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> | |
3cee6079 | 13 | #include <linux/fs.h> |
898127c3 JJ |
14 | #include <linux/file.h> |
15 | #include <linux/mount.h> | |
16 | #include <linux/syscalls.h> | |
17 | #include <linux/tracehook.h> | |
18 | #include <linux/personality.h> | |
8e51f908 | 19 | #include <linux/xattr.h> |
3cee6079 | 20 | #include <linux/user_namespace.h> |
898127c3 JJ |
21 | |
22 | #include "include/audit.h" | |
23 | #include "include/apparmorfs.h" | |
d8889d49 | 24 | #include "include/cred.h" |
898127c3 JJ |
25 | #include "include/domain.h" |
26 | #include "include/file.h" | |
27 | #include "include/ipc.h" | |
28 | #include "include/match.h" | |
29 | #include "include/path.h" | |
30 | #include "include/policy.h" | |
cff281f6 | 31 | #include "include/policy_ns.h" |
898127c3 JJ |
32 | |
33 | /** | |
34 | * aa_free_domain_entries - free entries in a domain table | |
35 | * @domain: the domain table to free (MAYBE NULL) | |
36 | */ | |
37 | void aa_free_domain_entries(struct aa_domain *domain) | |
38 | { | |
39 | int i; | |
40 | if (domain) { | |
41 | if (!domain->table) | |
42 | return; | |
43 | ||
44 | for (i = 0; i < domain->size; i++) | |
453431a5 WL |
45 | kfree_sensitive(domain->table[i]); |
46 | kfree_sensitive(domain->table); | |
898127c3 JJ |
47 | domain->table = NULL; |
48 | } | |
49 | } | |
50 | ||
51 | /** | |
52 | * may_change_ptraced_domain - check if can change profile on ptraced task | |
b2d09ae4 JJ |
53 | * @to_label: profile to change to (NOT NULL) |
54 | * @info: message if there is an error | |
898127c3 | 55 | * |
51775fe7 | 56 | * Check if current is ptraced and if so if the tracing task is allowed |
898127c3 JJ |
57 | * to trace the new domain |
58 | * | |
59 | * Returns: %0 or error if change not allowed | |
60 | */ | |
b2d09ae4 JJ |
61 | static int may_change_ptraced_domain(struct aa_label *to_label, |
62 | const char **info) | |
898127c3 JJ |
63 | { |
64 | struct task_struct *tracer; | |
637f688d | 65 | struct aa_label *tracerl = NULL; |
898127c3 JJ |
66 | int error = 0; |
67 | ||
68 | rcu_read_lock(); | |
51775fe7 | 69 | tracer = ptrace_parent(current); |
3cfcc19e | 70 | if (tracer) |
898127c3 | 71 | /* released below */ |
637f688d | 72 | tracerl = aa_get_task_label(tracer); |
898127c3 JJ |
73 | |
74 | /* not ptraced */ | |
637f688d | 75 | if (!tracer || unconfined(tracerl)) |
898127c3 JJ |
76 | goto out; |
77 | ||
b2d09ae4 | 78 | error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); |
898127c3 JJ |
79 | |
80 | out: | |
04fdc099 | 81 | rcu_read_unlock(); |
637f688d | 82 | aa_put_label(tracerl); |
898127c3 | 83 | |
b2d09ae4 JJ |
84 | if (error) |
85 | *info = "ptrace prevents transition"; | |
898127c3 JJ |
86 | return error; |
87 | } | |
88 | ||
93c98a48 JJ |
89 | /**** TODO: dedup to aa_label_match - needs perm and dfa, merging |
90 | * specifically this is an exact copy of aa_label_match except | |
91 | * aa_compute_perms is replaced with aa_compute_fperms | |
92 | * and policy.dfa with file.dfa | |
93 | ****/ | |
94 | /* match a profile and its associated ns component if needed | |
95 | * Assumes visibility test has already been done. | |
96 | * If a subns profile is not to be matched should be prescreened with | |
97 | * visibility test. | |
98 | */ | |
99 | static inline unsigned int match_component(struct aa_profile *profile, | |
100 | struct aa_profile *tp, | |
101 | bool stack, unsigned int state) | |
102 | { | |
103 | const char *ns_name; | |
104 | ||
105 | if (stack) | |
106 | state = aa_dfa_match(profile->file.dfa, state, "&"); | |
107 | if (profile->ns == tp->ns) | |
108 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
109 | ||
110 | /* try matching with namespace name and then profile */ | |
111 | ns_name = aa_ns_name(profile->ns, tp->ns, true); | |
112 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
113 | state = aa_dfa_match(profile->file.dfa, state, ns_name); | |
114 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
115 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
116 | } | |
117 | ||
118 | /** | |
119 | * label_compound_match - find perms for full compound label | |
120 | * @profile: profile to find perms for | |
121 | * @label: label to check access permissions for | |
122 | * @stack: whether this is a stacking request | |
123 | * @start: state to start match in | |
124 | * @subns: whether to do permission checks on components in a subns | |
125 | * @request: permissions to request | |
126 | * @perms: perms struct to set | |
127 | * | |
128 | * Returns: 0 on success else ERROR | |
129 | * | |
130 | * For the label A//&B//&C this does the perm match for A//&B//&C | |
131 | * @perms should be preinitialized with allperms OR a previous permission | |
132 | * check to be stacked. | |
133 | */ | |
134 | static int label_compound_match(struct aa_profile *profile, | |
135 | struct aa_label *label, bool stack, | |
136 | unsigned int state, bool subns, u32 request, | |
137 | struct aa_perms *perms) | |
138 | { | |
139 | struct aa_profile *tp; | |
140 | struct label_it i; | |
141 | struct path_cond cond = { }; | |
142 | ||
143 | /* find first subcomponent that is visible */ | |
144 | label_for_each(i, label, tp) { | |
145 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
146 | continue; | |
147 | state = match_component(profile, tp, stack, state); | |
148 | if (!state) | |
149 | goto fail; | |
150 | goto next; | |
151 | } | |
152 | ||
153 | /* no component visible */ | |
154 | *perms = allperms; | |
155 | return 0; | |
156 | ||
157 | next: | |
158 | label_for_each_cont(i, label, tp) { | |
159 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
160 | continue; | |
161 | state = aa_dfa_match(profile->file.dfa, state, "//&"); | |
162 | state = match_component(profile, tp, false, state); | |
163 | if (!state) | |
164 | goto fail; | |
165 | } | |
166 | *perms = aa_compute_fperms(profile->file.dfa, state, &cond); | |
167 | aa_apply_modes_to_perms(profile, perms); | |
168 | if ((perms->allow & request) != request) | |
169 | return -EACCES; | |
170 | ||
171 | return 0; | |
172 | ||
173 | fail: | |
174 | *perms = nullperms; | |
175 | return -EACCES; | |
176 | } | |
177 | ||
178 | /** | |
179 | * label_components_match - find perms for all subcomponents of a label | |
180 | * @profile: profile to find perms for | |
181 | * @label: label to check access permissions for | |
182 | * @stack: whether this is a stacking request | |
183 | * @start: state to start match in | |
184 | * @subns: whether to do permission checks on components in a subns | |
185 | * @request: permissions to request | |
186 | * @perms: an initialized perms struct to add accumulation to | |
187 | * | |
188 | * Returns: 0 on success else ERROR | |
189 | * | |
190 | * For the label A//&B//&C this does the perm match for each of A and B and C | |
