]>
git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - security/apparmor/domain.c
2 * AppArmor security module
4 * This file contains AppArmor policy attachment and domain transitions
6 * Copyright (C) 2002-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
15 #include <linux/errno.h>
16 #include <linux/fdtable.h>
17 #include <linux/file.h>
18 #include <linux/mount.h>
19 #include <linux/syscalls.h>
20 #include <linux/tracehook.h>
21 #include <linux/personality.h>
23 #include "include/audit.h"
24 #include "include/apparmorfs.h"
25 #include "include/context.h"
26 #include "include/domain.h"
27 #include "include/file.h"
28 #include "include/ipc.h"
29 #include "include/match.h"
30 #include "include/path.h"
31 #include "include/policy.h"
32 #include "include/policy_ns.h"
35 * aa_free_domain_entries - free entries in a domain table
36 * @domain: the domain table to free (MAYBE NULL)
38 void aa_free_domain_entries(struct aa_domain
*domain
)
45 for (i
= 0; i
< domain
->size
; i
++)
46 kzfree(domain
->table
[i
]);
47 kzfree(domain
->table
);
53 * may_change_ptraced_domain - check if can change profile on ptraced task
54 * @to_label: profile to change to (NOT NULL)
55 * @info: message if there is an error
57 * Check if current is ptraced and if so if the tracing task is allowed
58 * to trace the new domain
60 * Returns: %0 or error if change not allowed
62 static int may_change_ptraced_domain(struct aa_label
*to_label
,
65 struct task_struct
*tracer
;
66 struct aa_label
*tracerl
= NULL
;
70 tracer
= ptrace_parent(current
);
73 tracerl
= aa_get_task_label(tracer
);
76 if (!tracer
|| unconfined(tracerl
))
79 error
= aa_may_ptrace(tracerl
, to_label
, PTRACE_MODE_ATTACH
);
83 aa_put_label(tracerl
);
86 *info
= "ptrace prevents transition";
90 /**** TODO: dedup to aa_label_match - needs perm and dfa, merging
91 * specifically this is an exact copy of aa_label_match except
92 * aa_compute_perms is replaced with aa_compute_fperms
93 * and policy.dfa with file.dfa
95 /* match a profile and its associated ns component if needed
96 * Assumes visibility test has already been done.
97 * If a subns profile is not to be matched should be prescreened with
100 static inline unsigned int match_component(struct aa_profile
*profile
,
101 struct aa_profile
*tp
,
102 bool stack
, unsigned int state
)
107 state
= aa_dfa_match(profile
->file
.dfa
, state
, "&");
108 if (profile
->ns
== tp
->ns
)
109 return aa_dfa_match(profile
->file
.dfa
, state
, tp
->base
.hname
);
111 /* try matching with namespace name and then profile */
112 ns_name
= aa_ns_name(profile
->ns
, tp
->ns
, true);
113 state
= aa_dfa_match_len(profile
->file
.dfa
, state
, ":", 1);
114 state
= aa_dfa_match(profile
->file
.dfa
, state
, ns_name
);
115 state
= aa_dfa_match_len(profile
->file
.dfa
, state
, ":", 1);
116 return aa_dfa_match(profile
->file
.dfa
, state
, tp
->base
.hname
);
120 * label_compound_match - find perms for full compound label
121 * @profile: profile to find perms for
122 * @label: label to check access permissions for
123 * @stack: whether this is a stacking request
124 * @start: state to start match in
125 * @subns: whether to do permission checks on components in a subns
126 * @request: permissions to request
127 * @perms: perms struct to set
129 * Returns: 0 on success else ERROR
131 * For the label A//&B//&C this does the perm match for A//&B//&C
132 * @perms should be preinitialized with allperms OR a previous permission
133 * check to be stacked.
