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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 | 31 | |
898127c3 JJ |
32 | /** |
33 | * may_change_ptraced_domain - check if can change profile on ptraced task | |
b2d09ae4 JJ |
34 | * @to_label: profile to change to (NOT NULL) |
35 | * @info: message if there is an error | |
898127c3 | 36 | * |
51775fe7 | 37 | * Check if current is ptraced and if so if the tracing task is allowed |
898127c3 JJ |
38 | * to trace the new domain |
39 | * | |
40 | * Returns: %0 or error if change not allowed | |
41 | */ | |
b2d09ae4 JJ |
42 | static int may_change_ptraced_domain(struct aa_label *to_label, |
43 | const char **info) | |
898127c3 JJ |
44 | { |
45 | struct task_struct *tracer; | |
637f688d | 46 | struct aa_label *tracerl = NULL; |
898127c3 JJ |
47 | int error = 0; |
48 | ||
49 | rcu_read_lock(); | |
51775fe7 | 50 | tracer = ptrace_parent(current); |
3cfcc19e | 51 | if (tracer) |
898127c3 | 52 | /* released below */ |
637f688d | 53 | tracerl = aa_get_task_label(tracer); |
898127c3 JJ |
54 | |
55 | /* not ptraced */ | |
637f688d | 56 | if (!tracer || unconfined(tracerl)) |
898127c3 JJ |
57 | goto out; |
58 | ||
b2d09ae4 | 59 | error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); |
898127c3 JJ |
60 | |
61 | out: | |
04fdc099 | 62 | rcu_read_unlock(); |
637f688d | 63 | aa_put_label(tracerl); |
898127c3 | 64 | |
b2d09ae4 JJ |
65 | if (error) |
66 | *info = "ptrace prevents transition"; | |
898127c3 JJ |
67 | return error; |
68 | } | |
69 | ||
93c98a48 JJ |
70 | /**** TODO: dedup to aa_label_match - needs perm and dfa, merging |
71 | * specifically this is an exact copy of aa_label_match except | |
72 | * aa_compute_perms is replaced with aa_compute_fperms | |
73 | * and policy.dfa with file.dfa | |
74 | ****/ | |
75 | /* match a profile and its associated ns component if needed | |
76 | * Assumes visibility test has already been done. | |
77 | * If a subns profile is not to be matched should be prescreened with | |
78 | * visibility test. | |
79 | */ | |
33fc95d8 JJ |
80 | static inline aa_state_t match_component(struct aa_profile *profile, |
81 | struct aa_profile *tp, | |
82 | bool stack, aa_state_t state) | |
93c98a48 | 83 | { |
1ad22fcc JJ |
84 | struct aa_ruleset *rules = list_first_entry(&profile->rules, |
85 | typeof(*rules), list); | |
93c98a48 JJ |
86 | const char *ns_name; |
87 | ||
88 | if (stack) | |
217af7e2 | 89 | state = aa_dfa_match(rules->file.dfa, state, "&"); |
93c98a48 | 90 | if (profile->ns == tp->ns) |
217af7e2 | 91 | return aa_dfa_match(rules->file.dfa, state, tp->base.hname); |
93c98a48 JJ |
92 | |
93 | /* try matching with namespace name and then profile */ | |
94 | ns_name = aa_ns_name(profile->ns, tp->ns, true); | |
217af7e2 JJ |
95 | state = aa_dfa_match_len(rules->file.dfa, state, ":", 1); |
96 | state = aa_dfa_match(rules->file.dfa, state, ns_name); | |
97 | state = aa_dfa_match_len(rules->file.dfa, state, ":", 1); | |
98 | return aa_dfa_match(rules->file.dfa, state, tp->base.hname); | |
93c98a48 JJ |
99 | } |
100 | ||
101 | /** | |
102 | * label_compound_match - find perms for full compound label | |
103 | * @profile: profile to find perms for | |
104 | * @label: label to check access permissions for | |
105 | * @stack: whether this is a stacking request | |
bab1f77f | 106 | * @state: state to start match in |
93c98a48 JJ |
107 | * @subns: whether to do permission checks on components in a subns |
108 | * @request: permissions to request | |
109 | * @perms: perms struct to set | |
110 | * | |
111 | * Returns: 0 on success else ERROR | |
112 | * | |
113 | * For the label A//&B//&C this does the perm match for A//&B//&C | |
114 | * @perms should be preinitialized with allperms OR a previous permission | |
115 | * check to be stacked. | |
116 | */ | |
117 | static int label_compound_match(struct aa_profile *profile, | |
118 | struct aa_label *label, bool stack, | |
33fc95d8 | 119 | aa_state_t state, bool subns, u32 request, |
93c98a48 JJ |
120 | struct aa_perms *perms) |
121 | { | |
1ad22fcc JJ |
122 | struct aa_ruleset *rules = list_first_entry(&profile->rules, |
123 | typeof(*rules), list); | |
93c98a48 JJ |
124 | struct aa_profile *tp; |
125 | struct label_it i; | |
126 | struct path_cond cond = { }; | |
127 | ||
128 | /* find first subcomponent that is visible */ | |
129 | label_for_each(i, label, tp) { | |
130 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
131 | continue; | |
132 | state = match_component(profile, tp, stack, state); | |
133 | if (!state) | |
134 | goto fail; | |
135 | goto next; | |
136 | } | |
137 | ||
138 | /* no component visible */ | |
139 | *perms = allperms; | |
140 | return 0; | |
141 | ||
142 | next: | |
143 | label_for_each_cont(i, label, tp) { | |
144 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
145 | continue; | |
217af7e2 | 146 | state = aa_dfa_match(rules->file.dfa, state, "//&"); |
93c98a48 JJ |
147 | state = match_component(profile, tp, false, state); |
148 | if (!state) | |
149 | goto fail; | |
150 | } | |
217af7e2 | 151 | *perms = *(aa_lookup_fperms(&(rules->file), state, &cond)); |
93c98a48 JJ |
152 | aa_apply_modes_to_perms(profile, perms); |
153 | if ((perms->allow & request) != request) | |
154 | return -EACCES; | |
155 | ||
156 | return 0; | |
157 | ||
158 | fail: | |
159 | *perms = nullperms; | |
160 | return -EACCES; | |
161 | } | |
162 | ||
163 | /** | |
164 | * label_components_match - find perms for all subcomponents of a label | |
165 | * @profile: profile to find perms for | |
166 | * @label: label to check access permissions for | |
167 | * @stack: whether this is a stacking request | |
168 | * @start: state to start match in | |
169 | * @subns: whether to do permission checks on components in a subns | |
170 | * @request: permissions to request | |
171 | * @perms: an initialized perms struct to add accumulation to | |
172 | * | |
173 | * Returns: 0 on success else ERROR | |
174 | * | |
175 | * For the label A//&B//&C this does the perm match for each of A and B and C | |
176 | * @perms should be preinitialized with allperms OR a previous permission | |
177 | * check to be stacked. | |
178 | */ | |
179 | static int label_components_match(struct aa_profile *profile, | |
180 | struct aa_label *label, bool stack, | |
33fc95d8 | 181 | aa_state_t start, bool subns, u32 request, |
93c98a48 JJ |
182 | struct aa_perms *perms) |
183 | { | |
1ad22fcc JJ |
184 | struct aa_ruleset *rules = list_first_entry(&profile->rules, |
185 | typeof(*rules), list); | |
