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> | |
898127c3 | 17 | #include <linux/personality.h> |
8e51f908 | 18 | #include <linux/xattr.h> |
3cee6079 | 19 | #include <linux/user_namespace.h> |
898127c3 JJ |
20 | |
21 | #include "include/audit.h" | |
22 | #include "include/apparmorfs.h" | |
d8889d49 | 23 | #include "include/cred.h" |
898127c3 JJ |
24 | #include "include/domain.h" |
25 | #include "include/file.h" | |
26 | #include "include/ipc.h" | |
27 | #include "include/match.h" | |
28 | #include "include/path.h" | |
29 | #include "include/policy.h" | |
cff281f6 | 30 | #include "include/policy_ns.h" |
898127c3 JJ |
31 | |
32 | /** | |
33 | * aa_free_domain_entries - free entries in a domain table | |
34 | * @domain: the domain table to free (MAYBE NULL) | |
35 | */ | |
36 | void aa_free_domain_entries(struct aa_domain *domain) | |
37 | { | |
38 | int i; | |
39 | if (domain) { | |
40 | if (!domain->table) | |
41 | return; | |
42 | ||
43 | for (i = 0; i < domain->size; i++) | |
453431a5 WL |
44 | kfree_sensitive(domain->table[i]); |
45 | kfree_sensitive(domain->table); | |
898127c3 JJ |
46 | domain->table = NULL; |
47 | } | |
48 | } | |
49 | ||
50 | /** | |
51 | * may_change_ptraced_domain - check if can change profile on ptraced task | |
b2d09ae4 JJ |
52 | * @to_label: profile to change to (NOT NULL) |
53 | * @info: message if there is an error | |
898127c3 | 54 | * |
51775fe7 | 55 | * Check if current is ptraced and if so if the tracing task is allowed |
898127c3 JJ |
56 | * to trace the new domain |
57 | * | |
58 | * Returns: %0 or error if change not allowed | |
59 | */ | |
b2d09ae4 JJ |
60 | static int may_change_ptraced_domain(struct aa_label *to_label, |
61 | const char **info) | |
898127c3 JJ |
62 | { |
63 | struct task_struct *tracer; | |
637f688d | 64 | struct aa_label *tracerl = NULL; |
898127c3 JJ |
65 | int error = 0; |
66 | ||
67 | rcu_read_lock(); | |
51775fe7 | 68 | tracer = ptrace_parent(current); |
3cfcc19e | 69 | if (tracer) |
898127c3 | 70 | /* released below */ |
637f688d | 71 | tracerl = aa_get_task_label(tracer); |
898127c3 JJ |
72 | |
73 | /* not ptraced */ | |
637f688d | 74 | if (!tracer || unconfined(tracerl)) |
898127c3 JJ |
75 | goto out; |
76 | ||
b2d09ae4 | 77 | error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); |
898127c3 JJ |
78 | |
79 | out: | |
04fdc099 | 80 | rcu_read_unlock(); |
637f688d | 81 | aa_put_label(tracerl); |
898127c3 | 82 | |
b2d09ae4 JJ |
83 | if (error) |
84 | *info = "ptrace prevents transition"; | |
898127c3 JJ |
85 | return error; |
86 | } | |
87 | ||
93c98a48 JJ |
88 | /**** TODO: dedup to aa_label_match - needs perm and dfa, merging |
89 | * specifically this is an exact copy of aa_label_match except | |
90 | * aa_compute_perms is replaced with aa_compute_fperms | |
91 | * and policy.dfa with file.dfa | |
92 | ****/ | |
93 | /* match a profile and its associated ns component if needed | |
94 | * Assumes visibility test has already been done. | |
95 | * If a subns profile is not to be matched should be prescreened with | |
96 | * visibility test. | |
97 | */ | |
98 | static inline unsigned int match_component(struct aa_profile *profile, | |
99 | struct aa_profile *tp, | |
100 | bool stack, unsigned int state) | |
101 | { | |
102 | const char *ns_name; | |
103 | ||
104 | if (stack) | |
105 | state = aa_dfa_match(profile->file.dfa, state, "&"); | |
106 | if (profile->ns == tp->ns) | |
107 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
108 | ||
109 | /* try matching with namespace name and then profile */ | |
110 | ns_name = aa_ns_name(profile->ns, tp->ns, true); | |
111 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
112 | state = aa_dfa_match(profile->file.dfa, state, ns_name); | |
113 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
114 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
115 | } | |
116 | ||
117 | /** | |
118 | * label_compound_match - find perms for full compound label | |
119 | * @profile: profile to find perms for | |
120 | * @label: label to check access permissions for | |
121 | * @stack: whether this is a stacking request | |
bab1f77f | 122 | * @state: state to start match in |
93c98a48 JJ |
123 | * @subns: whether to do permission checks on components in a subns |
124 | * @request: permissions to request | |
125 | * @perms: perms struct to set | |
126 | * | |
127 | * Returns: 0 on success else ERROR | |
128 | * | |
129 | * For the label A//&B//&C this does the perm match for A//&B//&C | |
130 | * @perms should be preinitialized with allperms OR a previous permission | |
131 | * check to be stacked. | |
132 | */ | |
133 | static int label_compound_match(struct aa_profile *profile, | |
134 | struct aa_label *label, bool stack, | |
135 | unsigned int state, bool subns, u32 request, | |
136 | struct aa_perms *perms) | |
137 | { | |
138 | struct aa_profile *tp; | |
139 | struct label_it i; | |
140 | struct path_cond cond = { }; | |
141 | ||
142 | /* find first subcomponent that is visible */ | |
143 | label_for_each(i, label, tp) { | |
144 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
145 | continue; | |
146 | state = match_component(profile, tp, stack, state); | |
147 | if (!state) | |
148 | goto fail; | |
149 | goto next; | |
150 | } | |
151 | ||
152 | /* no component visible */ | |
153 | *perms = allperms; | |
154 | return 0; | |
155 | ||
156 | next: | |
157 | label_for_each_cont(i, label, tp) { | |
158 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
159 | continue; | |
160 | state = aa_dfa_match(profile->file.dfa, state, "//&"); | |
161 | state = match_component(profile, tp, false, state); | |
162 | if (!state) | |
163 | goto fail; | |
164 | } | |
408d53e9 | 165 | *perms = *(aa_lookup_fperms(&(profile->file), state, &cond)); |
93c98a48 JJ |
166 | aa_apply_modes_to_perms(profile, perms); |
167 | if ((perms->allow & request) != request) | |
168 | return -EACCES; | |
169 | ||
170 | return 0; | |
171 | ||
172 | fail: | |
173 | *perms = nullperms; | |
174 | return -EACCES; | |
175 | } | |
176 | ||
177 | /** | |
178 | * label_components_match - find perms for all subcomponents of a label | |
179 | * @profile: profile to find perms for | |
180 | * @label: label to check access permissions for | |
181 | * @stack: whether this is a stacking request | |
182 | * @start: state to start match in | |
183 | * @subns: whether to do permission checks on components in a subns | |
184 | * @request: permissions to request | |
185 | * @perms: an initialized perms struct to add accumulation to | |
186 | * | |
187 | * Returns: 0 on success else ERROR | |
188 | * | |
189 | * For the label A//&B//&C this does the perm match for each of A and B and C | |
190 | * @perms should be preinitialized with allperms OR a previous permission | |
191 | * check to be stacked. | |
192 | */ | |
193 | static int label_components_match(struct aa_profile *profile, | |
