Commit | Line | Data |
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898127c3 JJ |
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" | |
cff281f6 | 32 | #include "include/policy_ns.h" |
898127c3 JJ |
33 | |
34 | /** | |
35 | * aa_free_domain_entries - free entries in a domain table | |
36 | * @domain: the domain table to free (MAYBE NULL) | |
37 | */ | |
38 | void aa_free_domain_entries(struct aa_domain *domain) | |
39 | { | |
40 | int i; | |
41 | if (domain) { | |
42 | if (!domain->table) | |
43 | return; | |
44 | ||
45 | for (i = 0; i < domain->size; i++) | |
46 | kzfree(domain->table[i]); | |
47 | kzfree(domain->table); | |
48 | domain->table = NULL; | |
49 | } | |
50 | } | |
51 | ||
52 | /** | |
53 | * may_change_ptraced_domain - check if can change profile on ptraced task | |
b2d09ae4 JJ |
54 | * @to_label: profile to change to (NOT NULL) |
55 | * @info: message if there is an error | |
898127c3 | 56 | * |
51775fe7 | 57 | * Check if current is ptraced and if so if the tracing task is allowed |
898127c3 JJ |
58 | * to trace the new domain |
59 | * | |
60 | * Returns: %0 or error if change not allowed | |
61 | */ | |
b2d09ae4 JJ |
62 | static int may_change_ptraced_domain(struct aa_label *to_label, |
63 | const char **info) | |
898127c3 JJ |
64 | { |
65 | struct task_struct *tracer; | |
637f688d | 66 | struct aa_label *tracerl = NULL; |
898127c3 JJ |
67 | int error = 0; |
68 | ||
69 | rcu_read_lock(); | |
51775fe7 | 70 | tracer = ptrace_parent(current); |
3cfcc19e | 71 | if (tracer) |
898127c3 | 72 | /* released below */ |
637f688d | 73 | tracerl = aa_get_task_label(tracer); |
898127c3 JJ |
74 | |
75 | /* not ptraced */ | |
637f688d | 76 | if (!tracer || unconfined(tracerl)) |
898127c3 JJ |
77 | goto out; |
78 | ||
b2d09ae4 | 79 | error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); |
898127c3 JJ |
80 | |
81 | out: | |
04fdc099 | 82 | rcu_read_unlock(); |
637f688d | 83 | aa_put_label(tracerl); |
898127c3 | 84 | |
b2d09ae4 JJ |
85 | if (error) |
86 | *info = "ptrace prevents transition"; | |
898127c3 JJ |
87 | return error; |
88 | } | |
89 | ||
93c98a48 JJ |
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 | |
94 | ****/ | |
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 | |
98 | * visibility test. | |
99 | */ | |
100 | static inline unsigned int match_component(struct aa_profile *profile, | |
101 | struct aa_profile *tp, | |
102 | bool stack, unsigned int state) | |
103 | { | |
104 | const char *ns_name; | |
105 | ||
106 | if (stack) | |
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); | |
110 | ||
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); | |
117 | } | |
118 | ||
119 | /** | |
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 | |
128 | * | |
129 | * Returns: 0 on success else ERROR | |
130 | * | |
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. | |
134 | */ | |
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) | |
139 | { | |
140 | struct aa_profile *tp; | |
141 | struct label_it i; | |
142 | struct path_cond cond = { }; | |
143 | ||
144 | /* find first subcomponent that is visible */ | |
145 | label_for_each(i, label, tp) { | |
146 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
147 | continue; | |
148 | state = match_component(profile, tp, stack, state); | |
149 | if (!state) | |
150 | goto fail; | |
151 | goto next; | |
152 | } | |
153 | ||
154 | /* no component visible */ | |
155 | *perms = allperms; | |
156 | return 0; | |
157 | ||
158 | next: | |
159 | label_for_each_cont(i, label, tp) { | |
160 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
161 | continue; | |
162 | state = aa_dfa_match(profile->file.dfa, state, "//&"); | |
163 | state = match_component(profile, tp, false, state); | |
164 | if (!state) | |
165 | goto fail; | |
166 | } | |
167 | *perms = aa_compute_fperms(profile->file.dfa, state, &cond); | |
168 | aa_apply_modes_to_perms(profile, perms); | |
169 | if ((perms->allow & request) != request) | |
170 | return -EACCES; | |
171 | ||
172 | return 0; | |
173 | ||
174 | fail: | |
175 | *perms = nullperms; | |
176 | return -EACCES; | |
177 | } | |
178 | ||
179 | /** | |
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 | |
188 | * | |
189 | * Returns: 0 on success else ERROR | |
190 | * | |
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. | |
194 | */ | |
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) | |
199 | { | |
200 | struct aa_profile *tp; | |
201 | struct label_it i; | |
202 | struct aa_perms tmp; | |
203 | struct path_cond cond = { }; | |
204 | unsigned int state = 0; | |
205 | ||
206 | /* find first subcomponent to test */ | |
207 | label_for_each(i, label, tp) { | |
208 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
209 | continue; | |
210 | state = match_component(profile, tp, stack, start); | |
211 | if (!state) | |
212 | goto fail; | |
213 | goto next; | |
214 | } | |
215 | ||
216 | /* no subcomponents visible - no change in perms */ | |
217 | return 0; | |
218 | ||
219 | next: | |
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)) | |
225 | continue; | |
226 | state = match_component(profile, tp, stack, start); | |
227 | if (!state) | |
228 | goto fail; | |
229 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
230 | aa_apply_modes_to_perms(profile, &tmp); | |
231 | aa_perms_accum(perms, &tmp); | |
232 | } | |
233 | ||
234 | if ((perms->allow & request) != request) | |
235 | return -EACCES; | |
236 | ||
237 | return 0; | |
238 | ||
239 | fail: | |
240 | *perms = nullperms; | |
241 | return -EACCES; | |
242 | } | |
243 | ||
244 | /** | |
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) | |
