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Source at commit be977234bfb4a6dca8a39e7c52165e4cd536ad71 created 12 years 9 months ago. By Lars-Peter Clausen, jz4740: Fix compile error | |
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1 | /* |
2 | * AppArmor security module |
3 | * |
4 | * This file contains AppArmor policy attachment and domain transitions |
5 | * |
6 | * Copyright (C) 2002-2008 Novell/SUSE |
7 | * Copyright 2009-2010 Canonical Ltd. |
8 | * |
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 |
12 | * License. |
13 | */ |
14 | |
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 | |
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 | |
33 | /** |
34 | * aa_free_domain_entries - free entries in a domain table |
35 | * @domain: the domain table to free (MAYBE NULL) |
36 | */ |
37 | void aa_free_domain_entries(struct aa_domain *domain) |
38 | { |
39 | int i; |
40 | if (domain) { |
41 | if (!domain->table) |
42 | return; |
43 | |
44 | for (i = 0; i < domain->size; i++) |
45 | kzfree(domain->table[i]); |
46 | kzfree(domain->table); |
47 | domain->table = NULL; |
48 | } |
49 | } |
50 | |
51 | /** |
52 | * may_change_ptraced_domain - check if can change profile on ptraced task |
53 | * @task: task we want to change profile of (NOT NULL) |
54 | * @to_profile: profile to change to (NOT NULL) |
55 | * |
56 | * Check if the task is ptraced and if so if the tracing task is allowed |
57 | * to trace the new domain |
58 | * |
59 | * Returns: %0 or error if change not allowed |
60 | */ |
61 | static int may_change_ptraced_domain(struct task_struct *task, |
62 | struct aa_profile *to_profile) |
63 | { |
64 | struct task_struct *tracer; |
65 | const struct cred *cred = NULL; |
66 | struct aa_profile *tracerp = NULL; |
67 | int error = 0; |
68 | |
69 | rcu_read_lock(); |
70 | tracer = tracehook_tracer_task(task); |
71 | if (tracer) { |
72 | /* released below */ |
73 | cred = get_task_cred(tracer); |
74 | tracerp = aa_cred_profile(cred); |
75 | } |
76 | rcu_read_unlock(); |
77 | |
78 | /* not ptraced */ |
79 | if (!tracer || unconfined(tracerp)) |
80 | goto out; |
81 | |
82 | error = aa_may_ptrace(tracer, tracerp, to_profile, PTRACE_MODE_ATTACH); |
83 | |
84 | out: |
85 | if (cred) |
86 | put_cred(cred); |
87 | |
88 | return error; |
89 | } |
90 | |
91 | /** |
92 | * change_profile_perms - find permissions for change_profile |
93 | * @profile: the current profile (NOT NULL) |
94 | * @ns: the namespace being switched to (NOT NULL) |
95 | * @name: the name of the profile to change to (NOT NULL) |
96 | * @request: requested perms |
97 | * @start: state to start matching in |
98 | * |
99 | * Returns: permission set |
100 | */ |
101 | static struct file_perms change_profile_perms(struct aa_profile *profile, |
102 | struct aa_namespace *ns, |
103 | const char *name, u32 request, |
104 | unsigned int start) |
105 | { |
106 | struct file_perms perms; |
107 | struct path_cond cond = { }; |
108 | unsigned int state; |
109 | |
110 | if (unconfined(profile)) { |
111 | perms.allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; |
112 | perms.audit = perms.quiet = perms.kill = 0; |
113 | return perms; |
114 | } else if (!profile->file.dfa) { |
115 | return nullperms; |
116 | } else if ((ns == profile->ns)) { |
117 | /* try matching against rules with out namespace prepended */ |
118 | aa_str_perms(profile->file.dfa, start, name, &cond, &perms); |
119 | if (COMBINED_PERM_MASK(perms) & request) |
120 | return perms; |
121 | } |
122 | |
123 | /* try matching with namespace name and then profile */ |
124 | state = aa_dfa_match(profile->file.dfa, start, ns->base.name); |
125 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); |
126 | aa_str_perms(profile->file.dfa, state, name, &cond, &perms); |
127 | |
128 | return perms; |