191 | * @perms should be preinitialized with allperms OR a previous permission | |
192 | * check to be stacked. | |
193 | */ | |
194 | static int label_components_match(struct aa_profile *profile, | |
195 | struct aa_label *label, bool stack, | |
196 | unsigned int start, bool subns, u32 request, | |
197 | struct aa_perms *perms) | |
198 | { | |
199 | struct aa_profile *tp; | |
200 | struct label_it i; | |
201 | struct aa_perms tmp; | |
202 | struct path_cond cond = { }; | |
203 | unsigned int state = 0; | |
204 | ||
205 | /* find first subcomponent to test */ | |
206 | label_for_each(i, label, tp) { | |
207 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
208 | continue; | |
209 | state = match_component(profile, tp, stack, start); | |
210 | if (!state) | |
211 | goto fail; | |
212 | goto next; | |
213 | } | |
214 | ||
215 | /* no subcomponents visible - no change in perms */ | |
216 | return 0; | |
217 | ||
218 | next: | |
219 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
220 | aa_apply_modes_to_perms(profile, &tmp); | |
221 | aa_perms_accum(perms, &tmp); | |
222 | label_for_each_cont(i, label, tp) { | |
223 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
224 | continue; | |
225 | state = match_component(profile, tp, stack, start); | |
226 | if (!state) | |
227 | goto fail; | |
228 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
229 | aa_apply_modes_to_perms(profile, &tmp); | |
230 | aa_perms_accum(perms, &tmp); | |
231 | } | |
232 | ||
233 | if ((perms->allow & request) != request) | |
234 | return -EACCES; | |
235 | ||
236 | return 0; | |
237 | ||
238 | fail: | |
239 | *perms = nullperms; | |
240 | return -EACCES; | |
241 | } | |
242 | ||
243 | /** | |
244 | * label_match - do a multi-component label match | |
245 | * @profile: profile to match against (NOT NULL) | |
246 | * @label: label to match (NOT NULL) | |
247 | * @stack: whether this is a stacking request | |
248 | * @state: state to start in | |
249 | * @subns: whether to match subns components | |
250 | * @request: permission request | |
251 | * @perms: Returns computed perms (NOT NULL) | |
252 | * | |
253 | * Returns: the state the match finished in, may be the none matching state | |
254 | */ | |
255 | static int label_match(struct aa_profile *profile, struct aa_label *label, | |
256 | bool stack, unsigned int state, bool subns, u32 request, | |
257 | struct aa_perms *perms) | |
258 | { | |
259 | int error; | |
260 | ||
261 | *perms = nullperms; | |
262 | error = label_compound_match(profile, label, stack, state, subns, | |
263 | request, perms); | |
264 | if (!error) | |
265 | return error; | |
266 | ||
267 | *perms = allperms; | |
268 | return label_components_match(profile, label, stack, state, subns, | |
269 | request, perms); | |
270 | } | |
271 | ||
272 | /******* end TODO: dedup *****/ | |
273 | ||
898127c3 JJ |
274 | /** |
275 | * change_profile_perms - find permissions for change_profile | |
276 | * @profile: the current profile (NOT NULL) | |
93c98a48 JJ |
277 | * @target: label to transition to (NOT NULL) |
278 | * @stack: whether this is a stacking request | |
898127c3 JJ |
279 | * @request: requested perms |
280 | * @start: state to start matching in | |
281 | * | |
93c98a48 | 282 | * |
898127c3 | 283 | * Returns: permission set |
93c98a48 JJ |
284 | * |
285 | * currently only matches full label A//&B//&C or individual components A, B, C | |
286 | * not arbitrary combinations. Eg. A//&B, C | |
898127c3 | 287 | */ |
93c98a48 JJ |
288 | static int change_profile_perms(struct aa_profile *profile, |
289 | struct aa_label *target, bool stack, | |
290 | u32 request, unsigned int start, | |
291 | struct aa_perms *perms) | |
292 | { | |
293 | if (profile_unconfined(profile)) { | |
294 | perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; | |
295 | perms->audit = perms->quiet = perms->kill = 0; | |
296 | return 0; | |
297 | } | |
298 | ||
299 | /* TODO: add profile in ns screening */ | |
300 | return label_match(profile, target, stack, start, true, request, perms); | |
301 | } | |
302 | ||
8e51f908 MG |
303 | /** |
304 | * aa_xattrs_match - check whether a file matches the xattrs defined in profile | |
305 | * @bprm: binprm struct for the process to validate | |
306 | * @profile: profile to match against (NOT NULL) | |
73f488cd | 307 | * @state: state to start match in |
8e51f908 MG |
308 | * |
309 | * Returns: number of extended attributes that matched, or < 0 on error | |
310 | */ | |
311 | static int aa_xattrs_match(const struct linux_binprm *bprm, | |
73f488cd | 312 | struct aa_profile *profile, unsigned int state) |
8e51f908 MG |
313 | { |
314 | int i; | |
a61ecd32 | 315 | ssize_t size; |
8e51f908 MG |
316 | struct dentry *d; |
317 | char *value = NULL; | |
318 | int value_size = 0, ret = profile->xattr_count; | |
319 | ||
320 | if (!bprm || !profile->xattr_count) | |
321 | return 0; | |
8c62ed27 | 322 | might_sleep(); |
8e51f908 | 323 | |
73f488cd | 324 | /* transition from exec match to xattr set */ |
0df34a64 | 325 | state = aa_dfa_outofband_transition(profile->xmatch, state); |
8e51f908 MG |
326 | d = bprm->file->f_path.dentry; |
327 | ||
328 | for (i = 0; i < profile->xattr_count; i++) { | |
c7c7a1a1 TA |
329 | size = vfs_getxattr_alloc(&init_user_ns, d, profile->xattrs[i], |
330 | &value, value_size, GFP_KERNEL); | |
73f488cd JJ |
331 | if (size >= 0) { |
332 | u32 perm; | |
8e51f908 | 333 | |
0df34a64 JJ |
334 | /* |
335 | * Check the xattr presence before value. This ensure | |
336 | * that not present xattr can be distinguished from a 0 | |
337 | * length value or rule that matches any value | |
338 | */ | |
339 | state = aa_dfa_null_transition(profile->xmatch, state); | |
340 | /* Check xattr value */ | |
73f488cd JJ |
341 | state = aa_dfa_match_len(profile->xmatch, state, value, |
342 | size); | |
343 | perm = dfa_user_allow(profile->xmatch, state); | |
344 | if (!(perm & MAY_EXEC)) { | |
8e51f908 MG |
345 | ret = -EINVAL; |
346 | goto out; | |
347 | } | |
73f488cd JJ |
348 | } |
349 | /* transition to next element */ | |
0df34a64 | 350 | state = aa_dfa_outofband_transition(profile->xmatch, state); |
73f488cd JJ |
351 | if (size < 0) { |
352 | /* | |
353 | * No xattr match, so verify if transition to | |
354 | * next element was valid. IFF so the xattr | |
355 | * was optional. | |
356 | */ | |
357 | if (!state) { | |
8e51f908 MG |
358 | ret = -EINVAL; |
359 | goto out; | |
360 | } | |
73f488cd JJ |
361 | /* don't count missing optional xattr as matched */ |
362 | ret--; | |
8e51f908 MG |
363 | } |
364 | } | |
365 | ||
366 | out: | |
367 | kfree(value); | |
368 | return ret; | |
369 | } | |
370 | ||
898127c3 | 371 | /** |
8c62ed27 | 372 | * find_attach - do attachment search for unconfined processes |
8e51f908 | 373 | * @bprm - binprm structure of transitioning task |
8c62ed27 | 374 | * @ns: the current namespace (NOT NULL) |