194 | struct aa_label *label, bool stack, | |
195 | unsigned int start, bool subns, u32 request, | |
196 | struct aa_perms *perms) | |
197 | { | |
198 | struct aa_profile *tp; | |
199 | struct label_it i; | |
200 | struct aa_perms tmp; | |
201 | struct path_cond cond = { }; | |
202 | unsigned int state = 0; | |
203 | ||
204 | /* find first subcomponent to test */ | |
205 | label_for_each(i, label, tp) { | |
206 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
207 | continue; | |
208 | state = match_component(profile, tp, stack, start); | |
209 | if (!state) | |
210 | goto fail; | |
211 | goto next; | |
212 | } | |
213 | ||
214 | /* no subcomponents visible - no change in perms */ | |
215 | return 0; | |
216 | ||
217 | next: | |
408d53e9 | 218 | tmp = *(aa_lookup_fperms(&(profile->file), state, &cond)); |
93c98a48 JJ |
219 | aa_apply_modes_to_perms(profile, &tmp); |
220 | aa_perms_accum(perms, &tmp); | |
221 | label_for_each_cont(i, label, tp) { | |
222 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
223 | continue; | |
224 | state = match_component(profile, tp, stack, start); | |
225 | if (!state) | |
226 | goto fail; | |
408d53e9 | 227 | tmp = *(aa_lookup_fperms(&(profile->file), state, &cond)); |
93c98a48 JJ |
228 | aa_apply_modes_to_perms(profile, &tmp); |
229 | aa_perms_accum(perms, &tmp); | |
230 | } | |
231 | ||
232 | if ((perms->allow & request) != request) | |
233 | return -EACCES; | |
234 | ||
235 | return 0; | |
236 | ||
237 | fail: | |
238 | *perms = nullperms; | |
239 | return -EACCES; | |
240 | } | |
241 | ||
242 | /** | |
243 | * label_match - do a multi-component label match | |
244 | * @profile: profile to match against (NOT NULL) | |
245 | * @label: label to match (NOT NULL) | |
246 | * @stack: whether this is a stacking request | |
247 | * @state: state to start in | |
248 | * @subns: whether to match subns components | |
249 | * @request: permission request | |
250 | * @perms: Returns computed perms (NOT NULL) | |
251 | * | |
252 | * Returns: the state the match finished in, may be the none matching state | |
253 | */ | |
254 | static int label_match(struct aa_profile *profile, struct aa_label *label, | |
255 | bool stack, unsigned int state, bool subns, u32 request, | |
256 | struct aa_perms *perms) | |
257 | { | |
258 | int error; | |
259 | ||
260 | *perms = nullperms; | |
261 | error = label_compound_match(profile, label, stack, state, subns, | |
262 | request, perms); | |
263 | if (!error) | |
264 | return error; | |
265 | ||
266 | *perms = allperms; | |
267 | return label_components_match(profile, label, stack, state, subns, | |
268 | request, perms); | |
269 | } | |
270 | ||
271 | /******* end TODO: dedup *****/ | |
272 | ||
898127c3 JJ |
273 | /** |
274 | * change_profile_perms - find permissions for change_profile | |
275 | * @profile: the current profile (NOT NULL) | |
93c98a48 JJ |
276 | * @target: label to transition to (NOT NULL) |
277 | * @stack: whether this is a stacking request | |
898127c3 JJ |
278 | * @request: requested perms |
279 | * @start: state to start matching in | |
280 | * | |
93c98a48 | 281 | * |
898127c3 | 282 | * Returns: permission set |
93c98a48 JJ |
283 | * |
284 | * currently only matches full label A//&B//&C or individual components A, B, C | |
285 | * not arbitrary combinations. Eg. A//&B, C | |
898127c3 | 286 | */ |
93c98a48 JJ |
287 | static int change_profile_perms(struct aa_profile *profile, |
288 | struct aa_label *target, bool stack, | |
289 | u32 request, unsigned int start, | |
290 | struct aa_perms *perms) | |
291 | { | |
292 | if (profile_unconfined(profile)) { | |
293 | perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; | |
294 | perms->audit = perms->quiet = perms->kill = 0; | |
295 | return 0; | |
296 | } | |
297 | ||
298 | /* TODO: add profile in ns screening */ | |
299 | return label_match(profile, target, stack, start, true, request, perms); | |
300 | } | |
301 | ||
8e51f908 MG |
302 | /** |
303 | * aa_xattrs_match - check whether a file matches the xattrs defined in profile | |
304 | * @bprm: binprm struct for the process to validate | |
305 | * @profile: profile to match against (NOT NULL) | |
73f488cd | 306 | * @state: state to start match in |
8e51f908 MG |
307 | * |
308 | * Returns: number of extended attributes that matched, or < 0 on error | |
309 | */ | |
310 | static int aa_xattrs_match(const struct linux_binprm *bprm, | |
73f488cd | 311 | struct aa_profile *profile, unsigned int state) |
8e51f908 MG |
312 | { |
313 | int i; | |
a61ecd32 | 314 | ssize_t size; |
8e51f908 MG |
315 | struct dentry *d; |
316 | char *value = NULL; | |
317 | int value_size = 0, ret = profile->xattr_count; | |
318 | ||
319 | if (!bprm || !profile->xattr_count) | |
320 | return 0; | |
8c62ed27 | 321 | might_sleep(); |
8e51f908 | 322 | |
73f488cd | 323 | /* transition from exec match to xattr set */ |
048d4954 | 324 | state = aa_dfa_outofband_transition(profile->xmatch.dfa, state); |
8e51f908 MG |
325 | d = bprm->file->f_path.dentry; |
326 | ||
327 | for (i = 0; i < profile->xattr_count; i++) { | |
c7c7a1a1 TA |
328 | size = vfs_getxattr_alloc(&init_user_ns, d, profile->xattrs[i], |
329 | &value, value_size, GFP_KERNEL); | |
73f488cd | 330 | if (size >= 0) { |
2d63dd43 | 331 | u32 index, perm; |
8e51f908 | 332 | |
0df34a64 JJ |
333 | /* |
334 | * Check the xattr presence before value. This ensure | |
335 | * that not present xattr can be distinguished from a 0 | |
336 | * length value or rule that matches any value | |
337 | */ | |
048d4954 JJ |
338 | state = aa_dfa_null_transition(profile->xmatch.dfa, |
339 | state); | |
0df34a64 | 340 | /* Check xattr value */ |
048d4954 JJ |
341 | state = aa_dfa_match_len(profile->xmatch.dfa, state, |
342 | value, size); | |
2d63dd43 JJ |
343 | index = ACCEPT_TABLE(profile->xmatch.dfa)[state]; |
344 | perm = profile->xmatch.perms[index].allow; | |
73f488cd | 345 | if (!(perm & MAY_EXEC)) { |
8e51f908 MG |
346 | ret = -EINVAL; |
347 | goto out; | |
348 | } | |
73f488cd JJ |
349 | } |
350 | /* transition to next element */ | |
048d4954 | 351 | state = aa_dfa_outofband_transition(profile->xmatch.dfa, state); |
73f488cd JJ |
352 | if (size < 0) { |
353 | /* | |
354 | * No xattr match, so verify if transition to | |
355 | * next element was valid. IFF so the xattr | |
356 | * was optional. | |
357 | */ | |
358 | if (!state) { | |
8e51f908 MG |
359 | ret = -EINVAL; |
360 | goto out; | |
361 | } | |
73f488cd JJ |
362 | /* don't count missing optional xattr as matched */ |
363 | ret--; | |
8e51f908 MG |
364 | } |
365 | } | |
366 | ||
367 | out: | |
368 | kfree(value); | |
369 | return ret; | |
370 | } | |
371 | ||
898127c3 | 372 | /** |
8c62ed27 | 373 | * find_attach - do attachment search for unconfined processes |
8e51f908 | 374 | * @bprm - binprm structure of transitioning task |
8c62ed27 | 375 | * @ns: the current namespace (NOT NULL) |