135 static int label_compound_match(struct aa_profile
*profile
,
136 struct aa_label
*label
, bool stack
,
137 unsigned int state
, bool subns
, u32 request
,
138 struct aa_perms
*perms
)
140 struct aa_profile
*tp
;
142 struct path_cond cond
= { };
144 /* find first subcomponent that is visible */
145 label_for_each(i
, label
, tp
) {
146 if (!aa_ns_visible(profile
->ns
, tp
->ns
, subns
))
148 state
= match_component(profile
, tp
, stack
, state
);
154 /* no component visible */
159 label_for_each_cont(i
, label
, tp
) {
160 if (!aa_ns_visible(profile
->ns
, tp
->ns
, subns
))
162 state
= aa_dfa_match(profile
->file
.dfa
, state
, "//&");
163 state
= match_component(profile
, tp
, false, state
);
167 *perms
= aa_compute_fperms(profile
->file
.dfa
, state
, &cond
);
168 aa_apply_modes_to_perms(profile
, perms
);
169 if ((perms
->allow
& request
) != request
)
180 * label_components_match - find perms for all subcomponents of a label
181 * @profile: profile to find perms for
182 * @label: label to check access permissions for
183 * @stack: whether this is a stacking request
184 * @start: state to start match in
185 * @subns: whether to do permission checks on components in a subns
186 * @request: permissions to request
187 * @perms: an initialized perms struct to add accumulation to
189 * Returns: 0 on success else ERROR
191 * For the label A//&B//&C this does the perm match for each of A and B and C
192 * @perms should be preinitialized with allperms OR a previous permission
193 * check to be stacked.
195 static int label_components_match(struct aa_profile
*profile
,
196 struct aa_label
*label
, bool stack
,
197 unsigned int start
, bool subns
, u32 request
,
198 struct aa_perms
*perms
)
200 struct aa_profile
*tp
;
203 struct path_cond cond
= { };
204 unsigned int state
= 0;
206 /* find first subcomponent to test */
207 label_for_each(i
, label
, tp
) {
208 if (!aa_ns_visible(profile
->ns
, tp
->ns
, subns
))
210 state
= match_component(profile
, tp
, stack
, start
);
216 /* no subcomponents visible - no change in perms */
220 tmp
= aa_compute_fperms(profile
->file
.dfa
, state
, &cond
);
221 aa_apply_modes_to_perms(profile
, &tmp
);
222 aa_perms_accum(perms
, &tmp
);
223 label_for_each_cont(i
, label
, tp
) {
224 if (!aa_ns_visible(profile
->ns
, tp
->ns
, subns
))
226 state
= match_component(profile
, tp
, stack
, start
);
229 tmp
= aa_compute_fperms(profile
->file
.dfa
, state
, &cond
);
230 aa_apply_modes_to_perms(profile
, &tmp
);
231 aa_perms_accum(perms
, &tmp
);
234 if ((perms
->allow
& request
) != request
)
245 * label_match - do a multi-component label match
246 * @profile: profile to match against (NOT NULL)
247 * @label: label to match (NOT NULL)
248 * @stack: whether this is a stacking request
249 * @state: state to start in
250 * @subns: whether to match subns components
251 * @request: permission request
252 * @perms: Returns computed perms (NOT NULL)
254 * Returns: the state the match finished in, may be the none matching state
256 static int label_match(struct aa_profile
*profile
, struct aa_label
*label
,
257 bool stack
, unsigned int state
, bool subns
, u32 request
,
258 struct aa_perms
*perms
)
263 error
= label_compound_match(profile
, label
, stack
, state
, subns
,
269 return label_components_match(profile
, label
, stack
, state
, subns
,
273 /******* end TODO: dedup *****/
276 * change_profile_perms - find permissions for change_profile
277 * @profile: the current profile (NOT NULL)
278 * @target: label to transition to (NOT NULL)
279 * @stack: whether this is a stacking request
280 * @request: requested perms
281 * @start: state to start matching in
284 * Returns: permission set
286 * currently only matches full label A//&B//&C or individual components A, B, C
287 * not arbitrary combinations. Eg. A//&B, C
289 static int change_profile_perms(struct aa_profile
*profile
,
290 struct aa_label
*target
, bool stack
,
291 u32 request
, unsigned int start
,
292 struct aa_perms
*perms
)
294 if (profile_unconfined(profile
)) {
295 perms
->allow
= AA_MAY_CHANGE_PROFILE
| AA_MAY_ONEXEC
;
296 perms
->audit
= perms
->quiet
= perms
->kill
= 0;
300 /* TODO: add profile in ns screening */
301 return label_match(profile
, target
, stack
, start
, true, request
, perms
);
305 * __attach_match_ - find an attachment match
306 * @name - to match against (NOT NULL)
307 * @head - profile list to walk (NOT NULL)
308 * @info - info message if there was an error (NOT NULL)
310 * Do a linear search on the profiles in the list. There is a matching
311 * preference where an exact match is preferred over a name which uses
312 * expressions to match, and matching expressions with the greatest
313 * xmatch_len are preferred.