898127c3 | 375 | * @head - profile list to walk (NOT NULL) |
8c62ed27 | 376 | * @name - to match against (NOT NULL) |
844b8292 | 377 | * @info - info message if there was an error (NOT NULL) |
898127c3 JJ |
378 | * |
379 | * Do a linear search on the profiles in the list. There is a matching | |
380 | * preference where an exact match is preferred over a name which uses | |
381 | * expressions to match, and matching expressions with the greatest | |
382 | * xmatch_len are preferred. | |
383 | * | |
384 | * Requires: @head not be shared or have appropriate locks held | |
385 | * | |
8c62ed27 | 386 | * Returns: label or NULL if no match found |
898127c3 | 387 | */ |
8c62ed27 JJ |
388 | static struct aa_label *find_attach(const struct linux_binprm *bprm, |
389 | struct aa_ns *ns, struct list_head *head, | |
390 | const char *name, const char **info) | |
898127c3 | 391 | { |
21f60661 | 392 | int candidate_len = 0, candidate_xattrs = 0; |
844b8292 | 393 | bool conflict = false; |
898127c3 JJ |
394 | struct aa_profile *profile, *candidate = NULL; |
395 | ||
21f60661 JJ |
396 | AA_BUG(!name); |
397 | AA_BUG(!head); | |
398 | ||
8c62ed27 JJ |
399 | rcu_read_lock(); |
400 | restart: | |
01e2b670 | 401 | list_for_each_entry_rcu(profile, head, base.list) { |
06d426d1 JJ |
402 | if (profile->label.flags & FLAG_NULL && |
403 | &profile->label == ns_unconfined(profile->ns)) | |
898127c3 | 404 | continue; |
06d426d1 | 405 | |
8e51f908 MG |
406 | /* Find the "best" matching profile. Profiles must |
407 | * match the path and extended attributes (if any) | |
408 | * associated with the file. A more specific path | |
409 | * match will be preferred over a less specific one, | |
410 | * and a match with more matching extended attributes | |
411 | * will be preferred over one with fewer. If the best | |
412 | * match has both the same level of path specificity | |
413 | * and the same number of matching extended attributes | |
414 | * as another profile, signal a conflict and refuse to | |
415 | * match. | |
416 | */ | |
844b8292 | 417 | if (profile->xmatch) { |
21f60661 | 418 | unsigned int state, count; |
8e51f908 MG |
419 | u32 perm; |
420 | ||
21f60661 JJ |
421 | state = aa_dfa_leftmatch(profile->xmatch, DFA_START, |
422 | name, &count); | |
8e51f908 MG |
423 | perm = dfa_user_allow(profile->xmatch, state); |
424 | /* any accepting state means a valid match. */ | |
425 | if (perm & MAY_EXEC) { | |
8c62ed27 | 426 | int ret = 0; |
21f60661 JJ |
427 | |
428 | if (count < candidate_len) | |
429 | continue; | |
8e51f908 | 430 | |
8c62ed27 JJ |
431 | if (bprm && profile->xattr_count) { |
432 | long rev = READ_ONCE(ns->revision); | |
433 | ||
434 | if (!aa_get_profile_not0(profile)) | |
435 | goto restart; | |
436 | rcu_read_unlock(); | |
437 | ret = aa_xattrs_match(bprm, profile, | |
438 | state); | |
439 | rcu_read_lock(); | |
440 | aa_put_profile(profile); | |
441 | if (rev != | |
442 | READ_ONCE(ns->revision)) | |
443 | /* policy changed */ | |
444 | goto restart; | |
445 | /* | |
446 | * Fail matching if the xattrs don't | |
447 | * match | |
448 | */ | |
449 | if (ret < 0) | |
450 | continue; | |
451 | } | |
73f488cd JJ |
452 | /* |
453 | * TODO: allow for more flexible best match | |
454 | * | |
455 | * The new match isn't more specific | |
8e51f908 MG |
456 | * than the current best match |
457 | */ | |
21f60661 JJ |
458 | if (count == candidate_len && |
459 | ret <= candidate_xattrs) { | |
8e51f908 | 460 | /* Match is equivalent, so conflict */ |
21f60661 | 461 | if (ret == candidate_xattrs) |
1a3881d3 | 462 | conflict = true; |
8e51f908 | 463 | continue; |
844b8292 | 464 | } |
8e51f908 MG |
465 | |
466 | /* Either the same length with more matching | |
467 | * xattrs, or a longer match | |
468 | */ | |
469 | candidate = profile; | |
21f60661 JJ |
470 | candidate_len = profile->xmatch_len; |
471 | candidate_xattrs = ret; | |
8e51f908 | 472 | conflict = false; |
898127c3 | 473 | } |
8c62ed27 | 474 | } else if (!strcmp(profile->base.name, name)) { |
73f488cd JJ |
475 | /* |
476 | * old exact non-re match, without conditionals such | |
477 | * as xattrs. no more searching required | |
478 | */ | |
8c62ed27 JJ |
479 | candidate = profile; |
480 | goto out; | |
481 | } | |
898127c3 JJ |
482 | } |
483 | ||
8c62ed27 JJ |
484 | if (!candidate || conflict) { |
485 | if (conflict) | |
486 | *info = "conflicting profile attachments"; | |
487 | rcu_read_unlock(); | |
844b8292 JJ |
488 | return NULL; |
489 | } | |
490 | ||
8c62ed27 JJ |
491 | out: |
492 | candidate = aa_get_newest_profile(candidate); | |
01e2b670 | 493 | rcu_read_unlock(); |
898127c3 | 494 | |
8c62ed27 | 495 | return &candidate->label; |
898127c3 JJ |
496 | } |
497 | ||
498 | static const char *next_name(int xtype, const char *name) | |
499 | { | |
500 | return NULL; | |
501 | } | |
502 | ||
503 | /** | |
504 | * x_table_lookup - lookup an x transition name via transition table | |
505 | * @profile: current profile (NOT NULL) | |
506 | * @xindex: index into x transition table | |
93c98a48 | 507 | * @name: returns: name tested to find label (NOT NULL) |
898127c3 | 508 | * |
93c98a48 | 509 | * Returns: refcounted label, or NULL on failure (MAYBE NULL) |
898127c3 | 510 | */ |
2ea3ffb7 JJ |
511 | struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, |
512 | const char **name) | |
898127c3 | 513 | { |
93c98a48 | 514 | struct aa_label *label = NULL; |
898127c3 JJ |
515 | u32 xtype = xindex & AA_X_TYPE_MASK; |
516 | int index = xindex & AA_X_INDEX_MASK; | |
898127c3 | 517 | |
93c98a48 | 518 | AA_BUG(!name); |
898127c3 | 519 | |
93c98a48 JJ |
520 | /* index is guaranteed to be in range, validated at load time */ |
521 | /* TODO: move lookup parsing to unpack time so this is a straight | |
522 | * index into the resultant label | |
523 | */ | |
524 | for (*name = profile->file.trans.table[index]; !label && *name; | |
525 | *name = next_name(xtype, *name)) { | |
898127c3 | 526 | if (xindex & AA_X_CHILD) { |
93c98a48 | 527 | struct aa_profile *new_profile; |
898127c3 | 528 | /* release by caller */ |
93c98a48 JJ |
529 | new_profile = aa_find_child(profile, *name); |
530 | if (new_profile) | |
531 | label = &new_profile->label; | |
898127c3 | 532 | continue; |
898127c3 | 533 | } |
8ac2ca32 | 534 | label = aa_label_parse(&profile->label, *name, GFP_KERNEL, |
93c98a48 JJ |
535 | true, false); |
536 | if (IS_ERR(label)) | |
537 | label = NULL; | |
898127c3 JJ |
538 | } |
539 | ||
540 | /* released by caller */ | |
93c98a48 JJ |
541 | |
542 | return label; | |
898127c3 JJ |
543 | } |
544 | ||
545 | /** | |
93c98a48 | 546 | * x_to_label - get target label for a given xindex |
898127c3 | 547 | * @profile: current profile (NOT NULL) |
8e51f908 | 548 | * @bprm: binprm structure of transitioning task |
898127c3 JJ |
549 | * @name: name to lookup (NOT NULL) |