93c98a48 JJ |
186 | struct aa_profile *tp; |
187 | struct label_it i; | |
188 | struct aa_perms tmp; | |
189 | struct path_cond cond = { }; | |
33fc95d8 | 190 | aa_state_t state = 0; |
93c98a48 JJ |
191 | |
192 | /* find first subcomponent to test */ | |
193 | label_for_each(i, label, tp) { | |
194 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
195 | continue; | |
196 | state = match_component(profile, tp, stack, start); | |
197 | if (!state) | |
198 | goto fail; | |
199 | goto next; | |
200 | } | |
201 | ||
202 | /* no subcomponents visible - no change in perms */ | |
203 | return 0; | |
204 | ||
205 | next: | |
217af7e2 | 206 | tmp = *(aa_lookup_fperms(&(rules->file), state, &cond)); |
93c98a48 JJ |
207 | aa_apply_modes_to_perms(profile, &tmp); |
208 | aa_perms_accum(perms, &tmp); | |
209 | label_for_each_cont(i, label, tp) { | |
210 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
211 | continue; | |
212 | state = match_component(profile, tp, stack, start); | |
213 | if (!state) | |
214 | goto fail; | |
217af7e2 | 215 | tmp = *(aa_lookup_fperms(&(rules->file), state, &cond)); |
93c98a48 JJ |
216 | aa_apply_modes_to_perms(profile, &tmp); |
217 | aa_perms_accum(perms, &tmp); | |
218 | } | |
219 | ||
220 | if ((perms->allow & request) != request) | |
221 | return -EACCES; | |
222 | ||
223 | return 0; | |
224 | ||
225 | fail: | |
226 | *perms = nullperms; | |
227 | return -EACCES; | |
228 | } | |
229 | ||
230 | /** | |
231 | * label_match - do a multi-component label match | |
232 | * @profile: profile to match against (NOT NULL) | |
233 | * @label: label to match (NOT NULL) | |
234 | * @stack: whether this is a stacking request | |
235 | * @state: state to start in | |
236 | * @subns: whether to match subns components | |
237 | * @request: permission request | |
238 | * @perms: Returns computed perms (NOT NULL) | |
239 | * | |
240 | * Returns: the state the match finished in, may be the none matching state | |
241 | */ | |
242 | static int label_match(struct aa_profile *profile, struct aa_label *label, | |
33fc95d8 | 243 | bool stack, aa_state_t state, bool subns, u32 request, |
93c98a48 JJ |
244 | struct aa_perms *perms) |
245 | { | |
246 | int error; | |
247 | ||
248 | *perms = nullperms; | |
249 | error = label_compound_match(profile, label, stack, state, subns, | |
250 | request, perms); | |
251 | if (!error) | |
252 | return error; | |
253 | ||
254 | *perms = allperms; | |
255 | return label_components_match(profile, label, stack, state, subns, | |
256 | request, perms); | |
257 | } | |
258 | ||
259 | /******* end TODO: dedup *****/ | |
260 | ||
898127c3 JJ |
261 | /** |
262 | * change_profile_perms - find permissions for change_profile | |
263 | * @profile: the current profile (NOT NULL) | |
93c98a48 JJ |
264 | * @target: label to transition to (NOT NULL) |
265 | * @stack: whether this is a stacking request | |
898127c3 JJ |
266 | * @request: requested perms |
267 | * @start: state to start matching in | |
268 | * | |
93c98a48 | 269 | * |
898127c3 | 270 | * Returns: permission set |
93c98a48 JJ |
271 | * |
272 | * currently only matches full label A//&B//&C or individual components A, B, C | |
273 | * not arbitrary combinations. Eg. A//&B, C | |
898127c3 | 274 | */ |
93c98a48 JJ |
275 | static int change_profile_perms(struct aa_profile *profile, |
276 | struct aa_label *target, bool stack, | |
33fc95d8 | 277 | u32 request, aa_state_t start, |
93c98a48 JJ |
278 | struct aa_perms *perms) |
279 | { | |
280 | if (profile_unconfined(profile)) { | |
281 | perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; | |
282 | perms->audit = perms->quiet = perms->kill = 0; | |
283 | return 0; | |
284 | } | |
285 | ||
286 | /* TODO: add profile in ns screening */ | |
287 | return label_match(profile, target, stack, start, true, request, perms); | |
288 | } | |
289 | ||
8e51f908 MG |
290 | /** |
291 | * aa_xattrs_match - check whether a file matches the xattrs defined in profile | |
292 | * @bprm: binprm struct for the process to validate | |
293 | * @profile: profile to match against (NOT NULL) | |
73f488cd | 294 | * @state: state to start match in |
8e51f908 MG |
295 | * |
296 | * Returns: number of extended attributes that matched, or < 0 on error | |
297 | */ | |
298 | static int aa_xattrs_match(const struct linux_binprm *bprm, | |
33fc95d8 | 299 | struct aa_profile *profile, aa_state_t state) |
8e51f908 MG |
300 | { |
301 | int i; | |
8e51f908 MG |
302 | struct dentry *d; |
303 | char *value = NULL; | |
217af7e2 | 304 | struct aa_attachment *attach = &profile->attach; |
93761c93 | 305 | int size, value_size = 0, ret = attach->xattr_count; |
8e51f908 | 306 | |
217af7e2 | 307 | if (!bprm || !attach->xattr_count) |
8e51f908 | 308 | return 0; |
8c62ed27 | 309 | might_sleep(); |
8e51f908 | 310 | |
73f488cd | 311 | /* transition from exec match to xattr set */ |
217af7e2 | 312 | state = aa_dfa_outofband_transition(attach->xmatch.dfa, state); |
8e51f908 MG |
313 | d = bprm->file->f_path.dentry; |
314 | ||
217af7e2 | 315 | for (i = 0; i < attach->xattr_count; i++) { |
4609e1f1 | 316 | size = vfs_getxattr_alloc(&nop_mnt_idmap, d, attach->xattrs[i], |
c7c7a1a1 | 317 | &value, value_size, GFP_KERNEL); |
73f488cd | 318 | if (size >= 0) { |
2d63dd43 | 319 | u32 index, perm; |
8e51f908 | 320 | |
0df34a64 JJ |
321 | /* |
322 | * Check the xattr presence before value. This ensure | |
323 | * that not present xattr can be distinguished from a 0 | |
324 | * length value or rule that matches any value | |
325 | */ | |
217af7e2 | 326 | state = aa_dfa_null_transition(attach->xmatch.dfa, |
048d4954 | 327 | state); |
0df34a64 | 328 | /* Check xattr value */ |
217af7e2 | 329 | state = aa_dfa_match_len(attach->xmatch.dfa, state, |
048d4954 | 330 | value, size); |
217af7e2 JJ |
331 | index = ACCEPT_TABLE(attach->xmatch.dfa)[state]; |
332 | perm = attach->xmatch.perms[index].allow; | |
73f488cd | 333 | if (!(perm & MAY_EXEC)) { |
8e51f908 MG |
334 | ret = -EINVAL; |
335 | goto out; | |
336 | } | |
73f488cd JJ |
337 | } |
338 | /* transition to next element */ | |
217af7e2 | 339 | state = aa_dfa_outofband_transition(attach->xmatch.dfa, state); |
73f488cd JJ |
340 | if (size < 0) { |
341 | /* | |
342 | * No xattr match, so verify if transition to | |
343 | * next element was valid. IFF so the xattr | |
344 | * was optional. | |
345 | */ | |
346 | if (!state) { | |
8e51f908 MG |
347 | ret = -EINVAL; |
348 | goto out; | |
349 | } | |
73f488cd JJ |
350 | /* don't count missing optional xattr as matched */ |
351 | ret--; | |
