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Commit | Line | Data |
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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
898127c3 JJ |
2 | /* |
3 | * AppArmor security module | |
4 | * | |
5 | * This file contains AppArmor policy attachment and domain transitions | |
6 | * | |
7 | * Copyright (C) 2002-2008 Novell/SUSE | |
8 | * Copyright 2009-2010 Canonical Ltd. | |
898127c3 JJ |
9 | */ |
10 | ||
11 | #include <linux/errno.h> | |
12 | #include <linux/fdtable.h> | |
13 | #include <linux/file.h> | |
14 | #include <linux/mount.h> | |
15 | #include <linux/syscalls.h> | |
16 | #include <linux/tracehook.h> | |
17 | #include <linux/personality.h> | |
8e51f908 | 18 | #include <linux/xattr.h> |
898127c3 JJ |
19 | |
20 | #include "include/audit.h" | |
21 | #include "include/apparmorfs.h" | |
d8889d49 | 22 | #include "include/cred.h" |
898127c3 JJ |
23 | #include "include/domain.h" |
24 | #include "include/file.h" | |
25 | #include "include/ipc.h" | |
26 | #include "include/match.h" | |
27 | #include "include/path.h" | |
28 | #include "include/policy.h" | |
cff281f6 | 29 | #include "include/policy_ns.h" |
898127c3 JJ |
30 | |
31 | /** | |
32 | * aa_free_domain_entries - free entries in a domain table | |
33 | * @domain: the domain table to free (MAYBE NULL) | |
34 | */ | |
35 | void aa_free_domain_entries(struct aa_domain *domain) | |
36 | { | |
37 | int i; | |
38 | if (domain) { | |
39 | if (!domain->table) | |
40 | return; | |
41 | ||
42 | for (i = 0; i < domain->size; i++) | |
43 | kzfree(domain->table[i]); | |
44 | kzfree(domain->table); | |
45 | domain->table = NULL; | |
46 | } | |
47 | } | |
48 | ||
49 | /** | |
50 | * may_change_ptraced_domain - check if can change profile on ptraced task | |
b2d09ae4 JJ |
51 | * @to_label: profile to change to (NOT NULL) |
52 | * @info: message if there is an error | |
898127c3 | 53 | * |
51775fe7 | 54 | * Check if current is ptraced and if so if the tracing task is allowed |
898127c3 JJ |
55 | * to trace the new domain |
56 | * | |
57 | * Returns: %0 or error if change not allowed | |
58 | */ | |
b2d09ae4 JJ |
59 | static int may_change_ptraced_domain(struct aa_label *to_label, |
60 | const char **info) | |
898127c3 JJ |
61 | { |
62 | struct task_struct *tracer; | |
637f688d | 63 | struct aa_label *tracerl = NULL; |
898127c3 JJ |
64 | int error = 0; |
65 | ||
66 | rcu_read_lock(); | |
51775fe7 | 67 | tracer = ptrace_parent(current); |
3cfcc19e | 68 | if (tracer) |
898127c3 | 69 | /* released below */ |
637f688d | 70 | tracerl = aa_get_task_label(tracer); |
898127c3 JJ |
71 | |
72 | /* not ptraced */ | |
637f688d | 73 | if (!tracer || unconfined(tracerl)) |
898127c3 JJ |
74 | goto out; |
75 | ||
b2d09ae4 | 76 | error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); |
898127c3 JJ |
77 | |
78 | out: | |
04fdc099 | 79 | rcu_read_unlock(); |
637f688d | 80 | aa_put_label(tracerl); |
898127c3 | 81 | |
b2d09ae4 JJ |
82 | if (error) |
83 | *info = "ptrace prevents transition"; | |
898127c3 JJ |
84 | return error; |
85 | } | |
86 | ||
93c98a48 JJ |
87 | /**** TODO: dedup to aa_label_match - needs perm and dfa, merging |
88 | * specifically this is an exact copy of aa_label_match except | |
89 | * aa_compute_perms is replaced with aa_compute_fperms | |
90 | * and policy.dfa with file.dfa | |
91 | ****/ | |
92 | /* match a profile and its associated ns component if needed | |
93 | * Assumes visibility test has already been done. | |
94 | * If a subns profile is not to be matched should be prescreened with | |
95 | * visibility test. | |
96 | */ | |
97 | static inline unsigned int match_component(struct aa_profile *profile, | |
98 | struct aa_profile *tp, | |
99 | bool stack, unsigned int state) | |
100 | { | |
101 | const char *ns_name; | |
102 | ||
103 | if (stack) | |
104 | state = aa_dfa_match(profile->file.dfa, state, "&"); | |
105 | if (profile->ns == tp->ns) | |
106 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
107 | ||
108 | /* try matching with namespace name and then profile */ | |
109 | ns_name = aa_ns_name(profile->ns, tp->ns, true); | |
110 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
111 | state = aa_dfa_match(profile->file.dfa, state, ns_name); | |
112 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
113 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
114 | } | |
115 | ||
116 | /** | |
117 | * label_compound_match - find perms for full compound label | |
118 | * @profile: profile to find perms for | |
119 | * @label: label to check access permissions for | |
120 | * @stack: whether this is a stacking request | |
121 | * @start: state to start match in | |
122 | * @subns: whether to do permission checks on components in a subns | |
123 | * @request: permissions to request | |
124 | * @perms: perms struct to set | |
125 | * | |
126 | * Returns: 0 on success else ERROR | |
127 | * | |
128 | * For the label A//&B//&C this does the perm match for A//&B//&C | |
129 | * @perms should be preinitialized with allperms OR a previous permission | |
130 | * check to be stacked. | |
131 | */ | |
132 | static int label_compound_match(struct aa_profile *profile, | |
133 | struct aa_label *label, bool stack, | |
134 | unsigned int state, bool subns, u32 request, | |
135 | struct aa_perms *perms) | |
136 | { | |
137 | struct aa_profile *tp; | |
138 | struct label_it i; | |
139 | struct path_cond cond = { }; | |
140 | ||
141 | /* find first subcomponent that is visible */ | |
142 | label_for_each(i, label, tp) { | |
143 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
144 | continue; | |
145 | state = match_component(profile, tp, stack, state); | |
146 | if (!state) | |
147 | goto fail; | |
148 | goto next; | |
149 | } | |
150 | ||
151 | /* no component visible */ | |
152 | *perms = allperms; | |
153 | return 0; | |
154 | ||
155 | next: | |
156 | label_for_each_cont(i, label, tp) { | |
157 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
158 | continue; | |
159 | state = aa_dfa_match(profile->file.dfa, state, "//&"); | |
160 | state = match_component(profile, tp, false, state); | |
161 | if (!state) | |
162 | goto fail; | |
163 | } | |
164 | *perms = aa_compute_fperms(profile->file.dfa, state, &cond); | |
165 | aa_apply_modes_to_perms(profile, perms); | |
166 | if ((perms->allow & request) != request) | |
167 | return -EACCES; | |
168 | ||
169 | return 0; | |
170 | ||
171 | fail: | |
172 | *perms = nullperms; | |
173 | return -EACCES; | |
174 | } | |
175 | ||
176 | /** | |
177 | * label_components_match - find perms for all subcomponents of a label | |
178 | * @profile: profile to find perms for | |
179 | * @label: label to check access permissions for | |
180 | * @stack: whether this is a stacking request | |
181 | * @start: state to start match in | |
182 | * @subns: whether to do permission checks on components in a subns | |