550 | * @xindex: index into x transition table | |
93c98a48 | 551 | * @lookupname: returns: name used in lookup if one was specified (NOT NULL) |
898127c3 | 552 | * |
93c98a48 | 553 | * find label for a transition index |
898127c3 | 554 | * |
93c98a48 | 555 | * Returns: refcounted label or NULL if not found available |
898127c3 | 556 | */ |
93c98a48 | 557 | static struct aa_label *x_to_label(struct aa_profile *profile, |
8e51f908 | 558 | const struct linux_binprm *bprm, |
93c98a48 JJ |
559 | const char *name, u32 xindex, |
560 | const char **lookupname, | |
561 | const char **info) | |
898127c3 | 562 | { |
93c98a48 | 563 | struct aa_label *new = NULL; |
98849dff | 564 | struct aa_ns *ns = profile->ns; |
898127c3 | 565 | u32 xtype = xindex & AA_X_TYPE_MASK; |
93c98a48 | 566 | const char *stack = NULL; |
898127c3 JJ |
567 | |
568 | switch (xtype) { | |
569 | case AA_X_NONE: | |
570 | /* fail exec unless ix || ux fallback - handled by caller */ | |
93c98a48 JJ |
571 | *lookupname = NULL; |
572 | break; | |
573 | case AA_X_TABLE: | |
574 | /* TODO: fix when perm mapping done at unload */ | |
575 | stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; | |
576 | if (*stack != '&') { | |
577 | /* released by caller */ | |
578 | new = x_table_lookup(profile, xindex, lookupname); | |
579 | stack = NULL; | |
580 | break; | |
581 | } | |
df561f66 | 582 | fallthrough; /* to X_NAME */ |
898127c3 JJ |
583 | case AA_X_NAME: |
584 | if (xindex & AA_X_CHILD) | |
585 | /* released by caller */ | |
8e51f908 | 586 | new = find_attach(bprm, ns, &profile->base.profiles, |
844b8292 | 587 | name, info); |
898127c3 JJ |
588 | else |
589 | /* released by caller */ | |
8e51f908 | 590 | new = find_attach(bprm, ns, &ns->base.profiles, |
844b8292 | 591 | name, info); |
93c98a48 | 592 | *lookupname = name; |
898127c3 JJ |
593 | break; |
594 | } | |
595 | ||
93c98a48 JJ |
596 | if (!new) { |
597 | if (xindex & AA_X_INHERIT) { | |
598 | /* (p|c|n)ix - don't change profile but do | |
599 | * use the newest version | |
600 | */ | |
601 | *info = "ix fallback"; | |
602 | /* no profile && no error */ | |
603 | new = aa_get_newest_label(&profile->label); | |
604 | } else if (xindex & AA_X_UNCONFINED) { | |
605 | new = aa_get_newest_label(ns_unconfined(profile->ns)); | |
606 | *info = "ux fallback"; | |
607 | } | |
608 | } | |
609 | ||
610 | if (new && stack) { | |
611 | /* base the stack on post domain transition */ | |
612 | struct aa_label *base = new; | |
613 | ||
8ac2ca32 | 614 | new = aa_label_parse(base, stack, GFP_KERNEL, true, false); |
93c98a48 JJ |
615 | if (IS_ERR(new)) |
616 | new = NULL; | |
617 | aa_put_label(base); | |
618 | } | |
619 | ||
898127c3 | 620 | /* released by caller */ |
93c98a48 | 621 | return new; |
898127c3 JJ |
622 | } |
623 | ||
93c98a48 JJ |
624 | static struct aa_label *profile_transition(struct aa_profile *profile, |
625 | const struct linux_binprm *bprm, | |
626 | char *buffer, struct path_cond *cond, | |
627 | bool *secure_exec) | |
898127c3 | 628 | { |
93c98a48 JJ |
629 | struct aa_label *new = NULL; |
630 | const char *info = NULL, *name = NULL, *target = NULL; | |
631 | unsigned int state = profile->file.start; | |
2d679f3c | 632 | struct aa_perms perms = {}; |
93c98a48 | 633 | bool nonewprivs = false; |
b1d9e6b0 | 634 | int error = 0; |
898127c3 | 635 | |
93c98a48 JJ |
636 | AA_BUG(!profile); |
637 | AA_BUG(!bprm); | |
638 | AA_BUG(!buffer); | |
898127c3 | 639 | |
4227c333 | 640 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, |
72c8a768 | 641 | &name, &info, profile->disconnected); |
898127c3 | 642 | if (error) { |
637f688d | 643 | if (profile_unconfined(profile) || |
93c98a48 JJ |
644 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { |
645 | AA_DEBUG("name lookup ix on error"); | |
898127c3 | 646 | error = 0; |
93c98a48 JJ |
647 | new = aa_get_newest_label(&profile->label); |
648 | } | |
898127c3 JJ |
649 | name = bprm->filename; |
650 | goto audit; | |
651 | } | |
652 | ||
637f688d | 653 | if (profile_unconfined(profile)) { |
8e51f908 MG |
654 | new = find_attach(bprm, profile->ns, |
655 | &profile->ns->base.profiles, name, &info); | |
93c98a48 JJ |
656 | if (new) { |
657 | AA_DEBUG("unconfined attached to new label"); | |
658 | return new; | |
659 | } | |
660 | AA_DEBUG("unconfined exec no attachment"); | |
661 | return aa_get_newest_label(&profile->label); | |
898127c3 JJ |
662 | } |
663 | ||
664 | /* find exec permissions for name */ | |
93c98a48 | 665 | state = aa_str_perms(profile->file.dfa, state, name, cond, &perms); |
898127c3 JJ |
666 | if (perms.allow & MAY_EXEC) { |
667 | /* exec permission determine how to transition */ | |
8e51f908 MG |
668 | new = x_to_label(profile, bprm, name, perms.xindex, &target, |
669 | &info); | |
93c98a48 JJ |
670 | if (new && new->proxy == profile->label.proxy && info) { |
671 | /* hack ix fallback - improve how this is detected */ | |
672 | goto audit; | |
673 | } else if (!new) { | |
674 | error = -EACCES; | |
675 | info = "profile transition not found"; | |
676 | /* remove MAY_EXEC to audit as failure */ | |
677 | perms.allow &= ~MAY_EXEC; | |
898127c3 JJ |
678 | } |
679 | } else if (COMPLAIN_MODE(profile)) { | |
93c98a48 | 680 | /* no exec permission - learning mode */ |
5d7c44ef | 681 | struct aa_profile *new_profile = NULL; |
df323337 SAS |
682 | |
683 | new_profile = aa_new_null_profile(profile, false, name, | |
684 | GFP_KERNEL); | |
898127c3 JJ |
685 | if (!new_profile) { |
686 | error = -ENOMEM; | |
687 | info = "could not create null profile"; | |
93c98a48 | 688 | } else { |
898127c3 | 689 | error = -EACCES; |
93c98a48 JJ |
690 | new = &new_profile->label; |
691 | } | |
898127c3 JJ |
692 | perms.xindex |= AA_X_UNSAFE; |
693 | } else | |
694 | /* fail exec */ | |
695 | error = -EACCES; | |
696 | ||
93c98a48 JJ |
697 | if (!new) |
698 | goto audit; | |
699 | ||
93c98a48 JJ |
700 | |
701 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
702 | if (DEBUG_ON) { | |
703 | dbg_printk("apparmor: scrubbing environment variables" | |
704 | " for %s profile=", name); | |
8ac2ca32 | 705 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
706 | dbg_printk("\n"); |
707 | } | |
708 | *secure_exec = true; | |
c29bceb3 JJ |
709 | } |
710 | ||
93c98a48 JJ |
711 | audit: |
712 | aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, | |
713 | cond->uid, info, error); | |
714 | if (!new || nonewprivs) { | |
715 | aa_put_label(new); | |
716 | return ERR_PTR(error); | |
717 | } | |
718 | ||
719 | return new; | |
720 | } | |
721 | ||
722 | static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, | |
723 | bool stack, const struct linux_binprm *bprm, | |
724 | char *buffer, struct path_cond *cond, | |
725 | bool *secure_exec) | |
726 | { | |
727 | unsigned int state = profile->file.start; | |
728 | struct aa_perms perms = {}; | |