253 | * | |
254 | * Returns: the state the match finished in, may be the none matching state | |
255 | */ | |
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) | |
259 | { | |
260 | int error; | |
261 | ||
262 | *perms = nullperms; | |
263 | error = label_compound_match(profile, label, stack, state, subns, | |
264 | request, perms); | |
265 | if (!error) | |
266 | return error; | |
267 | ||
268 | *perms = allperms; | |
269 | return label_components_match(profile, label, stack, state, subns, | |
270 | request, perms); | |
271 | } | |
272 | ||
273 | /******* end TODO: dedup *****/ | |
274 | ||
898127c3 JJ |
275 | /** |
276 | * change_profile_perms - find permissions for change_profile | |
277 | * @profile: the current profile (NOT NULL) | |
93c98a48 JJ |
278 | * @target: label to transition to (NOT NULL) |
279 | * @stack: whether this is a stacking request | |
898127c3 JJ |
280 | * @request: requested perms |
281 | * @start: state to start matching in | |
282 | * | |
93c98a48 | 283 | * |
898127c3 | 284 | * Returns: permission set |
93c98a48 JJ |
285 | * |
286 | * currently only matches full label A//&B//&C or individual components A, B, C | |
287 | * not arbitrary combinations. Eg. A//&B, C | |
898127c3 | 288 | */ |
93c98a48 JJ |
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) | |
293 | { | |
294 | if (profile_unconfined(profile)) { | |
295 | perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; | |
296 | perms->audit = perms->quiet = perms->kill = 0; | |
297 | return 0; | |
298 | } | |
299 | ||
300 | /* TODO: add profile in ns screening */ | |
301 | return label_match(profile, target, stack, start, true, request, perms); | |
302 | } | |
303 | ||
898127c3 JJ |
304 | /** |
305 | * __attach_match_ - find an attachment match | |
306 | * @name - to match against (NOT NULL) | |
307 | * @head - profile list to walk (NOT NULL) | |
844b8292 | 308 | * @info - info message if there was an error (NOT NULL) |
898127c3 JJ |
309 | * |
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. | |
314 | * | |
315 | * Requires: @head not be shared or have appropriate locks held | |
316 | * | |
317 | * Returns: profile or NULL if no match found | |
318 | */ | |
319 | static struct aa_profile *__attach_match(const char *name, | |
844b8292 JJ |
320 | struct list_head *head, |
321 | const char **info) | |
898127c3 JJ |
322 | { |
323 | int len = 0; | |
844b8292 | 324 | bool conflict = false; |
898127c3 JJ |
325 | struct aa_profile *profile, *candidate = NULL; |
326 | ||
01e2b670 | 327 | list_for_each_entry_rcu(profile, head, base.list) { |
06d426d1 JJ |
328 | if (profile->label.flags & FLAG_NULL && |
329 | &profile->label == ns_unconfined(profile->ns)) | |
898127c3 | 330 | continue; |
06d426d1 | 331 | |
844b8292 | 332 | if (profile->xmatch) { |
1a3881d3 | 333 | if (profile->xmatch_len >= len) { |
844b8292 JJ |
334 | unsigned int state; |
335 | u32 perm; | |
336 | ||
337 | state = aa_dfa_match(profile->xmatch, | |
338 | DFA_START, name); | |
339 | perm = dfa_user_allow(profile->xmatch, state); | |
340 | /* any accepting state means a valid match. */ | |
341 | if (perm & MAY_EXEC) { | |
1a3881d3 MG |
342 | if (profile->xmatch_len == len) { |
343 | conflict = true; | |
344 | continue; | |
345 | } | |
844b8292 JJ |
346 | candidate = profile; |
347 | len = profile->xmatch_len; | |
348 | conflict = false; | |
349 | } | |
898127c3 JJ |
350 | } |
351 | } else if (!strcmp(profile->base.name, name)) | |
352 | /* exact non-re match, no more searching required */ | |
353 | return profile; | |
354 | } | |
355 | ||
844b8292 JJ |
356 | if (conflict) { |
357 | *info = "conflicting profile attachments"; | |
358 | return NULL; | |
359 | } | |
360 | ||
898127c3 JJ |
361 | return candidate; |
362 | } | |
363 | ||
364 | /** | |
365 | * find_attach - do attachment search for unconfined processes | |
366 | * @ns: the current namespace (NOT NULL) | |
367 | * @list: list to search (NOT NULL) | |
368 | * @name: the executable name to match against (NOT NULL) | |
844b8292 | 369 | * @info: info message if there was an error |
898127c3 | 370 | * |
93c98a48 | 371 | * Returns: label or NULL if no match found |
898127c3 | 372 | */ |
93c98a48 | 373 | static struct aa_label *find_attach(struct aa_ns *ns, struct list_head *list, |
844b8292 | 374 | const char *name, const char **info) |
898127c3 JJ |
375 | { |
376 | struct aa_profile *profile; | |
377 | ||
01e2b670 | 378 | rcu_read_lock(); |
844b8292 | 379 | profile = aa_get_profile(__attach_match(name, list, info)); |
01e2b670 | 380 | rcu_read_unlock(); |
898127c3 | 381 | |
93c98a48 | 382 | return profile ? &profile->label : NULL; |
898127c3 JJ |
383 | } |
384 | ||
385 | static const char *next_name(int xtype, const char *name) | |
386 | { | |
387 | return NULL; | |
388 | } | |
389 | ||
390 | /** | |
391 | * x_table_lookup - lookup an x transition name via transition table | |
392 | * @profile: current profile (NOT NULL) | |
393 | * @xindex: index into x transition table | |
93c98a48 | 394 | * @name: returns: name tested to find label (NOT NULL) |
898127c3 | 395 | * |
93c98a48 | 396 | * Returns: refcounted label, or NULL on failure (MAYBE NULL) |
898127c3 | 397 | */ |
2ea3ffb7 JJ |
398 | struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, |
399 | const char **name) | |
898127c3 | 400 | { |
93c98a48 | 401 | struct aa_label *label = NULL; |
898127c3 JJ |
402 | u32 xtype = xindex & AA_X_TYPE_MASK; |
403 | int index = xindex & AA_X_INDEX_MASK; | |
898127c3 | 404 | |
93c98a48 | 405 | AA_BUG(!name); |
898127c3 | 406 | |
93c98a48 JJ |
407 | /* index is guaranteed to be in range, validated at load time */ |