315 * Requires: @head not be shared or have appropriate locks held
317 * Returns: profile or NULL if no match found
319 static struct aa_profile
*__attach_match(const char *name
,
320 struct list_head
*head
,
324 bool conflict
= false;
325 struct aa_profile
*profile
, *candidate
= NULL
;
327 list_for_each_entry_rcu(profile
, head
, base
.list
) {
328 if (profile
->label
.flags
& FLAG_NULL
&&
329 &profile
->label
== ns_unconfined(profile
->ns
))
332 if (profile
->xmatch
) {
333 if (profile
->xmatch_len
== len
) {
336 } else if (profile
->xmatch_len
> len
) {
340 state
= aa_dfa_match(profile
->xmatch
,
342 perm
= dfa_user_allow(profile
->xmatch
, state
);
343 /* any accepting state means a valid match. */
344 if (perm
& MAY_EXEC
) {
346 len
= profile
->xmatch_len
;
350 } else if (!strcmp(profile
->base
.name
, name
))
351 /* exact non-re match, no more searching required */
356 *info
= "conflicting profile attachments";
364 * find_attach - do attachment search for unconfined processes
365 * @ns: the current namespace (NOT NULL)
366 * @list: list to search (NOT NULL)
367 * @name: the executable name to match against (NOT NULL)
368 * @info: info message if there was an error
370 * Returns: label or NULL if no match found
372 static struct aa_label
*find_attach(struct aa_ns
*ns
, struct list_head
*list
,
373 const char *name
, const char **info
)
375 struct aa_profile
*profile
;
378 profile
= aa_get_profile(__attach_match(name
, list
, info
));
381 return profile
? &profile
->label
: NULL
;
384 static const char *next_name(int xtype
, const char *name
)
390 * x_table_lookup - lookup an x transition name via transition table
391 * @profile: current profile (NOT NULL)
392 * @xindex: index into x transition table
393 * @name: returns: name tested to find label (NOT NULL)
395 * Returns: refcounted label, or NULL on failure (MAYBE NULL)
397 struct aa_label
*x_table_lookup(struct aa_profile
*profile
, u32 xindex
,
400 struct aa_label
*label
= NULL
;
401 u32 xtype
= xindex
& AA_X_TYPE_MASK
;
402 int index
= xindex
& AA_X_INDEX_MASK
;
406 /* index is guaranteed to be in range, validated at load time */
407 /* TODO: move lookup parsing to unpack time so this is a straight
408 * index into the resultant label
410 for (*name
= profile
->file
.trans
.table
[index
]; !label
&& *name
;
411 *name
= next_name(xtype
, *name
)) {
412 if (xindex
& AA_X_CHILD
) {
413 struct aa_profile
*new_profile
;
414 /* release by caller */
415 new_profile
= aa_find_child(profile
, *name
);
417 label
= &new_profile
->label
;
420 label
= aa_label_parse(&profile
->label
, *name
, GFP_ATOMIC
,
426 /* released by caller */
432 * x_to_label - get target label for a given xindex
433 * @profile: current profile (NOT NULL)
434 * @name: name to lookup (NOT NULL)
435 * @xindex: index into x transition table
436 * @lookupname: returns: name used in lookup if one was specified (NOT NULL)
438 * find label for a transition index
440 * Returns: refcounted label or NULL if not found available
442 static struct aa_label
*x_to_label(struct aa_profile
*profile
,
443 const char *name
, u32 xindex
,
444 const char **lookupname
,
447 struct aa_label
*new = NULL
;
448 struct aa_ns
*ns
= profile
->ns
;
449 u32 xtype
= xindex
& AA_X_TYPE_MASK
;
450 const char *stack
= NULL
;
454 /* fail exec unless ix || ux fallback - handled by caller */
458 /* TODO: fix when perm mapping done at unload */
459 stack
= profile
->file
.trans
.table
[xindex
& AA_X_INDEX_MASK
];
461 /* released by caller */
462 new = x_table_lookup(profile
, xindex
, lookupname
);
466 /* fall through to X_NAME */
468 if (xindex
& AA_X_CHILD
)
469 /* released by caller */
470 new = find_attach(ns
, &profile
->base
.profiles
,
473 /* released by caller */
474 new = find_attach(ns
, &ns
->base
.profiles
,
481 if (xindex
& AA_X_INHERIT
) {
482 /* (p|c|n)ix - don't change profile but do
