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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
898127c3 JJ |
2 | /* |
3 | * AppArmor security module | |
4 | * | |
5 | * This file contains AppArmor policy attachment and domain transitions | |
6 | * | |
7 | * Copyright (C) 2002-2008 Novell/SUSE | |
8 | * Copyright 2009-2010 Canonical Ltd. | |
898127c3 JJ |
9 | */ |
10 | ||
11 | #include <linux/errno.h> | |
12 | #include <linux/fdtable.h> | |
13 | #include <linux/file.h> | |
14 | #include <linux/mount.h> | |
15 | #include <linux/syscalls.h> | |
16 | #include <linux/tracehook.h> | |
17 | #include <linux/personality.h> | |
8e51f908 | 18 | #include <linux/xattr.h> |
898127c3 JJ |
19 | |
20 | #include "include/audit.h" | |
21 | #include "include/apparmorfs.h" | |
d8889d49 | 22 | #include "include/cred.h" |
898127c3 JJ |
23 | #include "include/domain.h" |
24 | #include "include/file.h" | |
25 | #include "include/ipc.h" | |
26 | #include "include/match.h" | |
27 | #include "include/path.h" | |
28 | #include "include/policy.h" | |
cff281f6 | 29 | #include "include/policy_ns.h" |
898127c3 JJ |
30 | |
31 | /** | |
32 | * aa_free_domain_entries - free entries in a domain table | |
33 | * @domain: the domain table to free (MAYBE NULL) | |
34 | */ | |
35 | void aa_free_domain_entries(struct aa_domain *domain) | |
36 | { | |
37 | int i; | |
38 | if (domain) { | |
39 | if (!domain->table) | |
40 | return; | |
41 | ||
42 | for (i = 0; i < domain->size; i++) | |
453431a5 WL |
43 | kfree_sensitive(domain->table[i]); |
44 | kfree_sensitive(domain->table); | |
898127c3 JJ |
45 | domain->table = NULL; |
46 | } | |
47 | } | |
48 | ||
49 | /** | |
50 | * may_change_ptraced_domain - check if can change profile on ptraced task | |
b2d09ae4 JJ |
51 | * @to_label: profile to change to (NOT NULL) |
52 | * @info: message if there is an error | |
898127c3 | 53 | * |
51775fe7 | 54 | * Check if current is ptraced and if so if the tracing task is allowed |
898127c3 JJ |
55 | * to trace the new domain |
56 | * | |
57 | * Returns: %0 or error if change not allowed | |
58 | */ | |
b2d09ae4 JJ |
59 | static int may_change_ptraced_domain(struct aa_label *to_label, |
60 | const char **info) | |
898127c3 JJ |
61 | { |
62 | struct task_struct *tracer; | |
637f688d | 63 | struct aa_label *tracerl = NULL; |
898127c3 JJ |
64 | int error = 0; |
65 | ||
66 | rcu_read_lock(); | |
51775fe7 | 67 | tracer = ptrace_parent(current); |
3cfcc19e | 68 | if (tracer) |
898127c3 | 69 | /* released below */ |
637f688d | 70 | tracerl = aa_get_task_label(tracer); |
898127c3 JJ |
71 | |
72 | /* not ptraced */ | |
637f688d | 73 | if (!tracer || unconfined(tracerl)) |
898127c3 JJ |
74 | goto out; |
75 | ||
b2d09ae4 | 76 | error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); |
898127c3 JJ |
77 | |
78 | out: | |
04fdc099 | 79 | rcu_read_unlock(); |
637f688d | 80 | aa_put_label(tracerl); |
898127c3 | 81 | |
b2d09ae4 JJ |
82 | if (error) |
83 | *info = "ptrace prevents transition"; | |
898127c3 JJ |
84 | return error; |
85 | } | |
86 | ||
93c98a48 JJ |
87 | /**** TODO: dedup to aa_label_match - needs perm and dfa, merging |
88 | * specifically this is an exact copy of aa_label_match except | |
89 | * aa_compute_perms is replaced with aa_compute_fperms | |
90 | * and policy.dfa with file.dfa | |
91 | ****/ | |
92 | /* match a profile and its associated ns component if needed | |
93 | * Assumes visibility test has already been done. | |
94 | * If a subns profile is not to be matched should be prescreened with | |
95 | * visibility test. | |
96 | */ | |
97 | static inline unsigned int match_component(struct aa_profile *profile, | |
98 | struct aa_profile *tp, | |
99 | bool stack, unsigned int state) | |
100 | { | |
101 | const char *ns_name; | |
102 | ||
103 | if (stack) | |
104 | state = aa_dfa_match(profile->file.dfa, state, "&"); | |
105 | if (profile->ns == tp->ns) | |
106 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
107 | ||
108 | /* try matching with namespace name and then profile */ | |
109 | ns_name = aa_ns_name(profile->ns, tp->ns, true); | |
110 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
111 | state = aa_dfa_match(profile->file.dfa, state, ns_name); | |
112 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
113 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
114 | } | |
115 | ||
116 | /** | |
117 | * label_compound_match - find perms for full compound label | |
118 | * @profile: profile to find perms for | |
119 | * @label: label to check access permissions for | |
120 | * @stack: whether this is a stacking request | |
121 | * @start: state to start match in | |
122 | * @subns: whether to do permission checks on components in a subns | |
123 | * @request: permissions to request | |
124 | * @perms: perms struct to set | |
125 | * | |
126 | * Returns: 0 on success else ERROR | |
127 | * | |
128 | * For the label A//&B//&C this does the perm match for A//&B//&C | |
129 | * @perms should be preinitialized with allperms OR a previous permission | |
130 | * check to be stacked. | |
131 | */ | |
132 | static int label_compound_match(struct aa_profile *profile, | |
133 | struct aa_label *label, bool stack, | |
134 | unsigned int state, bool subns, u32 request, | |
135 | struct aa_perms *perms) | |
136 | { | |
137 | struct aa_profile *tp; | |
138 | struct label_it i; | |
139 | struct path_cond cond = { }; | |
140 | ||
141 | /* find first subcomponent that is visible */ | |
142 | label_for_each(i, label, tp) { | |
143 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
144 | continue; | |
145 | state = match_component(profile, tp, stack, state); | |
146 | if (!state) | |
147 | goto fail; | |
148 | goto next; | |
149 | } | |
150 | ||
151 | /* no component visible */ | |
152 | *perms = allperms; | |
153 | return 0; | |
154 | ||
155 | next: | |
156 | label_for_each_cont(i, label, tp) { | |
157 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
158 | continue; | |
159 | state = aa_dfa_match(profile->file.dfa, state, "//&"); | |
160 | state = match_component(profile, tp, false, state); | |
161 | if (!state) | |
162 | goto fail; | |
163 | } | |
164 | *perms = aa_compute_fperms(profile->file.dfa, state, &cond); | |
165 | aa_apply_modes_to_perms(profile, perms); | |
166 | if ((perms->allow & request) != request) | |
167 | return -EACCES; | |
168 | ||
169 | return 0; | |