898127c3 | 376 | * @head - profile list to walk (NOT NULL) |
8c62ed27 | 377 | * @name - to match against (NOT NULL) |
844b8292 | 378 | * @info - info message if there was an error (NOT NULL) |
898127c3 JJ |
379 | * |
380 | * Do a linear search on the profiles in the list. There is a matching | |
381 | * preference where an exact match is preferred over a name which uses | |
382 | * expressions to match, and matching expressions with the greatest | |
383 | * xmatch_len are preferred. | |
384 | * | |
385 | * Requires: @head not be shared or have appropriate locks held | |
386 | * | |
8c62ed27 | 387 | * Returns: label or NULL if no match found |
898127c3 | 388 | */ |
8c62ed27 JJ |
389 | static struct aa_label *find_attach(const struct linux_binprm *bprm, |
390 | struct aa_ns *ns, struct list_head *head, | |
391 | const char *name, const char **info) | |
898127c3 | 392 | { |
21f60661 | 393 | int candidate_len = 0, candidate_xattrs = 0; |
844b8292 | 394 | bool conflict = false; |
898127c3 JJ |
395 | struct aa_profile *profile, *candidate = NULL; |
396 | ||
21f60661 JJ |
397 | AA_BUG(!name); |
398 | AA_BUG(!head); | |
399 | ||
8c62ed27 JJ |
400 | rcu_read_lock(); |
401 | restart: | |
01e2b670 | 402 | list_for_each_entry_rcu(profile, head, base.list) { |
06d426d1 JJ |
403 | if (profile->label.flags & FLAG_NULL && |
404 | &profile->label == ns_unconfined(profile->ns)) | |
898127c3 | 405 | continue; |
06d426d1 | 406 | |
8e51f908 MG |
407 | /* Find the "best" matching profile. Profiles must |
408 | * match the path and extended attributes (if any) | |
409 | * associated with the file. A more specific path | |
410 | * match will be preferred over a less specific one, | |
411 | * and a match with more matching extended attributes | |
412 | * will be preferred over one with fewer. If the best | |
413 | * match has both the same level of path specificity | |
414 | * and the same number of matching extended attributes | |
415 | * as another profile, signal a conflict and refuse to | |
416 | * match. | |
417 | */ | |
048d4954 | 418 | if (profile->xmatch.dfa) { |
21f60661 | 419 | unsigned int state, count; |
2d63dd43 | 420 | u32 index, perm; |
8e51f908 | 421 | |
048d4954 JJ |
422 | state = aa_dfa_leftmatch(profile->xmatch.dfa, |
423 | profile->xmatch.start[AA_CLASS_XMATCH], | |
424 | name, &count); | |
2d63dd43 JJ |
425 | index = ACCEPT_TABLE(profile->xmatch.dfa)[state]; |
426 | perm = profile->xmatch.perms[index].allow; | |
8e51f908 MG |
427 | /* any accepting state means a valid match. */ |
428 | if (perm & MAY_EXEC) { | |
8c62ed27 | 429 | int ret = 0; |
21f60661 JJ |
430 | |
431 | if (count < candidate_len) | |
432 | continue; | |
8e51f908 | 433 | |
8c62ed27 JJ |
434 | if (bprm && profile->xattr_count) { |
435 | long rev = READ_ONCE(ns->revision); | |
436 | ||
437 | if (!aa_get_profile_not0(profile)) | |
438 | goto restart; | |
439 | rcu_read_unlock(); | |
440 | ret = aa_xattrs_match(bprm, profile, | |
441 | state); | |
442 | rcu_read_lock(); | |
443 | aa_put_profile(profile); | |
444 | if (rev != | |
445 | READ_ONCE(ns->revision)) | |
446 | /* policy changed */ | |
447 | goto restart; | |
448 | /* | |
449 | * Fail matching if the xattrs don't | |
450 | * match | |
451 | */ | |
452 | if (ret < 0) | |
453 | continue; | |
454 | } | |
73f488cd JJ |
455 | /* |
456 | * TODO: allow for more flexible best match | |
457 | * | |
458 | * The new match isn't more specific | |
8e51f908 MG |
459 | * than the current best match |
460 | */ | |
21f60661 JJ |
461 | if (count == candidate_len && |
462 | ret <= candidate_xattrs) { | |
8e51f908 | 463 | /* Match is equivalent, so conflict */ |
21f60661 | 464 | if (ret == candidate_xattrs) |
1a3881d3 | 465 | conflict = true; |
8e51f908 | 466 | continue; |
844b8292 | 467 | } |
8e51f908 MG |
468 | |
469 | /* Either the same length with more matching | |
470 | * xattrs, or a longer match | |
471 | */ | |
472 | candidate = profile; | |
2504db20 | 473 | candidate_len = max(count, profile->xmatch_len); |
21f60661 | 474 | candidate_xattrs = ret; |
8e51f908 | 475 | conflict = false; |
898127c3 | 476 | } |
8c62ed27 | 477 | } else if (!strcmp(profile->base.name, name)) { |
73f488cd JJ |
478 | /* |
479 | * old exact non-re match, without conditionals such | |
480 | * as xattrs. no more searching required | |
481 | */ | |
8c62ed27 JJ |
482 | candidate = profile; |
483 | goto out; | |
484 | } | |
898127c3 JJ |
485 | } |
486 | ||
8c62ed27 JJ |
487 | if (!candidate || conflict) { |
488 | if (conflict) | |
489 | *info = "conflicting profile attachments"; | |
490 | rcu_read_unlock(); | |
844b8292 JJ |
491 | return NULL; |
492 | } | |
493 | ||
8c62ed27 JJ |
494 | out: |
495 | candidate = aa_get_newest_profile(candidate); | |
01e2b670 | 496 | rcu_read_unlock(); |
898127c3 | 497 | |
8c62ed27 | 498 | return &candidate->label; |
898127c3 JJ |
499 | } |
500 | ||
501 | static const char *next_name(int xtype, const char *name) | |
502 | { | |
503 | return NULL; | |
504 | } | |
505 | ||
506 | /** | |
507 | * x_table_lookup - lookup an x transition name via transition table | |
508 | * @profile: current profile (NOT NULL) | |
509 | * @xindex: index into x transition table | |
93c98a48 | 510 | * @name: returns: name tested to find label (NOT NULL) |
898127c3 | 511 | * |
93c98a48 | 512 | * Returns: refcounted label, or NULL on failure (MAYBE NULL) |
898127c3 | 513 | */ |
2ea3ffb7 JJ |
514 | struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, |
515 | const char **name) | |
898127c3 | 516 | { |
93c98a48 | 517 | struct aa_label *label = NULL; |
898127c3 JJ |
518 | u32 xtype = xindex & AA_X_TYPE_MASK; |
519 | int index = xindex & AA_X_INDEX_MASK; | |
898127c3 | 520 | |
93c98a48 | 521 | AA_BUG(!name); |
898127c3 | 522 | |
93c98a48 JJ |
523 | /* index is guaranteed to be in range, validated at load time */ |
524 | /* TODO: move lookup parsing to unpack time so this is a straight | |
525 | * index into the resultant label | |
526 | */ | |
527 | for (*name = profile->file.trans.table[index]; !label && *name; | |
528 | *name = next_name(xtype, *name)) { | |
898127c3 | 529 | if (xindex & AA_X_CHILD) { |
93c98a48 | 530 | struct aa_profile *new_profile; |
898127c3 | 531 | /* release by caller */ |
93c98a48 JJ |
532 | new_profile = aa_find_child(profile, *name); |
533 | if (new_profile) | |
534 | label = &new_profile->label; | |
898127c3 | 535 | continue; |
898127c3 | 536 | } |
8ac2ca32 | 537 | label = aa_label_parse(&profile->label, *name, GFP_KERNEL, |
93c98a48 JJ |
538 | true, false); |
539 | if (IS_ERR(label)) | |
540 | label = NULL; | |
898127c3 JJ |
541 | } |
542 | ||
543 | /* released by caller */ | |
93c98a48 JJ |
544 | |
545 | return label; | |
898127c3 JJ |
546 | } |
547 | ||
548 | /** | |
93c98a48 | 549 | * x_to_label - get target label for a given xindex |
898127c3 | 550 | * @profile: current profile (NOT NULL) |