483 * use the newest version
485 *info
= "ix fallback";
486 /* no profile && no error */
487 new = aa_get_newest_label(&profile
->label
);
488 } else if (xindex
& AA_X_UNCONFINED
) {
489 new = aa_get_newest_label(ns_unconfined(profile
->ns
));
490 *info
= "ux fallback";
495 /* base the stack on post domain transition */
496 struct aa_label
*base
= new;
498 new = aa_label_parse(base
, stack
, GFP_ATOMIC
, true, false);
504 /* released by caller */
508 static struct aa_label
*profile_transition(struct aa_profile
*profile
,
509 const struct linux_binprm
*bprm
,
510 char *buffer
, struct path_cond
*cond
,
513 struct aa_label
*new = NULL
;
514 const char *info
= NULL
, *name
= NULL
, *target
= NULL
;
515 unsigned int state
= profile
->file
.start
;
516 struct aa_perms perms
= {};
517 bool nonewprivs
= false;
524 error
= aa_path_name(&bprm
->file
->f_path
, profile
->path_flags
, buffer
,
525 &name
, &info
, profile
->disconnected
);
527 if (profile_unconfined(profile
) ||
528 (profile
->label
.flags
& FLAG_IX_ON_NAME_ERROR
)) {
529 AA_DEBUG("name lookup ix on error");
531 new = aa_get_newest_label(&profile
->label
);
533 name
= bprm
->filename
;
537 if (profile_unconfined(profile
)) {
538 new = find_attach(profile
->ns
, &profile
->ns
->base
.profiles
,
541 AA_DEBUG("unconfined attached to new label");
544 AA_DEBUG("unconfined exec no attachment");
545 return aa_get_newest_label(&profile
->label
);
548 /* find exec permissions for name */
549 state
= aa_str_perms(profile
->file
.dfa
, state
, name
, cond
, &perms
);
550 if (perms
.allow
& MAY_EXEC
) {
551 /* exec permission determine how to transition */
552 new = x_to_label(profile
, name
, perms
.xindex
, &target
, &info
);
553 if (new && new->proxy
== profile
->label
.proxy
&& info
) {
554 /* hack ix fallback - improve how this is detected */
558 info
= "profile transition not found";
559 /* remove MAY_EXEC to audit as failure */
560 perms
.allow
&= ~MAY_EXEC
;
562 } else if (COMPLAIN_MODE(profile
)) {
563 /* no exec permission - learning mode */
564 struct aa_profile
*new_profile
= NULL
;
565 char *n
= kstrdup(name
, GFP_ATOMIC
);
568 /* name is ptr into buffer */
569 long pos
= name
- buffer
;
570 /* break per cpu buffer hold */
572 new_profile
= aa_new_null_profile(profile
, false, n
,
576 strcpy((char *)name
, n
);
581 info
= "could not create null profile";
584 new = &new_profile
->label
;
586 perms
.xindex
|= AA_X_UNSAFE
;
594 /* Policy has specified a domain transitions. if no_new_privs and
595 * confined and not transitioning to the current domain fail.
597 * NOTE: Domain transitions from unconfined and to stritly stacked
598 * subsets are allowed even when no_new_privs is set because this
599 * aways results in a further reduction of permissions.
601 if ((bprm
->unsafe
& LSM_UNSAFE_NO_NEW_PRIVS
) &&
602 !profile_unconfined(profile
) &&
603 !aa_label_is_subset(new, &profile
->label
)) {
605 info
= "no new privs";
607 perms
.allow
&= ~MAY_EXEC
;
611 if (!(perms
.xindex
& AA_X_UNSAFE
)) {
613 dbg_printk("apparmor: scrubbing environment variables"
614 " for %s profile=", name
);
615 aa_label_printk(new, GFP_ATOMIC
);
622 aa_audit_file(profile
, &perms
, OP_EXEC
, MAY_EXEC
, name
, target
, new,
623 cond
->uid
, info
, error
);
624 if (!new || nonewprivs
) {
626 return ERR_PTR(error
);
632 static int profile_onexec(struct aa_profile
*profile
, struct aa_label
*onexec
,
633 bool stack
, const struct linux_binprm
*bprm
,
634 char *buffer
, struct path_cond
*cond
,
637 unsigned int state
= profile
->file
.start
;
638 struct aa_perms perms
= {};
639 const char *xname
= NULL
, *info
= "change_profile onexec";
647 if (profile_unconfined(profile
)) {
648 /* change_profile on exec already granted */
650 * NOTE: Domain transitions from unconfined are allowed
651 * even when no_new_privs is set because this aways results
652 * in a further reduction of permissions.