729 | const char *xname = NULL, *info = "change_profile onexec"; | |
730 | int error = -EACCES; | |
731 | ||
732 | AA_BUG(!profile); | |
733 | AA_BUG(!onexec); | |
734 | AA_BUG(!bprm); | |
735 | AA_BUG(!buffer); | |
736 | ||
737 | if (profile_unconfined(profile)) { | |
738 | /* change_profile on exec already granted */ | |
739 | /* | |
740 | * NOTE: Domain transitions from unconfined are allowed | |
741 | * even when no_new_privs is set because this aways results | |
742 | * in a further reduction of permissions. | |
743 | */ | |
744 | return 0; | |
745 | } | |
746 | ||
747 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, | |
748 | &xname, &info, profile->disconnected); | |
749 | if (error) { | |
750 | if (profile_unconfined(profile) || | |
751 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { | |
752 | AA_DEBUG("name lookup ix on error"); | |
753 | error = 0; | |
754 | } | |
755 | xname = bprm->filename; | |
898127c3 | 756 | goto audit; |
93c98a48 JJ |
757 | } |
758 | ||
759 | /* find exec permissions for name */ | |
760 | state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms); | |
761 | if (!(perms.allow & AA_MAY_ONEXEC)) { | |
762 | info = "no change_onexec valid for executable"; | |
763 | goto audit; | |
764 | } | |
765 | /* test if this exec can be paired with change_profile onexec. | |
766 | * onexec permission is linked to exec with a standard pairing | |
767 | * exec\0change_profile | |
768 | */ | |
769 | state = aa_dfa_null_transition(profile->file.dfa, state); | |
770 | error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, | |
771 | state, &perms); | |
772 | if (error) { | |
773 | perms.allow &= ~AA_MAY_ONEXEC; | |
774 | goto audit; | |
775 | } | |
93c98a48 JJ |
776 | |
777 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
778 | if (DEBUG_ON) { | |
779 | dbg_printk("apparmor: scrubbing environment " | |
780 | "variables for %s label=", xname); | |
8ac2ca32 | 781 | aa_label_printk(onexec, GFP_KERNEL); |
93c98a48 JJ |
782 | dbg_printk("\n"); |
783 | } | |
784 | *secure_exec = true; | |
785 | } | |
786 | ||
787 | audit: | |
788 | return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, | |
789 | NULL, onexec, cond->uid, info, error); | |
790 | } | |
791 | ||
792 | /* ensure none ns domain transitions are correctly applied with onexec */ | |
793 | ||
794 | static struct aa_label *handle_onexec(struct aa_label *label, | |
795 | struct aa_label *onexec, bool stack, | |
796 | const struct linux_binprm *bprm, | |
797 | char *buffer, struct path_cond *cond, | |
798 | bool *unsafe) | |
799 | { | |
800 | struct aa_profile *profile; | |
801 | struct aa_label *new; | |
802 | int error; | |
803 | ||
804 | AA_BUG(!label); | |
805 | AA_BUG(!onexec); | |
806 | AA_BUG(!bprm); | |
807 | AA_BUG(!buffer); | |
808 | ||
809 | if (!stack) { | |
810 | error = fn_for_each_in_ns(label, profile, | |
811 | profile_onexec(profile, onexec, stack, | |
812 | bprm, buffer, cond, unsafe)); | |
813 | if (error) | |
814 | return ERR_PTR(error); | |
8ac2ca32 | 815 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 JJ |
816 | aa_get_newest_label(onexec), |
817 | profile_transition(profile, bprm, buffer, | |
818 | cond, unsafe)); | |
819 | ||
820 | } else { | |
b2c2086c | 821 | /* TODO: determine how much we want to loosen this */ |
93c98a48 JJ |
822 | error = fn_for_each_in_ns(label, profile, |
823 | profile_onexec(profile, onexec, stack, bprm, | |
824 | buffer, cond, unsafe)); | |
825 | if (error) | |
826 | return ERR_PTR(error); | |
8ac2ca32 | 827 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 | 828 | aa_label_merge(&profile->label, onexec, |
8ac2ca32 | 829 | GFP_KERNEL), |
93c98a48 JJ |
830 | profile_transition(profile, bprm, buffer, |
831 | cond, unsafe)); | |
832 | } | |
833 | ||
834 | if (new) | |
835 | return new; | |
836 | ||
837 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
838 | error = fn_for_each_in_ns(label, profile, | |
839 | aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, | |
840 | AA_MAY_ONEXEC, bprm->filename, NULL, | |
841 | onexec, GLOBAL_ROOT_UID, | |
842 | "failed to build target label", -ENOMEM)); | |
843 | return ERR_PTR(error); | |
844 | } | |
845 | ||
846 | /** | |
b8bff599 | 847 | * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct |
93c98a48 JJ |
848 | * @bprm: binprm for the exec (NOT NULL) |
849 | * | |
850 | * Returns: %0 or error on failure | |
851 | * | |
852 | * TODO: once the other paths are done see if we can't refactor into a fn | |
853 | */ | |
b8bff599 | 854 | int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm) |
93c98a48 | 855 | { |
f175221a | 856 | struct aa_task_ctx *ctx; |
93c98a48 JJ |
857 | struct aa_label *label, *new = NULL; |
858 | struct aa_profile *profile; | |
859 | char *buffer = NULL; | |
860 | const char *info = NULL; | |
861 | int error = 0; | |
862 | bool unsafe = false; | |
3cee6079 CB |
863 | kuid_t i_uid = i_uid_into_mnt(file_mnt_user_ns(bprm->file), |
864 | file_inode(bprm->file)); | |
93c98a48 | 865 | struct path_cond cond = { |
3cee6079 | 866 | i_uid, |
93c98a48 JJ |
867 | file_inode(bprm->file)->i_mode |
868 | }; | |
869 | ||
de62de59 | 870 | ctx = task_ctx(current); |
d9087c49 | 871 | AA_BUG(!cred_label(bprm->cred)); |
f175221a | 872 | AA_BUG(!ctx); |
93c98a48 | 873 | |
d9087c49 | 874 | label = aa_get_newest_label(cred_label(bprm->cred)); |
93c98a48 | 875 | |
9fcf78cc JJ |
876 | /* |
877 | * Detect no new privs being set, and store the label it | |
878 | * occurred under. Ideally this would happen when nnp | |
879 | * is set but there isn't a good way to do that yet. | |
880 | * | |
881 | * Testing for unconfined must be done before the subset test | |
882 | */ | |
883 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) && | |
884 | !ctx->nnp) | |
885 | ctx->nnp = aa_get_label(label); | |
886 | ||
93c98a48 | 887 | /* buffer freed below, name is pointer into buffer */ |
341c1fda | 888 | buffer = aa_get_buffer(false); |
df323337 SAS |
889 | if (!buffer) { |
890 | error = -ENOMEM; | |
891 | goto done; | |
892 | } | |
893 | ||
93c98a48 | 894 | /* Test for onexec first as onexec override other x transitions. */ |
f175221a JJ |
895 | if (ctx->onexec) |
896 | new = handle_onexec(label, ctx->onexec, ctx->token, | |
93c98a48 JJ |
897 | bprm, buffer, &cond, &unsafe); |
898 | else | |
8ac2ca32 | 899 | new = fn_label_build(label, profile, GFP_KERNEL, |
93c98a48 JJ |
900 | profile_transition(profile, bprm, buffer, |
901 | &cond, &unsafe)); | |
902 | ||
903 | AA_BUG(!new); | |
904 | if (IS_ERR(new)) { | |
905 | error = PTR_ERR(new); | |
906 | goto done; | |
907 | } else if (!new) { | |
908 | error = -ENOMEM; | |
909 | goto done; | |
910 | } | |
911 | ||
9fcf78cc JJ |
912 | /* Policy has specified a domain transitions. If no_new_privs and |
913 | * confined ensure the transition is to confinement that is subset | |