8e51f908 | 551 | * @bprm: binprm structure of transitioning task |
898127c3 JJ |
552 | * @name: name to lookup (NOT NULL) |
553 | * @xindex: index into x transition table | |
93c98a48 | 554 | * @lookupname: returns: name used in lookup if one was specified (NOT NULL) |
898127c3 | 555 | * |
93c98a48 | 556 | * find label for a transition index |
898127c3 | 557 | * |
93c98a48 | 558 | * Returns: refcounted label or NULL if not found available |
898127c3 | 559 | */ |
93c98a48 | 560 | static struct aa_label *x_to_label(struct aa_profile *profile, |
8e51f908 | 561 | const struct linux_binprm *bprm, |
93c98a48 JJ |
562 | const char *name, u32 xindex, |
563 | const char **lookupname, | |
564 | const char **info) | |
898127c3 | 565 | { |
93c98a48 | 566 | struct aa_label *new = NULL; |
98849dff | 567 | struct aa_ns *ns = profile->ns; |
898127c3 | 568 | u32 xtype = xindex & AA_X_TYPE_MASK; |
93c98a48 | 569 | const char *stack = NULL; |
898127c3 JJ |
570 | |
571 | switch (xtype) { | |
572 | case AA_X_NONE: | |
573 | /* fail exec unless ix || ux fallback - handled by caller */ | |
93c98a48 JJ |
574 | *lookupname = NULL; |
575 | break; | |
576 | case AA_X_TABLE: | |
577 | /* TODO: fix when perm mapping done at unload */ | |
578 | stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; | |
579 | if (*stack != '&') { | |
580 | /* released by caller */ | |
581 | new = x_table_lookup(profile, xindex, lookupname); | |
582 | stack = NULL; | |
583 | break; | |
584 | } | |
df561f66 | 585 | fallthrough; /* to X_NAME */ |
898127c3 JJ |
586 | case AA_X_NAME: |
587 | if (xindex & AA_X_CHILD) | |
588 | /* released by caller */ | |
8e51f908 | 589 | new = find_attach(bprm, ns, &profile->base.profiles, |
844b8292 | 590 | name, info); |
898127c3 JJ |
591 | else |
592 | /* released by caller */ | |
8e51f908 | 593 | new = find_attach(bprm, ns, &ns->base.profiles, |
844b8292 | 594 | name, info); |
93c98a48 | 595 | *lookupname = name; |
898127c3 JJ |
596 | break; |
597 | } | |
598 | ||
93c98a48 JJ |
599 | if (!new) { |
600 | if (xindex & AA_X_INHERIT) { | |
601 | /* (p|c|n)ix - don't change profile but do | |
602 | * use the newest version | |
603 | */ | |
604 | *info = "ix fallback"; | |
605 | /* no profile && no error */ | |
606 | new = aa_get_newest_label(&profile->label); | |
607 | } else if (xindex & AA_X_UNCONFINED) { | |
608 | new = aa_get_newest_label(ns_unconfined(profile->ns)); | |
609 | *info = "ux fallback"; | |
610 | } | |
611 | } | |
612 | ||
613 | if (new && stack) { | |
614 | /* base the stack on post domain transition */ | |
615 | struct aa_label *base = new; | |
616 | ||
8ac2ca32 | 617 | new = aa_label_parse(base, stack, GFP_KERNEL, true, false); |
93c98a48 JJ |
618 | if (IS_ERR(new)) |
619 | new = NULL; | |
620 | aa_put_label(base); | |
621 | } | |
622 | ||
898127c3 | 623 | /* released by caller */ |
93c98a48 | 624 | return new; |
898127c3 JJ |
625 | } |
626 | ||
93c98a48 JJ |
627 | static struct aa_label *profile_transition(struct aa_profile *profile, |
628 | const struct linux_binprm *bprm, | |
629 | char *buffer, struct path_cond *cond, | |
630 | bool *secure_exec) | |
898127c3 | 631 | { |
93c98a48 JJ |
632 | struct aa_label *new = NULL; |
633 | const char *info = NULL, *name = NULL, *target = NULL; | |
53bdc46f | 634 | unsigned int state = profile->file.start[AA_CLASS_FILE]; |
2d679f3c | 635 | struct aa_perms perms = {}; |
93c98a48 | 636 | bool nonewprivs = false; |
b1d9e6b0 | 637 | int error = 0; |
898127c3 | 638 | |
93c98a48 JJ |
639 | AA_BUG(!profile); |
640 | AA_BUG(!bprm); | |
641 | AA_BUG(!buffer); | |
898127c3 | 642 | |
4227c333 | 643 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, |
72c8a768 | 644 | &name, &info, profile->disconnected); |
898127c3 | 645 | if (error) { |
637f688d | 646 | if (profile_unconfined(profile) || |
93c98a48 JJ |
647 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { |
648 | AA_DEBUG("name lookup ix on error"); | |
898127c3 | 649 | error = 0; |
93c98a48 JJ |
650 | new = aa_get_newest_label(&profile->label); |
651 | } | |
898127c3 JJ |
652 | name = bprm->filename; |
653 | goto audit; | |
654 | } | |
655 | ||
637f688d | 656 | if (profile_unconfined(profile)) { |
8e51f908 MG |
657 | new = find_attach(bprm, profile->ns, |
658 | &profile->ns->base.profiles, name, &info); | |
93c98a48 JJ |
659 | if (new) { |
660 | AA_DEBUG("unconfined attached to new label"); | |
661 | return new; | |
662 | } | |
663 | AA_DEBUG("unconfined exec no attachment"); | |
664 | return aa_get_newest_label(&profile->label); | |
898127c3 JJ |
665 | } |
666 | ||
667 | /* find exec permissions for name */ | |
408d53e9 | 668 | state = aa_str_perms(&(profile->file), state, name, cond, &perms); |
898127c3 JJ |
669 | if (perms.allow & MAY_EXEC) { |
670 | /* exec permission determine how to transition */ | |
8e51f908 MG |
671 | new = x_to_label(profile, bprm, name, perms.xindex, &target, |
672 | &info); | |
93c98a48 JJ |
673 | if (new && new->proxy == profile->label.proxy && info) { |
674 | /* hack ix fallback - improve how this is detected */ | |
675 | goto audit; | |
676 | } else if (!new) { | |
677 | error = -EACCES; | |
678 | info = "profile transition not found"; | |
679 | /* remove MAY_EXEC to audit as failure */ | |
680 | perms.allow &= ~MAY_EXEC; | |
898127c3 JJ |
681 | } |
682 | } else if (COMPLAIN_MODE(profile)) { | |
93c98a48 | 683 | /* no exec permission - learning mode */ |
5d7c44ef | 684 | struct aa_profile *new_profile = NULL; |
df323337 SAS |
685 | |
686 | new_profile = aa_new_null_profile(profile, false, name, | |
687 | GFP_KERNEL); | |
898127c3 JJ |
688 | if (!new_profile) { |
689 | error = -ENOMEM; | |
690 | info = "could not create null profile"; | |
93c98a48 | 691 | } else { |
898127c3 | 692 | error = -EACCES; |
93c98a48 JJ |
693 | new = &new_profile->label; |
694 | } | |
898127c3 JJ |
695 | perms.xindex |= AA_X_UNSAFE; |
696 | } else | |
697 | /* fail exec */ | |
698 | error = -EACCES; | |
699 | ||
93c98a48 JJ |
700 | if (!new) |
701 | goto audit; | |
702 | ||
93c98a48 JJ |
703 | |
704 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
705 | if (DEBUG_ON) { | |
706 | dbg_printk("apparmor: scrubbing environment variables" | |
707 | " for %s profile=", name); | |
8ac2ca32 | 708 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
709 | dbg_printk("\n"); |
710 | } | |
711 | *secure_exec = true; | |
c29bceb3 JJ |
712 | } |
713 | ||
93c98a48 JJ |
714 | audit: |
715 | aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, | |
716 | cond->uid, info, error); | |
717 | if (!new || nonewprivs) { | |
718 | aa_put_label(new); | |
719 | return ERR_PTR(error); | |
720 | } | |
721 | ||
722 | return new; | |
723 | } | |
724 | ||
725 | static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, | |
726 | bool stack, const struct linux_binprm *bprm, | |
727 | char *buffer, struct path_cond *cond, | |
728 | bool *secure_exec) | |
729 | { | |