129 | } |
130 | |
131 | /** |
132 | * __attach_match_ - find an attachment match |
133 | * @name - to match against (NOT NULL) |
134 | * @head - profile list to walk (NOT NULL) |
135 | * |
136 | * Do a linear search on the profiles in the list. There is a matching |
137 | * preference where an exact match is preferred over a name which uses |
138 | * expressions to match, and matching expressions with the greatest |
139 | * xmatch_len are preferred. |
140 | * |
141 | * Requires: @head not be shared or have appropriate locks held |
142 | * |
143 | * Returns: profile or NULL if no match found |
144 | */ |
145 | static struct aa_profile *__attach_match(const char *name, |
146 | struct list_head *head) |
147 | { |
148 | int len = 0; |
149 | struct aa_profile *profile, *candidate = NULL; |
150 | |
151 | list_for_each_entry(profile, head, base.list) { |
152 | if (profile->flags & PFLAG_NULL) |
153 | continue; |
154 | if (profile->xmatch && profile->xmatch_len > len) { |
155 | unsigned int state = aa_dfa_match(profile->xmatch, |
156 | DFA_START, name); |
157 | u32 perm = dfa_user_allow(profile->xmatch, state); |
158 | /* any accepting state means a valid match. */ |
159 | if (perm & MAY_EXEC) { |
160 | candidate = profile; |
161 | len = profile->xmatch_len; |
162 | } |
163 | } else if (!strcmp(profile->base.name, name)) |
164 | /* exact non-re match, no more searching required */ |
165 | return profile; |
166 | } |
167 | |
168 | return candidate; |
169 | } |
170 | |
171 | /** |
172 | * find_attach - do attachment search for unconfined processes |
173 | * @ns: the current namespace (NOT NULL) |
174 | * @list: list to search (NOT NULL) |
175 | * @name: the executable name to match against (NOT NULL) |
176 | * |
177 | * Returns: profile or NULL if no match found |
178 | */ |
179 | static struct aa_profile *find_attach(struct aa_namespace *ns, |
180 | struct list_head *list, const char *name) |
181 | { |
182 | struct aa_profile *profile; |
183 | |
184 | read_lock(&ns->lock); |
185 | profile = aa_get_profile(__attach_match(name, list)); |
186 | read_unlock(&ns->lock); |
187 | |
188 | return profile; |
189 | } |
190 | |
191 | /** |
192 | * separate_fqname - separate the namespace and profile names |
193 | * @fqname: the fqname name to split (NOT NULL) |
194 | * @ns_name: the namespace name if it exists (NOT NULL) |
195 | * |
196 | * This is the xtable equivalent routine of aa_split_fqname. It finds the |
197 | * split in an xtable fqname which contains an embedded \0 instead of a : |
198 | * if a namespace is specified. This is done so the xtable is constant and |
199 | * isn't re-split on every lookup. |
200 | * |
201 | * Either the profile or namespace name may be optional but if the namespace |
202 | * is specified the profile name termination must be present. This results |
203 | * in the following possible encodings: |
204 | * profile_name\0 |
205 | * :ns_name\0profile_name\0 |
206 | * :ns_name\0\0 |
207 | * |
208 | * NOTE: the xtable fqname is pre-validated at load time in unpack_trans_table |
209 | * |
210 | * Returns: profile name if it is specified else NULL |
211 | */ |
212 | static const char *separate_fqname(const char *fqname, const char **ns_name) |
213 | { |
214 | const char *name; |
215 | |
216 | if (fqname[0] == ':') { |
217 | /* In this case there is guaranteed to be two \0 terminators |
218 | * in the string. They are verified at load time by |
219 | * by unpack_trans_table |
220 | */ |
221 | *ns_name = fqname + 1; /* skip : */ |
222 | name = *ns_name + strlen(*ns_name) + 1; |
223 | if (!*name) |
224 | name = NULL; |
225 | } else { |
226 | *ns_name = NULL; |
227 | name = fqname; |
228 | } |
229 | |
230 | return name; |
231 | } |
232 | |
233 | static const char *next_name(int xtype, const char *name) |
234 | { |