183 | * @request: permissions to request | |
184 | * @perms: an initialized perms struct to add accumulation to | |
185 | * | |
186 | * Returns: 0 on success else ERROR | |
187 | * | |
188 | * For the label A//&B//&C this does the perm match for each of A and B and C | |
189 | * @perms should be preinitialized with allperms OR a previous permission | |
190 | * check to be stacked. | |
191 | */ | |
192 | static int label_components_match(struct aa_profile *profile, | |
193 | struct aa_label *label, bool stack, | |
194 | unsigned int start, bool subns, u32 request, | |
195 | struct aa_perms *perms) | |
196 | { | |
197 | struct aa_profile *tp; | |
198 | struct label_it i; | |
199 | struct aa_perms tmp; | |
200 | struct path_cond cond = { }; | |
201 | unsigned int state = 0; | |
202 | ||
203 | /* find first subcomponent to test */ | |
204 | label_for_each(i, label, tp) { | |
205 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
206 | continue; | |
207 | state = match_component(profile, tp, stack, start); | |
208 | if (!state) | |
209 | goto fail; | |
210 | goto next; | |
211 | } | |
212 | ||
213 | /* no subcomponents visible - no change in perms */ | |
214 | return 0; | |
215 | ||
216 | next: | |
217 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
218 | aa_apply_modes_to_perms(profile, &tmp); | |
219 | aa_perms_accum(perms, &tmp); | |
220 | label_for_each_cont(i, label, tp) { | |
221 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
222 | continue; | |
223 | state = match_component(profile, tp, stack, start); | |
224 | if (!state) | |
225 | goto fail; | |
226 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
227 | aa_apply_modes_to_perms(profile, &tmp); | |
228 | aa_perms_accum(perms, &tmp); | |
229 | } | |
230 | ||
231 | if ((perms->allow & request) != request) | |
232 | return -EACCES; | |
233 | ||
234 | return 0; | |
235 | ||
236 | fail: | |
237 | *perms = nullperms; | |
238 | return -EACCES; | |
239 | } | |
240 | ||
241 | /** | |
242 | * label_match - do a multi-component label match | |
243 | * @profile: profile to match against (NOT NULL) | |
244 | * @label: label to match (NOT NULL) | |
245 | * @stack: whether this is a stacking request | |
246 | * @state: state to start in | |
247 | * @subns: whether to match subns components | |
248 | * @request: permission request | |
249 | * @perms: Returns computed perms (NOT NULL) | |
250 | * | |
251 | * Returns: the state the match finished in, may be the none matching state | |
252 | */ | |
253 | static int label_match(struct aa_profile *profile, struct aa_label *label, | |
254 | bool stack, unsigned int state, bool subns, u32 request, | |
255 | struct aa_perms *perms) | |
256 | { | |
257 | int error; | |
258 | ||
259 | *perms = nullperms; | |
260 | error = label_compound_match(profile, label, stack, state, subns, | |
261 | request, perms); | |
262 | if (!error) | |
263 | return error; | |
264 | ||
265 | *perms = allperms; | |
266 | return label_components_match(profile, label, stack, state, subns, | |
267 | request, perms); | |
268 | } | |
269 | ||
270 | /******* end TODO: dedup *****/ | |
271 | ||
898127c3 JJ |
272 | /** |
273 | * change_profile_perms - find permissions for change_profile | |
274 | * @profile: the current profile (NOT NULL) | |
93c98a48 JJ |
275 | * @target: label to transition to (NOT NULL) |
276 | * @stack: whether this is a stacking request | |
898127c3 JJ |
277 | * @request: requested perms |
278 | * @start: state to start matching in | |
279 | * | |
93c98a48 | 280 | * |
898127c3 | 281 | * Returns: permission set |
93c98a48 JJ |
282 | * |
283 | * currently only matches full label A//&B//&C or individual components A, B, C | |
284 | * not arbitrary combinations. Eg. A//&B, C | |
898127c3 | 285 | */ |
93c98a48 JJ |
286 | static int change_profile_perms(struct aa_profile *profile, |
287 | struct aa_label *target, bool stack, | |
288 | u32 request, unsigned int start, | |
289 | struct aa_perms *perms) | |
290 | { | |
291 | if (profile_unconfined(profile)) { | |
292 | perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; | |
293 | perms->audit = perms->quiet = perms->kill = 0; | |
294 | return 0; | |
295 | } | |
296 | ||
297 | /* TODO: add profile in ns screening */ | |
298 | return label_match(profile, target, stack, start, true, request, perms); | |
299 | } | |
300 | ||
8e51f908 MG |
301 | /** |
302 | * aa_xattrs_match - check whether a file matches the xattrs defined in profile | |
303 | * @bprm: binprm struct for the process to validate | |
304 | * @profile: profile to match against (NOT NULL) | |
73f488cd | 305 | * @state: state to start match in |
8e51f908 MG |
306 | * |
307 | * Returns: number of extended attributes that matched, or < 0 on error | |
308 | */ | |
309 | static int aa_xattrs_match(const struct linux_binprm *bprm, | |
73f488cd | 310 | struct aa_profile *profile, unsigned int state) |
8e51f908 MG |
311 | { |
312 | int i; | |
a61ecd32 | 313 | ssize_t size; |
8e51f908 MG |
314 | struct dentry *d; |
315 | char *value = NULL; | |
316 | int value_size = 0, ret = profile->xattr_count; | |
317 | ||
318 | if (!bprm || !profile->xattr_count) | |
319 | return 0; | |
8c62ed27 | 320 | might_sleep(); |
8e51f908 | 321 | |
73f488cd JJ |
322 | /* transition from exec match to xattr set */ |
323 | state = aa_dfa_null_transition(profile->xmatch, state); | |
324 | ||
8e51f908 MG |
325 | d = bprm->file->f_path.dentry; |
326 | ||
327 | for (i = 0; i < profile->xattr_count; i++) { | |
328 | size = vfs_getxattr_alloc(d, profile->xattrs[i], &value, | |
329 | value_size, GFP_KERNEL); | |
73f488cd JJ |
330 | if (size >= 0) { |
331 | u32 perm; | |
8e51f908 | 332 | |
73f488cd JJ |
333 | /* Check the xattr value, not just presence */ |
334 | state = aa_dfa_match_len(profile->xmatch, state, value, | |
335 | size); | |
336 | perm = dfa_user_allow(profile->xmatch, state); | |
337 | if (!(perm & MAY_EXEC)) { | |
8e51f908 MG |
338 | ret = -EINVAL; |
339 | goto out; | |
340 | } | |
73f488cd JJ |
341 | } |
342 | /* transition to next element */ | |
343 | state = aa_dfa_null_transition(profile->xmatch, state); | |
344 | if (size < 0) { | |
345 | /* | |
346 | * No xattr match, so verify if transition to | |
347 | * next element was valid. IFF so the xattr | |
348 | * was optional. | |
349 | */ | |
350 | if (!state) { | |
8e51f908 MG |
351 | ret = -EINVAL; |
352 | goto out; | |
353 | } | |
73f488cd JJ |
354 | /* don't count missing optional xattr as matched */ |
355 | ret--; | |
8e51f908 MG |
356 | } |
357 | } | |
358 | ||
359 | out: | |
360 | kfree(value); | |
361 | return ret; | |
362 | } | |
363 | ||
898127c3 | 364 | /** |
8c62ed27 | 365 | * find_attach - do attachment search for unconfined processes |
8e51f908 | 366 | * @bprm - binprm structure of transitioning task |
8c62ed27 | 367 | * @ns: the current namespace (NOT NULL) |
898127c3 | 368 | * @head - profile list to walk (NOT NULL) |