170 | ||
171 | fail: | |
172 | *perms = nullperms; | |
173 | return -EACCES; | |
174 | } | |
175 | ||
176 | /** | |
177 | * label_components_match - find perms for all subcomponents of a label | |
178 | * @profile: profile to find perms for | |
179 | * @label: label to check access permissions for | |
180 | * @stack: whether this is a stacking request | |
181 | * @start: state to start match in | |
182 | * @subns: whether to do permission checks on components in a subns | |
183 | * @request: permissions to request | |
184 | * @perms: an initialized perms struct to add accumulation to | |
185 | * | |
186 | * Returns: 0 on success else ERROR | |
187 | * | |
188 | * For the label A//&B//&C this does the perm match for each of A and B and C | |
189 | * @perms should be preinitialized with allperms OR a previous permission | |
190 | * check to be stacked. | |
191 | */ | |
192 | static int label_components_match(struct aa_profile *profile, | |
193 | struct aa_label *label, bool stack, | |
194 | unsigned int start, bool subns, u32 request, | |
195 | struct aa_perms *perms) | |
196 | { | |
197 | struct aa_profile *tp; | |
198 | struct label_it i; | |
199 | struct aa_perms tmp; | |
200 | struct path_cond cond = { }; | |
201 | unsigned int state = 0; | |
202 | ||
203 | /* find first subcomponent to test */ | |
204 | label_for_each(i, label, tp) { | |
205 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
206 | continue; | |
207 | state = match_component(profile, tp, stack, start); | |
208 | if (!state) | |
209 | goto fail; | |
210 | goto next; | |
211 | } | |
212 | ||
213 | /* no subcomponents visible - no change in perms */ | |
214 | return 0; | |
215 | ||
216 | next: | |
217 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
218 | aa_apply_modes_to_perms(profile, &tmp); | |
219 | aa_perms_accum(perms, &tmp); | |
220 | label_for_each_cont(i, label, tp) { | |
221 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
222 | continue; | |
223 | state = match_component(profile, tp, stack, start); | |
224 | if (!state) | |
225 | goto fail; | |
226 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
227 | aa_apply_modes_to_perms(profile, &tmp); | |
228 | aa_perms_accum(perms, &tmp); | |
229 | } | |
230 | ||
231 | if ((perms->allow & request) != request) | |
232 | return -EACCES; | |
233 | ||
234 | return 0; | |
235 | ||
236 | fail: | |
237 | *perms = nullperms; | |
238 | return -EACCES; | |
239 | } | |
240 | ||
241 | /** | |
242 | * label_match - do a multi-component label match | |
243 | * @profile: profile to match against (NOT NULL) | |
244 | * @label: label to match (NOT NULL) | |
245 | * @stack: whether this is a stacking request | |
246 | * @state: state to start in | |
247 | * @subns: whether to match subns components | |
248 | * @request: permission request | |
249 | * @perms: Returns computed perms (NOT NULL) | |
250 | * | |
251 | * Returns: the state the match finished in, may be the none matching state | |
252 | */ | |
253 | static int label_match(struct aa_profile *profile, struct aa_label *label, | |
254 | bool stack, unsigned int state, bool subns, u32 request, | |
255 | struct aa_perms *perms) | |
256 | { | |
257 | int error; | |
258 | ||
259 | *perms = nullperms; | |
260 | error = label_compound_match(profile, label, stack, state, subns, | |
261 | request, perms); | |
262 | if (!error) | |
263 | return error; | |
264 | ||
265 | *perms = allperms; | |
266 | return label_components_match(profile, label, stack, state, subns, | |
267 | request, perms); | |
268 | } | |
269 | ||
270 | /******* end TODO: dedup *****/ | |
271 | ||
898127c3 JJ |
272 | /** |
273 | * change_profile_perms - find permissions for change_profile | |
274 | * @profile: the current profile (NOT NULL) | |
93c98a48 JJ |
275 | * @target: label to transition to (NOT NULL) |
276 | * @stack: whether this is a stacking request | |
898127c3 JJ |
277 | * @request: requested perms |
278 | * @start: state to start matching in | |
279 | * | |
93c98a48 | 280 | * |
898127c3 | 281 | * Returns: permission set |
93c98a48 JJ |
282 | * |
283 | * currently only matches full label A//&B//&C or individual components A, B, C | |
284 | * not arbitrary combinations. Eg. A//&B, C | |
898127c3 | 285 | */ |
93c98a48 JJ |
286 | static int change_profile_perms(struct aa_profile *profile, |
287 | struct aa_label *target, bool stack, | |
288 | u32 request, unsigned int start, | |
289 | struct aa_perms *perms) | |
290 | { | |
291 | if (profile_unconfined(profile)) { | |
292 | perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; | |
293 | perms->audit = perms->quiet = perms->kill = 0; | |
294 | return 0; | |
295 | } | |
296 | ||
297 | /* TODO: add profile in ns screening */ | |
298 | return label_match(profile, target, stack, start, true, request, perms); | |
299 | } | |
300 | ||
8e51f908 MG |
301 | /** |
302 | * aa_xattrs_match - check whether a file matches the xattrs defined in profile | |
303 | * @bprm: binprm struct for the process to validate | |
304 | * @profile: profile to match against (NOT NULL) | |
73f488cd | 305 | * @state: state to start match in |
8e51f908 MG |
306 | * |
307 | * Returns: number of extended attributes that matched, or < 0 on error | |
308 | */ | |
309 | static int aa_xattrs_match(const struct linux_binprm *bprm, | |
73f488cd | 310 | struct aa_profile *profile, unsigned int state) |
8e51f908 MG |
311 | { |
312 | int i; | |
a61ecd32 | 313 | ssize_t size; |
8e51f908 MG |
314 | struct dentry *d; |
315 | char *value = NULL; | |
316 | int value_size = 0, ret = profile->xattr_count; | |
317 | ||
318 | if (!bprm || !profile->xattr_count) | |
319 | return 0; | |
8c62ed27 | 320 | might_sleep(); |
8e51f908 | 321 | |
73f488cd | 322 | /* transition from exec match to xattr set */ |
0df34a64 | 323 | state = aa_dfa_outofband_transition(profile->xmatch, state); |
8e51f908 MG |
324 | d = bprm->file->f_path.dentry; |
325 | ||
326 | for (i = 0; i < profile->xattr_count; i++) { | |
327 | size = vfs_getxattr_alloc(d, profile->xattrs[i], &value, | |
328 | value_size, GFP_KERNEL); | |
73f488cd JJ |
329 | if (size >= 0) { |
330 | u32 perm; | |
8e51f908 | 331 | |
0df34a64 JJ |
332 | /* |
333 | * Check the xattr presence before value. This ensure | |
334 | * that not present xattr can be distinguished from a 0 | |
335 | * length value or rule that matches any value | |
336 | */ | |