408 | /* TODO: move lookup parsing to unpack time so this is a straight | |
409 | * index into the resultant label | |
410 | */ | |
411 | for (*name = profile->file.trans.table[index]; !label && *name; | |
412 | *name = next_name(xtype, *name)) { | |
898127c3 | 413 | if (xindex & AA_X_CHILD) { |
93c98a48 | 414 | struct aa_profile *new_profile; |
898127c3 | 415 | /* release by caller */ |
93c98a48 JJ |
416 | new_profile = aa_find_child(profile, *name); |
417 | if (new_profile) | |
418 | label = &new_profile->label; | |
898127c3 | 419 | continue; |
898127c3 | 420 | } |
93c98a48 JJ |
421 | label = aa_label_parse(&profile->label, *name, GFP_ATOMIC, |
422 | true, false); | |
423 | if (IS_ERR(label)) | |
424 | label = NULL; | |
898127c3 JJ |
425 | } |
426 | ||
427 | /* released by caller */ | |
93c98a48 JJ |
428 | |
429 | return label; | |
898127c3 JJ |
430 | } |
431 | ||
432 | /** | |
93c98a48 | 433 | * x_to_label - get target label for a given xindex |
898127c3 JJ |
434 | * @profile: current profile (NOT NULL) |
435 | * @name: name to lookup (NOT NULL) | |
436 | * @xindex: index into x transition table | |
93c98a48 | 437 | * @lookupname: returns: name used in lookup if one was specified (NOT NULL) |
898127c3 | 438 | * |
93c98a48 | 439 | * find label for a transition index |
898127c3 | 440 | * |
93c98a48 | 441 | * Returns: refcounted label or NULL if not found available |
898127c3 | 442 | */ |
93c98a48 JJ |
443 | static struct aa_label *x_to_label(struct aa_profile *profile, |
444 | const char *name, u32 xindex, | |
445 | const char **lookupname, | |
446 | const char **info) | |
898127c3 | 447 | { |
93c98a48 | 448 | struct aa_label *new = NULL; |
98849dff | 449 | struct aa_ns *ns = profile->ns; |
898127c3 | 450 | u32 xtype = xindex & AA_X_TYPE_MASK; |
93c98a48 | 451 | const char *stack = NULL; |
898127c3 JJ |
452 | |
453 | switch (xtype) { | |
454 | case AA_X_NONE: | |
455 | /* fail exec unless ix || ux fallback - handled by caller */ | |
93c98a48 JJ |
456 | *lookupname = NULL; |
457 | break; | |
458 | case AA_X_TABLE: | |
459 | /* TODO: fix when perm mapping done at unload */ | |
460 | stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; | |
461 | if (*stack != '&') { | |
462 | /* released by caller */ | |
463 | new = x_table_lookup(profile, xindex, lookupname); | |
464 | stack = NULL; | |
465 | break; | |
466 | } | |
467 | /* fall through to X_NAME */ | |
898127c3 JJ |
468 | case AA_X_NAME: |
469 | if (xindex & AA_X_CHILD) | |
470 | /* released by caller */ | |
93c98a48 | 471 | new = find_attach(ns, &profile->base.profiles, |
844b8292 | 472 | name, info); |
898127c3 JJ |
473 | else |
474 | /* released by caller */ | |
93c98a48 | 475 | new = find_attach(ns, &ns->base.profiles, |
844b8292 | 476 | name, info); |
93c98a48 | 477 | *lookupname = name; |
898127c3 JJ |
478 | break; |
479 | } | |
480 | ||
93c98a48 JJ |
481 | if (!new) { |
482 | if (xindex & AA_X_INHERIT) { | |
483 | /* (p|c|n)ix - don't change profile but do | |
484 | * use the newest version | |
485 | */ | |
486 | *info = "ix fallback"; | |
487 | /* no profile && no error */ | |
488 | new = aa_get_newest_label(&profile->label); | |
489 | } else if (xindex & AA_X_UNCONFINED) { | |
490 | new = aa_get_newest_label(ns_unconfined(profile->ns)); | |
491 | *info = "ux fallback"; | |
492 | } | |
493 | } | |
494 | ||
495 | if (new && stack) { | |
496 | /* base the stack on post domain transition */ | |
497 | struct aa_label *base = new; | |
498 | ||
499 | new = aa_label_parse(base, stack, GFP_ATOMIC, true, false); | |
500 | if (IS_ERR(new)) | |
501 | new = NULL; | |
502 | aa_put_label(base); | |
503 | } | |
504 | ||
898127c3 | 505 | /* released by caller */ |
93c98a48 | 506 | return new; |
898127c3 JJ |
507 | } |
508 | ||
93c98a48 JJ |
509 | static struct aa_label *profile_transition(struct aa_profile *profile, |
510 | const struct linux_binprm *bprm, | |
511 | char *buffer, struct path_cond *cond, | |
512 | bool *secure_exec) | |
898127c3 | 513 | { |
93c98a48 JJ |
514 | struct aa_label *new = NULL; |
515 | const char *info = NULL, *name = NULL, *target = NULL; | |
516 | unsigned int state = profile->file.start; | |
2d679f3c | 517 | struct aa_perms perms = {}; |
93c98a48 | 518 | bool nonewprivs = false; |
b1d9e6b0 | 519 | int error = 0; |
898127c3 | 520 | |
93c98a48 JJ |
521 | AA_BUG(!profile); |
522 | AA_BUG(!bprm); | |
523 | AA_BUG(!buffer); | |
898127c3 | 524 | |
4227c333 | 525 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, |
72c8a768 | 526 | &name, &info, profile->disconnected); |
898127c3 | 527 | if (error) { |
637f688d | 528 | if (profile_unconfined(profile) || |
93c98a48 JJ |
529 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { |
530 | AA_DEBUG("name lookup ix on error"); | |
898127c3 | 531 | error = 0; |
93c98a48 JJ |
532 | new = aa_get_newest_label(&profile->label); |
533 | } | |
898127c3 JJ |
534 | name = bprm->filename; |
535 | goto audit; | |
536 | } | |
537 | ||
637f688d | 538 | if (profile_unconfined(profile)) { |
93c98a48 | 539 | new = find_attach(profile->ns, &profile->ns->base.profiles, |
844b8292 | 540 | name, &info); |
93c98a48 JJ |
541 | if (new) { |
542 | AA_DEBUG("unconfined attached to new label"); | |
543 | return new; | |
544 | } | |
545 | AA_DEBUG("unconfined exec no attachment"); | |
546 | return aa_get_newest_label(&profile->label); | |
898127c3 JJ |
547 | } |
548 | ||
549 | /* find exec permissions for name */ | |
93c98a48 | 550 | state = aa_str_perms(profile->file.dfa, state, name, cond, &perms); |
898127c3 JJ |
551 | if (perms.allow & MAY_EXEC) { |
552 | /* exec permission determine how to transition */ | |
93c98a48 JJ |