914 | * of the confinement when the task entered no new privs. | |
915 | * | |
916 | * NOTE: Domain transitions from unconfined and to stacked | |
917 | * subsets are allowed even when no_new_privs is set because this | |
918 | * aways results in a further reduction of permissions. | |
919 | */ | |
920 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && | |
3ed4aaa9 JJ |
921 | !unconfined(label) && |
922 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { | |
9fcf78cc JJ |
923 | error = -EPERM; |
924 | info = "no new privs"; | |
925 | goto audit; | |
926 | } | |
898127c3 JJ |
927 | |
928 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
929 | /* FIXME: currently don't mediate shared state */ | |
930 | ; | |
931 | } | |
932 | ||
93c98a48 JJ |
933 | if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { |
934 | /* TODO: test needs to be profile of label to new */ | |
935 | error = may_change_ptraced_domain(new, &info); | |
f7da2de0 | 936 | if (error) |
898127c3 | 937 | goto audit; |
898127c3 JJ |
938 | } |
939 | ||
93c98a48 JJ |
940 | if (unsafe) { |
941 | if (DEBUG_ON) { | |
942 | dbg_printk("scrubbing environment variables for %s " | |
943 | "label=", bprm->filename); | |
8ac2ca32 | 944 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
945 | dbg_printk("\n"); |
946 | } | |
993b3ab0 | 947 | bprm->secureexec = 1; |
898127c3 | 948 | } |
898127c3 | 949 | |
93c98a48 JJ |
950 | if (label->proxy != new->proxy) { |
951 | /* when transitioning clear unsafe personality bits */ | |
952 | if (DEBUG_ON) { | |
953 | dbg_printk("apparmor: clearing unsafe personality " | |
954 | "bits. %s label=", bprm->filename); | |
8ac2ca32 | 955 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
956 | dbg_printk("\n"); |
957 | } | |
958 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
959 | } | |
d9087c49 JJ |
960 | aa_put_label(cred_label(bprm->cred)); |
961 | /* transfer reference, released when cred is freed */ | |
69b5a44a | 962 | set_cred_label(bprm->cred, new); |
898127c3 | 963 | |
93c98a48 | 964 | done: |
637f688d | 965 | aa_put_label(label); |
df323337 | 966 | aa_put_buffer(buffer); |
898127c3 JJ |
967 | |
968 | return error; | |
93c98a48 JJ |
969 | |
970 | audit: | |
971 | error = fn_for_each(label, profile, | |
972 | aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, | |
973 | bprm->filename, NULL, new, | |
3cee6079 | 974 | i_uid, info, error)); |
93c98a48 JJ |
975 | aa_put_label(new); |
976 | goto done; | |
898127c3 JJ |
977 | } |
978 | ||
898127c3 JJ |
979 | /* |
980 | * Functions for self directed profile change | |
981 | */ | |
982 | ||
89dbf196 JJ |
983 | |
984 | /* helper fn for change_hat | |
898127c3 | 985 | * |
89dbf196 | 986 | * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL |
898127c3 | 987 | */ |
89dbf196 JJ |
988 | static struct aa_label *build_change_hat(struct aa_profile *profile, |
989 | const char *name, bool sibling) | |
898127c3 | 990 | { |
89dbf196 JJ |
991 | struct aa_profile *root, *hat = NULL; |
992 | const char *info = NULL; | |
993 | int error = 0; | |
994 | ||
995 | if (sibling && PROFILE_IS_HAT(profile)) { | |
996 | root = aa_get_profile_rcu(&profile->parent); | |
997 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
998 | root = aa_get_profile(profile); | |
999 | } else { | |
1000 | info = "conflicting target types"; | |
1001 | error = -EPERM; | |
1002 | goto audit; | |
1003 | } | |
1004 | ||
1005 | hat = aa_find_child(root, name); | |
1006 | if (!hat) { | |
1007 | error = -ENOENT; | |
1008 | if (COMPLAIN_MODE(profile)) { | |
1009 | hat = aa_new_null_profile(profile, true, name, | |
1010 | GFP_KERNEL); | |
1011 | if (!hat) { | |
1012 | info = "failed null profile create"; | |
1013 | error = -ENOMEM; | |
1014 | } | |
1015 | } | |
1016 | } | |
1017 | aa_put_profile(root); | |
1018 | ||
1019 | audit: | |
1020 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, | |
1021 | name, hat ? hat->base.hname : NULL, | |
24b87a16 | 1022 | hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, |
89dbf196 JJ |
1023 | error); |
1024 | if (!hat || (error && error != -ENOENT)) | |
1025 | return ERR_PTR(error); | |
1026 | /* if hat && error - complain mode, already audited and we adjust for | |
1027 | * complain mode allow by returning hat->label | |
1028 | */ | |
1029 | return &hat->label; | |
1030 | } | |
1031 | ||
1032 | /* helper fn for changing into a hat | |
1033 | * | |
1034 | * Returns: label for hat transition or ERR_PTR. Does not return NULL | |
1035 | */ | |
1036 | static struct aa_label *change_hat(struct aa_label *label, const char *hats[], | |
1037 | int count, int flags) | |
1038 | { | |
1039 | struct aa_profile *profile, *root, *hat = NULL; | |
1040 | struct aa_label *new; | |
1041 | struct label_it it; | |
1042 | bool sibling = false; | |
1043 | const char *name, *info = NULL; | |
1044 | int i, error; | |
1045 | ||
1046 | AA_BUG(!label); | |
1047 | AA_BUG(!hats); | |
1048 | AA_BUG(count < 1); | |
1049 | ||
1050 | if (PROFILE_IS_HAT(labels_profile(label))) | |
1051 | sibling = true; | |
1052 | ||
1053 | /*find first matching hat */ | |
1054 | for (i = 0; i < count && !hat; i++) { | |
1055 | name = hats[i]; | |
1056 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1057 | if (sibling && PROFILE_IS_HAT(profile)) { | |
1058 | root = aa_get_profile_rcu(&profile->parent); | |
1059 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1060 | root = aa_get_profile(profile); | |
1061 | } else { /* conflicting change type */ | |
1062 | info = "conflicting targets types"; | |
1063 | error = -EPERM; | |
1064 | goto fail; | |
1065 | } | |
1066 | hat = aa_find_child(root, name); | |
1067 | aa_put_profile(root); | |
1068 | if (!hat) { | |
1069 | if (!COMPLAIN_MODE(profile)) | |
1070 | goto outer_continue; | |
1071 | /* complain mode succeed as if hat */ | |
1072 | } else if (!PROFILE_IS_HAT(hat)) { | |
1073 | info = "target not hat"; | |
1074 | error = -EPERM; | |
1075 | aa_put_profile(hat); | |
1076 | goto fail; | |
1077 | } | |
1078 | aa_put_profile(hat); | |
1079 | } | |
1080 | /* found a hat for all profiles in ns */ | |
1081 | goto build; | |
1082 | outer_continue: | |
1083 | ; | |
1084 | } | |
1085 | /* no hats that match, find appropriate error | |
1086 | * | |
1087 | * In complain mode audit of the failure is based off of the first | |
1088 | * hat supplied. This is done due how userspace interacts with | |
1089 | * change_hat. | |
1090 | */ | |
1091 | name = NULL; | |
1092 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1093 | if (!list_empty(&profile->base.profiles)) { | |
1094 | info = "hat not found"; | |
1095 | error = -ENOENT; | |
1096 | goto fail; | |
1097 | } | |
1098 | } | |
1099 | info = "no hats defined"; | |
1100 | error = -ECHILD; | |
1101 | ||
1102 | fail: | |
1103 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1104 | /* | |
1105 | * no target as it has failed to be found or built | |