8c62ed27 | 369 | * @name - to match against (NOT NULL) |
844b8292 | 370 | * @info - info message if there was an error (NOT NULL) |
898127c3 JJ |
371 | * |
372 | * Do a linear search on the profiles in the list. There is a matching | |
373 | * preference where an exact match is preferred over a name which uses | |
374 | * expressions to match, and matching expressions with the greatest | |
375 | * xmatch_len are preferred. | |
376 | * | |
377 | * Requires: @head not be shared or have appropriate locks held | |
378 | * | |
8c62ed27 | 379 | * Returns: label or NULL if no match found |
898127c3 | 380 | */ |
8c62ed27 JJ |
381 | static struct aa_label *find_attach(const struct linux_binprm *bprm, |
382 | struct aa_ns *ns, struct list_head *head, | |
383 | const char *name, const char **info) | |
898127c3 | 384 | { |
21f60661 | 385 | int candidate_len = 0, candidate_xattrs = 0; |
844b8292 | 386 | bool conflict = false; |
898127c3 JJ |
387 | struct aa_profile *profile, *candidate = NULL; |
388 | ||
21f60661 JJ |
389 | AA_BUG(!name); |
390 | AA_BUG(!head); | |
391 | ||
8c62ed27 JJ |
392 | rcu_read_lock(); |
393 | restart: | |
01e2b670 | 394 | list_for_each_entry_rcu(profile, head, base.list) { |
06d426d1 JJ |
395 | if (profile->label.flags & FLAG_NULL && |
396 | &profile->label == ns_unconfined(profile->ns)) | |
898127c3 | 397 | continue; |
06d426d1 | 398 | |
8e51f908 MG |
399 | /* Find the "best" matching profile. Profiles must |
400 | * match the path and extended attributes (if any) | |
401 | * associated with the file. A more specific path | |
402 | * match will be preferred over a less specific one, | |
403 | * and a match with more matching extended attributes | |
404 | * will be preferred over one with fewer. If the best | |
405 | * match has both the same level of path specificity | |
406 | * and the same number of matching extended attributes | |
407 | * as another profile, signal a conflict and refuse to | |
408 | * match. | |
409 | */ | |
844b8292 | 410 | if (profile->xmatch) { |
21f60661 | 411 | unsigned int state, count; |
8e51f908 MG |
412 | u32 perm; |
413 | ||
21f60661 JJ |
414 | state = aa_dfa_leftmatch(profile->xmatch, DFA_START, |
415 | name, &count); | |
8e51f908 MG |
416 | perm = dfa_user_allow(profile->xmatch, state); |
417 | /* any accepting state means a valid match. */ | |
418 | if (perm & MAY_EXEC) { | |
8c62ed27 | 419 | int ret = 0; |
21f60661 JJ |
420 | |
421 | if (count < candidate_len) | |
422 | continue; | |
8e51f908 | 423 | |
8c62ed27 JJ |
424 | if (bprm && profile->xattr_count) { |
425 | long rev = READ_ONCE(ns->revision); | |
426 | ||
427 | if (!aa_get_profile_not0(profile)) | |
428 | goto restart; | |
429 | rcu_read_unlock(); | |
430 | ret = aa_xattrs_match(bprm, profile, | |
431 | state); | |
432 | rcu_read_lock(); | |
433 | aa_put_profile(profile); | |
434 | if (rev != | |
435 | READ_ONCE(ns->revision)) | |
436 | /* policy changed */ | |
437 | goto restart; | |
438 | /* | |
439 | * Fail matching if the xattrs don't | |
440 | * match | |
441 | */ | |
442 | if (ret < 0) | |
443 | continue; | |
444 | } | |
73f488cd JJ |
445 | /* |
446 | * TODO: allow for more flexible best match | |
447 | * | |
448 | * The new match isn't more specific | |
8e51f908 MG |
449 | * than the current best match |
450 | */ | |
21f60661 JJ |
451 | if (count == candidate_len && |
452 | ret <= candidate_xattrs) { | |
8e51f908 | 453 | /* Match is equivalent, so conflict */ |
21f60661 | 454 | if (ret == candidate_xattrs) |
1a3881d3 | 455 | conflict = true; |
8e51f908 | 456 | continue; |
844b8292 | 457 | } |
8e51f908 MG |
458 | |
459 | /* Either the same length with more matching | |
460 | * xattrs, or a longer match | |
461 | */ | |
462 | candidate = profile; | |
21f60661 JJ |
463 | candidate_len = profile->xmatch_len; |
464 | candidate_xattrs = ret; | |
8e51f908 | 465 | conflict = false; |
898127c3 | 466 | } |
8c62ed27 | 467 | } else if (!strcmp(profile->base.name, name)) { |
73f488cd JJ |
468 | /* |
469 | * old exact non-re match, without conditionals such | |
470 | * as xattrs. no more searching required | |
471 | */ | |
8c62ed27 JJ |
472 | candidate = profile; |
473 | goto out; | |
474 | } | |
898127c3 JJ |
475 | } |
476 | ||
8c62ed27 JJ |
477 | if (!candidate || conflict) { |
478 | if (conflict) | |
479 | *info = "conflicting profile attachments"; | |
480 | rcu_read_unlock(); | |
844b8292 JJ |
481 | return NULL; |
482 | } | |
483 | ||
8c62ed27 JJ |
484 | out: |
485 | candidate = aa_get_newest_profile(candidate); | |
01e2b670 | 486 | rcu_read_unlock(); |
898127c3 | 487 | |
8c62ed27 | 488 | return &candidate->label; |
898127c3 JJ |
489 | } |
490 | ||
491 | static const char *next_name(int xtype, const char *name) | |
492 | { | |
493 | return NULL; | |
494 | } | |
495 | ||
496 | /** | |
497 | * x_table_lookup - lookup an x transition name via transition table | |
498 | * @profile: current profile (NOT NULL) | |
499 | * @xindex: index into x transition table | |
93c98a48 | 500 | * @name: returns: name tested to find label (NOT NULL) |
898127c3 | 501 | * |
93c98a48 | 502 | * Returns: refcounted label, or NULL on failure (MAYBE NULL) |
898127c3 | 503 | */ |
2ea3ffb7 JJ |
504 | struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, |
505 | const char **name) | |
898127c3 | 506 | { |
93c98a48 | 507 | struct aa_label *label = NULL; |
898127c3 JJ |
508 | u32 xtype = xindex & AA_X_TYPE_MASK; |
509 | int index = xindex & AA_X_INDEX_MASK; | |
898127c3 | 510 | |
93c98a48 | 511 | AA_BUG(!name); |
898127c3 | 512 | |
93c98a48 JJ |
513 | /* index is guaranteed to be in range, validated at load time */ |
514 | /* TODO: move lookup parsing to unpack time so this is a straight | |
515 | * index into the resultant label | |
516 | */ | |
517 | for (*name = profile->file.trans.table[index]; !label && *name; | |
518 | *name = next_name(xtype, *name)) { | |
898127c3 | 519 | if (xindex & AA_X_CHILD) { |
93c98a48 | 520 | struct aa_profile *new_profile; |
898127c3 | 521 | /* release by caller */ |
93c98a48 JJ |
522 | new_profile = aa_find_child(profile, *name); |
523 | if (new_profile) | |
524 | label = &new_profile->label; | |
898127c3 | 525 | continue; |
898127c3 | 526 | } |
8ac2ca32 | 527 | label = aa_label_parse(&profile->label, *name, GFP_KERNEL, |
93c98a48 JJ |
528 | true, false); |
529 | if (IS_ERR(label)) | |
530 | label = NULL; | |
898127c3 JJ |
531 | } |
532 | ||
533 | /* released by caller */ | |
93c98a48 JJ |
534 | |
535 | return label; | |
898127c3 JJ |
536 | } |
537 | ||
538 | /** | |
93c98a48 | 539 | * x_to_label - get target label for a given xindex |
898127c3 | 540 | * @profile: current profile (NOT NULL) |
8e51f908 | 541 | * @bprm: binprm structure of transitioning task |
898127c3 JJ |
542 | * @name: name to lookup (NOT NULL) |
543 | * @xindex: index into x transition table | |
93c98a48 | 544 | * @lookupname: returns: name used in lookup if one was specified (NOT NULL) |
898127c3 | 545 | * |