337 | state = aa_dfa_null_transition(profile->xmatch, state); | |
338 | /* Check xattr value */ | |
73f488cd JJ |
339 | state = aa_dfa_match_len(profile->xmatch, state, value, |
340 | size); | |
341 | perm = dfa_user_allow(profile->xmatch, state); | |
342 | if (!(perm & MAY_EXEC)) { | |
8e51f908 MG |
343 | ret = -EINVAL; |
344 | goto out; | |
345 | } | |
73f488cd JJ |
346 | } |
347 | /* transition to next element */ | |
0df34a64 | 348 | state = aa_dfa_outofband_transition(profile->xmatch, state); |
73f488cd JJ |
349 | if (size < 0) { |
350 | /* | |
351 | * No xattr match, so verify if transition to | |
352 | * next element was valid. IFF so the xattr | |
353 | * was optional. | |
354 | */ | |
355 | if (!state) { | |
8e51f908 MG |
356 | ret = -EINVAL; |
357 | goto out; | |
358 | } | |
73f488cd JJ |
359 | /* don't count missing optional xattr as matched */ |
360 | ret--; | |
8e51f908 MG |
361 | } |
362 | } | |
363 | ||
364 | out: | |
365 | kfree(value); | |
366 | return ret; | |
367 | } | |
368 | ||
898127c3 | 369 | /** |
8c62ed27 | 370 | * find_attach - do attachment search for unconfined processes |
8e51f908 | 371 | * @bprm - binprm structure of transitioning task |
8c62ed27 | 372 | * @ns: the current namespace (NOT NULL) |
898127c3 | 373 | * @head - profile list to walk (NOT NULL) |
8c62ed27 | 374 | * @name - to match against (NOT NULL) |
844b8292 | 375 | * @info - info message if there was an error (NOT NULL) |
898127c3 JJ |
376 | * |
377 | * Do a linear search on the profiles in the list. There is a matching | |
378 | * preference where an exact match is preferred over a name which uses | |
379 | * expressions to match, and matching expressions with the greatest | |
380 | * xmatch_len are preferred. | |
381 | * | |
382 | * Requires: @head not be shared or have appropriate locks held | |
383 | * | |
8c62ed27 | 384 | * Returns: label or NULL if no match found |
898127c3 | 385 | */ |
8c62ed27 JJ |
386 | static struct aa_label *find_attach(const struct linux_binprm *bprm, |
387 | struct aa_ns *ns, struct list_head *head, | |
388 | const char *name, const char **info) | |
898127c3 | 389 | { |
21f60661 | 390 | int candidate_len = 0, candidate_xattrs = 0; |
844b8292 | 391 | bool conflict = false; |
898127c3 JJ |
392 | struct aa_profile *profile, *candidate = NULL; |
393 | ||
21f60661 JJ |
394 | AA_BUG(!name); |
395 | AA_BUG(!head); | |
396 | ||
8c62ed27 JJ |
397 | rcu_read_lock(); |
398 | restart: | |
01e2b670 | 399 | list_for_each_entry_rcu(profile, head, base.list) { |
06d426d1 JJ |
400 | if (profile->label.flags & FLAG_NULL && |
401 | &profile->label == ns_unconfined(profile->ns)) | |
898127c3 | 402 | continue; |
06d426d1 | 403 | |
8e51f908 MG |
404 | /* Find the "best" matching profile. Profiles must |
405 | * match the path and extended attributes (if any) | |
406 | * associated with the file. A more specific path | |
407 | * match will be preferred over a less specific one, | |
408 | * and a match with more matching extended attributes | |
409 | * will be preferred over one with fewer. If the best | |
410 | * match has both the same level of path specificity | |
411 | * and the same number of matching extended attributes | |
412 | * as another profile, signal a conflict and refuse to | |
413 | * match. | |
414 | */ | |
844b8292 | 415 | if (profile->xmatch) { |
21f60661 | 416 | unsigned int state, count; |
8e51f908 MG |
417 | u32 perm; |
418 | ||
21f60661 JJ |
419 | state = aa_dfa_leftmatch(profile->xmatch, DFA_START, |
420 | name, &count); | |
8e51f908 MG |
421 | perm = dfa_user_allow(profile->xmatch, state); |
422 | /* any accepting state means a valid match. */ | |
423 | if (perm & MAY_EXEC) { | |
8c62ed27 | 424 | int ret = 0; |
21f60661 JJ |
425 | |
426 | if (count < candidate_len) | |
427 | continue; | |
8e51f908 | 428 | |
8c62ed27 JJ |
429 | if (bprm && profile->xattr_count) { |
430 | long rev = READ_ONCE(ns->revision); | |
431 | ||
432 | if (!aa_get_profile_not0(profile)) | |
433 | goto restart; | |
434 | rcu_read_unlock(); | |
435 | ret = aa_xattrs_match(bprm, profile, | |
436 | state); | |
437 | rcu_read_lock(); | |
438 | aa_put_profile(profile); | |
439 | if (rev != | |
440 | READ_ONCE(ns->revision)) | |
441 | /* policy changed */ | |
442 | goto restart; | |
443 | /* | |
444 | * Fail matching if the xattrs don't | |
445 | * match | |
446 | */ | |
447 | if (ret < 0) | |
448 | continue; | |
449 | } | |
73f488cd JJ |
450 | /* |
451 | * TODO: allow for more flexible best match | |
452 | * | |
453 | * The new match isn't more specific | |
8e51f908 MG |
454 | * than the current best match |
455 | */ | |
21f60661 JJ |
456 | if (count == candidate_len && |
457 | ret <= candidate_xattrs) { | |
8e51f908 | 458 | /* Match is equivalent, so conflict */ |
21f60661 | 459 | if (ret == candidate_xattrs) |
1a3881d3 | 460 | conflict = true; |
8e51f908 | 461 | continue; |
844b8292 | 462 | } |
8e51f908 MG |
463 | |
464 | /* Either the same length with more matching | |
465 | * xattrs, or a longer match | |
466 | */ | |
467 | candidate = profile; | |
21f60661 JJ |
468 | candidate_len = profile->xmatch_len; |
469 | candidate_xattrs = ret; | |
8e51f908 | 470 | conflict = false; |
898127c3 | 471 | } |
8c62ed27 | 472 | } else if (!strcmp(profile->base.name, name)) { |
73f488cd JJ |
473 | /* |
474 | * old exact non-re match, without conditionals such | |
475 | * as xattrs. no more searching required | |
476 | */ | |
8c62ed27 JJ |
477 | candidate = profile; |
478 | goto out; | |
479 | } | |
898127c3 JJ |
480 | } |
481 | ||
8c62ed27 JJ |
482 | if (!candidate || conflict) { |
483 | if (conflict) | |
484 | *info = "conflicting profile attachments"; | |
485 | rcu_read_unlock(); | |
844b8292 JJ |
486 | return NULL; |
487 | } | |
488 | ||
8c62ed27 JJ |
489 | out: |
490 | candidate = aa_get_newest_profile(candidate); | |
01e2b670 | 491 | rcu_read_unlock(); |
898127c3 | 492 | |
8c62ed27 | 493 | return &candidate->label; |
898127c3 JJ |
494 | } |
495 | ||
496 | static const char *next_name(int xtype, const char *name) | |
497 | { | |
498 | return NULL; | |
499 | } | |
500 | ||
501 | /** | |
502 | * x_table_lookup - lookup an x transition name via transition table | |
503 | * @profile: current profile (NOT NULL) | |
504 | * @xindex: index into x transition table | |
93c98a48 | 505 | * @name: returns: name tested to find label (NOT NULL) |
898127c3 | 506 | * |