8e51f908 MG |
352 | } |
353 | } | |
354 | ||
355 | out: | |
356 | kfree(value); | |
357 | return ret; | |
358 | } | |
359 | ||
898127c3 | 360 | /** |
8c62ed27 | 361 | * find_attach - do attachment search for unconfined processes |
8e51f908 | 362 | * @bprm - binprm structure of transitioning task |
8c62ed27 | 363 | * @ns: the current namespace (NOT NULL) |
898127c3 | 364 | * @head - profile list to walk (NOT NULL) |
8c62ed27 | 365 | * @name - to match against (NOT NULL) |
844b8292 | 366 | * @info - info message if there was an error (NOT NULL) |
898127c3 JJ |
367 | * |
368 | * Do a linear search on the profiles in the list. There is a matching | |
369 | * preference where an exact match is preferred over a name which uses | |
370 | * expressions to match, and matching expressions with the greatest | |
371 | * xmatch_len are preferred. | |
372 | * | |
373 | * Requires: @head not be shared or have appropriate locks held | |
374 | * | |
8c62ed27 | 375 | * Returns: label or NULL if no match found |
898127c3 | 376 | */ |
8c62ed27 JJ |
377 | static struct aa_label *find_attach(const struct linux_binprm *bprm, |
378 | struct aa_ns *ns, struct list_head *head, | |
379 | const char *name, const char **info) | |
898127c3 | 380 | { |
21f60661 | 381 | int candidate_len = 0, candidate_xattrs = 0; |
844b8292 | 382 | bool conflict = false; |
898127c3 JJ |
383 | struct aa_profile *profile, *candidate = NULL; |
384 | ||
21f60661 JJ |
385 | AA_BUG(!name); |
386 | AA_BUG(!head); | |
387 | ||
8c62ed27 JJ |
388 | rcu_read_lock(); |
389 | restart: | |
01e2b670 | 390 | list_for_each_entry_rcu(profile, head, base.list) { |
217af7e2 JJ |
391 | struct aa_attachment *attach = &profile->attach; |
392 | ||
06d426d1 JJ |
393 | if (profile->label.flags & FLAG_NULL && |
394 | &profile->label == ns_unconfined(profile->ns)) | |
898127c3 | 395 | continue; |
06d426d1 | 396 | |
8e51f908 MG |
397 | /* Find the "best" matching profile. Profiles must |
398 | * match the path and extended attributes (if any) | |
399 | * associated with the file. A more specific path | |
400 | * match will be preferred over a less specific one, | |
401 | * and a match with more matching extended attributes | |
402 | * will be preferred over one with fewer. If the best | |
403 | * match has both the same level of path specificity | |
404 | * and the same number of matching extended attributes | |
405 | * as another profile, signal a conflict and refuse to | |
406 | * match. | |
407 | */ | |
217af7e2 | 408 | if (attach->xmatch.dfa) { |
33fc95d8 JJ |
409 | unsigned int count; |
410 | aa_state_t state; | |
2d63dd43 | 411 | u32 index, perm; |
8e51f908 | 412 | |
217af7e2 JJ |
413 | state = aa_dfa_leftmatch(attach->xmatch.dfa, |
414 | attach->xmatch.start[AA_CLASS_XMATCH], | |
048d4954 | 415 | name, &count); |
217af7e2 JJ |
416 | index = ACCEPT_TABLE(attach->xmatch.dfa)[state]; |
417 | perm = attach->xmatch.perms[index].allow; | |
8e51f908 MG |
418 | /* any accepting state means a valid match. */ |
419 | if (perm & MAY_EXEC) { | |
8c62ed27 | 420 | int ret = 0; |
21f60661 JJ |
421 | |
422 | if (count < candidate_len) | |
423 | continue; | |
8e51f908 | 424 | |
217af7e2 | 425 | if (bprm && attach->xattr_count) { |
8c62ed27 JJ |
426 | long rev = READ_ONCE(ns->revision); |
427 | ||
428 | if (!aa_get_profile_not0(profile)) | |
429 | goto restart; | |
430 | rcu_read_unlock(); | |
431 | ret = aa_xattrs_match(bprm, profile, | |
432 | state); | |
433 | rcu_read_lock(); | |
434 | aa_put_profile(profile); | |
435 | if (rev != | |
436 | READ_ONCE(ns->revision)) | |
437 | /* policy changed */ | |
438 | goto restart; | |
439 | /* | |
440 | * Fail matching if the xattrs don't | |
441 | * match | |
442 | */ | |
443 | if (ret < 0) | |
444 | continue; | |
445 | } | |
73f488cd JJ |
446 | /* |
447 | * TODO: allow for more flexible best match | |
448 | * | |
449 | * The new match isn't more specific | |
8e51f908 MG |
450 | * than the current best match |
451 | */ | |
21f60661 JJ |
452 | if (count == candidate_len && |
453 | ret <= candidate_xattrs) { | |
8e51f908 | 454 | /* Match is equivalent, so conflict */ |
21f60661 | 455 | if (ret == candidate_xattrs) |
1a3881d3 | 456 | conflict = true; |
8e51f908 | 457 | continue; |
844b8292 | 458 | } |
8e51f908 MG |
459 | |
460 | /* Either the same length with more matching | |
461 | * xattrs, or a longer match | |
462 | */ | |
463 | candidate = profile; | |
217af7e2 | 464 | candidate_len = max(count, attach->xmatch_len); |
21f60661 | 465 | candidate_xattrs = ret; |
8e51f908 | 466 | conflict = false; |
898127c3 | 467 | } |
8c62ed27 | 468 | } else if (!strcmp(profile->base.name, name)) { |
73f488cd JJ |
469 | /* |
470 | * old exact non-re match, without conditionals such | |
471 | * as xattrs. no more searching required | |
472 | */ | |
8c62ed27 JJ |
473 | candidate = profile; |
474 | goto out; | |
475 | } | |
898127c3 JJ |
476 | } |
477 | ||
8c62ed27 JJ |
478 | if (!candidate || conflict) { |
479 | if (conflict) | |
480 | *info = "conflicting profile attachments"; | |
481 | rcu_read_unlock(); | |
844b8292 JJ |
482 | return NULL; |
483 | } | |
484 | ||
8c62ed27 JJ |
485 | out: |
486 | candidate = aa_get_newest_profile(candidate); | |
01e2b670 | 487 | rcu_read_unlock(); |
898127c3 | 488 | |
8c62ed27 | 489 | return &candidate->label; |
898127c3 JJ |
490 | } |
491 | ||
492 | static const char *next_name(int xtype, const char *name) | |
493 | { | |
494 | return NULL; | |
495 | } | |
496 | ||
497 | /** | |
498 | * x_table_lookup - lookup an x transition name via transition table | |
499 | * @profile: current profile (NOT NULL) | |
500 | * @xindex: index into x transition table | |
93c98a48 | 501 | * @name: returns: name tested to find label (NOT NULL) |
898127c3 | 502 | * |
93c98a48 | 503 | * Returns: refcounted label, or NULL on failure (MAYBE NULL) |
898127c3 | 504 | */ |
2ea3ffb7 JJ |
505 | struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, |
506 | const char **name) | |
898127c3 | 507 | { |
1ad22fcc JJ |
508 | struct aa_ruleset *rules = list_first_entry(&profile->rules, |
509 | typeof(*rules), list); | |
93c98a48 | 510 | struct aa_label *label = NULL; |
898127c3 JJ |
511 | u32 xtype = xindex & AA_X_TYPE_MASK; |
512 | int index = xindex & AA_X_INDEX_MASK; | |
898127c3 | 513 | |
93c98a48 | 514 | AA_BUG(!name); |
898127c3 | 515 | |
93c98a48 JJ |
516 | /* index is guaranteed to be in range, validated at load time */ |
517 | /* TODO: move lookup parsing to unpack time so this is a straight | |
518 | * index into the resultant label | |
519 | */ | |