93c98a48 | 546 | * find label for a transition index |
898127c3 | 547 | * |
93c98a48 | 548 | * Returns: refcounted label or NULL if not found available |
898127c3 | 549 | */ |
93c98a48 | 550 | static struct aa_label *x_to_label(struct aa_profile *profile, |
8e51f908 | 551 | const struct linux_binprm *bprm, |
93c98a48 JJ |
552 | const char *name, u32 xindex, |
553 | const char **lookupname, | |
554 | const char **info) | |
898127c3 | 555 | { |
93c98a48 | 556 | struct aa_label *new = NULL; |
98849dff | 557 | struct aa_ns *ns = profile->ns; |
898127c3 | 558 | u32 xtype = xindex & AA_X_TYPE_MASK; |
93c98a48 | 559 | const char *stack = NULL; |
898127c3 JJ |
560 | |
561 | switch (xtype) { | |
562 | case AA_X_NONE: | |
563 | /* fail exec unless ix || ux fallback - handled by caller */ | |
93c98a48 JJ |
564 | *lookupname = NULL; |
565 | break; | |
566 | case AA_X_TABLE: | |
567 | /* TODO: fix when perm mapping done at unload */ | |
568 | stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; | |
569 | if (*stack != '&') { | |
570 | /* released by caller */ | |
571 | new = x_table_lookup(profile, xindex, lookupname); | |
572 | stack = NULL; | |
573 | break; | |
574 | } | |
09186e50 | 575 | /* fall through - to X_NAME */ |
898127c3 JJ |
576 | case AA_X_NAME: |
577 | if (xindex & AA_X_CHILD) | |
578 | /* released by caller */ | |
8e51f908 | 579 | new = find_attach(bprm, ns, &profile->base.profiles, |
844b8292 | 580 | name, info); |
898127c3 JJ |
581 | else |
582 | /* released by caller */ | |
8e51f908 | 583 | new = find_attach(bprm, ns, &ns->base.profiles, |
844b8292 | 584 | name, info); |
93c98a48 | 585 | *lookupname = name; |
898127c3 JJ |
586 | break; |
587 | } | |
588 | ||
93c98a48 JJ |
589 | if (!new) { |
590 | if (xindex & AA_X_INHERIT) { | |
591 | /* (p|c|n)ix - don't change profile but do | |
592 | * use the newest version | |
593 | */ | |
594 | *info = "ix fallback"; | |
595 | /* no profile && no error */ | |
596 | new = aa_get_newest_label(&profile->label); | |
597 | } else if (xindex & AA_X_UNCONFINED) { | |
598 | new = aa_get_newest_label(ns_unconfined(profile->ns)); | |
599 | *info = "ux fallback"; | |
600 | } | |
601 | } | |
602 | ||
603 | if (new && stack) { | |
604 | /* base the stack on post domain transition */ | |
605 | struct aa_label *base = new; | |
606 | ||
8ac2ca32 | 607 | new = aa_label_parse(base, stack, GFP_KERNEL, true, false); |
93c98a48 JJ |
608 | if (IS_ERR(new)) |
609 | new = NULL; | |
610 | aa_put_label(base); | |
611 | } | |
612 | ||
898127c3 | 613 | /* released by caller */ |
93c98a48 | 614 | return new; |
898127c3 JJ |
615 | } |
616 | ||
93c98a48 JJ |
617 | static struct aa_label *profile_transition(struct aa_profile *profile, |
618 | const struct linux_binprm *bprm, | |
619 | char *buffer, struct path_cond *cond, | |
620 | bool *secure_exec) | |
898127c3 | 621 | { |
93c98a48 | 622 | struct aa_label *new = NULL; |
8e51f908 MG |
623 | struct aa_profile *component; |
624 | struct label_it i; | |
93c98a48 JJ |
625 | const char *info = NULL, *name = NULL, *target = NULL; |
626 | unsigned int state = profile->file.start; | |
2d679f3c | 627 | struct aa_perms perms = {}; |
93c98a48 | 628 | bool nonewprivs = false; |
b1d9e6b0 | 629 | int error = 0; |
898127c3 | 630 | |
93c98a48 JJ |
631 | AA_BUG(!profile); |
632 | AA_BUG(!bprm); | |
633 | AA_BUG(!buffer); | |
898127c3 | 634 | |
4227c333 | 635 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, |
72c8a768 | 636 | &name, &info, profile->disconnected); |
898127c3 | 637 | if (error) { |
637f688d | 638 | if (profile_unconfined(profile) || |
93c98a48 JJ |
639 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { |
640 | AA_DEBUG("name lookup ix on error"); | |
898127c3 | 641 | error = 0; |
93c98a48 JJ |
642 | new = aa_get_newest_label(&profile->label); |
643 | } | |
898127c3 JJ |
644 | name = bprm->filename; |
645 | goto audit; | |
646 | } | |
647 | ||
637f688d | 648 | if (profile_unconfined(profile)) { |
8e51f908 MG |
649 | new = find_attach(bprm, profile->ns, |
650 | &profile->ns->base.profiles, name, &info); | |
93c98a48 JJ |
651 | if (new) { |
652 | AA_DEBUG("unconfined attached to new label"); | |
653 | return new; | |
654 | } | |
655 | AA_DEBUG("unconfined exec no attachment"); | |
656 | return aa_get_newest_label(&profile->label); | |
898127c3 JJ |
657 | } |
658 | ||
659 | /* find exec permissions for name */ | |
93c98a48 | 660 | state = aa_str_perms(profile->file.dfa, state, name, cond, &perms); |
898127c3 JJ |
661 | if (perms.allow & MAY_EXEC) { |
662 | /* exec permission determine how to transition */ | |
8e51f908 MG |
663 | new = x_to_label(profile, bprm, name, perms.xindex, &target, |
664 | &info); | |
93c98a48 JJ |
665 | if (new && new->proxy == profile->label.proxy && info) { |
666 | /* hack ix fallback - improve how this is detected */ | |
667 | goto audit; | |
668 | } else if (!new) { | |
669 | error = -EACCES; | |
670 | info = "profile transition not found"; | |
671 | /* remove MAY_EXEC to audit as failure */ | |
672 | perms.allow &= ~MAY_EXEC; | |
8e51f908 MG |
673 | } else { |
674 | /* verify that each component's xattr requirements are | |
675 | * met, and fail execution otherwise | |
676 | */ | |
677 | label_for_each(i, new, component) { | |
73f488cd JJ |
678 | if (aa_xattrs_match(bprm, component, state) < |
679 | 0) { | |
8e51f908 MG |
680 | error = -EACCES; |
681 | info = "required xattrs not present"; | |
682 | perms.allow &= ~MAY_EXEC; | |
683 | aa_put_label(new); | |
684 | new = NULL; | |
685 | goto audit; | |
686 | } | |
687 | } | |
898127c3 JJ |
688 | } |
689 | } else if (COMPLAIN_MODE(profile)) { | |
93c98a48 | 690 | /* no exec permission - learning mode */ |
5d7c44ef | 691 | struct aa_profile *new_profile = NULL; |
df323337 SAS |
692 | |
693 | new_profile = aa_new_null_profile(profile, false, name, | |
694 | GFP_KERNEL); | |
898127c3 JJ |
695 | if (!new_profile) { |
696 | error = -ENOMEM; | |
697 | info = "could not create null profile"; | |
93c98a48 | 698 | } else { |
898127c3 | 699 | error = -EACCES; |
93c98a48 JJ |
700 | new = &new_profile->label; |
701 | } | |
898127c3 JJ |
702 | perms.xindex |= AA_X_UNSAFE; |
703 | } else | |
704 | /* fail exec */ | |
705 | error = -EACCES; | |
706 | ||
93c98a48 JJ |
707 | if (!new) |
708 | goto audit; | |
709 | ||
93c98a48 JJ |
710 | |
711 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
712 | if (DEBUG_ON) { | |
713 | dbg_printk("apparmor: scrubbing environment variables" | |
714 | " for %s profile=", name); | |
8ac2ca32 | 715 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
716 | dbg_printk("\n"); |
717 | } | |
718 | *secure_exec = true; | |
c29bceb3 JJ |
719 | } |
720 | ||
93c98a48 JJ |
721 | audit: |
722 | aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, | |
723 | cond->uid, info, error); | |
724 | if (!new || nonewprivs) { | |
725 | aa_put_label(new); | |
726 | return ERR_PTR(error); | |
727 | } | |
728 | ||