553 | new = x_to_label(profile, name, perms.xindex, &target, &info); |
554 | if (new && new->proxy == profile->label.proxy && info) { | |
555 | /* hack ix fallback - improve how this is detected */ | |
556 | goto audit; | |
557 | } else if (!new) { | |
558 | error = -EACCES; | |
559 | info = "profile transition not found"; | |
560 | /* remove MAY_EXEC to audit as failure */ | |
561 | perms.allow &= ~MAY_EXEC; | |
898127c3 JJ |
562 | } |
563 | } else if (COMPLAIN_MODE(profile)) { | |
93c98a48 | 564 | /* no exec permission - learning mode */ |
5d7c44ef JJ |
565 | struct aa_profile *new_profile = NULL; |
566 | char *n = kstrdup(name, GFP_ATOMIC); | |
567 | ||
568 | if (n) { | |
569 | /* name is ptr into buffer */ | |
570 | long pos = name - buffer; | |
571 | /* break per cpu buffer hold */ | |
572 | put_buffers(buffer); | |
573 | new_profile = aa_new_null_profile(profile, false, n, | |
574 | GFP_KERNEL); | |
575 | get_buffers(buffer); | |
576 | name = buffer + pos; | |
577 | strcpy((char *)name, n); | |
578 | kfree(n); | |
579 | } | |
898127c3 JJ |
580 | if (!new_profile) { |
581 | error = -ENOMEM; | |
582 | info = "could not create null profile"; | |
93c98a48 | 583 | } else { |
898127c3 | 584 | error = -EACCES; |
93c98a48 JJ |
585 | new = &new_profile->label; |
586 | } | |
898127c3 JJ |
587 | perms.xindex |= AA_X_UNSAFE; |
588 | } else | |
589 | /* fail exec */ | |
590 | error = -EACCES; | |
591 | ||
93c98a48 JJ |
592 | if (!new) |
593 | goto audit; | |
594 | ||
595 | /* Policy has specified a domain transitions. if no_new_privs and | |
596 | * confined and not transitioning to the current domain fail. | |
597 | * | |
598 | * NOTE: Domain transitions from unconfined and to stritly stacked | |
599 | * subsets are allowed even when no_new_privs is set because this | |
600 | * aways results in a further reduction of permissions. | |
c29bceb3 | 601 | */ |
93c98a48 JJ |
602 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && |
603 | !profile_unconfined(profile) && | |
604 | !aa_label_is_subset(new, &profile->label)) { | |
c29bceb3 | 605 | error = -EPERM; |
93c98a48 JJ |
606 | info = "no new privs"; |
607 | nonewprivs = true; | |
608 | perms.allow &= ~MAY_EXEC; | |
609 | goto audit; | |
610 | } | |
611 | ||
612 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
613 | if (DEBUG_ON) { | |
614 | dbg_printk("apparmor: scrubbing environment variables" | |
615 | " for %s profile=", name); | |
616 | aa_label_printk(new, GFP_ATOMIC); | |
617 | dbg_printk("\n"); | |
618 | } | |
619 | *secure_exec = true; | |
c29bceb3 JJ |
620 | } |
621 | ||
93c98a48 JJ |
622 | audit: |
623 | aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, | |
624 | cond->uid, info, error); | |
625 | if (!new || nonewprivs) { | |
626 | aa_put_label(new); | |
627 | return ERR_PTR(error); | |
628 | } | |
629 | ||
630 | return new; | |
631 | } | |
632 | ||
633 | static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, | |
634 | bool stack, const struct linux_binprm *bprm, | |
635 | char *buffer, struct path_cond *cond, | |
636 | bool *secure_exec) | |
637 | { | |
638 | unsigned int state = profile->file.start; | |
639 | struct aa_perms perms = {}; | |
640 | const char *xname = NULL, *info = "change_profile onexec"; | |
641 | int error = -EACCES; | |
642 | ||
643 | AA_BUG(!profile); | |
644 | AA_BUG(!onexec); | |
645 | AA_BUG(!bprm); | |
646 | AA_BUG(!buffer); | |
647 | ||
648 | if (profile_unconfined(profile)) { | |
649 | /* change_profile on exec already granted */ | |
650 | /* | |
651 | * NOTE: Domain transitions from unconfined are allowed | |
652 | * even when no_new_privs is set because this aways results | |
653 | * in a further reduction of permissions. | |
654 | */ | |
655 | return 0; | |
656 | } | |
657 | ||
658 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, | |
659 | &xname, &info, profile->disconnected); | |
660 | if (error) { | |
661 | if (profile_unconfined(profile) || | |
662 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { | |
663 | AA_DEBUG("name lookup ix on error"); | |
664 | error = 0; | |
665 | } | |
666 | xname = bprm->filename; | |
898127c3 | 667 | goto audit; |
93c98a48 JJ |
668 | } |
669 | ||
670 | /* find exec permissions for name */ | |
671 | state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms); | |
672 | if (!(perms.allow & AA_MAY_ONEXEC)) { | |
673 | info = "no change_onexec valid for executable"; | |
674 | goto audit; | |
675 | } | |
676 | /* test if this exec can be paired with change_profile onexec. | |
677 | * onexec permission is linked to exec with a standard pairing | |
678 | * exec\0change_profile | |
679 | */ | |
680 | state = aa_dfa_null_transition(profile->file.dfa, state); | |
681 | error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, | |
682 | state, &perms); | |
683 | if (error) { | |
684 | perms.allow &= ~AA_MAY_ONEXEC; | |
685 | goto audit; | |
686 | } | |
687 | /* Policy has specified a domain transitions. if no_new_privs and | |
688 | * confined and not transitioning to the current domain fail. | |
689 | * | |
690 | * NOTE: Domain transitions from unconfined and to stritly stacked | |
691 | * subsets are allowed even when no_new_privs is set because this | |
692 | * aways results in a further reduction of permissions. | |
693 | */ | |
694 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && | |
695 | !profile_unconfined(profile) && | |
696 | !aa_label_is_subset(onexec, &profile->label)) { | |
697 | error = -EPERM; | |
698 | info = "no new privs"; | |
699 | perms.allow &= ~AA_MAY_ONEXEC; | |
700 | goto audit; | |
701 | } | |
702 | ||
703 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