93c98a48 | 507 | * Returns: refcounted label, or NULL on failure (MAYBE NULL) |
898127c3 | 508 | */ |
2ea3ffb7 JJ |
509 | struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, |
510 | const char **name) | |
898127c3 | 511 | { |
93c98a48 | 512 | struct aa_label *label = NULL; |
898127c3 JJ |
513 | u32 xtype = xindex & AA_X_TYPE_MASK; |
514 | int index = xindex & AA_X_INDEX_MASK; | |
898127c3 | 515 | |
93c98a48 | 516 | AA_BUG(!name); |
898127c3 | 517 | |
93c98a48 JJ |
518 | /* index is guaranteed to be in range, validated at load time */ |
519 | /* TODO: move lookup parsing to unpack time so this is a straight | |
520 | * index into the resultant label | |
521 | */ | |
522 | for (*name = profile->file.trans.table[index]; !label && *name; | |
523 | *name = next_name(xtype, *name)) { | |
898127c3 | 524 | if (xindex & AA_X_CHILD) { |
93c98a48 | 525 | struct aa_profile *new_profile; |
898127c3 | 526 | /* release by caller */ |
93c98a48 JJ |
527 | new_profile = aa_find_child(profile, *name); |
528 | if (new_profile) | |
529 | label = &new_profile->label; | |
898127c3 | 530 | continue; |
898127c3 | 531 | } |
8ac2ca32 | 532 | label = aa_label_parse(&profile->label, *name, GFP_KERNEL, |
93c98a48 JJ |
533 | true, false); |
534 | if (IS_ERR(label)) | |
535 | label = NULL; | |
898127c3 JJ |
536 | } |
537 | ||
538 | /* released by caller */ | |
93c98a48 JJ |
539 | |
540 | return label; | |
898127c3 JJ |
541 | } |
542 | ||
543 | /** | |
93c98a48 | 544 | * x_to_label - get target label for a given xindex |
898127c3 | 545 | * @profile: current profile (NOT NULL) |
8e51f908 | 546 | * @bprm: binprm structure of transitioning task |
898127c3 JJ |
547 | * @name: name to lookup (NOT NULL) |
548 | * @xindex: index into x transition table | |
93c98a48 | 549 | * @lookupname: returns: name used in lookup if one was specified (NOT NULL) |
898127c3 | 550 | * |
93c98a48 | 551 | * find label for a transition index |
898127c3 | 552 | * |
93c98a48 | 553 | * Returns: refcounted label or NULL if not found available |
898127c3 | 554 | */ |
93c98a48 | 555 | static struct aa_label *x_to_label(struct aa_profile *profile, |
8e51f908 | 556 | const struct linux_binprm *bprm, |
93c98a48 JJ |
557 | const char *name, u32 xindex, |
558 | const char **lookupname, | |
559 | const char **info) | |
898127c3 | 560 | { |
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 */ | |
573 | stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; | |
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 | { |
93c98a48 JJ |
627 | struct aa_label *new = NULL; |
628 | const char *info = NULL, *name = NULL, *target = NULL; | |
629 | unsigned int state = profile->file.start; | |
2d679f3c | 630 | struct aa_perms perms = {}; |
93c98a48 | 631 | bool nonewprivs = false; |
b1d9e6b0 | 632 | int error = 0; |
898127c3 | 633 | |
93c98a48 JJ |
634 | AA_BUG(!profile); |
635 | AA_BUG(!bprm); | |
636 | AA_BUG(!buffer); | |
898127c3 | 637 | |
4227c333 | 638 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, |
72c8a768 | 639 | &name, &info, profile->disconnected); |
898127c3 | 640 | if (error) { |
637f688d | 641 | if (profile_unconfined(profile) || |
93c98a48 JJ |
642 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { |
643 | AA_DEBUG("name lookup ix on error"); | |
898127c3 | 644 | error = 0; |
93c98a48 JJ |
645 | new = aa_get_newest_label(&profile->label); |
646 | } | |
898127c3 JJ |
647 | name = bprm->filename; |
648 | goto audit; | |
649 | } | |
650 | ||
637f688d | 651 | if (profile_unconfined(profile)) { |
8e51f908 MG |
652 | new = find_attach(bprm, profile->ns, |
653 | &profile->ns->base.profiles, name, &info); | |
93c98a48 JJ |
654 | if (new) { |
655 | AA_DEBUG("unconfined attached to new label"); | |
656 | return new; | |
657 | } | |
658 | AA_DEBUG("unconfined exec no attachment"); | |
659 | return aa_get_newest_label(&profile->label); | |
898127c3 JJ |
660 | } |
661 | ||
662 | /* find exec permissions for name */ | |
93c98a48 | 663 | state = aa_str_perms(profile->file.dfa, state, name, cond, &perms); |
898127c3 JJ |
664 | if (perms.allow & MAY_EXEC) { |
665 | /* exec permission determine how to transition */ | |
8e51f908 MG |
666 | new = x_to_label(profile, bprm, name, perms.xindex, &target, |
667 | &info); | |
93c98a48 JJ |
668 | if (new && new->proxy == profile->label.proxy && info) { |
669 | /* hack ix fallback - improve how this is detected */ | |
670 | goto audit; | |
671 | } else if (!new) { | |
672 | error = -EACCES; | |
673 | info = "profile transition not found"; | |
674 | /* remove MAY_EXEC to audit as failure */ | |
675 | perms.allow &= ~MAY_EXEC; | |
898127c3 JJ |
676 | } |
677 | } else if (COMPLAIN_MODE(profile)) { | |
93c98a48 | 678 | /* no exec permission - learning mode */ |
5d7c44ef | 679 | struct aa_profile *new_profile = NULL; |
df323337 SAS |
680 | |
681 | new_profile = aa_new_null_profile(profile, false, name, | |
682 | GFP_KERNEL); | |
898127c3 JJ |
683 | if (!new_profile) { |
684 | error = -ENOMEM; | |
685 | info = "could not create null profile"; | |
93c98a48 | 686 | } else { |
898127c3 | 687 | error = -EACCES; |
93c98a48 JJ |
688 | new = &new_profile->label; |
689 | } | |
898127c3 JJ |
690 | perms.xindex |= AA_X_UNSAFE; |
691 | } else | |
692 | /* fail exec */ | |
693 | error = -EACCES; | |
694 | ||
93c98a48 JJ |
695 | if (!new) |
696 | goto audit; | |
697 | ||
93c98a48 JJ |
698 | |
699 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
700 | if (DEBUG_ON) { | |
701 | dbg_printk("apparmor: scrubbing environment variables" | |
702 | " for %s profile=", name); | |
8ac2ca32 | 703 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
704 | dbg_printk("\n"); |
705 | } | |
706 | *secure_exec = true; | |
c29bceb3 JJ |
707 | } |
708 | ||
93c98a48 JJ |
709 | audit: |
710 | aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, | |
711 | cond->uid, info, error); | |
712 | if (!new || nonewprivs) { | |
713 | aa_put_label(new); | |
714 | return ERR_PTR(error); | |
715 | } | |
716 | ||
717 | return new; | |
718 | } | |
719 | ||
720 | static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, | |
721 | bool stack, const struct linux_binprm *bprm, | |
722 | char *buffer, struct path_cond *cond, | |
723 | bool *secure_exec) | |
724 | { | |
725 | unsigned int state = profile->file.start; | |
726 | struct aa_perms perms = {}; | |
727 | const char *xname = NULL, *info = "change_profile onexec"; | |