657 error
= aa_path_name(&bprm
->file
->f_path
, profile
->path_flags
, buffer
,
658 &xname
, &info
, profile
->disconnected
);
660 if (profile_unconfined(profile
) ||
661 (profile
->label
.flags
& FLAG_IX_ON_NAME_ERROR
)) {
662 AA_DEBUG("name lookup ix on error");
665 xname
= bprm
->filename
;
669 /* find exec permissions for name */
670 state
= aa_str_perms(profile
->file
.dfa
, state
, xname
, cond
, &perms
);
671 if (!(perms
.allow
& AA_MAY_ONEXEC
)) {
672 info
= "no change_onexec valid for executable";
675 /* test if this exec can be paired with change_profile onexec.
676 * onexec permission is linked to exec with a standard pairing
677 * exec\0change_profile
679 state
= aa_dfa_null_transition(profile
->file
.dfa
, state
);
680 error
= change_profile_perms(profile
, onexec
, stack
, AA_MAY_ONEXEC
,
683 perms
.allow
&= ~AA_MAY_ONEXEC
;
686 /* Policy has specified a domain transitions. if no_new_privs and
687 * confined and not transitioning to the current domain fail.
689 * NOTE: Domain transitions from unconfined and to stritly stacked
690 * subsets are allowed even when no_new_privs is set because this
691 * aways results in a further reduction of permissions.
693 if ((bprm
->unsafe
& LSM_UNSAFE_NO_NEW_PRIVS
) &&
694 !profile_unconfined(profile
) &&
695 !aa_label_is_subset(onexec
, &profile
->label
)) {
697 info
= "no new privs";
698 perms
.allow
&= ~AA_MAY_ONEXEC
;
702 if (!(perms
.xindex
& AA_X_UNSAFE
)) {
704 dbg_printk("apparmor: scrubbing environment "
705 "variables for %s label=", xname
);
706 aa_label_printk(onexec
, GFP_ATOMIC
);
713 return aa_audit_file(profile
, &perms
, OP_EXEC
, AA_MAY_ONEXEC
, xname
,
714 NULL
, onexec
, cond
->uid
, info
, error
);
717 /* ensure none ns domain transitions are correctly applied with onexec */
719 static struct aa_label
*handle_onexec(struct aa_label
*label
,
720 struct aa_label
*onexec
, bool stack
,
721 const struct linux_binprm
*bprm
,
722 char *buffer
, struct path_cond
*cond
,
725 struct aa_profile
*profile
;
726 struct aa_label
*new;
735 error
= fn_for_each_in_ns(label
, profile
,
736 profile_onexec(profile
, onexec
, stack
,
737 bprm
, buffer
, cond
, unsafe
));
739 return ERR_PTR(error
);
740 new = fn_label_build_in_ns(label
, profile
, GFP_ATOMIC
,
741 aa_get_newest_label(onexec
),
742 profile_transition(profile
, bprm
, buffer
,
746 /* TODO: determine how much we want to losen this */
747 error
= fn_for_each_in_ns(label
, profile
,
748 profile_onexec(profile
, onexec
, stack
, bprm
,
749 buffer
, cond
, unsafe
));
751 return ERR_PTR(error
);
752 new = fn_label_build_in_ns(label
, profile
, GFP_ATOMIC
,
753 aa_label_merge(&profile
->label
, onexec
,
755 profile_transition(profile
, bprm
, buffer
,
762 /* TODO: get rid of GLOBAL_ROOT_UID */
763 error
= fn_for_each_in_ns(label
, profile
,
764 aa_audit_file(profile
, &nullperms
, OP_CHANGE_ONEXEC
,
765 AA_MAY_ONEXEC
, bprm
->filename
, NULL
,
766 onexec
, GLOBAL_ROOT_UID
,
767 "failed to build target label", -ENOMEM
));
768 return ERR_PTR(error
);
772 * apparmor_bprm_set_creds - set the new creds on the bprm struct
773 * @bprm: binprm for the exec (NOT NULL)
775 * Returns: %0 or error on failure
777 * TODO: once the other paths are done see if we can't refactor into a fn
779 int apparmor_bprm_set_creds(struct linux_binprm
*bprm
)
781 struct aa_task_ctx
*ctx
;
782 struct aa_label
*label
, *new = NULL
;
783 struct aa_profile
*profile
;
785 const char *info
= NULL
;
788 struct path_cond cond
= {
789 file_inode(bprm
->file
)->i_uid
,
790 file_inode(bprm
->file
)->i_mode
793 if (bprm
->called_set_creds
)
796 ctx
= cred_ctx(bprm
->cred
);
799 label
= aa_get_newest_label(ctx
->label
);
801 /* buffer freed below, name is pointer into buffer */
803 /* Test for onexec first as onexec override other x transitions. */
805 new = handle_onexec(label
, ctx
->onexec
, ctx
->token
,
806 bprm