1106 | * | |
1107 | * change_hat uses probing and should not log failures | |
1108 | * related to missing hats | |
1109 | */ | |
1110 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
1111 | if (count > 1 || COMPLAIN_MODE(profile)) { | |
1112 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, | |
1113 | AA_MAY_CHANGEHAT, name, NULL, NULL, | |
1114 | GLOBAL_ROOT_UID, info, error); | |
1115 | } | |
1116 | } | |
1117 | return ERR_PTR(error); | |
1118 | ||
1119 | build: | |
1120 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1121 | build_change_hat(profile, name, sibling), | |
1122 | aa_get_label(&profile->label)); | |
1123 | if (!new) { | |
1124 | info = "label build failed"; | |
1125 | error = -ENOMEM; | |
1126 | goto fail; | |
1127 | } /* else if (IS_ERR) build_change_hat has logged error so return new */ | |
1128 | ||
1129 | return new; | |
898127c3 JJ |
1130 | } |
1131 | ||
1132 | /** | |
1133 | * aa_change_hat - change hat to/from subprofile | |
1134 | * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) | |
1135 | * @count: number of hat names in @hats | |
1136 | * @token: magic value to validate the hat change | |
df8073c6 | 1137 | * @flags: flags affecting behavior of the change |
898127c3 | 1138 | * |
89dbf196 JJ |
1139 | * Returns %0 on success, error otherwise. |
1140 | * | |
898127c3 JJ |
1141 | * Change to the first profile specified in @hats that exists, and store |
1142 | * the @hat_magic in the current task context. If the count == 0 and the | |
1143 | * @token matches that stored in the current task context, return to the | |
1144 | * top level profile. | |
1145 | * | |
89dbf196 JJ |
1146 | * change_hat only applies to profiles in the current ns, and each profile |
1147 | * in the ns must make the same transition otherwise change_hat will fail. | |
898127c3 | 1148 | */ |
df8073c6 | 1149 | int aa_change_hat(const char *hats[], int count, u64 token, int flags) |
898127c3 JJ |
1150 | { |
1151 | const struct cred *cred; | |
9fcf78cc | 1152 | struct aa_task_ctx *ctx = task_ctx(current); |
89dbf196 JJ |
1153 | struct aa_label *label, *previous, *new = NULL, *target = NULL; |
1154 | struct aa_profile *profile; | |
2d679f3c | 1155 | struct aa_perms perms = {}; |
89dbf196 | 1156 | const char *info = NULL; |
898127c3 JJ |
1157 | int error = 0; |
1158 | ||
1159 | /* released below */ | |
1160 | cred = get_current_cred(); | |
637f688d | 1161 | label = aa_get_newest_cred_label(cred); |
f175221a | 1162 | previous = aa_get_newest_label(ctx->previous); |
898127c3 | 1163 | |
9fcf78cc JJ |
1164 | /* |
1165 | * Detect no new privs being set, and store the label it | |
1166 | * occurred under. Ideally this would happen when nnp | |
1167 | * is set but there isn't a good way to do that yet. | |
1168 | * | |
1169 | * Testing for unconfined must be done before the subset test | |
1170 | */ | |
1171 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1172 | ctx->nnp = aa_get_label(label); | |
1173 | ||
637f688d | 1174 | if (unconfined(label)) { |
89dbf196 | 1175 | info = "unconfined can not change_hat"; |
898127c3 | 1176 | error = -EPERM; |
89dbf196 | 1177 | goto fail; |
898127c3 JJ |
1178 | } |
1179 | ||
1180 | if (count) { | |
89dbf196 JJ |
1181 | new = change_hat(label, hats, count, flags); |
1182 | AA_BUG(!new); | |
1183 | if (IS_ERR(new)) { | |
1184 | error = PTR_ERR(new); | |
1185 | new = NULL; | |
1186 | /* already audited */ | |
1187 | goto out; | |
898127c3 JJ |
1188 | } |
1189 | ||
89dbf196 JJ |
1190 | error = may_change_ptraced_domain(new, &info); |
1191 | if (error) | |
1192 | goto fail; | |
898127c3 | 1193 | |
9fcf78cc JJ |
1194 | /* |
1195 | * no new privs prevents domain transitions that would | |
1196 | * reduce restrictions. | |
1197 | */ | |
1198 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1199 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { |
9fcf78cc JJ |
1200 | /* not an apparmor denial per se, so don't log it */ |
1201 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1202 | error = -EPERM; | |
1203 | goto out; | |
1204 | } | |
1205 | ||
89dbf196 JJ |
1206 | if (flags & AA_CHANGE_TEST) |
1207 | goto out; | |
1208 | ||
1209 | target = new; | |
1210 | error = aa_set_current_hat(new, token); | |
1211 | if (error == -EACCES) | |
1212 | /* kill task in case of brute force attacks */ | |
1213 | goto kill; | |
1214 | } else if (previous && !(flags & AA_CHANGE_TEST)) { | |
9fcf78cc JJ |
1215 | /* |
1216 | * no new privs prevents domain transitions that would | |
1217 | * reduce restrictions. | |
1218 | */ | |
1219 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1220 | !aa_label_is_unconfined_subset(previous, ctx->nnp)) { |
9fcf78cc JJ |
1221 | /* not an apparmor denial per se, so don't log it */ |
1222 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1223 | error = -EPERM; | |
1224 | goto out; | |
1225 | } | |
1226 | ||
89dbf196 | 1227 | /* Return to saved label. Kill task if restore fails |
898127c3 JJ |
1228 | * to avoid brute force attacks |
1229 | */ | |
89dbf196 | 1230 | target = previous; |
637f688d | 1231 | error = aa_restore_previous_label(token); |
89dbf196 JJ |
1232 | if (error) { |
1233 | if (error == -EACCES) | |
1234 | goto kill; | |
1235 | goto fail; | |
1236 | } | |
1237 | } /* else ignore @flags && restores when there is no saved profile */ | |
898127c3 JJ |
1238 | |
1239 | out: | |
89dbf196 JJ |
1240 | aa_put_label(new); |
1241 | aa_put_label(previous); | |
637f688d | 1242 | aa_put_label(label); |
898127c3 JJ |
1243 | put_cred(cred); |
1244 | ||
1245 | return error; | |
89dbf196 JJ |
1246 | |
1247 | kill: | |
1248 | info = "failed token match"; | |
1249 | perms.kill = AA_MAY_CHANGEHAT; | |
1250 | ||
1251 | fail: | |
1252 | fn_for_each_in_ns(label, profile, | |
1253 | aa_audit_file(profile, &perms, OP_CHANGE_HAT, | |
1254 | AA_MAY_CHANGEHAT, NULL, NULL, target, | |
1255 | GLOBAL_ROOT_UID, info, error)); | |
1256 | ||
1257 | goto out; | |
898127c3 JJ |
1258 | } |
1259 | ||
89dbf196 | 1260 | |
e00b02bb JJ |
1261 | static int change_profile_perms_wrapper(const char *op, const char *name, |
1262 | struct aa_profile *profile, | |
1263 | struct aa_label *target, bool stack, | |
1264 | u32 request, struct aa_perms *perms) | |
1265 | { | |
1266 | const char *info = NULL; | |
1267 | int error = 0; | |
1268 | ||
e00b02bb JJ |
1269 | if (!error) |
1270 | error = change_profile_perms(profile, target, stack, request, | |
1271 | profile->file.start, perms); | |
1272 | if (error) | |
1273 | error = aa_audit_file(profile, perms, op, request, name, | |
1274 | NULL, target, GLOBAL_ROOT_UID, info, | |
1275 | error); | |
1276 | ||
1277 | return error; | |
1278 | } | |
89dbf196 | 1279 | |
898127c3 JJ |
1280 | /** |
1281 | * aa_change_profile - perform a one-way profile transition | |
aa9a39ad | 1282 | * @fqname: name of profile may include namespace (NOT NULL) |