53bdc46f | 730 | unsigned int state = profile->file.start[AA_CLASS_FILE]; |
93c98a48 JJ |
731 | struct aa_perms perms = {}; |
732 | const char *xname = NULL, *info = "change_profile onexec"; | |
733 | int error = -EACCES; | |
734 | ||
735 | AA_BUG(!profile); | |
736 | AA_BUG(!onexec); | |
737 | AA_BUG(!bprm); | |
738 | AA_BUG(!buffer); | |
739 | ||
740 | if (profile_unconfined(profile)) { | |
741 | /* change_profile on exec already granted */ | |
742 | /* | |
743 | * NOTE: Domain transitions from unconfined are allowed | |
744 | * even when no_new_privs is set because this aways results | |
745 | * in a further reduction of permissions. | |
746 | */ | |
747 | return 0; | |
748 | } | |
749 | ||
750 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, | |
751 | &xname, &info, profile->disconnected); | |
752 | if (error) { | |
753 | if (profile_unconfined(profile) || | |
754 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { | |
755 | AA_DEBUG("name lookup ix on error"); | |
756 | error = 0; | |
757 | } | |
758 | xname = bprm->filename; | |
898127c3 | 759 | goto audit; |
93c98a48 JJ |
760 | } |
761 | ||
762 | /* find exec permissions for name */ | |
408d53e9 | 763 | state = aa_str_perms(&(profile->file), state, xname, cond, &perms); |
93c98a48 JJ |
764 | if (!(perms.allow & AA_MAY_ONEXEC)) { |
765 | info = "no change_onexec valid for executable"; | |
766 | goto audit; | |
767 | } | |
768 | /* test if this exec can be paired with change_profile onexec. | |
769 | * onexec permission is linked to exec with a standard pairing | |
770 | * exec\0change_profile | |
771 | */ | |
772 | state = aa_dfa_null_transition(profile->file.dfa, state); | |
773 | error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, | |
774 | state, &perms); | |
775 | if (error) { | |
776 | perms.allow &= ~AA_MAY_ONEXEC; | |
777 | goto audit; | |
778 | } | |
93c98a48 JJ |
779 | |
780 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
781 | if (DEBUG_ON) { | |
782 | dbg_printk("apparmor: scrubbing environment " | |
783 | "variables for %s label=", xname); | |
8ac2ca32 | 784 | aa_label_printk(onexec, GFP_KERNEL); |
93c98a48 JJ |
785 | dbg_printk("\n"); |
786 | } | |
787 | *secure_exec = true; | |
788 | } | |
789 | ||
790 | audit: | |
791 | return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, | |
792 | NULL, onexec, cond->uid, info, error); | |
793 | } | |
794 | ||
795 | /* ensure none ns domain transitions are correctly applied with onexec */ | |
796 | ||
797 | static struct aa_label *handle_onexec(struct aa_label *label, | |
798 | struct aa_label *onexec, bool stack, | |
799 | const struct linux_binprm *bprm, | |
800 | char *buffer, struct path_cond *cond, | |
801 | bool *unsafe) | |
802 | { | |
803 | struct aa_profile *profile; | |
804 | struct aa_label *new; | |
805 | int error; | |
806 | ||
807 | AA_BUG(!label); | |
808 | AA_BUG(!onexec); | |
809 | AA_BUG(!bprm); | |
810 | AA_BUG(!buffer); | |
811 | ||
812 | if (!stack) { | |
813 | error = fn_for_each_in_ns(label, profile, | |
814 | profile_onexec(profile, onexec, stack, | |
815 | bprm, buffer, cond, unsafe)); | |
816 | if (error) | |
817 | return ERR_PTR(error); | |
8ac2ca32 | 818 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 JJ |
819 | aa_get_newest_label(onexec), |
820 | profile_transition(profile, bprm, buffer, | |
821 | cond, unsafe)); | |
822 | ||
823 | } else { | |
b2c2086c | 824 | /* TODO: determine how much we want to loosen this */ |
93c98a48 JJ |
825 | error = fn_for_each_in_ns(label, profile, |
826 | profile_onexec(profile, onexec, stack, bprm, | |
827 | buffer, cond, unsafe)); | |
828 | if (error) | |
829 | return ERR_PTR(error); | |
8ac2ca32 | 830 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 | 831 | aa_label_merge(&profile->label, onexec, |
8ac2ca32 | 832 | GFP_KERNEL), |
93c98a48 JJ |
833 | profile_transition(profile, bprm, buffer, |
834 | cond, unsafe)); | |
835 | } | |
836 | ||
837 | if (new) | |
838 | return new; | |
839 | ||
840 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
841 | error = fn_for_each_in_ns(label, profile, | |
842 | aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, | |
843 | AA_MAY_ONEXEC, bprm->filename, NULL, | |
844 | onexec, GLOBAL_ROOT_UID, | |
845 | "failed to build target label", -ENOMEM)); | |
846 | return ERR_PTR(error); | |
847 | } | |
848 | ||
849 | /** | |
b8bff599 | 850 | * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct |
93c98a48 JJ |
851 | * @bprm: binprm for the exec (NOT NULL) |
852 | * | |
853 | * Returns: %0 or error on failure | |
854 | * | |
855 | * TODO: once the other paths are done see if we can't refactor into a fn | |
856 | */ | |
b8bff599 | 857 | int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm) |
93c98a48 | 858 | { |
f175221a | 859 | struct aa_task_ctx *ctx; |
93c98a48 JJ |
860 | struct aa_label *label, *new = NULL; |
861 | struct aa_profile *profile; | |
862 | char *buffer = NULL; | |
863 | const char *info = NULL; | |
864 | int error = 0; | |
865 | bool unsafe = false; | |
3cee6079 CB |
866 | kuid_t i_uid = i_uid_into_mnt(file_mnt_user_ns(bprm->file), |
867 | file_inode(bprm->file)); | |
93c98a48 | 868 | struct path_cond cond = { |
3cee6079 | 869 | i_uid, |
93c98a48 JJ |
870 | file_inode(bprm->file)->i_mode |
871 | }; | |
872 | ||
de62de59 | 873 | ctx = task_ctx(current); |
d9087c49 | 874 | AA_BUG(!cred_label(bprm->cred)); |
f175221a | 875 | AA_BUG(!ctx); |
93c98a48 | 876 | |
d9087c49 | 877 | label = aa_get_newest_label(cred_label(bprm->cred)); |
93c98a48 | 878 | |
9fcf78cc JJ |
879 | /* |
880 | * Detect no new privs being set, and store the label it | |
881 | * occurred under. Ideally this would happen when nnp | |
882 | * is set but there isn't a good way to do that yet. | |
883 | * | |
884 | * Testing for unconfined must be done before the subset test | |
885 | */ | |
886 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) && | |
887 | !ctx->nnp) | |
888 | ctx->nnp = aa_get_label(label); | |
889 | ||
93c98a48 | 890 | /* buffer freed below, name is pointer into buffer */ |
341c1fda | 891 | buffer = aa_get_buffer(false); |
df323337 SAS |
892 | if (!buffer) { |
893 | error = -ENOMEM; | |
894 | goto done; | |
895 | } | |
896 | ||
93c98a48 | 897 | /* Test for onexec first as onexec override other x transitions. */ |
f175221a JJ |
898 | if (ctx->onexec) |
899 | new = handle_onexec(label, ctx->onexec, ctx->token, | |
93c98a48 JJ |
900 | bprm, buffer, &cond, &unsafe); |
901 | else | |
8ac2ca32 | 902 | new = fn_label_build(label, profile, GFP_KERNEL, |
93c98a48 JJ |
903 | profile_transition(profile, bprm, buffer, |
904 | &cond, &unsafe)); | |
905 | ||
906 | AA_BUG(!new); | |
907 | if (IS_ERR(new)) { | |
908 | error = PTR_ERR(new); | |
909 | goto done; | |
910 | } else if (!new) { | |
911 | error = -ENOMEM; | |
912 | goto done; | |
913 | } | |
914 | ||
9fcf78cc JJ |
915 | /* Policy has specified a domain transitions. If no_new_privs and |