, buffer
, &cond
, &unsafe
);
808 new = fn_label_build(label
, profile
, GFP_ATOMIC
,
809 profile_transition(profile
, bprm
, buffer
,
814 error
= PTR_ERR(new);
821 /* TODO: Add ns level no_new_privs subset test */
823 if (bprm
->unsafe
& LSM_UNSAFE_SHARE
) {
824 /* FIXME: currently don't mediate shared state */
828 if (bprm
->unsafe
& (LSM_UNSAFE_PTRACE
)) {
829 /* TODO: test needs to be profile of label to new */
830 error
= may_change_ptraced_domain(new, &info
);
837 dbg_printk("scrubbing environment variables for %s "
838 "label=", bprm
->filename
);
839 aa_label_printk(new, GFP_ATOMIC
);
842 bprm
->secureexec
= 1;
845 if (label
->proxy
!= new->proxy
) {
846 /* when transitioning clear unsafe personality bits */
848 dbg_printk("apparmor: clearing unsafe personality "
849 "bits. %s label=", bprm
->filename
);
850 aa_label_printk(new, GFP_ATOMIC
);
853 bprm
->per_clear
|= PER_CLEAR_ON_SETID
;
855 aa_put_label(ctx
->label
);
856 /* transfer reference, released when ctx is freed */
860 /* clear out temporary/transitional state from the context */
861 aa_clear_task_ctx_trans(ctx
);
869 error
= fn_for_each(label
, profile
,
870 aa_audit_file(profile
, &nullperms
, OP_EXEC
, MAY_EXEC
,
871 bprm
->filename
, NULL
, new,
872 file_inode(bprm
->file
)->i_uid
, info
,
879 * Functions for self directed profile change
883 /* helper fn for change_hat
885 * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL
887 static struct aa_label
*build_change_hat(struct aa_profile
*profile
,
888 const char *name
, bool sibling
)
890 struct aa_profile
*root
, *hat
= NULL
;
891 const char *info
= NULL
;
894 if (sibling
&& PROFILE_IS_HAT(profile
)) {
895 root
= aa_get_profile_rcu(&profile
->parent
);
896 } else if (!sibling
&& !PROFILE_IS_HAT(profile
)) {
897 root
= aa_get_profile(profile
);
899 info
= "conflicting target types";
904 hat
= aa_find_child(root
, name
);
907 if (COMPLAIN_MODE(profile
)) {
908 hat
= aa_new_null_profile(profile
, true, name
,
911 info
= "failed null profile create";
916 aa_put_profile(root
);
919 aa_audit_file(profile
, &nullperms
, OP_CHANGE_HAT
, AA_MAY_CHANGEHAT
,
920 name
, hat
? hat
->base
.hname
: NULL
,
921 hat
? &hat
->label
: NULL
, GLOBAL_ROOT_UID
, NULL
,
923 if (!hat
|| (error
&& error
!= -ENOENT
))
924 return ERR_PTR(error
);
925 /* if hat && error - complain mode, already audited and we adjust for
926 * complain mode allow by returning hat->label
931 /* helper fn for changing into a hat
933 * Returns: label for hat transition or ERR_PTR. Does not return NULL
935 static struct aa_label
*change_hat(struct aa_label
*label
, const char *hats
[],
936 int count
, int flags
)
938 struct aa_profile
*profile
, *root
, *hat
= NULL
;
939 struct aa_label
*new;
941 bool sibling
= false;
942 const char *name
, *info
= NULL
;
949 if (PROFILE_IS_HAT(labels_profile(label
)))
952 /*find first matching hat */
953 for (i
= 0; i
< count
&& !hat
; i
++) {
955 label_for_each_in_ns(it
, labels_ns(label
), label
, profile
) {
956 if (sibling
&& PROFILE_IS_HAT(profile
)) {
957 root
= aa_get_profile_rcu(&profile
->parent
);
958 } else if (!sibling
&& !PROFILE_IS_HAT(profile
)) {
959 root
= aa_get_profile(profile
);
960 } else { /* conflicting change type */
961 info
= "conflicting targets types";
965 hat
= aa_find_child(root
, name
);
966 aa_put_profile(root
);
968 if (!COMPLAIN_MODE(profile
))
970 /* complain mode succeed as if hat */
971 } else if (!PROFILE_IS_HAT(hat
)) {
972 info
= "target not hat";
979 /* found a hat for all profiles in ns */
984 /* no hats that match, find appropriate error
986 * In complain mode audit of the failure is based off of the first
987 * hat supplied. This is done due how userspace interacts with
991 label_for_each_in_ns(it
, labels_ns(label
), label
, profile
) {
992 if (!list_empty(&profile
->base
.profiles
)) {
993 info
= "hat not found";
998 info