728 | int error = -EACCES; | |
729 | ||
730 | AA_BUG(!profile); | |
731 | AA_BUG(!onexec); | |
732 | AA_BUG(!bprm); | |
733 | AA_BUG(!buffer); | |
734 | ||
735 | if (profile_unconfined(profile)) { | |
736 | /* change_profile on exec already granted */ | |
737 | /* | |
738 | * NOTE: Domain transitions from unconfined are allowed | |
739 | * even when no_new_privs is set because this aways results | |
740 | * in a further reduction of permissions. | |
741 | */ | |
742 | return 0; | |
743 | } | |
744 | ||
745 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, | |
746 | &xname, &info, profile->disconnected); | |
747 | if (error) { | |
748 | if (profile_unconfined(profile) || | |
749 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { | |
750 | AA_DEBUG("name lookup ix on error"); | |
751 | error = 0; | |
752 | } | |
753 | xname = bprm->filename; | |
898127c3 | 754 | goto audit; |
93c98a48 JJ |
755 | } |
756 | ||
757 | /* find exec permissions for name */ | |
758 | state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms); | |
759 | if (!(perms.allow & AA_MAY_ONEXEC)) { | |
760 | info = "no change_onexec valid for executable"; | |
761 | goto audit; | |
762 | } | |
763 | /* test if this exec can be paired with change_profile onexec. | |
764 | * onexec permission is linked to exec with a standard pairing | |
765 | * exec\0change_profile | |
766 | */ | |
767 | state = aa_dfa_null_transition(profile->file.dfa, state); | |
768 | error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, | |
769 | state, &perms); | |
770 | if (error) { | |
771 | perms.allow &= ~AA_MAY_ONEXEC; | |
772 | goto audit; | |
773 | } | |
93c98a48 JJ |
774 | |
775 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
776 | if (DEBUG_ON) { | |
777 | dbg_printk("apparmor: scrubbing environment " | |
778 | "variables for %s label=", xname); | |
8ac2ca32 | 779 | aa_label_printk(onexec, GFP_KERNEL); |
93c98a48 JJ |
780 | dbg_printk("\n"); |
781 | } | |
782 | *secure_exec = true; | |
783 | } | |
784 | ||
785 | audit: | |
786 | return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, | |
787 | NULL, onexec, cond->uid, info, error); | |
788 | } | |
789 | ||
790 | /* ensure none ns domain transitions are correctly applied with onexec */ | |
791 | ||
792 | static struct aa_label *handle_onexec(struct aa_label *label, | |
793 | struct aa_label *onexec, bool stack, | |
794 | const struct linux_binprm *bprm, | |
795 | char *buffer, struct path_cond *cond, | |
796 | bool *unsafe) | |
797 | { | |
798 | struct aa_profile *profile; | |
799 | struct aa_label *new; | |
800 | int error; | |
801 | ||
802 | AA_BUG(!label); | |
803 | AA_BUG(!onexec); | |
804 | AA_BUG(!bprm); | |
805 | AA_BUG(!buffer); | |
806 | ||
807 | if (!stack) { | |
808 | error = fn_for_each_in_ns(label, profile, | |
809 | profile_onexec(profile, onexec, stack, | |
810 | bprm, buffer, cond, unsafe)); | |
811 | if (error) | |
812 | return ERR_PTR(error); | |
8ac2ca32 | 813 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 JJ |
814 | aa_get_newest_label(onexec), |
815 | profile_transition(profile, bprm, buffer, | |
816 | cond, unsafe)); | |
817 | ||
818 | } else { | |
b2c2086c | 819 | /* TODO: determine how much we want to loosen this */ |
93c98a48 JJ |
820 | error = fn_for_each_in_ns(label, profile, |
821 | profile_onexec(profile, onexec, stack, bprm, | |
822 | buffer, cond, unsafe)); | |
823 | if (error) | |
824 | return ERR_PTR(error); | |
8ac2ca32 | 825 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, |
93c98a48 | 826 | aa_label_merge(&profile->label, onexec, |
8ac2ca32 | 827 | GFP_KERNEL), |
93c98a48 JJ |
828 | profile_transition(profile, bprm, buffer, |
829 | cond, unsafe)); | |
830 | } | |
831 | ||
832 | if (new) | |
833 | return new; | |
834 | ||
835 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
836 | error = fn_for_each_in_ns(label, profile, | |
837 | aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, | |
838 | AA_MAY_ONEXEC, bprm->filename, NULL, | |
839 | onexec, GLOBAL_ROOT_UID, | |
840 | "failed to build target label", -ENOMEM)); | |
841 | return ERR_PTR(error); | |
842 | } | |
843 | ||
844 | /** | |
b8bff599 | 845 | * apparmor_bprm_creds_for_exec - Update the new creds on the bprm struct |
93c98a48 JJ |
846 | * @bprm: binprm for the exec (NOT NULL) |
847 | * | |
848 | * Returns: %0 or error on failure | |
849 | * | |
850 | * TODO: once the other paths are done see if we can't refactor into a fn | |
851 | */ | |
b8bff599 | 852 | int apparmor_bprm_creds_for_exec(struct linux_binprm *bprm) |
93c98a48 | 853 | { |
f175221a | 854 | struct aa_task_ctx *ctx; |
93c98a48 JJ |
855 | struct aa_label *label, *new = NULL; |
856 | struct aa_profile *profile; | |
857 | char *buffer = NULL; | |
858 | const char *info = NULL; | |
859 | int error = 0; | |
860 | bool unsafe = false; | |
861 | struct path_cond cond = { | |
862 | file_inode(bprm->file)->i_uid, | |
863 | file_inode(bprm->file)->i_mode | |
864 | }; | |
865 | ||
de62de59 | 866 | ctx = task_ctx(current); |
d9087c49 | 867 | AA_BUG(!cred_label(bprm->cred)); |
f175221a | 868 | AA_BUG(!ctx); |
93c98a48 | 869 | |
d9087c49 | 870 | label = aa_get_newest_label(cred_label(bprm->cred)); |
93c98a48 | 871 | |
9fcf78cc JJ |
872 | /* |
873 | * Detect no new privs being set, and store the label it | |
874 | * occurred under. Ideally this would happen when nnp | |
875 | * is set but there isn't a good way to do that yet. | |
876 | * | |
877 | * Testing for unconfined must be done before the subset test | |
878 | */ | |
879 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) && | |
880 | !ctx->nnp) | |
881 | ctx->nnp = aa_get_label(label); | |
882 | ||
93c98a48 | 883 | /* buffer freed below, name is pointer into buffer */ |
341c1fda | 884 | buffer = aa_get_buffer(false); |
df323337 SAS |
885 | if (!buffer) { |
886 | error = -ENOMEM; | |
887 | goto done; | |
888 | } | |
889 | ||
93c98a48 | 890 | /* Test for onexec first as onexec override other x transitions. */ |
f175221a JJ |
891 | if (ctx->onexec) |
892 | new = handle_onexec(label, ctx->onexec, ctx->token, | |
93c98a48 JJ |
893 | bprm, buffer, &cond, &unsafe); |
894 | else | |
8ac2ca32 | 895 | new = fn_label_build(label, profile, GFP_KERNEL, |
93c98a48 JJ |
896 | profile_transition(profile, bprm, buffer, |
897 | &cond, &unsafe)); | |
898 | ||
899 | AA_BUG(!new); | |