704 | if (DEBUG_ON) { | |
705 | dbg_printk("apparmor: scrubbing environment " | |
706 | "variables for %s label=", xname); | |
707 | aa_label_printk(onexec, GFP_ATOMIC); | |
708 | dbg_printk("\n"); | |
709 | } | |
710 | *secure_exec = true; | |
711 | } | |
712 | ||
713 | audit: | |
714 | return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, | |
715 | NULL, onexec, cond->uid, info, error); | |
716 | } | |
717 | ||
718 | /* ensure none ns domain transitions are correctly applied with onexec */ | |
719 | ||
720 | static struct aa_label *handle_onexec(struct aa_label *label, | |
721 | struct aa_label *onexec, bool stack, | |
722 | const struct linux_binprm *bprm, | |
723 | char *buffer, struct path_cond *cond, | |
724 | bool *unsafe) | |
725 | { | |
726 | struct aa_profile *profile; | |
727 | struct aa_label *new; | |
728 | int error; | |
729 | ||
730 | AA_BUG(!label); | |
731 | AA_BUG(!onexec); | |
732 | AA_BUG(!bprm); | |
733 | AA_BUG(!buffer); | |
734 | ||
735 | if (!stack) { | |
736 | error = fn_for_each_in_ns(label, profile, | |
737 | profile_onexec(profile, onexec, stack, | |
738 | bprm, buffer, cond, unsafe)); | |
739 | if (error) | |
740 | return ERR_PTR(error); | |
741 | new = fn_label_build_in_ns(label, profile, GFP_ATOMIC, | |
742 | aa_get_newest_label(onexec), | |
743 | profile_transition(profile, bprm, buffer, | |
744 | cond, unsafe)); | |
745 | ||
746 | } else { | |
747 | /* TODO: determine how much we want to losen this */ | |
748 | error = fn_for_each_in_ns(label, profile, | |
749 | profile_onexec(profile, onexec, stack, bprm, | |
750 | buffer, cond, unsafe)); | |
751 | if (error) | |
752 | return ERR_PTR(error); | |
753 | new = fn_label_build_in_ns(label, profile, GFP_ATOMIC, | |
754 | aa_label_merge(&profile->label, onexec, | |
755 | GFP_ATOMIC), | |
756 | profile_transition(profile, bprm, buffer, | |
757 | cond, unsafe)); | |
758 | } | |
759 | ||
760 | if (new) | |
761 | return new; | |
762 | ||
763 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
764 | error = fn_for_each_in_ns(label, profile, | |
765 | aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, | |
766 | AA_MAY_ONEXEC, bprm->filename, NULL, | |
767 | onexec, GLOBAL_ROOT_UID, | |
768 | "failed to build target label", -ENOMEM)); | |
769 | return ERR_PTR(error); | |
770 | } | |
771 | ||
772 | /** | |
773 | * apparmor_bprm_set_creds - set the new creds on the bprm struct | |
774 | * @bprm: binprm for the exec (NOT NULL) | |
775 | * | |
776 | * Returns: %0 or error on failure | |
777 | * | |
778 | * TODO: once the other paths are done see if we can't refactor into a fn | |
779 | */ | |
780 | int apparmor_bprm_set_creds(struct linux_binprm *bprm) | |
781 | { | |
4d2f8ba3 | 782 | struct aa_cred_ctx *ctx; |
3b529a76 | 783 | struct aa_task_ctx *tctx; |
93c98a48 JJ |
784 | struct aa_label *label, *new = NULL; |
785 | struct aa_profile *profile; | |
786 | char *buffer = NULL; | |
787 | const char *info = NULL; | |
788 | int error = 0; | |
789 | bool unsafe = false; | |
790 | struct path_cond cond = { | |
791 | file_inode(bprm->file)->i_uid, | |
792 | file_inode(bprm->file)->i_mode | |
793 | }; | |
794 | ||
ddb4a144 | 795 | if (bprm->called_set_creds) |
93c98a48 JJ |
796 | return 0; |
797 | ||
798 | ctx = cred_ctx(bprm->cred); | |
3b529a76 | 799 | tctx = current_task_ctx(); |
93c98a48 | 800 | AA_BUG(!ctx); |
3b529a76 | 801 | AA_BUG(!tctx); |
93c98a48 JJ |
802 | |
803 | label = aa_get_newest_label(ctx->label); | |
804 | ||
805 | /* buffer freed below, name is pointer into buffer */ | |
806 | get_buffers(buffer); | |
807 | /* Test for onexec first as onexec override other x transitions. */ | |
3b529a76 JJ |
808 | if (tctx->onexec) |
809 | new = handle_onexec(label, tctx->onexec, tctx->token, | |
93c98a48 JJ |
810 | bprm, buffer, &cond, &unsafe); |
811 | else | |
812 | new = fn_label_build(label, profile, GFP_ATOMIC, | |
813 | profile_transition(profile, bprm, buffer, | |
814 | &cond, &unsafe)); | |
815 | ||
816 | AA_BUG(!new); | |
817 | if (IS_ERR(new)) { | |
818 | error = PTR_ERR(new); | |
819 | goto done; | |
820 | } else if (!new) { | |
821 | error = -ENOMEM; | |
822 | goto done; | |
823 | } | |
824 | ||
825 | /* TODO: Add ns level no_new_privs subset test */ | |
898127c3 JJ |
826 | |
827 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
828 | /* FIXME: currently don't mediate shared state */ | |
829 | ; | |
830 | } | |
831 | ||
93c98a48 JJ |
832 | if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { |
833 | /* TODO: test needs to be profile of label to new */ | |
834 | error = may_change_ptraced_domain(new, &info); | |
f7da2de0 | 835 | if (error) |
898127c3 | 836 | goto audit; |
898127c3 JJ |
837 | } |
838 | ||
93c98a48 JJ |
839 | if (unsafe) { |
840 | if (DEBUG_ON) { | |
841 | dbg_printk("scrubbing environment variables for %s " | |
842 | "label=", bprm->filename); | |
843 | aa_label_printk(new, GFP_ATOMIC); | |
844 | dbg_printk("\n"); | |
845 | } | |
993b3ab0 | 846 | bprm->secureexec = 1; |
898127c3 | 847 | } |
898127c3 | 848 | |
93c98a48 JJ |
849 | if (label->proxy != new->proxy) { |
850 | /* when transitioning clear unsafe personality bits */ | |
851 | if (DEBUG_ON) { | |
852 | dbg_printk("apparmor: clearing unsafe personality " | |
853 | "bits. %s label=", bprm->filename); | |
854 | aa_label_printk(new, GFP_ATOMIC); | |
855 | dbg_printk("\n"); | |
856 | } | |
857 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
858 | } | |
637f688d | 859 | aa_put_label(ctx->label); |
93c98a48 JJ |
860 | /* transfer reference, released when ctx is freed */ |
861 | ctx->label = new; | |
898127c3 | 862 | |
93c98a48 | 863 | done: |