= "no hats defined";
1002 label_for_each_in_ns(it
, labels_ns(label
), label
, profile
) {
1004 * no target as it has failed to be found or built
1006 * change_hat uses probing and should not log failures
1007 * related to missing hats
1009 /* TODO: get rid of GLOBAL_ROOT_UID */
1010 if (count
> 1 || COMPLAIN_MODE(profile
)) {
1011 aa_audit_file(profile
, &nullperms
, OP_CHANGE_HAT
,
1012 AA_MAY_CHANGEHAT
, name
, NULL
, NULL
,
1013 GLOBAL_ROOT_UID
, info
, error
);
1016 return ERR_PTR(error
);
1019 new = fn_label_build_in_ns(label
, profile
, GFP_KERNEL
,
1020 build_change_hat(profile
, name
, sibling
),
1021 aa_get_label(&profile
->label
));
1023 info
= "label build failed";
1026 } /* else if (IS_ERR) build_change_hat has logged error so return new */
1032 * aa_change_hat - change hat to/from subprofile
1033 * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
1034 * @count: number of hat names in @hats
1035 * @token: magic value to validate the hat change
1036 * @flags: flags affecting behavior of the change
1038 * Returns %0 on success, error otherwise.
1040 * Change to the first profile specified in @hats that exists, and store
1041 * the @hat_magic in the current task context. If the count == 0 and the
1042 * @token matches that stored in the current task context, return to the
1043 * top level profile.
1045 * change_hat only applies to profiles in the current ns, and each profile
1046 * in the ns must make the same transition otherwise change_hat will fail.
1048 int aa_change_hat(const char *hats
[], int count
, u64 token
, int flags
)
1050 const struct cred
*cred
;
1051 struct aa_task_ctx
*ctx
;
1052 struct aa_label
*label
, *previous
, *new = NULL
, *target
= NULL
;
1053 struct aa_profile
*profile
;
1054 struct aa_perms perms
= {};
1055 const char *info
= NULL
;
1059 * Fail explicitly requested domain transitions if no_new_privs.
1060 * There is no exception for unconfined as change_hat is not
1063 if (task_no_new_privs(current
)) {
1064 /* not an apparmor denial per se, so don't log it */
1065 AA_DEBUG("no_new_privs - change_hat denied");
1069 /* released below */
1070 cred
= get_current_cred();
1071 ctx
= cred_ctx(cred
);
1072 label
= aa_get_newest_cred_label(cred
);
1073 previous
= aa_get_newest_label(ctx
->previous
);
1075 if (unconfined(label
)) {
1076 info
= "unconfined can not change_hat";
1082 new = change_hat(label
, hats
, count
, flags
);
1085 error
= PTR_ERR(new);
1087 /* already audited */
1091 error
= may_change_ptraced_domain(new, &info
);
1095 if (flags
& AA_CHANGE_TEST
)
1099 error
= aa_set_current_hat(new, token
);
1100 if (error
== -EACCES
)
1101 /* kill task in case of brute force attacks */
1103 } else if (previous
&& !(flags
& AA_CHANGE_TEST
)) {
1104 /* Return to saved label. Kill task if restore fails
1105 * to avoid brute force attacks
1108 error
= aa_restore_previous_label(token
);
1110 if (error
== -EACCES
)
1114 } /* else ignore @flags && restores when there is no saved profile */
1118 aa_put_label(previous
);
1119 aa_put_label(label
);
1125 info
= "failed token match";
1126 perms
.kill
= AA_MAY_CHANGEHAT
;
1129 fn_for_each_in_ns(label
, profile
,
1130 aa_audit_file(profile
, &perms
, OP_CHANGE_HAT
,
1131 AA_MAY_CHANGEHAT
, NULL
, NULL
, target
,
1132 GLOBAL_ROOT_UID
, info
, error
));
1138 static int change_profile_perms_wrapper(const char *op
, const char *name
,
1139 struct aa_profile
*profile
,
1140 struct aa_label
*target
, bool stack
,
1141 u32 request
, struct aa_perms
*perms
)
1143 const char *info
= NULL
;
1147 * Fail explicitly requested domain transitions when no_new_privs
1148 * and not unconfined OR the transition results in a stack on
1149 * the current label.
1150 * Stacking domain transitions and transitions from unconfined are
1151 * allowed even when no_new_privs is set because this aways results
1152 * in a reduction of permissions.