900 | if (IS_ERR(new)) { | |
901 | error = PTR_ERR(new); | |
902 | goto done; | |
903 | } else if (!new) { | |
904 | error = -ENOMEM; | |
905 | goto done; | |
906 | } | |
907 | ||
9fcf78cc JJ |
908 | /* Policy has specified a domain transitions. If no_new_privs and |
909 | * confined ensure the transition is to confinement that is subset | |
910 | * of the confinement when the task entered no new privs. | |
911 | * | |
912 | * NOTE: Domain transitions from unconfined and to stacked | |
913 | * subsets are allowed even when no_new_privs is set because this | |
914 | * aways results in a further reduction of permissions. | |
915 | */ | |
916 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && | |
3ed4aaa9 JJ |
917 | !unconfined(label) && |
918 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { | |
9fcf78cc JJ |
919 | error = -EPERM; |
920 | info = "no new privs"; | |
921 | goto audit; | |
922 | } | |
898127c3 JJ |
923 | |
924 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
925 | /* FIXME: currently don't mediate shared state */ | |
926 | ; | |
927 | } | |
928 | ||
93c98a48 JJ |
929 | if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { |
930 | /* TODO: test needs to be profile of label to new */ | |
931 | error = may_change_ptraced_domain(new, &info); | |
f7da2de0 | 932 | if (error) |
898127c3 | 933 | goto audit; |
898127c3 JJ |
934 | } |
935 | ||
93c98a48 JJ |
936 | if (unsafe) { |
937 | if (DEBUG_ON) { | |
938 | dbg_printk("scrubbing environment variables for %s " | |
939 | "label=", bprm->filename); | |
8ac2ca32 | 940 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
941 | dbg_printk("\n"); |
942 | } | |
993b3ab0 | 943 | bprm->secureexec = 1; |
898127c3 | 944 | } |
898127c3 | 945 | |
93c98a48 JJ |
946 | if (label->proxy != new->proxy) { |
947 | /* when transitioning clear unsafe personality bits */ | |
948 | if (DEBUG_ON) { | |
949 | dbg_printk("apparmor: clearing unsafe personality " | |
950 | "bits. %s label=", bprm->filename); | |
8ac2ca32 | 951 | aa_label_printk(new, GFP_KERNEL); |
93c98a48 JJ |
952 | dbg_printk("\n"); |
953 | } | |
954 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
955 | } | |
d9087c49 JJ |
956 | aa_put_label(cred_label(bprm->cred)); |
957 | /* transfer reference, released when cred is freed */ | |
69b5a44a | 958 | set_cred_label(bprm->cred, new); |
898127c3 | 959 | |
93c98a48 | 960 | done: |
637f688d | 961 | aa_put_label(label); |
df323337 | 962 | aa_put_buffer(buffer); |
898127c3 JJ |
963 | |
964 | return error; | |
93c98a48 JJ |
965 | |
966 | audit: | |
967 | error = fn_for_each(label, profile, | |
968 | aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, | |
969 | bprm->filename, NULL, new, | |
970 | file_inode(bprm->file)->i_uid, info, | |
971 | error)); | |
972 | aa_put_label(new); | |
973 | goto done; | |
898127c3 JJ |
974 | } |
975 | ||
898127c3 JJ |
976 | /* |
977 | * Functions for self directed profile change | |
978 | */ | |
979 | ||
89dbf196 JJ |
980 | |
981 | /* helper fn for change_hat | |
898127c3 | 982 | * |
89dbf196 | 983 | * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL |
898127c3 | 984 | */ |
89dbf196 JJ |
985 | static struct aa_label *build_change_hat(struct aa_profile *profile, |
986 | const char *name, bool sibling) | |
898127c3 | 987 | { |
89dbf196 JJ |
988 | struct aa_profile *root, *hat = NULL; |
989 | const char *info = NULL; | |
990 | int error = 0; | |
991 | ||
992 | if (sibling && PROFILE_IS_HAT(profile)) { | |
993 | root = aa_get_profile_rcu(&profile->parent); | |
994 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
995 | root = aa_get_profile(profile); | |
996 | } else { | |
997 | info = "conflicting target types"; | |
998 | error = -EPERM; | |
999 | goto audit; | |
1000 | } | |
1001 | ||
1002 | hat = aa_find_child(root, name); | |
1003 | if (!hat) { | |
1004 | error = -ENOENT; | |
1005 | if (COMPLAIN_MODE(profile)) { | |
1006 | hat = aa_new_null_profile(profile, true, name, | |
1007 | GFP_KERNEL); | |
1008 | if (!hat) { | |
1009 | info = "failed null profile create"; | |
1010 | error = -ENOMEM; | |
1011 | } | |
1012 | } | |
1013 | } | |
1014 | aa_put_profile(root); | |
1015 | ||
1016 | audit: | |
1017 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, | |
1018 | name, hat ? hat->base.hname : NULL, | |
24b87a16 | 1019 | hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, |
89dbf196 JJ |
1020 | error); |
1021 | if (!hat || (error && error != -ENOENT)) | |
1022 | return ERR_PTR(error); | |
1023 | /* if hat && error - complain mode, already audited and we adjust for | |
1024 | * complain mode allow by returning hat->label | |
1025 | */ | |
1026 | return &hat->label; | |
1027 | } | |
1028 | ||
1029 | /* helper fn for changing into a hat | |
1030 | * | |
1031 | * Returns: label for hat transition or ERR_PTR. Does not return NULL | |
1032 | */ | |
1033 | static struct aa_label *change_hat(struct aa_label *label, const char *hats[], | |
1034 | int count, int flags) | |
1035 | { | |
1036 | struct aa_profile *profile, *root, *hat = NULL; | |
1037 | struct aa_label *new; | |
1038 | struct label_it it; | |
1039 | bool sibling = false; | |
1040 | const char *name, *info = NULL; | |
1041 | int i, error; | |
1042 | ||
1043 | AA_BUG(!label); | |
1044 | AA_BUG(!hats); | |
1045 | AA_BUG(count < 1); | |
1046 | ||
1047 | if (PROFILE_IS_HAT(labels_profile(label))) | |
1048 | sibling = true; | |
1049 | ||
1050 | /*find first matching hat */ | |
1051 | for (i = 0; i < count && !hat; i++) { | |
1052 | name = hats[i]; | |
1053 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1054 | if (sibling && PROFILE_IS_HAT(profile)) { | |
1055 | root = aa_get_profile_rcu(&profile->parent); | |
1056 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1057 | root = aa_get_profile(profile); | |
1058 | } else { /* conflicting change type */ | |
1059 | info = "conflicting targets types"; | |
1060 | error = -EPERM; | |
1061 | goto fail; | |
1062 | } | |
1063 | hat = aa_find_child(root, name); | |
1064 | aa_put_profile(root); | |
1065 | if (!hat) { | |
1066 | if (!COMPLAIN_MODE(profile)) | |
1067 | goto outer_continue; | |
1068 | /* complain mode succeed as if hat */ | |
1069 | } else if (!PROFILE_IS_HAT(hat)) { | |
1070 | info = "target not hat"; | |
1071 | error = -EPERM; | |
1072 | aa_put_profile(hat); | |
1073 | goto fail; | |
1074 | } | |
1075 | aa_put_profile(hat); | |