235 | return NULL; |
236 | } |
237 | |
238 | /** |
239 | * x_table_lookup - lookup an x transition name via transition table |
240 | * @profile: current profile (NOT NULL) |
241 | * @xindex: index into x transition table |
242 | * |
243 | * Returns: refcounted profile, or NULL on failure (MAYBE NULL) |
244 | */ |
245 | static struct aa_profile *x_table_lookup(struct aa_profile *profile, u32 xindex) |
246 | { |
247 | struct aa_profile *new_profile = NULL; |
248 | struct aa_namespace *ns = profile->ns; |
249 | u32 xtype = xindex & AA_X_TYPE_MASK; |
250 | int index = xindex & AA_X_INDEX_MASK; |
251 | const char *name; |
252 | |
253 | /* index is guaranteed to be in range, validated at load time */ |
254 | for (name = profile->file.trans.table[index]; !new_profile && name; |
255 | name = next_name(xtype, name)) { |
256 | struct aa_namespace *new_ns; |
257 | const char *xname = NULL; |
258 | |
259 | new_ns = NULL; |
260 | if (xindex & AA_X_CHILD) { |
261 | /* release by caller */ |
262 | new_profile = aa_find_child(profile, name); |
263 | continue; |
264 | } else if (*name == ':') { |
265 | /* switching namespace */ |
266 | const char *ns_name; |
267 | xname = name = separate_fqname(name, &ns_name); |
268 | if (!xname) |
269 | /* no name so use profile name */ |
270 | xname = profile->base.hname; |
271 | if (*ns_name == '@') { |
272 | /* TODO: variable support */ |
273 | ; |
274 | } |
275 | /* released below */ |
276 | new_ns = aa_find_namespace(ns, ns_name); |
277 | if (!new_ns) |
278 | continue; |
279 | } else if (*name == '@') { |
280 | /* TODO: variable support */ |
281 | continue; |
282 | } else { |
283 | /* basic namespace lookup */ |
284 | xname = name; |
285 | } |
286 | |
287 | /* released by caller */ |
288 | new_profile = aa_lookup_profile(new_ns ? new_ns : ns, xname); |
289 | aa_put_namespace(new_ns); |
290 | } |
291 | |
292 | /* released by caller */ |
293 | return new_profile; |
294 | } |
295 | |
296 | /** |
297 | * x_to_profile - get target profile for a given xindex |
298 | * @profile: current profile (NOT NULL) |
299 | * @name: name to lookup (NOT NULL) |
300 | * @xindex: index into x transition table |
301 | * |
302 | * find profile for a transition index |
303 | * |
304 | * Returns: refcounted profile or NULL if not found available |
305 | */ |
306 | static struct aa_profile *x_to_profile(struct aa_profile *profile, |
307 | const char *name, u32 xindex) |
308 | { |
309 | struct aa_profile *new_profile = NULL; |
310 | struct aa_namespace *ns = profile->ns; |
311 | u32 xtype = xindex & AA_X_TYPE_MASK; |
312 | |
313 | switch (xtype) { |
314 | case AA_X_NONE: |
315 | /* fail exec unless ix || ux fallback - handled by caller */ |
316 | return NULL; |
317 | case AA_X_NAME: |
318 | if (xindex & AA_X_CHILD) |
319 | /* released by caller */ |
320 | new_profile = find_attach(ns, &profile->base.profiles, |
321 | name); |
322 | else |
323 | /* released by caller */ |
324 | new_profile = find_attach(ns, &ns->base.profiles, |
325 | name); |
326 | break; |
327 | case AA_X_TABLE: |
328 | /* released by caller */ |
329 | new_profile = x_table_lookup(profile, xindex); |
330 | break; |
331 | } |
332 | |
333 | /* released by caller */ |
334 | return new_profile; |
335 | } |
336 | |
337 | /** |
338 | * apparmor_bprm_set_creds - set the new creds on the bprm struct |
339 | * @bprm: binprm for the exec (NOT NULL) |
340 | * |
341 | * Returns: %0 or error on failure |
342 | */ |
343 | int apparmor_bprm_set_creds(struct linux_binprm *bprm) |
344 | { |
345 | struct aa_task_cxt *cxt; |
346 | struct aa_profile *profile, *new_profile = NULL; |
347 | struct aa_namespace *ns; |
348 | char *buffer = NULL; |
349 | unsigned int state; |
350 | struct file_perms perms = {}; |
351 | struct path_cond cond = { |
352 | bprm->file->f_path.dentry->d_inode->i_uid, |