898127c3 | 1283 | * @onexec: whether this transition is to take place immediately or at exec |
df8073c6 | 1284 | * @flags: flags affecting change behavior |
898127c3 JJ |
1285 | * |
1286 | * Change to new profile @name. Unlike with hats, there is no way | |
1287 | * to change back. If @name isn't specified the current profile name is | |
1288 | * used. | |
1289 | * If @onexec then the transition is delayed until | |
1290 | * the next exec. | |
1291 | * | |
1292 | * Returns %0 on success, error otherwise. | |
1293 | */ | |
df8073c6 | 1294 | int aa_change_profile(const char *fqname, int flags) |
898127c3 | 1295 | { |
e00b02bb JJ |
1296 | struct aa_label *label, *new = NULL, *target = NULL; |
1297 | struct aa_profile *profile; | |
2d679f3c | 1298 | struct aa_perms perms = {}; |
e00b02bb JJ |
1299 | const char *info = NULL; |
1300 | const char *auditname = fqname; /* retain leading & if stack */ | |
1301 | bool stack = flags & AA_CHANGE_STACK; | |
9fcf78cc | 1302 | struct aa_task_ctx *ctx = task_ctx(current); |
47f6e5cc | 1303 | int error = 0; |
e00b02bb | 1304 | char *op; |
898127c3 JJ |
1305 | u32 request; |
1306 | ||
9fcf78cc JJ |
1307 | label = aa_get_current_label(); |
1308 | ||
1309 | /* | |
1310 | * Detect no new privs being set, and store the label it | |
1311 | * occurred under. Ideally this would happen when nnp | |
1312 | * is set but there isn't a good way to do that yet. | |
1313 | * | |
1314 | * Testing for unconfined must be done before the subset test | |
1315 | */ | |
1316 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1317 | ctx->nnp = aa_get_label(label); | |
1318 | ||
aa9a39ad | 1319 | if (!fqname || !*fqname) { |
a0b845ff | 1320 | aa_put_label(label); |
aa9a39ad | 1321 | AA_DEBUG("no profile name"); |
898127c3 | 1322 | return -EINVAL; |
aa9a39ad | 1323 | } |
898127c3 | 1324 | |
df8073c6 | 1325 | if (flags & AA_CHANGE_ONEXEC) { |
898127c3 | 1326 | request = AA_MAY_ONEXEC; |
e00b02bb JJ |
1327 | if (stack) |
1328 | op = OP_STACK_ONEXEC; | |
1329 | else | |
1330 | op = OP_CHANGE_ONEXEC; | |
898127c3 JJ |
1331 | } else { |
1332 | request = AA_MAY_CHANGE_PROFILE; | |
e00b02bb JJ |
1333 | if (stack) |
1334 | op = OP_STACK; | |
1335 | else | |
1336 | op = OP_CHANGE_PROFILE; | |
898127c3 JJ |
1337 | } |
1338 | ||
e00b02bb JJ |
1339 | if (*fqname == '&') { |
1340 | stack = true; | |
1341 | /* don't have label_parse() do stacking */ | |
1342 | fqname++; | |
c29bceb3 | 1343 | } |
e00b02bb JJ |
1344 | target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); |
1345 | if (IS_ERR(target)) { | |
1346 | struct aa_profile *tprofile; | |
c29bceb3 | 1347 | |
e00b02bb JJ |
1348 | info = "label not found"; |
1349 | error = PTR_ERR(target); | |
1350 | target = NULL; | |
1351 | /* | |
1352 | * TODO: fixme using labels_profile is not right - do profile | |
1353 | * per complain profile | |
1354 | */ | |
df8073c6 | 1355 | if ((flags & AA_CHANGE_TEST) || |
e00b02bb | 1356 | !COMPLAIN_MODE(labels_profile(label))) |
898127c3 JJ |
1357 | goto audit; |
1358 | /* released below */ | |
e00b02bb JJ |
1359 | tprofile = aa_new_null_profile(labels_profile(label), false, |
1360 | fqname, GFP_KERNEL); | |
1361 | if (!tprofile) { | |
898127c3 JJ |
1362 | info = "failed null profile create"; |
1363 | error = -ENOMEM; | |
1364 | goto audit; | |
1365 | } | |
e00b02bb JJ |
1366 | target = &tprofile->label; |
1367 | goto check; | |
898127c3 JJ |
1368 | } |
1369 | ||
e00b02bb JJ |
1370 | /* |
1371 | * self directed transitions only apply to current policy ns | |
1372 | * TODO: currently requiring perms for stacking and straight change | |
1373 | * stacking doesn't strictly need this. Determine how much | |
1374 | * we want to loosen this restriction for stacking | |
1375 | * | |
1376 | * if (!stack) { | |
1377 | */ | |
1378 | error = fn_for_each_in_ns(label, profile, | |
1379 | change_profile_perms_wrapper(op, auditname, | |
1380 | profile, target, stack, | |
1381 | request, &perms)); | |
1382 | if (error) | |
1383 | /* auditing done in change_profile_perms_wrapper */ | |
1384 | goto out; | |
aa9a39ad | 1385 | |
e00b02bb JJ |
1386 | /* } */ |
1387 | ||
1388 | check: | |
898127c3 | 1389 | /* check if tracing task is allowed to trace target domain */ |
e00b02bb JJ |
1390 | error = may_change_ptraced_domain(target, &info); |
1391 | if (error && !fn_for_each_in_ns(label, profile, | |
1392 | COMPLAIN_MODE(profile))) | |
898127c3 | 1393 | goto audit; |
898127c3 | 1394 | |
e00b02bb JJ |
1395 | /* TODO: add permission check to allow this |
1396 | * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { | |
1397 | * info = "not a single threaded task"; | |
1398 | * error = -EACCES; | |
1399 | * goto audit; | |
1400 | * } | |
1401 | */ | |
df8073c6 | 1402 | if (flags & AA_CHANGE_TEST) |
e00b02bb | 1403 | goto out; |
898127c3 | 1404 | |
9fcf78cc JJ |
1405 | /* stacking is always a subset, so only check the nonstack case */ |
1406 | if (!stack) { | |
1407 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1408 | aa_get_label(target), | |
1409 | aa_get_label(&profile->label)); | |
1410 | /* | |
1411 | * no new privs prevents domain transitions that would | |
1412 | * reduce restrictions. | |
1413 | */ | |
1414 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1415 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { |
9fcf78cc JJ |
1416 | /* not an apparmor denial per se, so don't log it */ |
1417 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1418 | error = -EPERM; | |
1419 | goto out; | |
1420 | } | |
1421 | } | |
1422 | ||
e00b02bb JJ |
1423 | if (!(flags & AA_CHANGE_ONEXEC)) { |
1424 | /* only transition profiles in the current ns */ | |
1425 | if (stack) | |
1426 | new = aa_label_merge(label, target, GFP_KERNEL); | |
e00b02bb JJ |
1427 | if (IS_ERR_OR_NULL(new)) { |
1428 | info = "failed to build target label"; | |
d6d478ae JJ |
1429 | if (!new) |
1430 | error = -ENOMEM; | |
1431 | else | |
1432 | error = PTR_ERR(new); | |
e00b02bb JJ |
1433 | new = NULL; |
1434 | perms.allow = 0; | |
1435 | goto audit; | |
1436 | } | |
1437 | error = aa_replace_current_label(new); | |
9fcf78cc JJ |
1438 | } else { |
1439 | if (new) { | |
1440 | aa_put_label(new); | |
1441 | new = NULL; | |
1442 | } | |
1443 | ||
e00b02bb JJ |
1444 | /* full transition will be built in exec path */ |
1445 | error = aa_set_current_onexec(target, stack); | |
9fcf78cc | 1446 | } |
898127c3 JJ |
1447 | |
1448 | audit: | |
e00b02bb JJ |
1449 | error = fn_for_each_in_ns(label, profile, |
1450 | aa_audit_file(profile, &perms, op, request, auditname, | |
1451 | NULL, new ? new : target, | |
1452 | GLOBAL_ROOT_UID, info, error)); | |
898127c3 | 1453 | |
e00b02bb JJ |
1454 | out: |
1455 | aa_put_label(new); | |
1456 | aa_put_label(target); | |
637f688d | 1457 | aa_put_label(label); |
898127c3 JJ |
1458 | |
1459 | return error; | |
1460 | } |