1076 | } | |
1077 | /* found a hat for all profiles in ns */ | |
1078 | goto build; | |
1079 | outer_continue: | |
1080 | ; | |
1081 | } | |
1082 | /* no hats that match, find appropriate error | |
1083 | * | |
1084 | * In complain mode audit of the failure is based off of the first | |
1085 | * hat supplied. This is done due how userspace interacts with | |
1086 | * change_hat. | |
1087 | */ | |
1088 | name = NULL; | |
1089 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1090 | if (!list_empty(&profile->base.profiles)) { | |
1091 | info = "hat not found"; | |
1092 | error = -ENOENT; | |
1093 | goto fail; | |
1094 | } | |
1095 | } | |
1096 | info = "no hats defined"; | |
1097 | error = -ECHILD; | |
1098 | ||
1099 | fail: | |
1100 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1101 | /* | |
1102 | * no target as it has failed to be found or built | |
1103 | * | |
1104 | * change_hat uses probing and should not log failures | |
1105 | * related to missing hats | |
1106 | */ | |
1107 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
1108 | if (count > 1 || COMPLAIN_MODE(profile)) { | |
1109 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, | |
1110 | AA_MAY_CHANGEHAT, name, NULL, NULL, | |
1111 | GLOBAL_ROOT_UID, info, error); | |
1112 | } | |
1113 | } | |
1114 | return ERR_PTR(error); | |
1115 | ||
1116 | build: | |
1117 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1118 | build_change_hat(profile, name, sibling), | |
1119 | aa_get_label(&profile->label)); | |
1120 | if (!new) { | |
1121 | info = "label build failed"; | |
1122 | error = -ENOMEM; | |
1123 | goto fail; | |
1124 | } /* else if (IS_ERR) build_change_hat has logged error so return new */ | |
1125 | ||
1126 | return new; | |
898127c3 JJ |
1127 | } |
1128 | ||
1129 | /** | |
1130 | * aa_change_hat - change hat to/from subprofile | |
1131 | * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) | |
1132 | * @count: number of hat names in @hats | |
1133 | * @token: magic value to validate the hat change | |
df8073c6 | 1134 | * @flags: flags affecting behavior of the change |
898127c3 | 1135 | * |
89dbf196 JJ |
1136 | * Returns %0 on success, error otherwise. |
1137 | * | |
898127c3 JJ |
1138 | * Change to the first profile specified in @hats that exists, and store |
1139 | * the @hat_magic in the current task context. If the count == 0 and the | |
1140 | * @token matches that stored in the current task context, return to the | |
1141 | * top level profile. | |
1142 | * | |
89dbf196 JJ |
1143 | * change_hat only applies to profiles in the current ns, and each profile |
1144 | * in the ns must make the same transition otherwise change_hat will fail. | |
898127c3 | 1145 | */ |
df8073c6 | 1146 | int aa_change_hat(const char *hats[], int count, u64 token, int flags) |
898127c3 JJ |
1147 | { |
1148 | const struct cred *cred; | |
9fcf78cc | 1149 | struct aa_task_ctx *ctx = task_ctx(current); |
89dbf196 JJ |
1150 | struct aa_label *label, *previous, *new = NULL, *target = NULL; |
1151 | struct aa_profile *profile; | |
2d679f3c | 1152 | struct aa_perms perms = {}; |
89dbf196 | 1153 | const char *info = NULL; |
898127c3 JJ |
1154 | int error = 0; |
1155 | ||
1156 | /* released below */ | |
1157 | cred = get_current_cred(); | |
637f688d | 1158 | label = aa_get_newest_cred_label(cred); |
f175221a | 1159 | previous = aa_get_newest_label(ctx->previous); |
898127c3 | 1160 | |
9fcf78cc JJ |
1161 | /* |
1162 | * Detect no new privs being set, and store the label it | |
1163 | * occurred under. Ideally this would happen when nnp | |
1164 | * is set but there isn't a good way to do that yet. | |
1165 | * | |
1166 | * Testing for unconfined must be done before the subset test | |
1167 | */ | |
1168 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1169 | ctx->nnp = aa_get_label(label); | |
1170 | ||
637f688d | 1171 | if (unconfined(label)) { |
89dbf196 | 1172 | info = "unconfined can not change_hat"; |
898127c3 | 1173 | error = -EPERM; |
89dbf196 | 1174 | goto fail; |
898127c3 JJ |
1175 | } |
1176 | ||
1177 | if (count) { | |
89dbf196 JJ |
1178 | new = change_hat(label, hats, count, flags); |
1179 | AA_BUG(!new); | |
1180 | if (IS_ERR(new)) { | |
1181 | error = PTR_ERR(new); | |
1182 | new = NULL; | |
1183 | /* already audited */ | |
1184 | goto out; | |
898127c3 JJ |
1185 | } |
1186 | ||
89dbf196 JJ |
1187 | error = may_change_ptraced_domain(new, &info); |
1188 | if (error) | |
1189 | goto fail; | |
898127c3 | 1190 | |
9fcf78cc JJ |
1191 | /* |
1192 | * no new privs prevents domain transitions that would | |
1193 | * reduce restrictions. | |
1194 | */ | |
1195 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1196 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { |
9fcf78cc JJ |
1197 | /* not an apparmor denial per se, so don't log it */ |
1198 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1199 | error = -EPERM; | |
1200 | goto out; | |
1201 | } | |
1202 | ||
89dbf196 JJ |
1203 | if (flags & AA_CHANGE_TEST) |
1204 | goto out; | |
1205 | ||
1206 | target = new; | |
1207 | error = aa_set_current_hat(new, token); | |
1208 | if (error == -EACCES) | |
1209 | /* kill task in case of brute force attacks */ | |
1210 | goto kill; | |
1211 | } else if (previous && !(flags & AA_CHANGE_TEST)) { | |
9fcf78cc JJ |
1212 | /* |
1213 | * no new privs prevents domain transitions that would | |
1214 | * reduce restrictions. | |
1215 | */ | |
1216 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1217 | !aa_label_is_unconfined_subset(previous, ctx->nnp)) { |
9fcf78cc JJ |
1218 | /* not an apparmor denial per se, so don't log it */ |
1219 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1220 | error = -EPERM; | |
1221 | goto out; | |
1222 | } | |
1223 | ||
89dbf196 | 1224 | /* Return to saved label. Kill task if restore fails |
898127c3 JJ |
1225 | * to avoid brute force attacks |
1226 | */ | |
89dbf196 | 1227 | target = previous; |
637f688d | 1228 | error = aa_restore_previous_label(token); |
89dbf196 JJ |
1229 | if (error) { |
1230 | if (error == -EACCES) | |
1231 | goto kill; | |
1232 | goto fail; | |
1233 | } | |
1234 | } /* else ignore @flags && restores when there is no saved profile */ | |
898127c3 JJ |
1235 | |
1236 | out: | |
89dbf196 JJ |
1237 | aa_put_label(new); |
1238 | aa_put_label(previous); | |
637f688d | 1239 | aa_put_label(label); |
898127c3 JJ |