353 | bprm->file->f_path.dentry->d_inode->i_mode |
354 | }; |
355 | const char *name = NULL, *target = NULL, *info = NULL; |
356 | int error = cap_bprm_set_creds(bprm); |
357 | if (error) |
358 | return error; |
359 | |
360 | if (bprm->cred_prepared) |
361 | return 0; |
362 | |
363 | cxt = bprm->cred->security; |
364 | BUG_ON(!cxt); |
365 | |
366 | profile = aa_get_profile(aa_newest_version(cxt->profile)); |
367 | /* |
368 | * get the namespace from the replacement profile as replacement |
369 | * can change the namespace |
370 | */ |
371 | ns = profile->ns; |
372 | state = profile->file.start; |
373 | |
374 | /* buffer freed below, name is pointer into buffer */ |
375 | error = aa_get_name(&bprm->file->f_path, profile->path_flags, &buffer, |
376 | &name); |
377 | if (error) { |
378 | if (profile->flags & |
379 | (PFLAG_IX_ON_NAME_ERROR | PFLAG_UNCONFINED)) |
380 | error = 0; |
381 | info = "Exec failed name resolution"; |
382 | name = bprm->filename; |
383 | goto audit; |
384 | } |
385 | |
386 | /* Test for onexec first as onexec directives override other |
387 | * x transitions. |
388 | */ |
389 | if (unconfined(profile)) { |
390 | /* unconfined task */ |
391 | if (cxt->onexec) |
392 | /* change_profile on exec already been granted */ |
393 | new_profile = aa_get_profile(cxt->onexec); |
394 | else |
395 | new_profile = find_attach(ns, &ns->base.profiles, name); |
396 | if (!new_profile) |
397 | goto cleanup; |
398 | goto apply; |
399 | } |
400 | |
401 | /* find exec permissions for name */ |
402 | state = aa_str_perms(profile->file.dfa, state, name, &cond, &perms); |
403 | if (cxt->onexec) { |
404 | struct file_perms cp; |
405 | info = "change_profile onexec"; |
406 | if (!(perms.allow & AA_MAY_ONEXEC)) |
407 | goto audit; |
408 | |
409 | /* test if this exec can be paired with change_profile onexec. |
410 | * onexec permission is linked to exec with a standard pairing |
411 | * exec\0change_profile |
412 | */ |
413 | state = aa_dfa_null_transition(profile->file.dfa, state); |
414 | cp = change_profile_perms(profile, cxt->onexec->ns, name, |
415 | AA_MAY_ONEXEC, state); |
416 | |
417 | if (!(cp.allow & AA_MAY_ONEXEC)) |
418 | goto audit; |
419 | new_profile = aa_get_profile(aa_newest_version(cxt->onexec)); |
420 | goto apply; |
421 | } |
422 | |
423 | if (perms.allow & MAY_EXEC) { |
424 | /* exec permission determine how to transition */ |
425 | new_profile = x_to_profile(profile, name, perms.xindex); |
426 | if (!new_profile) { |
427 | if (perms.xindex & AA_X_INHERIT) { |
428 | /* (p|c|n)ix - don't change profile but do |
429 | * use the newest version, which was picked |
430 | * up above when getting profile |
431 | */ |
432 | info = "ix fallback"; |
433 | new_profile = aa_get_profile(profile); |
434 | goto x_clear; |
435 | } else if (perms.xindex & AA_X_UNCONFINED) { |
436 | new_profile = aa_get_profile(ns->unconfined); |
437 | info = "ux fallback"; |
438 | } else { |
439 | error = -ENOENT; |
440 | info = "profile not found"; |
441 | } |
442 | } |
443 | } else if (COMPLAIN_MODE(profile)) { |
444 | /* no exec permission - are we in learning mode */ |
445 | new_profile = aa_new_null_profile(profile, 0); |
446 | if (!new_profile) { |
447 | error = -ENOMEM; |
448 | info = "could not create null profile"; |
449 | } else { |
450 | error = -EACCES; |
451 | target = new_profile->base.hname; |
452 | } |
453 | perms.xindex |= AA_X_UNSAFE; |
454 | } else |
455 | /* fail exec */ |
456 | error = -EACCES; |
457 | |
458 | if (!new_profile) |
459 | goto audit; |
460 | |
461 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { |
462 | /* FIXME: currently don't mediate shared state */ |
463 | ; |
464 | } |
465 | |
466 | if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { |
467 | error = may_change_ptraced_domain(current, new_profile); |