729 | return new; | |
730 | } | |
731 | ||
732 | static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, | |
733 | bool stack, const struct linux_binprm *bprm, | |
734 | char *buffer, struct path_cond *cond, | |
735 | bool *secure_exec) | |
736 | { | |
737 | unsigned int state = profile->file.start; | |
738 | struct aa_perms perms = {}; | |
739 | const char *xname = NULL, *info = "change_profile onexec"; | |
740 | int error = -EACCES; | |
741 | ||
742 | AA_BUG(!profile); | |
743 | AA_BUG(!onexec); | |
744 | AA_BUG(!bprm); | |
745 | AA_BUG(!buffer); | |
746 | ||
747 | if (profile_unconfined(profile)) { | |
748 | /* change_profile on exec already granted */ | |
749 | /* | |
750 | * NOTE: Domain transitions from unconfined are allowed | |
751 | * even when no_new_privs is set because this aways results | |
752 | * in a further reduction of permissions. | |
753 | */ | |
754 | return 0; | |
755 | } | |
756 | ||
757 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, | |
758 | &xname, &info, profile->disconnected); | |
759 | if (error) { | |
760 | if (profile_unconfined(profile) || | |
761 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { | |
762 | AA_DEBUG("name lookup ix on error"); | |
763 | error = 0; | |
764 | } | |
765 | xname = bprm->filename; | |
898127c3 | 766 | goto audit; |
93c98a48 JJ |
767 | } |
768 | ||
769 | /* find exec permissions for name */ | |
770 | state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms); | |
771 | if (!(perms.allow & AA_MAY_ONEXEC)) { | |
772 | info = "no change_onexec valid for executable"; | |
773 | goto audit; | |
774 | } | |
775 | /* test if this exec can be paired with change_profile onexec. | |
776 | * onexec permission is linked to exec with a standard pairing | |
777 | * exec\0change_profile | |
778 | */ | |
779 | state = aa_dfa_null_transition(profile->file.dfa, state); | |
780 | error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, | |
781 | state, &perms); | |
782 | if (error) { | |
783 | perms.allow &= ~AA_MAY_ONEXEC; | |
784 | goto audit; | |
785 | } | |
93c98a48 JJ |
786 | |
787 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
788 | if (DEBUG_ON) { | |
789 | dbg_printk("apparmor: scrubbing environment " | |
790 | "variables for %s label=", xname); | |
8ac2ca32 | 791 | aa_label_printk(onexec, GFP_KERNEL); |
93c98a48 JJ |
792 | dbg_printk("\n"); |
793 | } | |
794 | *secure_exec = true; | |
795 | } | |
796 | ||
797 | audit: | |
798 | return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, | |
799 | NULL, onexec, cond->uid, info, error); | |
800 | } | |
801 | ||
802 | /* ensure none ns domain transitions are correctly applied with onexec */ | |
803 | ||
804 | static struct aa_label *handle_onexec(struct aa_label *label, | |
805 | struct aa_label *onexec, bool stack, | |
806 | const struct linux_binprm *bprm, | |
807 | char *buffer, struct path_cond *cond, | |
808 | bool *unsafe) | |
809 | { | |
810 | struct aa_profile *profile; | |
811 | struct aa_label *new; | |
812 | int error; | |
813 | ||
814 | AA_BUG(!label); | |
815 | AA_BUG(!onexec); | |
816 | AA_BUG(!bprm); | |
817 | AA_BUG(!buffer); | |
818 | ||
819 | if (!stack) { | |
820 | error = fn_for_each_in_ns(label, profile, | |
821 | profile_onexec(profile, onexec, stack, | |
822 | bprm, buffer, cond, unsafe)); | |
823 | if (error) | |
824 | return ERR_PTR(error); | |
8ac2ca32 | 825 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 JJ |
826 | aa_get_newest_label(onexec), |
827 | profile_transition(profile, bprm, buffer, | |
828 | cond, unsafe)); | |
829 | ||
830 | } else { | |
b2c2086c | 831 | /* TODO: determine how much we want to loosen this */ |
93c98a48 JJ |
832 | error = fn_for_each_in_ns(label, profile, |
833 | profile_onexec(profile, onexec, stack, bprm, | |
834 | buffer, cond, unsafe)); | |
835 | if (error) | |
836 | return ERR_PTR(error); | |
8ac2ca32 | 837 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 | 838 | aa_label_merge(&profile->label, onexec, |
8ac2ca32 | 839 | GFP_KERNEL), |
93c98a48 JJ |
840 | profile_transition(profile, bprm, buffer, |
841 | cond, unsafe)); | |
842 | } | |
843 | ||
844 | if (new) | |
845 | return new; | |
846 | ||
847 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
848 | error = fn_for_each_in_ns(label, profile, | |
849 | aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, | |
850 | AA_MAY_ONEXEC, bprm->filename, NULL, | |
851 | onexec, GLOBAL_ROOT_UID, | |
852 | "failed to build target label", -ENOMEM)); | |
853 | return ERR_PTR(error); | |
854 | } | |
855 | ||
856 | /** | |
857 | * apparmor_bprm_set_creds - set the new creds on the bprm struct | |
858 | * @bprm: binprm for the exec (NOT NULL) | |
859 | * | |
860 | * Returns: %0 or error on failure | |
861 | * | |
862 | * TODO: once the other paths are done see if we can't refactor into a fn | |
863 | */ | |
864 | int apparmor_bprm_set_creds(struct linux_binprm *bprm) | |
865 | { | |
f175221a | 866 | struct aa_task_ctx *ctx; |
93c98a48 JJ |
867 | struct aa_label *label, *new = NULL; |
868 | struct aa_profile *profile; | |
869 | char *buffer = NULL; | |
870 | const char *info = NULL; | |
871 | int error = 0; | |
872 | bool unsafe = false; | |
873 | struct path_cond cond = { | |
874 | file_inode(bprm->file)->i_uid, | |
875 | file_inode(bprm->file)->i_mode | |
876 | }; | |
877 | ||
ddb4a144 | 878 | if (bprm->called_set_creds) |
93c98a48 JJ |
879 | return 0; |
880 | ||
de62de59 | 881 | ctx = task_ctx(current); |
d9087c49 | 882 | AA_BUG(!cred_label(bprm->cred)); |
f175221a | 883 | AA_BUG(!ctx); |
93c98a48 | 884 | |
d9087c49 | 885 | label = aa_get_newest_label(cred_label(bprm->cred)); |
93c98a48 | 886 | |
9fcf78cc JJ |
887 | /* |
888 | * Detect no new privs being set, and store the label it | |
889 | * occurred under. Ideally this would happen when nnp | |
890 | * is set but there isn't a good way to do that yet. | |
891 | * | |
892 | * Testing for unconfined must be done before the subset test | |
893 | */ | |
894 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) && | |
895 | !ctx->nnp) | |
896 | ctx->nnp = aa_get_label(label); | |
897 | ||
93c98a48 | 898 | /* buffer freed below, name is pointer into buffer */ |
341c1fda | 899 | buffer = aa_get_buffer(false); |
df323337 SAS |
900 | if (!buffer) { |
901 | error = -ENOMEM; | |
902 | goto done; | |
903 | } | |
904 | ||
93c98a48 | 905 | /* Test for onexec first as onexec override other x transitions. */ |
f175221a JJ |
906 | if (ctx->onexec) |
907 | new = handle_onexec(label, ctx->onexec, ctx->token, | |
93c98a48 JJ |
908 | bprm, buffer, &cond, &unsafe); |
909 | else | |
8ac2ca32 | 910 | new = fn_label_build(label, profile, GFP_KERNEL, |
93c98a48 JJ |
911 | profile_transition(profile, bprm, buffer, |
912 | &cond, &unsafe)); | |
913 | ||
914 | AA_BUG(!new); | |
915 | if (IS_ERR(new)) { | |
916 | error = PTR_ERR(new); | |
917 | goto done; | |
918 | } else if (!new) { | |
919 | error = -ENOMEM; | |