1154 if (task_no_new_privs(current
) && !stack
&&
1155 !profile_unconfined(profile
) &&
1156 !aa_label_is_subset(target
, &profile
->label
)) {
1157 info
= "no new privs";
1162 error
= change_profile_perms(profile
, target
, stack
, request
,
1163 profile
->file
.start
, perms
);
1165 error
= aa_audit_file(profile
, perms
, op
, request
, name
,
1166 NULL
, target
, GLOBAL_ROOT_UID
, info
,
1173 * aa_change_profile - perform a one-way profile transition
1174 * @fqname: name of profile may include namespace (NOT NULL)
1175 * @onexec: whether this transition is to take place immediately or at exec
1176 * @flags: flags affecting change behavior
1178 * Change to new profile @name. Unlike with hats, there is no way
1179 * to change back. If @name isn't specified the current profile name is
1181 * If @onexec then the transition is delayed until
1184 * Returns %0 on success, error otherwise.
1186 int aa_change_profile(const char *fqname
, int flags
)
1188 struct aa_label
*label
, *new = NULL
, *target
= NULL
;
1189 struct aa_profile
*profile
;
1190 struct aa_perms perms
= {};
1191 const char *info
= NULL
;
1192 const char *auditname
= fqname
; /* retain leading & if stack */
1193 bool stack
= flags
& AA_CHANGE_STACK
;
1198 if (!fqname
|| !*fqname
) {
1199 AA_DEBUG("no profile name");
1203 if (flags
& AA_CHANGE_ONEXEC
) {
1204 request
= AA_MAY_ONEXEC
;
1206 op
= OP_STACK_ONEXEC
;
1208 op
= OP_CHANGE_ONEXEC
;
1210 request
= AA_MAY_CHANGE_PROFILE
;
1214 op
= OP_CHANGE_PROFILE
;
1217 label
= aa_get_current_label();
1219 if (*fqname
== '&') {
1221 /* don't have label_parse() do stacking */
1224 target
= aa_label_parse(label
, fqname
, GFP_KERNEL
, true, false);
1225 if (IS_ERR(target
)) {
1226 struct aa_profile
*tprofile
;
1228 info
= "label not found";
1229 error
= PTR_ERR(target
);
1232 * TODO: fixme using labels_profile is not right - do profile
1233 * per complain profile
1235 if ((flags
& AA_CHANGE_TEST
) ||
1236 !COMPLAIN_MODE(labels_profile(label
)))
1238 /* released below */
1239 tprofile
= aa_new_null_profile(labels_profile(label
), false,
1240 fqname
, GFP_KERNEL
);
1242 info
= "failed null profile create";
1246 target
= &tprofile
->label
;
1251 * self directed transitions only apply to current policy ns
1252 * TODO: currently requiring perms for stacking and straight change
1253 * stacking doesn't strictly need this. Determine how much
1254 * we want to loosen this restriction for stacking
1258 error
= fn_for_each_in_ns(label
, profile
,
1259 change_profile_perms_wrapper(op
, auditname
,
1260 profile
, target
, stack
,
1263 /* auditing done in change_profile_perms_wrapper */
1269 /* check if tracing task is allowed to trace target domain */
1270 error
= may_change_ptraced_domain(target
, &info
);
1271 if (error
&& !fn_for_each_in_ns(label
, profile
,
1272 COMPLAIN_MODE(profile
)))
1275 /* TODO: add permission check to allow this
1276 * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
1277 * info = "not a single threaded task";
1282 if (flags
& AA_CHANGE_TEST
)
1285 if (!(flags
& AA_CHANGE_ONEXEC
)) {
1286 /* only transition profiles in the current ns */
1288 new = aa_label_merge(label
, target
, GFP_KERNEL
);
1290 new = fn_label_build_in_ns(label
, profile
, GFP_KERNEL
,
1291 aa_get_label(target
),
1292 aa_get_label(&profile
->label
));
1293 if (IS_ERR_OR_NULL(new)) {
1294 info
= "failed to build target label";
1295 error
= PTR_ERR(new);
1300 error
= aa_replace_current_label(new);
1302 /* full transition will be built in exec path */
1303 error
= aa_set_current_onexec(target
, stack
);
1306 error
= fn_for_each_in_ns(label
, profile
,
1307 aa_audit_file(profile
, &perms
, op
, request
, auditname
,
1308 NULL
, new ? new : target
,
1309 GLOBAL_ROOT_UID
, info
, error
));
1313 aa_put_label(target
);
1314 aa_put_label(label
);