468 | if (error) { |
469 | aa_put_profile(new_profile); |
470 | goto audit; |
471 | } |
472 | } |
473 | |
474 | /* Determine if secure exec is needed. |
475 | * Can be at this point for the following reasons: |
476 | * 1. unconfined switching to confined |
477 | * 2. confined switching to different confinement |
478 | * 3. confined switching to unconfined |
479 | * |
480 | * Cases 2 and 3 are marked as requiring secure exec |
481 | * (unless policy specified "unsafe exec") |
482 | * |
483 | * bprm->unsafe is used to cache the AA_X_UNSAFE permission |
484 | * to avoid having to recompute in secureexec |
485 | */ |
486 | if (!(perms.xindex & AA_X_UNSAFE)) { |
487 | AA_DEBUG("scrubbing environment variables for %s profile=%s\n", |
488 | name, new_profile->base.hname); |
489 | bprm->unsafe |= AA_SECURE_X_NEEDED; |
490 | } |
491 | apply: |
492 | target = new_profile->base.hname; |
493 | /* when transitioning profiles clear unsafe personality bits */ |
494 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
495 | |
496 | x_clear: |
497 | aa_put_profile(cxt->profile); |
498 | /* transfer new profile reference will be released when cxt is freed */ |
499 | cxt->profile = new_profile; |
500 | |
501 | /* clear out all temporary/transitional state from the context */ |
502 | aa_put_profile(cxt->previous); |
503 | aa_put_profile(cxt->onexec); |
504 | cxt->previous = NULL; |
505 | cxt->onexec = NULL; |
506 | cxt->token = 0; |
507 | |
508 | audit: |
509 | error = aa_audit_file(profile, &perms, GFP_KERNEL, OP_EXEC, MAY_EXEC, |
510 | name, target, cond.uid, info, error); |
511 | |
512 | cleanup: |
513 | aa_put_profile(profile); |
514 | kfree(buffer); |
515 | |
516 | return error; |
517 | } |
518 | |
519 | /** |
520 | * apparmor_bprm_secureexec - determine if secureexec is needed |
521 | * @bprm: binprm for exec (NOT NULL) |
522 | * |
523 | * Returns: %1 if secureexec is needed else %0 |
524 | */ |
525 | int apparmor_bprm_secureexec(struct linux_binprm *bprm) |
526 | { |
527 | int ret = cap_bprm_secureexec(bprm); |
528 | |
529 | /* the decision to use secure exec is computed in set_creds |
530 | * and stored in bprm->unsafe. |
531 | */ |
532 | if (!ret && (bprm->unsafe & AA_SECURE_X_NEEDED)) |
533 | ret = 1; |
534 | |
535 | return ret; |
536 | } |
537 | |
538 | /** |
539 | * apparmor_bprm_committing_creds - do task cleanup on committing new creds |
540 | * @bprm: binprm for the exec (NOT NULL) |
541 | */ |
542 | void apparmor_bprm_committing_creds(struct linux_binprm *bprm) |
543 | { |
544 | struct aa_profile *profile = __aa_current_profile(); |
545 | struct aa_task_cxt *new_cxt = bprm->cred->security; |
546 | |
547 | /* bail out if unconfined or not changing profile */ |
548 | if ((new_cxt->profile == profile) || |
549 | (unconfined(new_cxt->profile))) |
550 | return; |
551 | |
552 | current->pdeath_signal = 0; |
553 | |
554 | /* reset soft limits and set hard limits for the new profile */ |
555 | __aa_transition_rlimits(profile, new_cxt->profile); |
556 | } |
557 | |
558 | /** |
559 | * apparmor_bprm_commited_cred - do cleanup after new creds committed |
560 | * @bprm: binprm for the exec (NOT NULL) |
561 | */ |
562 | void apparmor_bprm_committed_creds(struct linux_binprm *bprm) |
563 | { |
564 | /* TODO: cleanup signals - ipc mediation */ |
565 | return; |
566 | } |
567 | |
568 | /* |
569 | * Functions for self directed profile change |
570 | */ |
571 | |
572 | /** |
573 | * new_compound_name - create an hname with @n2 appended to @n1 |
574 | * @n1: base of hname (NOT NULL) |
575 | * @n2: name to append (NOT NULL) |
576 | * |
577 | * Returns: new name or NULL on error |
578 | */ |
579 | static char *new_compound_name(const char *n1, const char *n2) |
580 | { |
581 | char *name = kmalloc(strlen(n1) + strlen(n2) + 3, GFP_KERNEL); |