920 | goto done; | |
921 | } | |
922 | ||
9fcf78cc JJ |
923 | /* Policy has specified a domain transitions. If no_new_privs and |
924 | * confined ensure the transition is to confinement that is subset | |
925 | * of the confinement when the task entered no new privs. | |
926 | * | |
927 | * NOTE: Domain transitions from unconfined and to stacked | |
928 | * subsets are allowed even when no_new_privs is set because this | |
929 | * aways results in a further reduction of permissions. | |
930 | */ | |
931 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && | |
932 | !unconfined(label) && !aa_label_is_subset(new, ctx->nnp)) { | |
933 | error = -EPERM; | |
934 | info = "no new privs"; | |
935 | goto audit; | |
936 | } | |
898127c3 JJ |
937 | |
938 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
939 | /* FIXME: currently don't mediate shared state */ | |
940 | ; | |
941 | } | |
942 | ||
93c98a48 JJ |
943 | if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { |
944 | /* TODO: test needs to be profile of label to new */ | |
945 | error = may_change_ptraced_domain(new, &info); | |
f7da2de0 | 946 | if (error) |
898127c3 | 947 | goto audit; |
898127c3 JJ |
948 | } |
949 | ||
93c98a48 JJ |
950 | if (unsafe) { |
951 | if (DEBUG_ON) { | |
952 | dbg_printk("scrubbing environment variables for %s " | |
953 | "label=", bprm->filename); | |
8ac2ca32 | 954 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
955 | dbg_printk("\n"); |
956 | } | |
993b3ab0 | 957 | bprm->secureexec = 1; |
898127c3 | 958 | } |
898127c3 | 959 | |
93c98a48 JJ |
960 | if (label->proxy != new->proxy) { |
961 | /* when transitioning clear unsafe personality bits */ | |
962 | if (DEBUG_ON) { | |
963 | dbg_printk("apparmor: clearing unsafe personality " | |
964 | "bits. %s label=", bprm->filename); | |
8ac2ca32 | 965 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
966 | dbg_printk("\n"); |
967 | } | |
968 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
969 | } | |
d9087c49 JJ |
970 | aa_put_label(cred_label(bprm->cred)); |
971 | /* transfer reference, released when cred is freed */ | |
69b5a44a | 972 | set_cred_label(bprm->cred, new); |
898127c3 | 973 | |
93c98a48 | 974 | done: |
637f688d | 975 | aa_put_label(label); |
df323337 | 976 | aa_put_buffer(buffer); |
898127c3 JJ |
977 | |
978 | return error; | |
93c98a48 JJ |
979 | |
980 | audit: | |
981 | error = fn_for_each(label, profile, | |
982 | aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, | |
983 | bprm->filename, NULL, new, | |
984 | file_inode(bprm->file)->i_uid, info, | |
985 | error)); | |
986 | aa_put_label(new); | |
987 | goto done; | |
898127c3 JJ |
988 | } |
989 | ||
898127c3 JJ |
990 | /* |
991 | * Functions for self directed profile change | |
992 | */ | |
993 | ||
89dbf196 JJ |
994 | |
995 | /* helper fn for change_hat | |
898127c3 | 996 | * |
89dbf196 | 997 | * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL |
898127c3 | 998 | */ |
89dbf196 JJ |
999 | static struct aa_label *build_change_hat(struct aa_profile *profile, |
1000 | const char *name, bool sibling) | |
898127c3 | 1001 | { |
89dbf196 JJ |
1002 | struct aa_profile *root, *hat = NULL; |
1003 | const char *info = NULL; | |
1004 | int error = 0; | |
1005 | ||
1006 | if (sibling && PROFILE_IS_HAT(profile)) { | |
1007 | root = aa_get_profile_rcu(&profile->parent); | |
1008 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1009 | root = aa_get_profile(profile); | |
1010 | } else { | |
1011 | info = "conflicting target types"; | |
1012 | error = -EPERM; | |
1013 | goto audit; | |
1014 | } | |
1015 | ||
1016 | hat = aa_find_child(root, name); | |
1017 | if (!hat) { | |
1018 | error = -ENOENT; | |
1019 | if (COMPLAIN_MODE(profile)) { | |
1020 | hat = aa_new_null_profile(profile, true, name, | |
1021 | GFP_KERNEL); | |
1022 | if (!hat) { | |
1023 | info = "failed null profile create"; | |
1024 | error = -ENOMEM; | |
1025 | } | |
1026 | } | |
1027 | } | |
1028 | aa_put_profile(root); | |
1029 | ||
1030 | audit: | |
1031 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, | |
1032 | name, hat ? hat->base.hname : NULL, | |
24b87a16 | 1033 | hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, |
89dbf196 JJ |
1034 | error); |
1035 | if (!hat || (error && error != -ENOENT)) | |
1036 | return ERR_PTR(error); | |
1037 | /* if hat && error - complain mode, already audited and we adjust for | |
1038 | * complain mode allow by returning hat->label | |
1039 | */ | |
1040 | return &hat->label; | |
1041 | } | |
1042 | ||
1043 | /* helper fn for changing into a hat | |
1044 | * | |
1045 | * Returns: label for hat transition or ERR_PTR. Does not return NULL | |
1046 | */ | |
1047 | static struct aa_label *change_hat(struct aa_label *label, const char *hats[], | |
1048 | int count, int flags) | |
1049 | { | |
1050 | struct aa_profile *profile, *root, *hat = NULL; | |
1051 | struct aa_label *new; | |
1052 | struct label_it it; | |
1053 | bool sibling = false; | |
1054 | const char *name, *info = NULL; | |
1055 | int i, error; | |
1056 | ||
1057 | AA_BUG(!label); | |
1058 | AA_BUG(!hats); | |
1059 | AA_BUG(count < 1); | |
1060 | ||
1061 | if (PROFILE_IS_HAT(labels_profile(label))) | |
1062 | sibling = true; | |
1063 | ||
1064 | /*find first matching hat */ | |
1065 | for (i = 0; i < count && !hat; i++) { | |
1066 | name = hats[i]; | |
1067 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1068 | if (sibling && PROFILE_IS_HAT(profile)) { | |
1069 | root = aa_get_profile_rcu(&profile->parent); | |
1070 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1071 | root = aa_get_profile(profile); | |
1072 | } else { /* conflicting change type */ | |
1073 | info = "conflicting targets types"; | |
1074 | error = -EPERM; | |
1075 | goto fail; | |
1076 | } | |
1077 | hat = aa_find_child(root, name); | |
1078 | aa_put_profile(root); | |
1079 | if (!hat) { | |
1080 | if (!COMPLAIN_MODE(profile)) | |
1081 | goto outer_continue; | |
1082 | /* complain mode succeed as if hat */ | |
1083 | } else if (!PROFILE_IS_HAT(hat)) { | |
1084 | info = "target not hat"; | |
1085 | error = -EPERM; | |
1086 | aa_put_profile(hat); | |
1087 | goto fail; | |
1088 | } | |
1089 | aa_put_profile(hat); | |
1090 | } | |
1091 | /* found a hat for all profiles in ns */ | |
1092 | goto build; | |
1093 | outer_continue: | |
1094 | ; | |
1095 | } | |
1096 | /* no hats that match, find appropriate error | |
1097 | * | |
1098 | * In complain mode audit of the failure is based off of the first | |
1099 | * hat supplied. This is done due how userspace interacts with | |
1100 | * change_hat. | |
1101 | */ | |
1102 | name = NULL; | |
1103 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1104 | if (!list_empty(&profile->base.profiles)) { | |
1105 | info = "hat not found"; | |
1106 | error = -ENOENT; | |
1107 | goto fail; | |
1108 | } | |
1109 | } | |
1110 | info = "no hats defined"; | |