217af7e2 | 520 | for (*name = rules->file.trans.table[index]; !label && *name; |
93c98a48 | 521 | *name = next_name(xtype, *name)) { |
898127c3 | 522 | if (xindex & AA_X_CHILD) { |
93c98a48 | 523 | struct aa_profile *new_profile; |
898127c3 | 524 | /* release by caller */ |
93c98a48 JJ |
525 | new_profile = aa_find_child(profile, *name); |
526 | if (new_profile) | |
527 | label = &new_profile->label; | |
898127c3 | 528 | continue; |
898127c3 | 529 | } |
8ac2ca32 | 530 | label = aa_label_parse(&profile->label, *name, GFP_KERNEL, |
93c98a48 JJ |
531 | true, false); |
532 | if (IS_ERR(label)) | |
533 | label = NULL; | |
898127c3 JJ |
534 | } |
535 | ||
536 | /* released by caller */ | |
93c98a48 JJ |
537 | |
538 | return label; | |
898127c3 JJ |
539 | } |
540 | ||
541 | /** | |
93c98a48 | 542 | * x_to_label - get target label for a given xindex |
898127c3 | 543 | * @profile: current profile (NOT NULL) |
8e51f908 | 544 | * @bprm: binprm structure of transitioning task |
898127c3 JJ |
545 | * @name: name to lookup (NOT NULL) |
546 | * @xindex: index into x transition table | |
93c98a48 | 547 | * @lookupname: returns: name used in lookup if one was specified (NOT NULL) |
898127c3 | 548 | * |
93c98a48 | 549 | * find label for a transition index |
898127c3 | 550 | * |
93c98a48 | 551 | * Returns: refcounted label or NULL if not found available |
898127c3 | 552 | */ |
93c98a48 | 553 | static struct aa_label *x_to_label(struct aa_profile *profile, |
8e51f908 | 554 | const struct linux_binprm *bprm, |
93c98a48 JJ |
555 | const char *name, u32 xindex, |
556 | const char **lookupname, | |
557 | const char **info) | |
898127c3 | 558 | { |
1ad22fcc JJ |
559 | struct aa_ruleset *rules = list_first_entry(&profile->rules, |
560 | typeof(*rules), list); | |
93c98a48 | 561 | struct aa_label *new = NULL; |
98849dff | 562 | struct aa_ns *ns = profile->ns; |
898127c3 | 563 | u32 xtype = xindex & AA_X_TYPE_MASK; |
93c98a48 | 564 | const char *stack = NULL; |
898127c3 JJ |
565 | |
566 | switch (xtype) { | |
567 | case AA_X_NONE: | |
568 | /* fail exec unless ix || ux fallback - handled by caller */ | |
93c98a48 JJ |
569 | *lookupname = NULL; |
570 | break; | |
571 | case AA_X_TABLE: | |
572 | /* TODO: fix when perm mapping done at unload */ | |
217af7e2 | 573 | stack = rules->file.trans.table[xindex & AA_X_INDEX_MASK]; |
93c98a48 JJ |
574 | if (*stack != '&') { |
575 | /* released by caller */ | |
576 | new = x_table_lookup(profile, xindex, lookupname); | |
577 | stack = NULL; | |
578 | break; | |
579 | } | |
df561f66 | 580 | fallthrough; /* to X_NAME */ |
898127c3 JJ |
581 | case AA_X_NAME: |
582 | if (xindex & AA_X_CHILD) | |
583 | /* released by caller */ | |
8e51f908 | 584 | new = find_attach(bprm, ns, &profile->base.profiles, |
844b8292 | 585 | name, info); |
898127c3 JJ |
586 | else |
587 | /* released by caller */ | |
8e51f908 | 588 | new = find_attach(bprm, ns, &ns->base.profiles, |
844b8292 | 589 | name, info); |
93c98a48 | 590 | *lookupname = name; |
898127c3 JJ |
591 | break; |
592 | } | |
593 | ||
93c98a48 JJ |
594 | if (!new) { |
595 | if (xindex & AA_X_INHERIT) { | |
596 | /* (p|c|n)ix - don't change profile but do | |
597 | * use the newest version | |
598 | */ | |
599 | *info = "ix fallback"; | |
600 | /* no profile && no error */ | |
601 | new = aa_get_newest_label(&profile->label); | |
602 | } else if (xindex & AA_X_UNCONFINED) { | |
603 | new = aa_get_newest_label(ns_unconfined(profile->ns)); | |
604 | *info = "ux fallback"; | |
605 | } | |
606 | } | |
607 | ||
608 | if (new && stack) { | |
609 | /* base the stack on post domain transition */ | |
610 | struct aa_label *base = new; | |
611 | ||
8ac2ca32 | 612 | new = aa_label_parse(base, stack, GFP_KERNEL, true, false); |
93c98a48 JJ |
613 | if (IS_ERR(new)) |
614 | new = NULL; | |
615 | aa_put_label(base); | |
616 | } | |
617 | ||
898127c3 | 618 | /* released by caller */ |
93c98a48 | 619 | return new; |
898127c3 JJ |
620 | } |
621 | ||
93c98a48 JJ |
622 | static struct aa_label *profile_transition(struct aa_profile *profile, |
623 | const struct linux_binprm *bprm, | |
624 | char *buffer, struct path_cond *cond, | |
625 | bool *secure_exec) | |
898127c3 | 626 | { |
1ad22fcc JJ |
627 | struct aa_ruleset *rules = list_first_entry(&profile->rules, |
628 | typeof(*rules), list); | |
93c98a48 JJ |
629 | struct aa_label *new = NULL; |
630 | const char *info = NULL, *name = NULL, *target = NULL; | |
217af7e2 | 631 | aa_state_t state = rules->file.start[AA_CLASS_FILE]; |
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 */ | |
217af7e2 | 665 | state = aa_str_perms(&(rules->file), 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 | 682 | |
58f89ce5 JJ |
683 | new_profile = aa_new_learning_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 | { | |
1ad22fcc JJ |
727 | struct aa_ruleset *rules = list_first_entry(&profile->rules, |
728 | typeof(*rules), list); | |
217af7e2 | 729 | aa_state_t state = rules->file.start[AA_CLASS_FILE]; |
93c98a48 JJ |
730 | struct aa_perms perms = {}; |
731 | const char *xname = NULL, *info = "change_profile onexec"; | |
732 | int error = -EACCES; | |
733 | ||
734 | AA_BUG(!profile); | |
735 | AA_BUG(!onexec); | |
736 | AA_BUG(!bprm); | |
737 | AA_BUG(!buffer); | |
738 | ||
739 | if (profile_unconfined(profile)) { | |
740 | /* change_profile on exec already granted */ | |
741 | /* | |
742 | * NOTE: Domain transitions from unconfined are allowed | |
743 | * even when no_new_privs is set because this aways results | |
744 | * in a further reduction of permissions. | |
745 | */ | |
746 | return 0; | |
747 | } | |
748 | ||
749 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, | |
750 | &xname, &info, profile->disconnected); | |
751 | if (error) { | |
752 | if (profile_unconfined(profile) || | |
753 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { | |
754 | AA_DEBUG("name lookup ix on error"); | |
755 | error = 0; | |
756 | } | |
757 | xname = bprm->filename; | |
898127c3 | 758 | goto audit; |
93c98a48 JJ |
759 | } |
760 | ||
761 | /* find exec permissions for name */ | |
217af7e2 | 762 | state = aa_str_perms(&(rules->file), state, xname, cond, &perms); |
93c98a48 JJ |
763 | if (!(perms.allow & AA_MAY_ONEXEC)) { |
764 | info = "no change_onexec valid for executable"; | |
765 | goto audit; | |
766 | } | |
767 | /* test if this exec can be paired with change_profile onexec. | |
768 | * onexec permission is linked to exec with a standard pairing | |
769 | * exec\0change_profile | |
770 | */ | |