916 | * confined ensure the transition is to confinement that is subset | |
917 | * of the confinement when the task entered no new privs. | |
918 | * | |
919 | * NOTE: Domain transitions from unconfined and to stacked | |
920 | * subsets are allowed even when no_new_privs is set because this | |
921 | * aways results in a further reduction of permissions. | |
922 | */ | |
923 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && | |
3ed4aaa9 JJ |
924 | !unconfined(label) && |
925 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { | |
9fcf78cc JJ |
926 | error = -EPERM; |
927 | info = "no new privs"; | |
928 | goto audit; | |
929 | } | |
898127c3 JJ |
930 | |
931 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
932 | /* FIXME: currently don't mediate shared state */ | |
933 | ; | |
934 | } | |
935 | ||
93c98a48 JJ |
936 | if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { |
937 | /* TODO: test needs to be profile of label to new */ | |
938 | error = may_change_ptraced_domain(new, &info); | |
f7da2de0 | 939 | if (error) |
898127c3 | 940 | goto audit; |
898127c3 JJ |
941 | } |
942 | ||
93c98a48 JJ |
943 | if (unsafe) { |
944 | if (DEBUG_ON) { | |
945 | dbg_printk("scrubbing environment variables for %s " | |
946 | "label=", bprm->filename); | |
8ac2ca32 | 947 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
948 | dbg_printk("\n"); |
949 | } | |
993b3ab0 | 950 | bprm->secureexec = 1; |
898127c3 | 951 | } |
898127c3 | 952 | |
93c98a48 JJ |
953 | if (label->proxy != new->proxy) { |
954 | /* when transitioning clear unsafe personality bits */ | |
955 | if (DEBUG_ON) { | |
956 | dbg_printk("apparmor: clearing unsafe personality " | |
957 | "bits. %s label=", bprm->filename); | |
8ac2ca32 | 958 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
959 | dbg_printk("\n"); |
960 | } | |
961 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
962 | } | |
d9087c49 JJ |
963 | aa_put_label(cred_label(bprm->cred)); |
964 | /* transfer reference, released when cred is freed */ | |
69b5a44a | 965 | set_cred_label(bprm->cred, new); |
898127c3 | 966 | |
93c98a48 | 967 | done: |
637f688d | 968 | aa_put_label(label); |
df323337 | 969 | aa_put_buffer(buffer); |
898127c3 JJ |
970 | |
971 | return error; | |
93c98a48 JJ |
972 | |
973 | audit: | |
974 | error = fn_for_each(label, profile, | |
975 | aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, | |
976 | bprm->filename, NULL, new, | |
3cee6079 | 977 | i_uid, info, error)); |
93c98a48 JJ |
978 | aa_put_label(new); |
979 | goto done; | |
898127c3 JJ |
980 | } |
981 | ||
898127c3 JJ |
982 | /* |
983 | * Functions for self directed profile change | |
984 | */ | |
985 | ||
89dbf196 JJ |
986 | |
987 | /* helper fn for change_hat | |
898127c3 | 988 | * |
89dbf196 | 989 | * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL |
898127c3 | 990 | */ |
89dbf196 JJ |
991 | static struct aa_label *build_change_hat(struct aa_profile *profile, |
992 | const char *name, bool sibling) | |
898127c3 | 993 | { |
89dbf196 JJ |
994 | struct aa_profile *root, *hat = NULL; |
995 | const char *info = NULL; | |
996 | int error = 0; | |
997 | ||
998 | if (sibling && PROFILE_IS_HAT(profile)) { | |
999 | root = aa_get_profile_rcu(&profile->parent); | |
1000 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1001 | root = aa_get_profile(profile); | |
1002 | } else { | |
1003 | info = "conflicting target types"; | |
1004 | error = -EPERM; | |
1005 | goto audit; | |
1006 | } | |
1007 | ||
1008 | hat = aa_find_child(root, name); | |
1009 | if (!hat) { | |
1010 | error = -ENOENT; | |
1011 | if (COMPLAIN_MODE(profile)) { | |
1012 | hat = aa_new_null_profile(profile, true, name, | |
1013 | GFP_KERNEL); | |
1014 | if (!hat) { | |
1015 | info = "failed null profile create"; | |
1016 | error = -ENOMEM; | |
1017 | } | |
1018 | } | |
1019 | } | |
1020 | aa_put_profile(root); | |
1021 | ||
1022 | audit: | |
1023 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, | |
1024 | name, hat ? hat->base.hname : NULL, | |
24b87a16 | 1025 | hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, |
89dbf196 JJ |
1026 | error); |
1027 | if (!hat || (error && error != -ENOENT)) | |
1028 | return ERR_PTR(error); | |
1029 | /* if hat && error - complain mode, already audited and we adjust for | |
1030 | * complain mode allow by returning hat->label | |
1031 | */ | |
1032 | return &hat->label; | |
1033 | } | |
1034 | ||
1035 | /* helper fn for changing into a hat | |
1036 | * | |
1037 | * Returns: label for hat transition or ERR_PTR. Does not return NULL | |
1038 | */ | |
1039 | static struct aa_label *change_hat(struct aa_label *label, const char *hats[], | |
1040 | int count, int flags) | |
1041 | { | |
1042 | struct aa_profile *profile, *root, *hat = NULL; | |
1043 | struct aa_label *new; | |
1044 | struct label_it it; | |
1045 | bool sibling = false; | |
1046 | const char *name, *info = NULL; | |
1047 | int i, error; | |
1048 | ||
1049 | AA_BUG(!label); | |
1050 | AA_BUG(!hats); | |
1051 | AA_BUG(count < 1); | |
1052 | ||
1053 | if (PROFILE_IS_HAT(labels_profile(label))) | |
1054 | sibling = true; | |
1055 | ||
1056 | /*find first matching hat */ | |
1057 | for (i = 0; i < count && !hat; i++) { | |
1058 | name = hats[i]; | |
1059 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1060 | if (sibling && PROFILE_IS_HAT(profile)) { | |
1061 | root = aa_get_profile_rcu(&profile->parent); | |
1062 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1063 | root = aa_get_profile(profile); | |
1064 | } else { /* conflicting change type */ | |
1065 | info = "conflicting targets types"; | |
1066 | error = -EPERM; | |
1067 | goto fail; | |
1068 | } | |
1069 | hat = aa_find_child(root, name); | |
1070 | aa_put_profile(root); | |
1071 | if (!hat) { | |
1072 | if (!COMPLAIN_MODE(profile)) | |
1073 | goto outer_continue; | |
1074 | /* complain mode succeed as if hat */ | |
1075 | } else if (!PROFILE_IS_HAT(hat)) { | |
1076 | info = "target not hat"; | |
1077 | error = -EPERM; | |
1078 | aa_put_profile(hat); | |
1079 | goto fail; | |
1080 | } | |
1081 | aa_put_profile(hat); | |
1082 | } | |
1083 | /* found a hat for all profiles in ns */ | |
1084 | goto build; | |
1085 | outer_continue: | |
1086 | ; | |
1087 | } | |
1088 | /* no hats that match, find appropriate error | |
1089 | * | |
1090 | * In complain mode audit of the failure is based off of the first | |
1091 | * hat supplied. This is done due how userspace interacts with | |
1092 | * change_hat. | |
1093 | */ | |
1094 | name = NULL; | |
1095 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1096 | if (!list_empty(&profile->base.profiles)) { | |
1097 | info = "hat not found"; | |
1098 | error = -ENOENT; | |
1099 | goto fail; | |
1100 | } | |
1101 | } | |
1102 | info = "no hats defined"; | |
1103 | error = -ECHILD; | |
1104 | ||
1105 | fail: | |