1111 | error = -ECHILD; | |
1112 | ||
1113 | fail: | |
1114 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1115 | /* | |
1116 | * no target as it has failed to be found or built | |
1117 | * | |
1118 | * change_hat uses probing and should not log failures | |
1119 | * related to missing hats | |
1120 | */ | |
1121 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
1122 | if (count > 1 || COMPLAIN_MODE(profile)) { | |
1123 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, | |
1124 | AA_MAY_CHANGEHAT, name, NULL, NULL, | |
1125 | GLOBAL_ROOT_UID, info, error); | |
1126 | } | |
1127 | } | |
1128 | return ERR_PTR(error); | |
1129 | ||
1130 | build: | |
1131 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1132 | build_change_hat(profile, name, sibling), | |
1133 | aa_get_label(&profile->label)); | |
1134 | if (!new) { | |
1135 | info = "label build failed"; | |
1136 | error = -ENOMEM; | |
1137 | goto fail; | |
1138 | } /* else if (IS_ERR) build_change_hat has logged error so return new */ | |
1139 | ||
1140 | return new; | |
898127c3 JJ |
1141 | } |
1142 | ||
1143 | /** | |
1144 | * aa_change_hat - change hat to/from subprofile | |
1145 | * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) | |
1146 | * @count: number of hat names in @hats | |
1147 | * @token: magic value to validate the hat change | |
df8073c6 | 1148 | * @flags: flags affecting behavior of the change |
898127c3 | 1149 | * |
89dbf196 JJ |
1150 | * Returns %0 on success, error otherwise. |
1151 | * | |
898127c3 JJ |
1152 | * Change to the first profile specified in @hats that exists, and store |
1153 | * the @hat_magic in the current task context. If the count == 0 and the | |
1154 | * @token matches that stored in the current task context, return to the | |
1155 | * top level profile. | |
1156 | * | |
89dbf196 JJ |
1157 | * change_hat only applies to profiles in the current ns, and each profile |
1158 | * in the ns must make the same transition otherwise change_hat will fail. | |
898127c3 | 1159 | */ |
df8073c6 | 1160 | int aa_change_hat(const char *hats[], int count, u64 token, int flags) |
898127c3 JJ |
1161 | { |
1162 | const struct cred *cred; | |
9fcf78cc | 1163 | struct aa_task_ctx *ctx = task_ctx(current); |
89dbf196 JJ |
1164 | struct aa_label *label, *previous, *new = NULL, *target = NULL; |
1165 | struct aa_profile *profile; | |
2d679f3c | 1166 | struct aa_perms perms = {}; |
89dbf196 | 1167 | const char *info = NULL; |
898127c3 JJ |
1168 | int error = 0; |
1169 | ||
1170 | /* released below */ | |
1171 | cred = get_current_cred(); | |
637f688d | 1172 | label = aa_get_newest_cred_label(cred); |
f175221a | 1173 | previous = aa_get_newest_label(ctx->previous); |
898127c3 | 1174 | |
9fcf78cc JJ |
1175 | /* |
1176 | * Detect no new privs being set, and store the label it | |
1177 | * occurred under. Ideally this would happen when nnp | |
1178 | * is set but there isn't a good way to do that yet. | |
1179 | * | |
1180 | * Testing for unconfined must be done before the subset test | |
1181 | */ | |
1182 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1183 | ctx->nnp = aa_get_label(label); | |
1184 | ||
637f688d | 1185 | if (unconfined(label)) { |
89dbf196 | 1186 | info = "unconfined can not change_hat"; |
898127c3 | 1187 | error = -EPERM; |
89dbf196 | 1188 | goto fail; |
898127c3 JJ |
1189 | } |
1190 | ||
1191 | if (count) { | |
89dbf196 JJ |
1192 | new = change_hat(label, hats, count, flags); |
1193 | AA_BUG(!new); | |
1194 | if (IS_ERR(new)) { | |
1195 | error = PTR_ERR(new); | |
1196 | new = NULL; | |
1197 | /* already audited */ | |
1198 | goto out; | |
898127c3 JJ |
1199 | } |
1200 | ||
89dbf196 JJ |
1201 | error = may_change_ptraced_domain(new, &info); |
1202 | if (error) | |
1203 | goto fail; | |
898127c3 | 1204 | |
9fcf78cc JJ |
1205 | /* |
1206 | * no new privs prevents domain transitions that would | |
1207 | * reduce restrictions. | |
1208 | */ | |
1209 | if (task_no_new_privs(current) && !unconfined(label) && | |
1210 | !aa_label_is_subset(new, ctx->nnp)) { | |
1211 | /* not an apparmor denial per se, so don't log it */ | |
1212 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1213 | error = -EPERM; | |
1214 | goto out; | |
1215 | } | |
1216 | ||
89dbf196 JJ |
1217 | if (flags & AA_CHANGE_TEST) |
1218 | goto out; | |
1219 | ||
1220 | target = new; | |
1221 | error = aa_set_current_hat(new, token); | |
1222 | if (error == -EACCES) | |
1223 | /* kill task in case of brute force attacks */ | |
1224 | goto kill; | |
1225 | } else if (previous && !(flags & AA_CHANGE_TEST)) { | |
9fcf78cc JJ |
1226 | /* |
1227 | * no new privs prevents domain transitions that would | |
1228 | * reduce restrictions. | |
1229 | */ | |
1230 | if (task_no_new_privs(current) && !unconfined(label) && | |
1231 | !aa_label_is_subset(previous, ctx->nnp)) { | |
1232 | /* not an apparmor denial per se, so don't log it */ | |
1233 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1234 | error = -EPERM; | |
1235 | goto out; | |
1236 | } | |
1237 | ||
89dbf196 | 1238 | /* Return to saved label. Kill task if restore fails |
898127c3 JJ |
1239 | * to avoid brute force attacks |
1240 | */ | |
89dbf196 | 1241 | target = previous; |
637f688d | 1242 | error = aa_restore_previous_label(token); |
89dbf196 JJ |
1243 | if (error) { |
1244 | if (error == -EACCES) | |
1245 | goto kill; | |
1246 | goto fail; | |
1247 | } | |
1248 | } /* else ignore @flags && restores when there is no saved profile */ | |
898127c3 JJ |
1249 | |
1250 | out: | |
89dbf196 JJ |
1251 | aa_put_label(new); |
1252 | aa_put_label(previous); | |
637f688d | 1253 | aa_put_label(label); |
898127c3 JJ |
1254 | put_cred(cred); |
1255 | ||
1256 | return error; | |
89dbf196 JJ |
1257 | |
1258 | kill: | |
1259 | info = "failed token match"; | |
1260 | perms.kill = AA_MAY_CHANGEHAT; | |
1261 | ||
1262 | fail: | |
1263 | fn_for_each_in_ns(label, profile, | |
1264 | aa_audit_file(profile, &perms, OP_CHANGE_HAT, | |
1265 | AA_MAY_CHANGEHAT, NULL, NULL, target, | |
1266 | GLOBAL_ROOT_UID, info, error)); | |
1267 | ||
1268 | goto out; | |
898127c3 JJ |
1269 | } |
1270 | ||
89dbf196 | 1271 | |
e00b02bb JJ |
1272 | static int change_profile_perms_wrapper(const char *op, const char *name, |
1273 | struct aa_profile *profile, | |
1274 | struct aa_label *target, bool stack, | |
1275 | u32 request, struct aa_perms *perms) | |
1276 | { | |
1277 | const char *info = NULL; | |
1278 | int error = 0; | |
1279 | ||
e00b02bb JJ |
1280 | if (!error) |
1281 | error = change_profile_perms(profile, target, stack, request, | |
1282 | profile->file.start, perms); | |
1283 | if (error) | |
1284 | error = aa_audit_file(profile, perms, op, request, name, | |
1285 | NULL, target, GLOBAL_ROOT_UID, info, | |
1286 | error); | |
1287 | ||
1288 | return error; | |
1289 | } | |
89dbf196 | 1290 | |
898127c3 JJ |
1291 | /** |
1292 | * aa_change_profile - perform a one-way profile transition | |