582 | if (name) |
583 | sprintf(name, "%s//%s", n1, n2); |
584 | return name; |
585 | } |
586 | |
587 | /** |
588 | * aa_change_hat - change hat to/from subprofile |
589 | * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) |
590 | * @count: number of hat names in @hats |
591 | * @token: magic value to validate the hat change |
592 | * @permtest: true if this is just a permission test |
593 | * |
594 | * Change to the first profile specified in @hats that exists, and store |
595 | * the @hat_magic in the current task context. If the count == 0 and the |
596 | * @token matches that stored in the current task context, return to the |
597 | * top level profile. |
598 | * |
599 | * Returns %0 on success, error otherwise. |
600 | */ |
601 | int aa_change_hat(const char *hats[], int count, u64 token, bool permtest) |
602 | { |
603 | const struct cred *cred; |
604 | struct aa_task_cxt *cxt; |
605 | struct aa_profile *profile, *previous_profile, *hat = NULL; |
606 | char *name = NULL; |
607 | int i; |
608 | struct file_perms perms = {}; |
609 | const char *target = NULL, *info = NULL; |
610 | int error = 0; |
611 | |
612 | /* released below */ |
613 | cred = get_current_cred(); |
614 | cxt = cred->security; |
615 | profile = aa_cred_profile(cred); |
616 | previous_profile = cxt->previous; |
617 | |
618 | if (unconfined(profile)) { |
619 | info = "unconfined"; |
620 | error = -EPERM; |
621 | goto audit; |
622 | } |
623 | |
624 | if (count) { |
625 | /* attempting to change into a new hat or switch to a sibling */ |
626 | struct aa_profile *root; |
627 | root = PROFILE_IS_HAT(profile) ? profile->parent : profile; |
628 | |
629 | /* find first matching hat */ |
630 | for (i = 0; i < count && !hat; i++) |
631 | /* released below */ |
632 | hat = aa_find_child(root, hats[i]); |
633 | if (!hat) { |
634 | if (!COMPLAIN_MODE(root) || permtest) { |
635 | if (list_empty(&root->base.profiles)) |
636 | error = -ECHILD; |
637 | else |
638 | error = -ENOENT; |
639 | goto out; |
640 | } |
641 | |
642 | /* |
643 | * In complain mode and failed to match any hats. |
644 | * Audit the failure is based off of the first hat |
645 | * supplied. This is done due how userspace |
646 | * interacts with change_hat. |
647 | * |
648 | * TODO: Add logging of all failed hats |
649 | */ |
650 | |
651 | /* freed below */ |
652 | name = new_compound_name(root->base.hname, hats[0]); |
653 | target = name; |
654 | /* released below */ |
655 | hat = aa_new_null_profile(profile, 1); |
656 | if (!hat) { |
657 | info = "failed null profile create"; |
658 | error = -ENOMEM; |
659 | goto audit; |
660 | } |
661 | } else { |
662 | target = hat->base.hname; |
663 | if (!PROFILE_IS_HAT(hat)) { |
664 | info = "target not hat"; |
665 | error = -EPERM; |
666 | goto audit; |
667 | } |
668 | } |
669 | |
670 | error = may_change_ptraced_domain(current, hat); |
671 | if (error) { |
672 | info = "ptraced"; |
673 | error = -EPERM; |
674 | goto audit; |
675 | } |
676 | |
677 | if (!permtest) { |
678 | error = aa_set_current_hat(hat, token); |
679 | if (error == -EACCES) |
680 | /* kill task in case of brute force attacks */ |
681 | perms.kill = AA_MAY_CHANGEHAT; |
682 | else if (name && !error) |
683 | /* reset error for learning of new hats */ |
684 | error = -ENOENT; |
685 | } |
686 | } else if (previous_profile) { |
687 | /* Return to saved profile. Kill task if restore fails |
688 | * to avoid brute force attacks |
689 | */ |
690 | target = previous_profile->base.hname; |
691 | error = aa_restore_previous_profile(token); |
692 | perms.kill = AA_MAY_CHANGEHAT; |
693 | } else |
694 | /* ignore restores when there is no saved profile */ |
695 | goto out; |
696 | |
697 | audit: |
698 | if (!permtest) |
699 | error = aa_audit_file(profile, &perms, GFP_KERNEL, |