217af7e2 | 771 | state = aa_dfa_null_transition(rules->file.dfa, state); |
93c98a48 JJ |
772 | error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, |
773 | state, &perms); | |
774 | if (error) { | |
775 | perms.allow &= ~AA_MAY_ONEXEC; | |
776 | goto audit; | |
777 | } | |
93c98a48 JJ |
778 | |
779 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
780 | if (DEBUG_ON) { | |
781 | dbg_printk("apparmor: scrubbing environment " | |
782 | "variables for %s label=", xname); | |
8ac2ca32 | 783 | aa_label_printk(onexec, GFP_KERNEL); |
93c98a48 JJ |
784 | dbg_printk("\n"); |
785 | } | |
786 | *secure_exec = true; | |
787 | } | |
788 | ||
789 | audit: | |
790 | return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, | |
791 | NULL, onexec, cond->uid, info, error); | |
792 | } | |
793 | ||
794 | /* ensure none ns domain transitions are correctly applied with onexec */ | |
795 | ||
796 | static struct aa_label *handle_onexec(struct aa_label *label, | |
797 | struct aa_label *onexec, bool stack, | |
798 | const struct linux_binprm *bprm, | |
799 | char *buffer, struct path_cond *cond, | |
800 | bool *unsafe) | |
801 | { | |
802 | struct aa_profile *profile; | |
803 | struct aa_label *new; | |
804 | int error; | |
805 | ||
806 | AA_BUG(!label); | |
807 | AA_BUG(!onexec); | |
808 | AA_BUG(!bprm); | |
809 | AA_BUG(!buffer); | |
810 | ||
811 | if (!stack) { | |
812 | error = fn_for_each_in_ns(label, profile, | |
813 | profile_onexec(profile, onexec, stack, | |
814 | bprm, buffer, cond, unsafe)); | |
815 | if (error) | |
816 | return ERR_PTR(error); | |
8ac2ca32 | 817 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 JJ |
818 | aa_get_newest_label(onexec), |
819 | profile_transition(profile, bprm, buffer, | |
820 | cond, unsafe)); | |
821 | ||
822 | } else { | |
b2c2086c | 823 | /* TODO: determine how much we want to loosen this */ |
93c98a48 JJ |
824 | error = fn_for_each_in_ns(label, profile, |
825 | profile_onexec(profile, onexec, stack, bprm, | |
826 | buffer, cond, unsafe)); | |
827 | if (error) | |
828 | return ERR_PTR(error); | |
8ac2ca32 | 829 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 | 830 | aa_label_merge(&profile->label, onexec, |
8ac2ca32 | 831 | GFP_KERNEL), |
93c98a48 JJ |
832 | profile_transition(profile, bprm, buffer, |
833 | cond, unsafe)); | |
834 | } | |
835 | ||
836 | if (new) | |
837 | return new; | |
838 | ||
839 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
840 | error = fn_for_each_in_ns(label, profile, | |
841 | aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, | |
842 | AA_MAY_ONEXEC, bprm->filename, NULL, | |
843 | onexec, GLOBAL_ROOT_UID, | |
844 | "failed to build target label", -ENOMEM)); | |
845 | return ERR_PTR(error); | |
846 | } | |
847 | ||
848 | /** | |
b8bff599 | 849 | * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct |
93c98a48 JJ |
850 | * @bprm: binprm for the exec (NOT NULL) |
851 | * | |
852 | * Returns: %0 or error on failure | |
853 | * | |
854 | * TODO: once the other paths are done see if we can't refactor into a fn | |
855 | */ | |
b8bff599 | 856 | int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm) |
93c98a48 | 857 | { |
f175221a | 858 | struct aa_task_ctx *ctx; |
93c98a48 JJ |
859 | struct aa_label *label, *new = NULL; |
860 | struct aa_profile *profile; | |
861 | char *buffer = NULL; | |
862 | const char *info = NULL; | |
863 | int error = 0; | |
864 | bool unsafe = false; | |
e67fe633 | 865 | vfsuid_t vfsuid = i_uid_into_vfsuid(file_mnt_idmap(bprm->file), |
5e26a01e | 866 | file_inode(bprm->file)); |
93c98a48 | 867 | struct path_cond cond = { |
5e26a01e | 868 | vfsuid_into_kuid(vfsuid), |
93c98a48 JJ |
869 | file_inode(bprm->file)->i_mode |
870 | }; | |
871 | ||
de62de59 | 872 | ctx = task_ctx(current); |
d9087c49 | 873 | AA_BUG(!cred_label(bprm->cred)); |
f175221a | 874 | AA_BUG(!ctx); |
93c98a48 | 875 | |
d9087c49 | 876 | label = aa_get_newest_label(cred_label(bprm->cred)); |
93c98a48 | 877 | |
9fcf78cc JJ |
878 | /* |
879 | * Detect no new privs being set, and store the label it | |
880 | * occurred under. Ideally this would happen when nnp | |
881 | * is set but there isn't a good way to do that yet. | |
882 | * | |
883 | * Testing for unconfined must be done before the subset test | |
884 | */ | |
885 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) && | |
886 | !ctx->nnp) | |
887 | ctx->nnp = aa_get_label(label); | |
888 | ||
93c98a48 | 889 | /* buffer freed below, name is pointer into buffer */ |
341c1fda | 890 | buffer = aa_get_buffer(false); |
df323337 SAS |
891 | if (!buffer) { |
892 | error = -ENOMEM; | |
893 | goto done; | |
894 | } | |
895 | ||
93c98a48 | 896 | /* Test for onexec first as onexec override other x transitions. */ |
f175221a JJ |
897 | if (ctx->onexec) |
898 | new = handle_onexec(label, ctx->onexec, ctx->token, | |
93c98a48 JJ |
899 | bprm, buffer, &cond, &unsafe); |
900 | else | |
8ac2ca32 | 901 | new = fn_label_build(label, profile, GFP_KERNEL, |
93c98a48 JJ |
902 | profile_transition(profile, bprm, buffer, |
903 | &cond, &unsafe)); | |
904 | ||
905 | AA_BUG(!new); | |
906 | if (IS_ERR(new)) { | |
907 | error = PTR_ERR(new); | |
908 | goto done; | |
909 | } else if (!new) { | |
910 | error = -ENOMEM; | |
911 | goto done; | |
912 | } | |
913 | ||
9fcf78cc JJ |
914 | /* Policy has specified a domain transitions. If no_new_privs and |
915 | * confined ensure the transition is to confinement that is subset | |
916 | * of the confinement when the task entered no new privs. | |
917 | * | |
918 | * NOTE: Domain transitions from unconfined and to stacked | |
919 | * subsets are allowed even when no_new_privs is set because this | |
920 | * aways results in a further reduction of permissions. | |
921 | */ | |
922 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && | |
3ed4aaa9 JJ |
923 | !unconfined(label) && |
924 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { | |
9fcf78cc JJ |
925 | error = -EPERM; |
926 | info = "no new privs"; | |
927 | goto audit; | |
928 | } | |
898127c3 JJ |
929 | |
930 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
931 | /* FIXME: currently don't mediate shared state */ | |
932 | ; | |
933 | } | |
934 | ||
93c98a48 JJ |
935 | if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { |
936 | /* TODO: test needs to be profile of label to new */ | |
937 | error = may_change_ptraced_domain(new, &info); | |
f7da2de0 | 938 | if (error) |
898127c3 | 939 | goto audit; |
898127c3 JJ |
940 | } |
941 | ||
93c98a48 JJ |
942 | if (unsafe) { |
943 | if (DEBUG_ON) { | |