637f688d | 864 | aa_put_label(label); |
4227c333 | 865 | put_buffers(buffer); |
898127c3 JJ |
866 | |
867 | return error; | |
93c98a48 JJ |
868 | |
869 | audit: | |
870 | error = fn_for_each(label, profile, | |
871 | aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, | |
872 | bprm->filename, NULL, new, | |
873 | file_inode(bprm->file)->i_uid, info, | |
874 | error)); | |
875 | aa_put_label(new); | |
876 | goto done; | |
898127c3 JJ |
877 | } |
878 | ||
898127c3 JJ |
879 | /* |
880 | * Functions for self directed profile change | |
881 | */ | |
882 | ||
89dbf196 JJ |
883 | |
884 | /* helper fn for change_hat | |
898127c3 | 885 | * |
89dbf196 | 886 | * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL |
898127c3 | 887 | */ |
89dbf196 JJ |
888 | static struct aa_label *build_change_hat(struct aa_profile *profile, |
889 | const char *name, bool sibling) | |
898127c3 | 890 | { |
89dbf196 JJ |
891 | struct aa_profile *root, *hat = NULL; |
892 | const char *info = NULL; | |
893 | int error = 0; | |
894 | ||
895 | if (sibling && PROFILE_IS_HAT(profile)) { | |
896 | root = aa_get_profile_rcu(&profile->parent); | |
897 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
898 | root = aa_get_profile(profile); | |
899 | } else { | |
900 | info = "conflicting target types"; | |
901 | error = -EPERM; | |
902 | goto audit; | |
903 | } | |
904 | ||
905 | hat = aa_find_child(root, name); | |
906 | if (!hat) { | |
907 | error = -ENOENT; | |
908 | if (COMPLAIN_MODE(profile)) { | |
909 | hat = aa_new_null_profile(profile, true, name, | |
910 | GFP_KERNEL); | |
911 | if (!hat) { | |
912 | info = "failed null profile create"; | |
913 | error = -ENOMEM; | |
914 | } | |
915 | } | |
916 | } | |
917 | aa_put_profile(root); | |
918 | ||
919 | audit: | |
920 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, | |
921 | name, hat ? hat->base.hname : NULL, | |
922 | hat ? &hat->label : NULL, GLOBAL_ROOT_UID, NULL, | |
923 | error); | |
924 | if (!hat || (error && error != -ENOENT)) | |
925 | return ERR_PTR(error); | |
926 | /* if hat && error - complain mode, already audited and we adjust for | |
927 | * complain mode allow by returning hat->label | |
928 | */ | |
929 | return &hat->label; | |
930 | } | |
931 | ||
932 | /* helper fn for changing into a hat | |
933 | * | |
934 | * Returns: label for hat transition or ERR_PTR. Does not return NULL | |
935 | */ | |
936 | static struct aa_label *change_hat(struct aa_label *label, const char *hats[], | |
937 | int count, int flags) | |
938 | { | |
939 | struct aa_profile *profile, *root, *hat = NULL; | |
940 | struct aa_label *new; | |
941 | struct label_it it; | |
942 | bool sibling = false; | |
943 | const char *name, *info = NULL; | |
944 | int i, error; | |
945 | ||
946 | AA_BUG(!label); | |
947 | AA_BUG(!hats); | |
948 | AA_BUG(count < 1); | |
949 | ||
950 | if (PROFILE_IS_HAT(labels_profile(label))) | |
951 | sibling = true; | |
952 | ||
953 | /*find first matching hat */ | |
954 | for (i = 0; i < count && !hat; i++) { | |
955 | name = hats[i]; | |
956 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
957 | if (sibling && PROFILE_IS_HAT(profile)) { | |
958 | root = aa_get_profile_rcu(&profile->parent); | |
959 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
960 | root = aa_get_profile(profile); | |
961 | } else { /* conflicting change type */ | |
962 | info = "conflicting targets types"; | |
963 | error = -EPERM; | |
964 | goto fail; | |
965 | } | |
966 | hat = aa_find_child(root, name); | |
967 | aa_put_profile(root); | |
968 | if (!hat) { | |
969 | if (!COMPLAIN_MODE(profile)) | |
970 | goto outer_continue; | |
971 | /* complain mode succeed as if hat */ | |
972 | } else if (!PROFILE_IS_HAT(hat)) { | |
973 | info = "target not hat"; | |
974 | error = -EPERM; | |
975 | aa_put_profile(hat); | |
976 | goto fail; | |
977 | } | |
978 | aa_put_profile(hat); | |
979 | } | |
980 | /* found a hat for all profiles in ns */ | |
981 | goto build; | |
982 | outer_continue: | |
983 | ; | |
984 | } | |
985 | /* no hats that match, find appropriate error | |
986 | * | |
987 | * In complain mode audit of the failure is based off of the first | |
988 | * hat supplied. This is done due how userspace interacts with | |
989 | * change_hat. | |
990 | */ | |
991 | name = NULL; | |
992 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
993 | if (!list_empty(&profile->base.profiles)) { | |
994 | info = "hat not found"; | |
995 | error = -ENOENT; | |
996 | goto fail; | |
997 | } | |
998 | } | |
999 | info = "no hats defined"; | |
1000 | error = -ECHILD; | |
1001 | ||
1002 | fail: | |
1003 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1004 | /* | |
1005 | * no target as it has failed to be found or built | |
1006 | * | |
1007 | * change_hat uses probing and should not log failures | |
1008 | * related to missing hats | |
1009 | */ | |
1010 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
1011 | if (count > 1 || COMPLAIN_MODE(profile)) { | |
1012 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, | |
1013 | AA_MAY_CHANGEHAT, name, NULL, NULL, | |
1014 | GLOBAL_ROOT_UID, info, error); | |
1015 | } | |
1016 | } | |
1017 | return ERR_PTR(error); | |
1018 | ||
1019 | build: | |
1020 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1021 | build_change_hat(profile, name, sibling), | |
1022 | aa_get_label(&profile->label)); | |
1023 | if (!new) { | |
1024 | info = "label build failed"; | |
1025 | error = -ENOMEM; | |
1026 | goto fail; | |
1027 | } /* else if (IS_ERR) build_change_hat has logged error so return new */ | |
1028 | ||
1029 | return new; | |
898127c3 JJ |
1030 | } |
1031 | ||
1032 | /** | |