1106 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1107 | /* | |
1108 | * no target as it has failed to be found or built | |
1109 | * | |
1110 | * change_hat uses probing and should not log failures | |
1111 | * related to missing hats | |
1112 | */ | |
1113 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
1114 | if (count > 1 || COMPLAIN_MODE(profile)) { | |
1115 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, | |
1116 | AA_MAY_CHANGEHAT, name, NULL, NULL, | |
1117 | GLOBAL_ROOT_UID, info, error); | |
1118 | } | |
1119 | } | |
1120 | return ERR_PTR(error); | |
1121 | ||
1122 | build: | |
1123 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1124 | build_change_hat(profile, name, sibling), | |
1125 | aa_get_label(&profile->label)); | |
1126 | if (!new) { | |
1127 | info = "label build failed"; | |
1128 | error = -ENOMEM; | |
1129 | goto fail; | |
1130 | } /* else if (IS_ERR) build_change_hat has logged error so return new */ | |
1131 | ||
1132 | return new; | |
898127c3 JJ |
1133 | } |
1134 | ||
1135 | /** | |
1136 | * aa_change_hat - change hat to/from subprofile | |
1137 | * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) | |
1138 | * @count: number of hat names in @hats | |
1139 | * @token: magic value to validate the hat change | |
df8073c6 | 1140 | * @flags: flags affecting behavior of the change |
898127c3 | 1141 | * |
89dbf196 JJ |
1142 | * Returns %0 on success, error otherwise. |
1143 | * | |
898127c3 JJ |
1144 | * Change to the first profile specified in @hats that exists, and store |
1145 | * the @hat_magic in the current task context. If the count == 0 and the | |
1146 | * @token matches that stored in the current task context, return to the | |
1147 | * top level profile. | |
1148 | * | |
89dbf196 JJ |
1149 | * change_hat only applies to profiles in the current ns, and each profile |
1150 | * in the ns must make the same transition otherwise change_hat will fail. | |
898127c3 | 1151 | */ |
df8073c6 | 1152 | int aa_change_hat(const char *hats[], int count, u64 token, int flags) |
898127c3 JJ |
1153 | { |
1154 | const struct cred *cred; | |
9fcf78cc | 1155 | struct aa_task_ctx *ctx = task_ctx(current); |
89dbf196 JJ |
1156 | struct aa_label *label, *previous, *new = NULL, *target = NULL; |
1157 | struct aa_profile *profile; | |
2d679f3c | 1158 | struct aa_perms perms = {}; |
89dbf196 | 1159 | const char *info = NULL; |
898127c3 JJ |
1160 | int error = 0; |
1161 | ||
1162 | /* released below */ | |
1163 | cred = get_current_cred(); | |
637f688d | 1164 | label = aa_get_newest_cred_label(cred); |
f175221a | 1165 | previous = aa_get_newest_label(ctx->previous); |
898127c3 | 1166 | |
9fcf78cc JJ |
1167 | /* |
1168 | * Detect no new privs being set, and store the label it | |
1169 | * occurred under. Ideally this would happen when nnp | |
1170 | * is set but there isn't a good way to do that yet. | |
1171 | * | |
1172 | * Testing for unconfined must be done before the subset test | |
1173 | */ | |
1174 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1175 | ctx->nnp = aa_get_label(label); | |
1176 | ||
637f688d | 1177 | if (unconfined(label)) { |
89dbf196 | 1178 | info = "unconfined can not change_hat"; |
898127c3 | 1179 | error = -EPERM; |
89dbf196 | 1180 | goto fail; |
898127c3 JJ |
1181 | } |
1182 | ||
1183 | if (count) { | |
89dbf196 JJ |
1184 | new = change_hat(label, hats, count, flags); |
1185 | AA_BUG(!new); | |
1186 | if (IS_ERR(new)) { | |
1187 | error = PTR_ERR(new); | |
1188 | new = NULL; | |
1189 | /* already audited */ | |
1190 | goto out; | |
898127c3 JJ |
1191 | } |
1192 | ||
89dbf196 JJ |
1193 | error = may_change_ptraced_domain(new, &info); |
1194 | if (error) | |
1195 | goto fail; | |
898127c3 | 1196 | |
9fcf78cc JJ |
1197 | /* |
1198 | * no new privs prevents domain transitions that would | |
1199 | * reduce restrictions. | |
1200 | */ | |
1201 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1202 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { |
9fcf78cc JJ |
1203 | /* not an apparmor denial per se, so don't log it */ |
1204 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1205 | error = -EPERM; | |
1206 | goto out; | |
1207 | } | |
1208 | ||
89dbf196 JJ |
1209 | if (flags & AA_CHANGE_TEST) |
1210 | goto out; | |
1211 | ||
1212 | target = new; | |
1213 | error = aa_set_current_hat(new, token); | |
1214 | if (error == -EACCES) | |
1215 | /* kill task in case of brute force attacks */ | |
1216 | goto kill; | |
1217 | } else if (previous && !(flags & AA_CHANGE_TEST)) { | |
9fcf78cc JJ |
1218 | /* |
1219 | * no new privs prevents domain transitions that would | |
1220 | * reduce restrictions. | |
1221 | */ | |
1222 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1223 | !aa_label_is_unconfined_subset(previous, ctx->nnp)) { |
9fcf78cc JJ |
1224 | /* not an apparmor denial per se, so don't log it */ |
1225 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1226 | error = -EPERM; | |
1227 | goto out; | |
1228 | } | |
1229 | ||
89dbf196 | 1230 | /* Return to saved label. Kill task if restore fails |
898127c3 JJ |
1231 | * to avoid brute force attacks |
1232 | */ | |
89dbf196 | 1233 | target = previous; |
637f688d | 1234 | error = aa_restore_previous_label(token); |
89dbf196 JJ |
1235 | if (error) { |
1236 | if (error == -EACCES) | |
1237 | goto kill; | |
1238 | goto fail; | |
1239 | } | |
1240 | } /* else ignore @flags && restores when there is no saved profile */ | |
898127c3 JJ |
1241 | |
1242 | out: | |
89dbf196 JJ |
1243 | aa_put_label(new); |
1244 | aa_put_label(previous); | |
637f688d | 1245 | aa_put_label(label); |
898127c3 JJ |
1246 | put_cred(cred); |
1247 | ||
1248 | return error; | |
89dbf196 JJ |
1249 | |
1250 | kill: | |
1251 | info = "failed token match"; | |
1252 | perms.kill = AA_MAY_CHANGEHAT; | |
1253 | ||
1254 | fail: | |
1255 | fn_for_each_in_ns(label, profile, | |
1256 | aa_audit_file(profile, &perms, OP_CHANGE_HAT, | |
1257 | AA_MAY_CHANGEHAT, NULL, NULL, target, | |
1258 | GLOBAL_ROOT_UID, info, error)); | |
1259 | ||
1260 | goto out; | |
898127c3 JJ |
1261 | } |
1262 | ||
89dbf196 | 1263 | |
e00b02bb JJ |
1264 | static int change_profile_perms_wrapper(const char *op, const char *name, |
1265 | struct aa_profile *profile, | |
1266 | struct aa_label *target, bool stack, | |
1267 | u32 request, struct aa_perms *perms) | |
1268 | { | |
1269 | const char *info = NULL; | |
1270 | int error = 0; | |
1271 | ||
e00b02bb JJ |
1272 | if (!error) |
1273 | error = change_profile_perms(profile, target, stack, request, | |
53bdc46f JJ |
1274 | profile->file.start[AA_CLASS_FILE], |
1275 | perms); | |
e00b02bb JJ |
1276 | if (error) |
1277 | error = aa_audit_file(profile, perms, op, request, name, | |
1278 | NULL, target, GLOBAL_ROOT_UID, info, | |
1279 | error); | |
1280 | ||
1281 | return error; | |
1282 | } | |
89dbf196 | 1283 | |
898127c3 JJ |
1284 | /** |