944 | dbg_printk("scrubbing environment variables for %s " | |
945 | "label=", bprm->filename); | |
8ac2ca32 | 946 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
947 | dbg_printk("\n"); |
948 | } | |
993b3ab0 | 949 | bprm->secureexec = 1; |
898127c3 | 950 | } |
898127c3 | 951 | |
93c98a48 JJ |
952 | if (label->proxy != new->proxy) { |
953 | /* when transitioning clear unsafe personality bits */ | |
954 | if (DEBUG_ON) { | |
955 | dbg_printk("apparmor: clearing unsafe personality " | |
956 | "bits. %s label=", bprm->filename); | |
8ac2ca32 | 957 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
958 | dbg_printk("\n"); |
959 | } | |
960 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
961 | } | |
d9087c49 JJ |
962 | aa_put_label(cred_label(bprm->cred)); |
963 | /* transfer reference, released when cred is freed */ | |
69b5a44a | 964 | set_cred_label(bprm->cred, new); |
898127c3 | 965 | |
93c98a48 | 966 | done: |
637f688d | 967 | aa_put_label(label); |
df323337 | 968 | aa_put_buffer(buffer); |
898127c3 JJ |
969 | |
970 | return error; | |
93c98a48 JJ |
971 | |
972 | audit: | |
973 | error = fn_for_each(label, profile, | |
974 | aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, | |
975 | bprm->filename, NULL, new, | |
5e26a01e | 976 | vfsuid_into_kuid(vfsuid), info, error)); |
93c98a48 JJ |
977 | aa_put_label(new); |
978 | goto done; | |
898127c3 JJ |
979 | } |
980 | ||
898127c3 JJ |
981 | /* |
982 | * Functions for self directed profile change | |
983 | */ | |
984 | ||
89dbf196 JJ |
985 | |
986 | /* helper fn for change_hat | |
898127c3 | 987 | * |
89dbf196 | 988 | * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL |
898127c3 | 989 | */ |
89dbf196 JJ |
990 | static struct aa_label *build_change_hat(struct aa_profile *profile, |
991 | const char *name, bool sibling) | |
898127c3 | 992 | { |
89dbf196 JJ |
993 | struct aa_profile *root, *hat = NULL; |
994 | const char *info = NULL; | |
995 | int error = 0; | |
996 | ||
997 | if (sibling && PROFILE_IS_HAT(profile)) { | |
998 | root = aa_get_profile_rcu(&profile->parent); | |
999 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1000 | root = aa_get_profile(profile); | |
1001 | } else { | |
1002 | info = "conflicting target types"; | |
1003 | error = -EPERM; | |
1004 | goto audit; | |
1005 | } | |
1006 | ||
1007 | hat = aa_find_child(root, name); | |
1008 | if (!hat) { | |
1009 | error = -ENOENT; | |
1010 | if (COMPLAIN_MODE(profile)) { | |
58f89ce5 JJ |
1011 | hat = aa_new_learning_profile(profile, true, name, |
1012 | GFP_KERNEL); | |
89dbf196 JJ |
1013 | if (!hat) { |
1014 | info = "failed null profile create"; | |
1015 | error = -ENOMEM; | |
1016 | } | |
1017 | } | |
1018 | } | |
1019 | aa_put_profile(root); | |
1020 | ||
1021 | audit: | |
1022 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, | |
1023 | name, hat ? hat->base.hname : NULL, | |
24b87a16 | 1024 | hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, |
89dbf196 JJ |
1025 | error); |
1026 | if (!hat || (error && error != -ENOENT)) | |
1027 | return ERR_PTR(error); | |
1028 | /* if hat && error - complain mode, already audited and we adjust for | |
1029 | * complain mode allow by returning hat->label | |
1030 | */ | |
1031 | return &hat->label; | |
1032 | } | |
1033 | ||
1034 | /* helper fn for changing into a hat | |
1035 | * | |
1036 | * Returns: label for hat transition or ERR_PTR. Does not return NULL | |
1037 | */ | |
1038 | static struct aa_label *change_hat(struct aa_label *label, const char *hats[], | |
1039 | int count, int flags) | |
1040 | { | |
1041 | struct aa_profile *profile, *root, *hat = NULL; | |
1042 | struct aa_label *new; | |
1043 | struct label_it it; | |
1044 | bool sibling = false; | |
1045 | const char *name, *info = NULL; | |
1046 | int i, error; | |
1047 | ||
1048 | AA_BUG(!label); | |
1049 | AA_BUG(!hats); | |
1050 | AA_BUG(count < 1); | |
1051 | ||
1052 | if (PROFILE_IS_HAT(labels_profile(label))) | |
1053 | sibling = true; | |
1054 | ||
1055 | /*find first matching hat */ | |
1056 | for (i = 0; i < count && !hat; i++) { | |
1057 | name = hats[i]; | |
1058 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1059 | if (sibling && PROFILE_IS_HAT(profile)) { | |
1060 | root = aa_get_profile_rcu(&profile->parent); | |
1061 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1062 | root = aa_get_profile(profile); | |
1063 | } else { /* conflicting change type */ | |
1064 | info = "conflicting targets types"; | |
1065 | error = -EPERM; | |
1066 | goto fail; | |
1067 | } | |
1068 | hat = aa_find_child(root, name); | |
1069 | aa_put_profile(root); | |
1070 | if (!hat) { | |
1071 | if (!COMPLAIN_MODE(profile)) | |
1072 | goto outer_continue; | |
1073 | /* complain mode succeed as if hat */ | |
1074 | } else if (!PROFILE_IS_HAT(hat)) { | |
1075 | info = "target not hat"; | |
1076 | error = -EPERM; | |
1077 | aa_put_profile(hat); | |
1078 | goto fail; | |
1079 | } | |
1080 | aa_put_profile(hat); | |
1081 | } | |
1082 | /* found a hat for all profiles in ns */ | |
1083 | goto build; | |
1084 | outer_continue: | |
1085 | ; | |
1086 | } | |
1087 | /* no hats that match, find appropriate error | |
1088 | * | |
1089 | * In complain mode audit of the failure is based off of the first | |
1090 | * hat supplied. This is done due how userspace interacts with | |
1091 | * change_hat. | |
1092 | */ | |
1093 | name = NULL; | |
1094 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1095 | if (!list_empty(&profile->base.profiles)) { | |
1096 | info = "hat not found"; | |
1097 | error = -ENOENT; | |
1098 | goto fail; | |
1099 | } | |
1100 | } | |
1101 | info = "no hats defined"; | |
1102 | error = -ECHILD; | |
1103 | ||
1104 | fail: | |
1105 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1106 | /* | |
1107 | * no target as it has failed to be found or built | |
1108 | * | |
1109 | * change_hat uses probing and should not log failures | |
1110 | * related to missing hats | |
1111 | */ | |
1112 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
1113 | if (count > 1 || COMPLAIN_MODE(profile)) { | |
1114 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, | |
1115 | AA_MAY_CHANGEHAT, name, NULL, NULL, | |
1116 | GLOBAL_ROOT_UID, info, error); | |
1117 | } | |
1118 | } | |
1119 | return ERR_PTR(error); | |
1120 | ||
1121 | build: | |
1122 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1123 | build_change_hat(profile, name, sibling), | |
1124 | aa_get_label(&profile->label)); | |
1125 | if (!new) { | |
1126 | info = "label build failed"; | |