1033 | * aa_change_hat - change hat to/from subprofile | |
1034 | * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) | |
1035 | * @count: number of hat names in @hats | |
1036 | * @token: magic value to validate the hat change | |
df8073c6 | 1037 | * @flags: flags affecting behavior of the change |
898127c3 | 1038 | * |
89dbf196 JJ |
1039 | * Returns %0 on success, error otherwise. |
1040 | * | |
898127c3 JJ |
1041 | * Change to the first profile specified in @hats that exists, and store |
1042 | * the @hat_magic in the current task context. If the count == 0 and the | |
1043 | * @token matches that stored in the current task context, return to the | |
1044 | * top level profile. | |
1045 | * | |
89dbf196 JJ |
1046 | * change_hat only applies to profiles in the current ns, and each profile |
1047 | * in the ns must make the same transition otherwise change_hat will fail. | |
898127c3 | 1048 | */ |
df8073c6 | 1049 | int aa_change_hat(const char *hats[], int count, u64 token, int flags) |
898127c3 JJ |
1050 | { |
1051 | const struct cred *cred; | |
4d2f8ba3 | 1052 | struct aa_cred_ctx *ctx; |
3b529a76 | 1053 | struct aa_task_ctx *tctx; |
89dbf196 JJ |
1054 | struct aa_label *label, *previous, *new = NULL, *target = NULL; |
1055 | struct aa_profile *profile; | |
2d679f3c | 1056 | struct aa_perms perms = {}; |
89dbf196 | 1057 | const char *info = NULL; |
898127c3 JJ |
1058 | int error = 0; |
1059 | ||
c29bceb3 JJ |
1060 | /* |
1061 | * Fail explicitly requested domain transitions if no_new_privs. | |
1062 | * There is no exception for unconfined as change_hat is not | |
1063 | * available. | |
1064 | */ | |
89dbf196 JJ |
1065 | if (task_no_new_privs(current)) { |
1066 | /* not an apparmor denial per se, so don't log it */ | |
1067 | AA_DEBUG("no_new_privs - change_hat denied"); | |
c29bceb3 | 1068 | return -EPERM; |
89dbf196 | 1069 | } |
c29bceb3 | 1070 | |
898127c3 JJ |
1071 | /* released below */ |
1072 | cred = get_current_cred(); | |
55a26ebf | 1073 | ctx = cred_ctx(cred); |
3b529a76 | 1074 | tctx = current_task_ctx(); |
637f688d | 1075 | label = aa_get_newest_cred_label(cred); |
3b529a76 | 1076 | previous = aa_get_newest_label(tctx->previous); |
898127c3 | 1077 | |
637f688d | 1078 | if (unconfined(label)) { |
89dbf196 | 1079 | info = "unconfined can not change_hat"; |
898127c3 | 1080 | error = -EPERM; |
89dbf196 | 1081 | goto fail; |
898127c3 JJ |
1082 | } |
1083 | ||
1084 | if (count) { | |
89dbf196 JJ |
1085 | new = change_hat(label, hats, count, flags); |
1086 | AA_BUG(!new); | |
1087 | if (IS_ERR(new)) { | |
1088 | error = PTR_ERR(new); | |
1089 | new = NULL; | |
1090 | /* already audited */ | |
1091 | goto out; | |
898127c3 JJ |
1092 | } |
1093 | ||
89dbf196 JJ |
1094 | error = may_change_ptraced_domain(new, &info); |
1095 | if (error) | |
1096 | goto fail; | |
898127c3 | 1097 | |
89dbf196 JJ |
1098 | if (flags & AA_CHANGE_TEST) |
1099 | goto out; | |
1100 | ||
1101 | target = new; | |
1102 | error = aa_set_current_hat(new, token); | |
1103 | if (error == -EACCES) | |
1104 | /* kill task in case of brute force attacks */ | |
1105 | goto kill; | |
1106 | } else if (previous && !(flags & AA_CHANGE_TEST)) { | |
1107 | /* Return to saved label. Kill task if restore fails | |
898127c3 JJ |
1108 | * to avoid brute force attacks |
1109 | */ | |
89dbf196 | 1110 | target = previous; |
637f688d | 1111 | error = aa_restore_previous_label(token); |
89dbf196 JJ |
1112 | if (error) { |
1113 | if (error == -EACCES) | |
1114 | goto kill; | |
1115 | goto fail; | |
1116 | } | |
1117 | } /* else ignore @flags && restores when there is no saved profile */ | |
898127c3 JJ |
1118 | |
1119 | out: | |
89dbf196 JJ |
1120 | aa_put_label(new); |
1121 | aa_put_label(previous); | |
637f688d | 1122 | aa_put_label(label); |
898127c3 JJ |
1123 | put_cred(cred); |
1124 | ||
1125 | return error; | |
89dbf196 JJ |
1126 | |
1127 | kill: | |
1128 | info = "failed token match"; | |
1129 | perms.kill = AA_MAY_CHANGEHAT; | |
1130 | ||
1131 | fail: | |
1132 | fn_for_each_in_ns(label, profile, | |
1133 | aa_audit_file(profile, &perms, OP_CHANGE_HAT, | |
1134 | AA_MAY_CHANGEHAT, NULL, NULL, target, | |
1135 | GLOBAL_ROOT_UID, info, error)); | |
1136 | ||
1137 | goto out; | |
898127c3 JJ |
1138 | } |
1139 | ||
89dbf196 | 1140 | |
e00b02bb JJ |
1141 | static int change_profile_perms_wrapper(const char *op, const char *name, |
1142 | struct aa_profile *profile, | |
1143 | struct aa_label *target, bool stack, | |
1144 | u32 request, struct aa_perms *perms) | |
1145 | { | |
1146 | const char *info = NULL; | |
1147 | int error = 0; | |
1148 | ||
1149 | /* | |
1150 | * Fail explicitly requested domain transitions when no_new_privs | |
1151 | * and not unconfined OR the transition results in a stack on | |
1152 | * the current label. | |
1153 | * Stacking domain transitions and transitions from unconfined are | |
1154 | * allowed even when no_new_privs is set because this aways results | |
1155 | * in a reduction of permissions. | |
1156 | */ | |
1157 | if (task_no_new_privs(current) && !stack && | |
1158 | !profile_unconfined(profile) && | |
1159 | !aa_label_is_subset(target, &profile->label)) { | |
1160 | info = "no new privs"; | |
1161 | error = -EPERM; | |
1162 | } | |
1163 | ||
1164 | if (!error) | |
1165 | error = change_profile_perms(profile, target, stack, request, | |
1166 | profile->file.start, perms); | |
1167 | if (error) | |
1168 | error = aa_audit_file(profile, perms, op, request, name, | |
1169 | NULL, target, GLOBAL_ROOT_UID, info, | |
1170 | error); | |
1171 | ||
1172 | return error; | |
1173 | } | |
89dbf196 | 1174 | |
898127c3 JJ |
1175 | /** |