700 | OP_CHANGE_HAT, AA_MAY_CHANGEHAT, NULL, |
701 | target, 0, info, error); |
702 | |
703 | out: |
704 | aa_put_profile(hat); |
705 | kfree(name); |
706 | put_cred(cred); |
707 | |
708 | return error; |
709 | } |
710 | |
711 | /** |
712 | * aa_change_profile - perform a one-way profile transition |
713 | * @ns_name: name of the profile namespace to change to (MAYBE NULL) |
714 | * @hname: name of profile to change to (MAYBE NULL) |
715 | * @onexec: whether this transition is to take place immediately or at exec |
716 | * @permtest: true if this is just a permission test |
717 | * |
718 | * Change to new profile @name. Unlike with hats, there is no way |
719 | * to change back. If @name isn't specified the current profile name is |
720 | * used. |
721 | * If @onexec then the transition is delayed until |
722 | * the next exec. |
723 | * |
724 | * Returns %0 on success, error otherwise. |
725 | */ |
726 | int aa_change_profile(const char *ns_name, const char *hname, bool onexec, |
727 | bool permtest) |
728 | { |
729 | const struct cred *cred; |
730 | struct aa_task_cxt *cxt; |
731 | struct aa_profile *profile, *target = NULL; |
732 | struct aa_namespace *ns = NULL; |
733 | struct file_perms perms = {}; |
734 | const char *name = NULL, *info = NULL; |
735 | int op, error = 0; |
736 | u32 request; |
737 | |
738 | if (!hname && !ns_name) |
739 | return -EINVAL; |
740 | |
741 | if (onexec) { |
742 | request = AA_MAY_ONEXEC; |
743 | op = OP_CHANGE_ONEXEC; |
744 | } else { |
745 | request = AA_MAY_CHANGE_PROFILE; |
746 | op = OP_CHANGE_PROFILE; |
747 | } |
748 | |
749 | cred = get_current_cred(); |
750 | cxt = cred->security; |
751 | profile = aa_cred_profile(cred); |
752 | |
753 | if (ns_name) { |
754 | /* released below */ |
755 | ns = aa_find_namespace(profile->ns, ns_name); |
756 | if (!ns) { |
757 | /* we don't create new namespace in complain mode */ |
758 | name = ns_name; |
759 | info = "namespace not found"; |
760 | error = -ENOENT; |
761 | goto audit; |
762 | } |
763 | } else |
764 | /* released below */ |
765 | ns = aa_get_namespace(profile->ns); |
766 | |
767 | /* if the name was not specified, use the name of the current profile */ |
768 | if (!hname) { |
769 | if (unconfined(profile)) |
770 | hname = ns->unconfined->base.hname; |
771 | else |
772 | hname = profile->base.hname; |
773 | } |
774 | |
775 | perms = change_profile_perms(profile, ns, hname, request, |
776 | profile->file.start); |
777 | if (!(perms.allow & request)) { |
778 | error = -EACCES; |
779 | goto audit; |
780 | } |
781 | |
782 | /* released below */ |
783 | target = aa_lookup_profile(ns, hname); |
784 | if (!target) { |
785 | info = "profile not found"; |
786 | error = -ENOENT; |
787 | if (permtest || !COMPLAIN_MODE(profile)) |
788 | goto audit; |
789 | /* released below */ |
790 | target = aa_new_null_profile(profile, 0); |
791 | if (!target) { |
792 | info = "failed null profile create"; |
793 | error = -ENOMEM; |
794 | goto audit; |
795 | } |
796 | } |
797 | |
798 | /* check if tracing task is allowed to trace target domain */ |
799 | error = may_change_ptraced_domain(current, target); |
800 | if (error) { |
801 | info = "ptrace prevents transition"; |
802 | goto audit; |
803 | } |
804 | |
805 | if (permtest) |
806 | goto audit; |
807 | |
808 | if (onexec) |
809 | error = aa_set_current_onexec(target); |
810 | else |
811 | error = aa_replace_current_profile(target); |
812 | |
813 | audit: |
814 | if (!permtest) |
815 | error = aa_audit_file(profile, &perms, GFP_KERNEL, op, request, |
816 | name, hname, 0, info, error); |
817 | |
818 | aa_put_namespace(ns); |
819 | aa_put_profile(target); |
820 | put_cred(cred); |
821 | |
822 | return error; |
823 | } |
824 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
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