1127 | error = -ENOMEM; | |
1128 | goto fail; | |
1129 | } /* else if (IS_ERR) build_change_hat has logged error so return new */ | |
1130 | ||
1131 | return new; | |
898127c3 JJ |
1132 | } |
1133 | ||
1134 | /** | |
1135 | * aa_change_hat - change hat to/from subprofile | |
1136 | * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) | |
1137 | * @count: number of hat names in @hats | |
1138 | * @token: magic value to validate the hat change | |
df8073c6 | 1139 | * @flags: flags affecting behavior of the change |
898127c3 | 1140 | * |
89dbf196 JJ |
1141 | * Returns %0 on success, error otherwise. |
1142 | * | |
898127c3 JJ |
1143 | * Change to the first profile specified in @hats that exists, and store |
1144 | * the @hat_magic in the current task context. If the count == 0 and the | |
1145 | * @token matches that stored in the current task context, return to the | |
1146 | * top level profile. | |
1147 | * | |
89dbf196 JJ |
1148 | * change_hat only applies to profiles in the current ns, and each profile |
1149 | * in the ns must make the same transition otherwise change_hat will fail. | |
898127c3 | 1150 | */ |
df8073c6 | 1151 | int aa_change_hat(const char *hats[], int count, u64 token, int flags) |
898127c3 JJ |
1152 | { |
1153 | const struct cred *cred; | |
9fcf78cc | 1154 | struct aa_task_ctx *ctx = task_ctx(current); |
89dbf196 JJ |
1155 | struct aa_label *label, *previous, *new = NULL, *target = NULL; |
1156 | struct aa_profile *profile; | |
2d679f3c | 1157 | struct aa_perms perms = {}; |
89dbf196 | 1158 | const char *info = NULL; |
898127c3 JJ |
1159 | int error = 0; |
1160 | ||
1161 | /* released below */ | |
1162 | cred = get_current_cred(); | |
637f688d | 1163 | label = aa_get_newest_cred_label(cred); |
f175221a | 1164 | previous = aa_get_newest_label(ctx->previous); |
898127c3 | 1165 | |
9fcf78cc JJ |
1166 | /* |
1167 | * Detect no new privs being set, and store the label it | |
1168 | * occurred under. Ideally this would happen when nnp | |
1169 | * is set but there isn't a good way to do that yet. | |
1170 | * | |
1171 | * Testing for unconfined must be done before the subset test | |
1172 | */ | |
1173 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1174 | ctx->nnp = aa_get_label(label); | |
1175 | ||
637f688d | 1176 | if (unconfined(label)) { |
89dbf196 | 1177 | info = "unconfined can not change_hat"; |
898127c3 | 1178 | error = -EPERM; |
89dbf196 | 1179 | goto fail; |
898127c3 JJ |
1180 | } |
1181 | ||
1182 | if (count) { | |
89dbf196 JJ |
1183 | new = change_hat(label, hats, count, flags); |
1184 | AA_BUG(!new); | |
1185 | if (IS_ERR(new)) { | |
1186 | error = PTR_ERR(new); | |
1187 | new = NULL; | |
1188 | /* already audited */ | |
1189 | goto out; | |
898127c3 JJ |
1190 | } |
1191 | ||
89dbf196 JJ |
1192 | error = may_change_ptraced_domain(new, &info); |
1193 | if (error) | |
1194 | goto fail; | |
898127c3 | 1195 | |
9fcf78cc JJ |
1196 | /* |
1197 | * no new privs prevents domain transitions that would | |
1198 | * reduce restrictions. | |
1199 | */ | |
1200 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1201 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { |
9fcf78cc JJ |
1202 | /* not an apparmor denial per se, so don't log it */ |
1203 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1204 | error = -EPERM; | |
1205 | goto out; | |
1206 | } | |
1207 | ||
89dbf196 JJ |
1208 | if (flags & AA_CHANGE_TEST) |
1209 | goto out; | |
1210 | ||
1211 | target = new; | |
1212 | error = aa_set_current_hat(new, token); | |
1213 | if (error == -EACCES) | |
1214 | /* kill task in case of brute force attacks */ | |
1215 | goto kill; | |
1216 | } else if (previous && !(flags & AA_CHANGE_TEST)) { | |
9fcf78cc JJ |
1217 | /* |
1218 | * no new privs prevents domain transitions that would | |
1219 | * reduce restrictions. | |
1220 | */ | |
1221 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1222 | !aa_label_is_unconfined_subset(previous, ctx->nnp)) { |
9fcf78cc JJ |
1223 | /* not an apparmor denial per se, so don't log it */ |
1224 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1225 | error = -EPERM; | |
1226 | goto out; | |
1227 | } | |
1228 | ||
89dbf196 | 1229 | /* Return to saved label. Kill task if restore fails |
898127c3 JJ |
1230 | * to avoid brute force attacks |
1231 | */ | |
89dbf196 | 1232 | target = previous; |
637f688d | 1233 | error = aa_restore_previous_label(token); |
89dbf196 JJ |
1234 | if (error) { |
1235 | if (error == -EACCES) | |
1236 | goto kill; | |
1237 | goto fail; | |
1238 | } | |
1239 | } /* else ignore @flags && restores when there is no saved profile */ | |
898127c3 JJ |
1240 | |
1241 | out: | |
89dbf196 JJ |
1242 | aa_put_label(new); |
1243 | aa_put_label(previous); | |
637f688d | 1244 | aa_put_label(label); |
898127c3 JJ |
1245 | put_cred(cred); |
1246 | ||
1247 | return error; | |
89dbf196 JJ |
1248 | |
1249 | kill: | |
1250 | info = "failed token match"; | |
1251 | perms.kill = AA_MAY_CHANGEHAT; | |
1252 | ||
1253 | fail: | |
1254 | fn_for_each_in_ns(label, profile, | |
1255 | aa_audit_file(profile, &perms, OP_CHANGE_HAT, | |
1256 | AA_MAY_CHANGEHAT, NULL, NULL, target, | |
1257 | GLOBAL_ROOT_UID, info, error)); | |
1258 | ||
1259 | goto out; | |
898127c3 JJ |
1260 | } |
1261 | ||
89dbf196 | 1262 | |
e00b02bb JJ |
1263 | static int change_profile_perms_wrapper(const char *op, const char *name, |
1264 | struct aa_profile *profile, | |
1265 | struct aa_label *target, bool stack, | |
1266 | u32 request, struct aa_perms *perms) | |
1267 | { | |
1ad22fcc JJ |
1268 | struct aa_ruleset *rules = list_first_entry(&profile->rules, |
1269 | typeof(*rules), list); | |
e00b02bb JJ |
1270 | const char *info = NULL; |
1271 | int error = 0; | |
1272 | ||
e00b02bb JJ |
1273 | if (!error) |
1274 | error = change_profile_perms(profile, target, stack, request, | |
217af7e2 | 1275 | rules->file.start[AA_CLASS_FILE], |
53bdc46f | 1276 | perms); |
e00b02bb JJ |
1277 | if (error) |
1278 | error = aa_audit_file(profile, perms, op, request, name, | |
1279 | NULL, target, GLOBAL_ROOT_UID, info, | |
1280 | error); | |
1281 | ||
1282 | return error; | |
1283 | } | |
89dbf196 | 1284 | |
898127c3 JJ |
1285 | /** |
1286 | * aa_change_profile - perform a one-way profile transition | |
aa9a39ad | 1287 | * @fqname: name of profile may include namespace (NOT NULL) |
df8073c6 | 1288 | * @flags: flags affecting change behavior |
898127c3 JJ |
1289 | * |
1290 | * Change to new profile @name. Unlike with hats, there is no way | |
1291 | * to change back. If @name isn't specified the current profile name is | |