1176 | * aa_change_profile - perform a one-way profile transition | |
aa9a39ad | 1177 | * @fqname: name of profile may include namespace (NOT NULL) |
898127c3 | 1178 | * @onexec: whether this transition is to take place immediately or at exec |
df8073c6 | 1179 | * @flags: flags affecting change behavior |
898127c3 JJ |
1180 | * |
1181 | * Change to new profile @name. Unlike with hats, there is no way | |
1182 | * to change back. If @name isn't specified the current profile name is | |
1183 | * used. | |
1184 | * If @onexec then the transition is delayed until | |
1185 | * the next exec. | |
1186 | * | |
1187 | * Returns %0 on success, error otherwise. | |
1188 | */ | |
df8073c6 | 1189 | int aa_change_profile(const char *fqname, int flags) |
898127c3 | 1190 | { |
e00b02bb JJ |
1191 | struct aa_label *label, *new = NULL, *target = NULL; |
1192 | struct aa_profile *profile; | |
2d679f3c | 1193 | struct aa_perms perms = {}; |
e00b02bb JJ |
1194 | const char *info = NULL; |
1195 | const char *auditname = fqname; /* retain leading & if stack */ | |
1196 | bool stack = flags & AA_CHANGE_STACK; | |
47f6e5cc | 1197 | int error = 0; |
e00b02bb | 1198 | char *op; |
898127c3 JJ |
1199 | u32 request; |
1200 | ||
aa9a39ad JJ |
1201 | if (!fqname || !*fqname) { |
1202 | AA_DEBUG("no profile name"); | |
898127c3 | 1203 | return -EINVAL; |
aa9a39ad | 1204 | } |
898127c3 | 1205 | |
df8073c6 | 1206 | if (flags & AA_CHANGE_ONEXEC) { |
898127c3 | 1207 | request = AA_MAY_ONEXEC; |
e00b02bb JJ |
1208 | if (stack) |
1209 | op = OP_STACK_ONEXEC; | |
1210 | else | |
1211 | op = OP_CHANGE_ONEXEC; | |
898127c3 JJ |
1212 | } else { |
1213 | request = AA_MAY_CHANGE_PROFILE; | |
e00b02bb JJ |
1214 | if (stack) |
1215 | op = OP_STACK; | |
1216 | else | |
1217 | op = OP_CHANGE_PROFILE; | |
898127c3 JJ |
1218 | } |
1219 | ||
e00b02bb | 1220 | label = aa_get_current_label(); |
898127c3 | 1221 | |
e00b02bb JJ |
1222 | if (*fqname == '&') { |
1223 | stack = true; | |
1224 | /* don't have label_parse() do stacking */ | |
1225 | fqname++; | |
c29bceb3 | 1226 | } |
e00b02bb JJ |
1227 | target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); |
1228 | if (IS_ERR(target)) { | |
1229 | struct aa_profile *tprofile; | |
c29bceb3 | 1230 | |
e00b02bb JJ |
1231 | info = "label not found"; |
1232 | error = PTR_ERR(target); | |
1233 | target = NULL; | |
1234 | /* | |
1235 | * TODO: fixme using labels_profile is not right - do profile | |
1236 | * per complain profile | |
1237 | */ | |
df8073c6 | 1238 | if ((flags & AA_CHANGE_TEST) || |
e00b02bb | 1239 | !COMPLAIN_MODE(labels_profile(label))) |
898127c3 JJ |
1240 | goto audit; |
1241 | /* released below */ | |
e00b02bb JJ |
1242 | tprofile = aa_new_null_profile(labels_profile(label), false, |
1243 | fqname, GFP_KERNEL); | |
1244 | if (!tprofile) { | |
898127c3 JJ |
1245 | info = "failed null profile create"; |
1246 | error = -ENOMEM; | |
1247 | goto audit; | |
1248 | } | |
e00b02bb JJ |
1249 | target = &tprofile->label; |
1250 | goto check; | |
898127c3 JJ |
1251 | } |
1252 | ||
e00b02bb JJ |
1253 | /* |
1254 | * self directed transitions only apply to current policy ns | |
1255 | * TODO: currently requiring perms for stacking and straight change | |
1256 | * stacking doesn't strictly need this. Determine how much | |
1257 | * we want to loosen this restriction for stacking | |
1258 | * | |
1259 | * if (!stack) { | |
1260 | */ | |
1261 | error = fn_for_each_in_ns(label, profile, | |
1262 | change_profile_perms_wrapper(op, auditname, | |
1263 | profile, target, stack, | |
1264 | request, &perms)); | |
1265 | if (error) | |
1266 | /* auditing done in change_profile_perms_wrapper */ | |
1267 | goto out; | |
aa9a39ad | 1268 | |
e00b02bb JJ |
1269 | /* } */ |
1270 | ||
1271 | check: | |
898127c3 | 1272 | /* check if tracing task is allowed to trace target domain */ |
e00b02bb JJ |
1273 | error = may_change_ptraced_domain(target, &info); |
1274 | if (error && !fn_for_each_in_ns(label, profile, | |
1275 | COMPLAIN_MODE(profile))) | |
898127c3 | 1276 | goto audit; |
898127c3 | 1277 | |
e00b02bb JJ |
1278 | /* TODO: add permission check to allow this |
1279 | * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { | |
1280 | * info = "not a single threaded task"; | |
1281 | * error = -EACCES; | |
1282 | * goto audit; | |
1283 | * } | |
1284 | */ | |
df8073c6 | 1285 | if (flags & AA_CHANGE_TEST) |
e00b02bb | 1286 | goto out; |
898127c3 | 1287 | |
e00b02bb JJ |
1288 | if (!(flags & AA_CHANGE_ONEXEC)) { |
1289 | /* only transition profiles in the current ns */ | |
1290 | if (stack) | |
1291 | new = aa_label_merge(label, target, GFP_KERNEL); | |
1292 | else | |
1293 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1294 | aa_get_label(target), | |
1295 | aa_get_label(&profile->label)); | |
1296 | if (IS_ERR_OR_NULL(new)) { | |
1297 | info = "failed to build target label"; | |
1298 | error = PTR_ERR(new); | |
1299 | new = NULL; | |
1300 | perms.allow = 0; | |
1301 | goto audit; | |
1302 | } | |
1303 | error = aa_replace_current_label(new); | |
1304 | } else | |
1305 | /* full transition will be built in exec path */ | |
1306 | error = aa_set_current_onexec(target, stack); | |
898127c3 JJ |
1307 | |
1308 | audit: | |
e00b02bb JJ |
1309 | error = fn_for_each_in_ns(label, profile, |
1310 | aa_audit_file(profile, &perms, op, request, auditname, | |
1311 | NULL, new ? new : target, | |
1312 | GLOBAL_ROOT_UID, info, error)); | |
898127c3 | 1313 | |
e00b02bb JJ |
1314 | out: |
1315 | aa_put_label(new); | |
1316 | aa_put_label(target); | |
637f688d | 1317 | aa_put_label(label); |
898127c3 JJ |
1318 | |
1319 | return error; | |
1320 | } |