1285 | * aa_change_profile - perform a one-way profile transition | |
aa9a39ad | 1286 | * @fqname: name of profile may include namespace (NOT NULL) |
df8073c6 | 1287 | * @flags: flags affecting change behavior |
898127c3 JJ |
1288 | * |
1289 | * Change to new profile @name. Unlike with hats, there is no way | |
1290 | * to change back. If @name isn't specified the current profile name is | |
1291 | * used. | |
1292 | * If @onexec then the transition is delayed until | |
1293 | * the next exec. | |
1294 | * | |
1295 | * Returns %0 on success, error otherwise. | |
1296 | */ | |
df8073c6 | 1297 | int aa_change_profile(const char *fqname, int flags) |
898127c3 | 1298 | { |
e00b02bb JJ |
1299 | struct aa_label *label, *new = NULL, *target = NULL; |
1300 | struct aa_profile *profile; | |
2d679f3c | 1301 | struct aa_perms perms = {}; |
e00b02bb JJ |
1302 | const char *info = NULL; |
1303 | const char *auditname = fqname; /* retain leading & if stack */ | |
1304 | bool stack = flags & AA_CHANGE_STACK; | |
9fcf78cc | 1305 | struct aa_task_ctx *ctx = task_ctx(current); |
47f6e5cc | 1306 | int error = 0; |
e00b02bb | 1307 | char *op; |
898127c3 JJ |
1308 | u32 request; |
1309 | ||
9fcf78cc JJ |
1310 | label = aa_get_current_label(); |
1311 | ||
1312 | /* | |
1313 | * Detect no new privs being set, and store the label it | |
1314 | * occurred under. Ideally this would happen when nnp | |
1315 | * is set but there isn't a good way to do that yet. | |
1316 | * | |
1317 | * Testing for unconfined must be done before the subset test | |
1318 | */ | |
1319 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1320 | ctx->nnp = aa_get_label(label); | |
1321 | ||
aa9a39ad | 1322 | if (!fqname || !*fqname) { |
a0b845ff | 1323 | aa_put_label(label); |
aa9a39ad | 1324 | AA_DEBUG("no profile name"); |
898127c3 | 1325 | return -EINVAL; |
aa9a39ad | 1326 | } |
898127c3 | 1327 | |
df8073c6 | 1328 | if (flags & AA_CHANGE_ONEXEC) { |
898127c3 | 1329 | request = AA_MAY_ONEXEC; |
e00b02bb JJ |
1330 | if (stack) |
1331 | op = OP_STACK_ONEXEC; | |
1332 | else | |
1333 | op = OP_CHANGE_ONEXEC; | |
898127c3 JJ |
1334 | } else { |
1335 | request = AA_MAY_CHANGE_PROFILE; | |
e00b02bb JJ |
1336 | if (stack) |
1337 | op = OP_STACK; | |
1338 | else | |
1339 | op = OP_CHANGE_PROFILE; | |
898127c3 JJ |
1340 | } |
1341 | ||
e00b02bb JJ |
1342 | if (*fqname == '&') { |
1343 | stack = true; | |
1344 | /* don't have label_parse() do stacking */ | |
1345 | fqname++; | |
c29bceb3 | 1346 | } |
e00b02bb JJ |
1347 | target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); |
1348 | if (IS_ERR(target)) { | |
1349 | struct aa_profile *tprofile; | |
c29bceb3 | 1350 | |
e00b02bb JJ |
1351 | info = "label not found"; |
1352 | error = PTR_ERR(target); | |
1353 | target = NULL; | |
1354 | /* | |
1355 | * TODO: fixme using labels_profile is not right - do profile | |
1356 | * per complain profile | |
1357 | */ | |
df8073c6 | 1358 | if ((flags & AA_CHANGE_TEST) || |
e00b02bb | 1359 | !COMPLAIN_MODE(labels_profile(label))) |
898127c3 JJ |
1360 | goto audit; |
1361 | /* released below */ | |
e00b02bb JJ |
1362 | tprofile = aa_new_null_profile(labels_profile(label), false, |
1363 | fqname, GFP_KERNEL); | |
1364 | if (!tprofile) { | |
898127c3 JJ |
1365 | info = "failed null profile create"; |
1366 | error = -ENOMEM; | |
1367 | goto audit; | |
1368 | } | |
e00b02bb JJ |
1369 | target = &tprofile->label; |
1370 | goto check; | |
898127c3 JJ |
1371 | } |
1372 | ||
e00b02bb JJ |
1373 | /* |
1374 | * self directed transitions only apply to current policy ns | |
1375 | * TODO: currently requiring perms for stacking and straight change | |
1376 | * stacking doesn't strictly need this. Determine how much | |
1377 | * we want to loosen this restriction for stacking | |
1378 | * | |
1379 | * if (!stack) { | |
1380 | */ | |
1381 | error = fn_for_each_in_ns(label, profile, | |
1382 | change_profile_perms_wrapper(op, auditname, | |
1383 | profile, target, stack, | |
1384 | request, &perms)); | |
1385 | if (error) | |
1386 | /* auditing done in change_profile_perms_wrapper */ | |
1387 | goto out; | |
aa9a39ad | 1388 | |
e00b02bb JJ |
1389 | /* } */ |
1390 | ||
1391 | check: | |
898127c3 | 1392 | /* check if tracing task is allowed to trace target domain */ |
e00b02bb JJ |
1393 | error = may_change_ptraced_domain(target, &info); |
1394 | if (error && !fn_for_each_in_ns(label, profile, | |
1395 | COMPLAIN_MODE(profile))) | |
898127c3 | 1396 | goto audit; |
898127c3 | 1397 | |
e00b02bb JJ |
1398 | /* TODO: add permission check to allow this |
1399 | * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { | |
1400 | * info = "not a single threaded task"; | |
1401 | * error = -EACCES; | |
1402 | * goto audit; | |
1403 | * } | |
1404 | */ | |
df8073c6 | 1405 | if (flags & AA_CHANGE_TEST) |
e00b02bb | 1406 | goto out; |
898127c3 | 1407 | |
9fcf78cc JJ |
1408 | /* stacking is always a subset, so only check the nonstack case */ |
1409 | if (!stack) { | |
1410 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1411 | aa_get_label(target), | |
1412 | aa_get_label(&profile->label)); | |
1413 | /* | |
1414 | * no new privs prevents domain transitions that would | |
1415 | * reduce restrictions. | |
1416 | */ | |
1417 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1418 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { |
9fcf78cc JJ |
1419 | /* not an apparmor denial per se, so don't log it */ |
1420 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1421 | error = -EPERM; | |
1422 | goto out; | |
1423 | } | |
1424 | } | |
1425 | ||
e00b02bb JJ |
1426 | if (!(flags & AA_CHANGE_ONEXEC)) { |
1427 | /* only transition profiles in the current ns */ | |
1428 | if (stack) | |
1429 | new = aa_label_merge(label, target, GFP_KERNEL); | |
e00b02bb JJ |
1430 | if (IS_ERR_OR_NULL(new)) { |
1431 | info = "failed to build target label"; | |
d6d478ae JJ |
1432 | if (!new) |
1433 | error = -ENOMEM; | |
1434 | else | |
1435 | error = PTR_ERR(new); | |
e00b02bb JJ |
1436 | new = NULL; |
1437 | perms.allow = 0; | |
1438 | goto audit; | |
1439 | } | |
1440 | error = aa_replace_current_label(new); | |
9fcf78cc JJ |
1441 | } else { |
1442 | if (new) { | |
1443 | aa_put_label(new); | |
1444 | new = NULL; | |
1445 | } | |
1446 | ||
e00b02bb JJ |
1447 | /* full transition will be built in exec path */ |
1448 | error = aa_set_current_onexec(target, stack); | |
9fcf78cc | 1449 | } |
898127c3 JJ |
1450 | |
1451 | audit: | |
e00b02bb JJ |
1452 | error = fn_for_each_in_ns(label, profile, |
1453 | aa_audit_file(profile, &perms, op, request, auditname, | |
1454 | NULL, new ? new : target, | |
1455 | GLOBAL_ROOT_UID, info, error)); | |
898127c3 | 1456 | |
e00b02bb JJ |
1457 | out: |
1458 | aa_put_label(new); | |
1459 | aa_put_label(target); | |
637f688d | 1460 | aa_put_label(label); |
898127c3 JJ |
1461 | |
1462 | return error; | |
1463 | } |