1292 | * used. | |
1293 | * If @onexec then the transition is delayed until | |
1294 | * the next exec. | |
1295 | * | |
1296 | * Returns %0 on success, error otherwise. | |
1297 | */ | |
df8073c6 | 1298 | int aa_change_profile(const char *fqname, int flags) |
898127c3 | 1299 | { |
e00b02bb JJ |
1300 | struct aa_label *label, *new = NULL, *target = NULL; |
1301 | struct aa_profile *profile; | |
2d679f3c | 1302 | struct aa_perms perms = {}; |
e00b02bb JJ |
1303 | const char *info = NULL; |
1304 | const char *auditname = fqname; /* retain leading & if stack */ | |
1305 | bool stack = flags & AA_CHANGE_STACK; | |
9fcf78cc | 1306 | struct aa_task_ctx *ctx = task_ctx(current); |
47f6e5cc | 1307 | int error = 0; |
e00b02bb | 1308 | char *op; |
898127c3 JJ |
1309 | u32 request; |
1310 | ||
9fcf78cc JJ |
1311 | label = aa_get_current_label(); |
1312 | ||
1313 | /* | |
1314 | * Detect no new privs being set, and store the label it | |
1315 | * occurred under. Ideally this would happen when nnp | |
1316 | * is set but there isn't a good way to do that yet. | |
1317 | * | |
1318 | * Testing for unconfined must be done before the subset test | |
1319 | */ | |
1320 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1321 | ctx->nnp = aa_get_label(label); | |
1322 | ||
aa9a39ad | 1323 | if (!fqname || !*fqname) { |
a0b845ff | 1324 | aa_put_label(label); |
aa9a39ad | 1325 | AA_DEBUG("no profile name"); |
898127c3 | 1326 | return -EINVAL; |
aa9a39ad | 1327 | } |
898127c3 | 1328 | |
df8073c6 | 1329 | if (flags & AA_CHANGE_ONEXEC) { |
898127c3 | 1330 | request = AA_MAY_ONEXEC; |
e00b02bb JJ |
1331 | if (stack) |
1332 | op = OP_STACK_ONEXEC; | |
1333 | else | |
1334 | op = OP_CHANGE_ONEXEC; | |
898127c3 JJ |
1335 | } else { |
1336 | request = AA_MAY_CHANGE_PROFILE; | |
e00b02bb JJ |
1337 | if (stack) |
1338 | op = OP_STACK; | |
1339 | else | |
1340 | op = OP_CHANGE_PROFILE; | |
898127c3 JJ |
1341 | } |
1342 | ||
e00b02bb JJ |
1343 | if (*fqname == '&') { |
1344 | stack = true; | |
1345 | /* don't have label_parse() do stacking */ | |
1346 | fqname++; | |
c29bceb3 | 1347 | } |
e00b02bb JJ |
1348 | target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); |
1349 | if (IS_ERR(target)) { | |
1350 | struct aa_profile *tprofile; | |
c29bceb3 | 1351 | |
e00b02bb JJ |
1352 | info = "label not found"; |
1353 | error = PTR_ERR(target); | |
1354 | target = NULL; | |
1355 | /* | |
1356 | * TODO: fixme using labels_profile is not right - do profile | |
1357 | * per complain profile | |
1358 | */ | |
df8073c6 | 1359 | if ((flags & AA_CHANGE_TEST) || |
e00b02bb | 1360 | !COMPLAIN_MODE(labels_profile(label))) |
898127c3 JJ |
1361 | goto audit; |
1362 | /* released below */ | |
58f89ce5 JJ |
1363 | tprofile = aa_new_learning_profile(labels_profile(label), false, |
1364 | fqname, GFP_KERNEL); | |
e00b02bb | 1365 | if (!tprofile) { |
898127c3 JJ |
1366 | info = "failed null profile create"; |
1367 | error = -ENOMEM; | |
1368 | goto audit; | |
1369 | } | |
e00b02bb JJ |
1370 | target = &tprofile->label; |
1371 | goto check; | |
898127c3 JJ |
1372 | } |
1373 | ||
e00b02bb JJ |
1374 | /* |
1375 | * self directed transitions only apply to current policy ns | |
1376 | * TODO: currently requiring perms for stacking and straight change | |
1377 | * stacking doesn't strictly need this. Determine how much | |
1378 | * we want to loosen this restriction for stacking | |
1379 | * | |
1380 | * if (!stack) { | |
1381 | */ | |
1382 | error = fn_for_each_in_ns(label, profile, | |
1383 | change_profile_perms_wrapper(op, auditname, | |
1384 | profile, target, stack, | |
1385 | request, &perms)); | |
1386 | if (error) | |
1387 | /* auditing done in change_profile_perms_wrapper */ | |
1388 | goto out; | |
aa9a39ad | 1389 | |
e00b02bb JJ |
1390 | /* } */ |
1391 | ||
1392 | check: | |
898127c3 | 1393 | /* check if tracing task is allowed to trace target domain */ |
e00b02bb JJ |
1394 | error = may_change_ptraced_domain(target, &info); |
1395 | if (error && !fn_for_each_in_ns(label, profile, | |
1396 | COMPLAIN_MODE(profile))) | |
898127c3 | 1397 | goto audit; |
898127c3 | 1398 | |
e00b02bb JJ |
1399 | /* TODO: add permission check to allow this |
1400 | * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { | |
1401 | * info = "not a single threaded task"; | |
1402 | * error = -EACCES; | |
1403 | * goto audit; | |
1404 | * } | |
1405 | */ | |
df8073c6 | 1406 | if (flags & AA_CHANGE_TEST) |
e00b02bb | 1407 | goto out; |
898127c3 | 1408 | |
9fcf78cc JJ |
1409 | /* stacking is always a subset, so only check the nonstack case */ |
1410 | if (!stack) { | |
1411 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1412 | aa_get_label(target), | |
1413 | aa_get_label(&profile->label)); | |
1414 | /* | |
1415 | * no new privs prevents domain transitions that would | |
1416 | * reduce restrictions. | |
1417 | */ | |
1418 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1419 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { |
9fcf78cc JJ |
1420 | /* not an apparmor denial per se, so don't log it */ |
1421 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1422 | error = -EPERM; | |
1423 | goto out; | |
1424 | } | |
1425 | } | |
1426 | ||
e00b02bb JJ |
1427 | if (!(flags & AA_CHANGE_ONEXEC)) { |
1428 | /* only transition profiles in the current ns */ | |
1429 | if (stack) | |
1430 | new = aa_label_merge(label, target, GFP_KERNEL); | |
e00b02bb JJ |
1431 | if (IS_ERR_OR_NULL(new)) { |
1432 | info = "failed to build target label"; | |
d6d478ae JJ |
1433 | if (!new) |
1434 | error = -ENOMEM; | |
1435 | else | |
1436 | error = PTR_ERR(new); | |
e00b02bb JJ |
1437 | new = NULL; |
1438 | perms.allow = 0; | |
1439 | goto audit; | |
1440 | } | |
1441 | error = aa_replace_current_label(new); | |
9fcf78cc JJ |
1442 | } else { |
1443 | if (new) { | |
1444 | aa_put_label(new); | |
1445 | new = NULL; | |
1446 | } | |
1447 | ||
e00b02bb JJ |
1448 | /* full transition will be built in exec path */ |
1449 | error = aa_set_current_onexec(target, stack); | |
9fcf78cc | 1450 | } |
898127c3 JJ |
1451 | |
1452 | audit: | |
e00b02bb JJ |
1453 | error = fn_for_each_in_ns(label, profile, |
1454 | aa_audit_file(profile, &perms, op, request, auditname, | |
1455 | NULL, new ? new : target, | |
1456 | GLOBAL_ROOT_UID, info, error)); | |
898127c3 | 1457 | |
e00b02bb JJ |
1458 | out: |
1459 | aa_put_label(new); | |
1460 | aa_put_label(target); | |
637f688d | 1461 | aa_put_label(label); |
898127c3 JJ |
1462 | |
1463 | return error; | |
1464 | } |