aa9a39ad | 1293 | * @fqname: name of profile may include namespace (NOT NULL) |
898127c3 | 1294 | * @onexec: whether this transition is to take place immediately or at exec |
df8073c6 | 1295 | * @flags: flags affecting change behavior |
898127c3 JJ |
1296 | * |
1297 | * Change to new profile @name. Unlike with hats, there is no way | |
1298 | * to change back. If @name isn't specified the current profile name is | |
1299 | * used. | |
1300 | * If @onexec then the transition is delayed until | |
1301 | * the next exec. | |
1302 | * | |
1303 | * Returns %0 on success, error otherwise. | |
1304 | */ | |
df8073c6 | 1305 | int aa_change_profile(const char *fqname, int flags) |
898127c3 | 1306 | { |
e00b02bb JJ |
1307 | struct aa_label *label, *new = NULL, *target = NULL; |
1308 | struct aa_profile *profile; | |
2d679f3c | 1309 | struct aa_perms perms = {}; |
e00b02bb JJ |
1310 | const char *info = NULL; |
1311 | const char *auditname = fqname; /* retain leading & if stack */ | |
1312 | bool stack = flags & AA_CHANGE_STACK; | |
9fcf78cc | 1313 | struct aa_task_ctx *ctx = task_ctx(current); |
47f6e5cc | 1314 | int error = 0; |
e00b02bb | 1315 | char *op; |
898127c3 JJ |
1316 | u32 request; |
1317 | ||
9fcf78cc JJ |
1318 | label = aa_get_current_label(); |
1319 | ||
1320 | /* | |
1321 | * Detect no new privs being set, and store the label it | |
1322 | * occurred under. Ideally this would happen when nnp | |
1323 | * is set but there isn't a good way to do that yet. | |
1324 | * | |
1325 | * Testing for unconfined must be done before the subset test | |
1326 | */ | |
1327 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1328 | ctx->nnp = aa_get_label(label); | |
1329 | ||
aa9a39ad | 1330 | if (!fqname || !*fqname) { |
a0b845ff | 1331 | aa_put_label(label); |
aa9a39ad | 1332 | AA_DEBUG("no profile name"); |
898127c3 | 1333 | return -EINVAL; |
aa9a39ad | 1334 | } |
898127c3 | 1335 | |
df8073c6 | 1336 | if (flags & AA_CHANGE_ONEXEC) { |
898127c3 | 1337 | request = AA_MAY_ONEXEC; |
e00b02bb JJ |
1338 | if (stack) |
1339 | op = OP_STACK_ONEXEC; | |
1340 | else | |
1341 | op = OP_CHANGE_ONEXEC; | |
898127c3 JJ |
1342 | } else { |
1343 | request = AA_MAY_CHANGE_PROFILE; | |
e00b02bb JJ |
1344 | if (stack) |
1345 | op = OP_STACK; | |
1346 | else | |
1347 | op = OP_CHANGE_PROFILE; | |
898127c3 JJ |
1348 | } |
1349 | ||
e00b02bb JJ |
1350 | if (*fqname == '&') { |
1351 | stack = true; | |
1352 | /* don't have label_parse() do stacking */ | |
1353 | fqname++; | |
c29bceb3 | 1354 | } |
e00b02bb JJ |
1355 | target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); |
1356 | if (IS_ERR(target)) { | |
1357 | struct aa_profile *tprofile; | |
c29bceb3 | 1358 | |
e00b02bb JJ |
1359 | info = "label not found"; |
1360 | error = PTR_ERR(target); | |
1361 | target = NULL; | |
1362 | /* | |
1363 | * TODO: fixme using labels_profile is not right - do profile | |
1364 | * per complain profile | |
1365 | */ | |
df8073c6 | 1366 | if ((flags & AA_CHANGE_TEST) || |
e00b02bb | 1367 | !COMPLAIN_MODE(labels_profile(label))) |
898127c3 JJ |
1368 | goto audit; |
1369 | /* released below */ | |
e00b02bb JJ |
1370 | tprofile = aa_new_null_profile(labels_profile(label), false, |
1371 | fqname, GFP_KERNEL); | |
1372 | if (!tprofile) { | |
898127c3 JJ |
1373 | info = "failed null profile create"; |
1374 | error = -ENOMEM; | |
1375 | goto audit; | |
1376 | } | |
e00b02bb JJ |
1377 | target = &tprofile->label; |
1378 | goto check; | |
898127c3 JJ |
1379 | } |
1380 | ||
e00b02bb JJ |
1381 | /* |
1382 | * self directed transitions only apply to current policy ns | |
1383 | * TODO: currently requiring perms for stacking and straight change | |
1384 | * stacking doesn't strictly need this. Determine how much | |
1385 | * we want to loosen this restriction for stacking | |
1386 | * | |
1387 | * if (!stack) { | |
1388 | */ | |
1389 | error = fn_for_each_in_ns(label, profile, | |
1390 | change_profile_perms_wrapper(op, auditname, | |
1391 | profile, target, stack, | |
1392 | request, &perms)); | |
1393 | if (error) | |
1394 | /* auditing done in change_profile_perms_wrapper */ | |
1395 | goto out; | |
aa9a39ad | 1396 | |
e00b02bb JJ |
1397 | /* } */ |
1398 | ||
1399 | check: | |
898127c3 | 1400 | /* check if tracing task is allowed to trace target domain */ |
e00b02bb JJ |
1401 | error = may_change_ptraced_domain(target, &info); |
1402 | if (error && !fn_for_each_in_ns(label, profile, | |
1403 | COMPLAIN_MODE(profile))) | |
898127c3 | 1404 | goto audit; |
898127c3 | 1405 | |
e00b02bb JJ |
1406 | /* TODO: add permission check to allow this |
1407 | * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { | |
1408 | * info = "not a single threaded task"; | |
1409 | * error = -EACCES; | |
1410 | * goto audit; | |
1411 | * } | |
1412 | */ | |
df8073c6 | 1413 | if (flags & AA_CHANGE_TEST) |
e00b02bb | 1414 | goto out; |
898127c3 | 1415 | |
9fcf78cc JJ |
1416 | /* stacking is always a subset, so only check the nonstack case */ |
1417 | if (!stack) { | |
1418 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1419 | aa_get_label(target), | |
1420 | aa_get_label(&profile->label)); | |
1421 | /* | |
1422 | * no new privs prevents domain transitions that would | |
1423 | * reduce restrictions. | |
1424 | */ | |
1425 | if (task_no_new_privs(current) && !unconfined(label) && | |
1426 | !aa_label_is_subset(new, ctx->nnp)) { | |
1427 | /* not an apparmor denial per se, so don't log it */ | |
1428 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1429 | error = -EPERM; | |
1430 | goto out; | |
1431 | } | |
1432 | } | |
1433 | ||
e00b02bb JJ |
1434 | if (!(flags & AA_CHANGE_ONEXEC)) { |
1435 | /* only transition profiles in the current ns */ | |
1436 | if (stack) | |
1437 | new = aa_label_merge(label, target, GFP_KERNEL); | |
e00b02bb JJ |
1438 | if (IS_ERR_OR_NULL(new)) { |
1439 | info = "failed to build target label"; | |
d6d478ae JJ |
1440 | if (!new) |
1441 | error = -ENOMEM; | |
1442 | else | |
1443 | error = PTR_ERR(new); | |
e00b02bb JJ |
1444 | new = NULL; |
1445 | perms.allow = 0; | |
1446 | goto audit; | |
1447 | } | |
1448 | error = aa_replace_current_label(new); | |
9fcf78cc JJ |
1449 | } else { |
1450 | if (new) { | |
1451 | aa_put_label(new); | |
1452 | new = NULL; | |
1453 | } | |
1454 | ||
e00b02bb JJ |
1455 | /* full transition will be built in exec path */ |
1456 | error = aa_set_current_onexec(target, stack); | |
9fcf78cc | 1457 | } |
898127c3 JJ |
1458 | |
1459 | audit: | |
e00b02bb JJ |
1460 | error = fn_for_each_in_ns(label, profile, |
1461 | aa_audit_file(profile, &perms, op, request, auditname, | |
1462 | NULL, new ? new : target, | |
1463 | GLOBAL_ROOT_UID, info, error)); | |
898127c3 | 1464 | |
e00b02bb JJ |
1465 | out: |
1466 | aa_put_label(new); | |
1467 | aa_put_label(target); | |
637f688d | 1468 | aa_put_label(label); |
898127c3 JJ |
1469 | |
1470 | return error; | |
1471 | } |