling && !PROFILE_IS_HAT(profile)) {
1082 root = aa_get_profile(profile);
1083 } else { /* conflicting change type */
1084 info = "conflicting targets types";
1088 hat = aa_find_child(root, name);
1089 aa_put_profile(root);
1091 if (!COMPLAIN_MODE(profile))
1092 goto outer_continue;
1093 /* complain mode succeed as if hat */
1094 } else if (!PROFILE_IS_HAT(hat)) {
1095 info = "target not hat";
1097 aa_put_profile(hat);
1100 aa_put_profile(hat);
1102 /* found a hat for all profiles in ns */
1107 /* no hats that match, find appropriate error
1109 * In complain mode audit of the failure is based off of the first
1110 * hat supplied. This is done due how userspace interacts with
1114 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1115 if (!list_empty(&profile->base.profiles)) {
1116 info = "hat not found";
1121 info = "no hats defined";
1125 label_for_each_in_ns(it, labels_ns(label), label, profile) {
1127 * no target as it has failed to be found or built
1129 * change_hat uses probing and should not log failures
1130 * related to missing hats
1132 /* TODO: get rid of GLOBAL_ROOT_UID */
1133 if (count > 1 || COMPLAIN_MODE(profile)) {
1134 aa_audit_file(profile, &nullperms, OP_CHANGE_HAT,
1135 AA_MAY_CHANGEHAT, name, NULL, NULL,
1136 GLOBAL_ROOT_UID, info, error);
1139 return ERR_PTR(error);
1142 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1143 build_change_hat(profile, name, sibling),
1144 aa_get_label(&profile->label));
1146 info = "label build failed";
1149 } /* else if (IS_ERR) build_change_hat has logged error so return new */
1155 * aa_change_hat - change hat to/from subprofile
1156 * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
1157 * @count: number of hat names in @hats
1158 * @token: magic value to validate the hat change
1159 * @flags: flags affecting behavior of the change
1161 * Returns %0 on success, error otherwise.
1163 * Change to the first profile specified in @hats that exists, and store
1164 * the @hat_magic in the current task context. If the count == 0 and the
1165 * @token matches that stored in the current task context, return to the
1166 * top level profile.
1168 * change_hat only applies to profiles in the current ns, and each profile
1169 * in the ns must make the same transition otherwise change_hat will fail.
1171 int aa_change_hat(const char *hats[], int count, u64 token, int flags)
1173 const struct cred *cred;
1174 struct aa_task_ctx *ctx = task_ctx(current);
1175 struct aa_label *label, *previous, *new = NULL, *target = NULL;
1176 struct aa_profile *profile;
1177 struct aa_perms perms = {};
1178 const char *info = NULL;
1181 /* released below */
1182 cred = get_current_cred();
1183 label = aa_get_newest_cred_label(cred);
1184 previous = aa_get_newest_label(ctx->previous);
1187 * Detect no new privs being set, and store the label it
1188 * occurred under. Ideally this would happen when nnp
1189 * is set but there isn't a good way to do that yet.
1191 * Testing for unconfined must be done before the subset test
1193 if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1194 ctx->nnp = aa_get_label(label);
1196 if (unconfined(label)) {
1197 info = "unconfined can not change_hat";
1203 new = change_hat(label, hats, count, flags);
1206 error = PTR_ERR(new);
1208 /* already audited */
1212 error = may_change_ptraced_domain(new, &info);
1217 * no new privs prevents domain transitions that would
1218 * reduce restrictions.
1220 if (task_no_new_privs(current) && !unconfined(label) &&
1221 !aa_label_is_unconfined_subset(new, ctx->nnp)) {
1222 /* not an apparmor denial per se, so don't log it */
1223 AA_DEBUG("no_new_privs - change_hat denied");
1228 if (flags & AA_CHANGE_TEST)
1232 error = aa_set_current_hat(new, token);
1233 if (error == -EACCES)
1234 /* kill task in case of brute force attacks */
1236 } else if (previous && !(flags & AA_CHANGE_TEST)) {
1238 * no new privs prevents domain transitions that would
1239 * reduce restrictions.
1241 if (task_no_new_privs(current) && !unconfined(label) &&
1242 !aa_label_is_unconfined_subset(previous, ctx->nnp)) {
1243 /* not an apparmor denial per se, so don't log it */
1244 AA_DEBUG("no_new_privs - change_hat denied");
1249 /* Return to saved label. Kill task if restore fails
1250 * to avoid brute force attacks
1253 error = aa_restore_previous_label(token);
1255 if (error == -EACCES)
1259 } /* else ignore @flags && restores when there is no saved profile */
1263 aa_put_label(previous);
1264 aa_put_label(label);
1270 info = "failed token match";
1271 perms.kill = AA_MAY_CHANGEHAT;
1274 fn_for_each_in_ns(label, profile,
1275 aa_audit_file(profile, &perms, OP_CHANGE_HAT,
1276 AA_MAY_CHANGEHAT, NULL, NULL, target,
1277 GLOBAL_ROOT_UID, info, error));
1283 static int change_profile_perms_wrapper(const char *op, const char *name,
1284 struct aa_profile *profile,
1285 struct aa_label *target, bool stack,
1286 u32 request, struct aa_perms *perms)
1288 const char *info = NULL;
1292 error = change_profile_perms(profile, target, stack, request,
1293 profile->file.start, perms);
1295 error = aa_audit_file(profile, perms, op, request, name,
1296 NULL, target, GLOBAL_ROOT_UID, info,
1303 * aa_change_profile - perform a one-way profile transition
1304 * @fqname: name of profile may include namespace (NOT NULL)
1305 * @onexec: whether this transition is to take place immediately or at exec
1306 * @flags: flags affecting change behavior
1308 * Change to new profile @name. Unlike with hats, there is no way
1309 * to change back. If @name isn't specified the current profile name is
1311 * If @onexec then the transition is delayed until
1314 * Returns %0 on success, error otherwise.
1316 int aa_change_profile(const char *fqname, int flags)
1318 struct aa_label *label, *new = NULL, *target = NULL;
1319 struct aa_profile *profile;
1320 struct aa_perms perms = {};
1321 const char *info = NULL;
1322 const char *auditname = fqname; /* retain leading & if stack */
1323 bool stack = flags & AA_CHANGE_STACK;
1324 struct aa_task_ctx *ctx = task_ctx(current);
1329 label = aa_get_current_label();
1332 * Detect no new privs being set, and store the label it
1333 * occurred under. Ideally this would happen when nnp
1334 * is set but there isn't a good way to do that yet.
1336 * Testing for unconfined must be done before the subset test
1338 if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp)
1339 ctx->nnp = aa_get_label(label);
1341 if (!fqname || !*fqname) {
1342 aa_put_label(label);
1343 AA_DEBUG("no profile name");
1347 if (flags & AA_CHANGE_ONEXEC) {
1348 request = AA_MAY_ONEXEC;
1350 op = OP_STACK_ONEXEC;
1352 op = OP_CHANGE_ONEXEC;
1354 request = AA_MAY_CHANGE_PROFILE;
1358 op = OP_CHANGE_PROFILE;
1361 if (*fqname == '&') {
1363 /* don't have label_parse() do stacking */
1366 target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
1367 if (IS_ERR(target)) {
1368 struct aa_profile *tprofile;
1370 info = "label not found";
1371 error = PTR_ERR(target);
1374 * TODO: fixme using labels_profile is not right - do profile
1375 * per complain profile
1377 if ((flags & AA_CHANGE_TEST) ||
1378 !COMPLAIN_MODE(labels_profile(label)))
1380 /* released below */
1381 tprofile = aa_new_null_profile(labels_profile(label), false,
1382 fqname, GFP_KERNEL);
1384 info = "failed null profile create";
1388 target = &tprofile->label;
1393 * self directed transitions only apply to current policy ns
1394 * TODO: currently requiring perms for stacking and straight change
1395 * stacking doesn't strictly need this. Determine how much
1396 * we want to loosen this restriction for stacking
1400 error = fn_for_each_in_ns(label, profile,
1401 change_profile_perms_wrapper(op, auditname,
1402 profile, target, stack,
1405 /* auditing done in change_profile_perms_wrapper */
1411 /* check if tracing task is allowed to trace target domain */
1412 error = may_change_ptraced_domain(target, &info);
1413 if (error && !fn_for_each_in_ns(label, profile,
1414 COMPLAIN_MODE(profile)))
1417 /* TODO: add permission check to allow this
1418 * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
1419 * info = "not a single threaded task";
1424 if (flags & AA_CHANGE_TEST)
1427 /* stacking is always a subset, so only check the nonstack case */
1429 new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
1430 aa_get_label(target),
1431 aa_get_label(&profile->label));
1433 * no new privs prevents domain transitions that would
1434 * reduce restrictions.
1436 if (task_no_new_privs(current) && !unconfined(label) &&
1437 !aa_label_is_unconfined_subset(new, ctx->nnp)) {
1438 /* not an apparmor denial per se, so don't log it */
1439 AA_DEBUG("no_new_privs - change_hat denied");
1445 if (!(flags & AA_CHANGE_ONEXEC)) {
1446 /* only transition profiles in the current ns */
1448 new = aa_label_merge(label, target, GFP_KERNEL);
1449 if (IS_ERR_OR_NULL(new)) {
1450 info = "failed to build target label";
1454 error = PTR_ERR(new);
1459 error = aa_replace_current_label(new);
1466 /* full transition will be built in exec path */
1467 error = aa_set_current_onexec(target, stack);
1471 error = fn_for_each_in_ns(label, profile,
1472 aa_audit_file(profile, &perms, op, request, auditname,
1473 NULL, new ? new : target,
1474 GLOBAL_ROOT_UID, info, error));
1478 aa_put_label(target);
1479 aa_put_label(label);