1240 | put_cred(cred); |
1241 | ||
1242 | return error; | |
89dbf196 JJ |
1243 | |
1244 | kill: | |
1245 | info = "failed token match"; | |
1246 | perms.kill = AA_MAY_CHANGEHAT; | |
1247 | ||
1248 | fail: | |
1249 | fn_for_each_in_ns(label, profile, | |
1250 | aa_audit_file(profile, &perms, OP_CHANGE_HAT, | |
1251 | AA_MAY_CHANGEHAT, NULL, NULL, target, | |
1252 | GLOBAL_ROOT_UID, info, error)); | |
1253 | ||
1254 | goto out; | |
898127c3 JJ |
1255 | } |
1256 | ||
89dbf196 | 1257 | |
e00b02bb JJ |
1258 | static int change_profile_perms_wrapper(const char *op, const char *name, |
1259 | struct aa_profile *profile, | |
1260 | struct aa_label *target, bool stack, | |
1261 | u32 request, struct aa_perms *perms) | |
1262 | { | |
1263 | const char *info = NULL; | |
1264 | int error = 0; | |
1265 | ||
e00b02bb JJ |
1266 | if (!error) |
1267 | error = change_profile_perms(profile, target, stack, request, | |
1268 | profile->file.start, perms); | |
1269 | if (error) | |
1270 | error = aa_audit_file(profile, perms, op, request, name, | |
1271 | NULL, target, GLOBAL_ROOT_UID, info, | |
1272 | error); | |
1273 | ||
1274 | return error; | |
1275 | } | |
89dbf196 | 1276 | |
898127c3 JJ |
1277 | /** |
1278 | * aa_change_profile - perform a one-way profile transition | |
aa9a39ad | 1279 | * @fqname: name of profile may include namespace (NOT NULL) |
898127c3 | 1280 | * @onexec: whether this transition is to take place immediately or at exec |
df8073c6 | 1281 | * @flags: flags affecting change behavior |
898127c3 JJ |
1282 | * |
1283 | * Change to new profile @name. Unlike with hats, there is no way | |
1284 | * to change back. If @name isn't specified the current profile name is | |
1285 | * used. | |
1286 | * If @onexec then the transition is delayed until | |
1287 | * the next exec. | |
1288 | * | |
1289 | * Returns %0 on success, error otherwise. | |
1290 | */ | |
df8073c6 | 1291 | int aa_change_profile(const char *fqname, int flags) |
898127c3 | 1292 | { |
e00b02bb JJ |
1293 | struct aa_label *label, *new = NULL, *target = NULL; |
1294 | struct aa_profile *profile; | |
2d679f3c | 1295 | struct aa_perms perms = {}; |
e00b02bb JJ |
1296 | const char *info = NULL; |
1297 | const char *auditname = fqname; /* retain leading & if stack */ | |
1298 | bool stack = flags & AA_CHANGE_STACK; | |
9fcf78cc | 1299 | struct aa_task_ctx *ctx = task_ctx(current); |
47f6e5cc | 1300 | int error = 0; |
e00b02bb | 1301 | char *op; |
898127c3 JJ |
1302 | u32 request; |
1303 | ||
9fcf78cc JJ |
1304 | label = aa_get_current_label(); |
1305 | ||
1306 | /* | |
1307 | * Detect no new privs being set, and store the label it | |
1308 | * occurred under. Ideally this would happen when nnp | |
1309 | * is set but there isn't a good way to do that yet. | |
1310 | * | |
1311 | * Testing for unconfined must be done before the subset test | |
1312 | */ | |
1313 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1314 | ctx->nnp = aa_get_label(label); | |
1315 | ||
aa9a39ad | 1316 | if (!fqname || !*fqname) { |
a0b845ff | 1317 | aa_put_label(label); |
aa9a39ad | 1318 | AA_DEBUG("no profile name"); |
898127c3 | 1319 | return -EINVAL; |
aa9a39ad | 1320 | } |
898127c3 | 1321 | |
df8073c6 | 1322 | if (flags & AA_CHANGE_ONEXEC) { |
898127c3 | 1323 | request = AA_MAY_ONEXEC; |
e00b02bb JJ |
1324 | if (stack) |
1325 | op = OP_STACK_ONEXEC; | |
1326 | else | |
1327 | op = OP_CHANGE_ONEXEC; | |
898127c3 JJ |
1328 | } else { |
1329 | request = AA_MAY_CHANGE_PROFILE; | |
e00b02bb JJ |
1330 | if (stack) |
1331 | op = OP_STACK; | |
1332 | else | |
1333 | op = OP_CHANGE_PROFILE; | |
898127c3 JJ |
1334 | } |
1335 | ||
e00b02bb JJ |
1336 | if (*fqname == '&') { |
1337 | stack = true; | |
1338 | /* don't have label_parse() do stacking */ | |
1339 | fqname++; | |
c29bceb3 | 1340 | } |
e00b02bb JJ |
1341 | target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); |
1342 | if (IS_ERR(target)) { | |
1343 | struct aa_profile *tprofile; | |
c29bceb3 | 1344 | |
e00b02bb JJ |
1345 | info = "label not found"; |
1346 | error = PTR_ERR(target); | |
1347 | target = NULL; | |
1348 | /* | |
1349 | * TODO: fixme using labels_profile is not right - do profile | |
1350 | * per complain profile | |
1351 | */ | |
df8073c6 | 1352 | if ((flags & AA_CHANGE_TEST) || |
e00b02bb | 1353 | !COMPLAIN_MODE(labels_profile(label))) |
898127c3 JJ |
1354 | goto audit; |
1355 | /* released below */ | |
e00b02bb JJ |
1356 | tprofile = aa_new_null_profile(labels_profile(label), false, |
1357 | fqname, GFP_KERNEL); | |
1358 | if (!tprofile) { | |
898127c3 JJ |
1359 | info = "failed null profile create"; |
1360 | error = -ENOMEM; | |
1361 | goto audit; | |
1362 | } | |
e00b02bb JJ |
1363 | target = &tprofile->label; |
1364 | goto check; | |
898127c3 JJ |
1365 | } |
1366 | ||
e00b02bb JJ |
1367 | /* |
1368 | * self directed transitions only apply to current policy ns | |
1369 | * TODO: currently requiring perms for stacking and straight change | |
1370 | * stacking doesn't strictly need this. Determine how much | |
1371 | * we want to loosen this restriction for stacking | |
1372 | * | |
1373 | * if (!stack) { | |
1374 | */ | |
1375 | error = fn_for_each_in_ns(label, profile, | |
1376 | change_profile_perms_wrapper(op, auditname, | |
1377 | profile, target, stack, | |
1378 | request, &perms)); | |
1379 | if (error) | |
1380 | /* auditing done in change_profile_perms_wrapper */ | |
1381 | goto out; | |
aa9a39ad | 1382 | |
e00b02bb JJ |
1383 | /* } */ |
1384 | ||
1385 | check: | |
898127c3 | 1386 | /* check if tracing task is allowed to trace target domain */ |
e00b02bb JJ |
1387 | error = may_change_ptraced_domain(target, &info); |
1388 | if (error && !fn_for_each_in_ns(label, profile, | |
1389 | COMPLAIN_MODE(profile))) | |
898127c3 | 1390 | goto audit; |
898127c3 | 1391 | |
e00b02bb JJ |
1392 | /* TODO: add permission check to allow this |
1393 | * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { | |
1394 | * info = "not a single threaded task"; | |
1395 | * error = -EACCES; | |
1396 | * goto audit; | |
1397 | * } | |
1398 | */ | |
df8073c6 | 1399 | if (flags & AA_CHANGE_TEST) |
e00b02bb | 1400 | goto out; |
898127c3 | 1401 | |
9fcf78cc JJ |
1402 | /* stacking is always a subset, so only check the nonstack case */ |
1403 | if (!stack) { | |
1404 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1405 | aa_get_label(target), | |
1406 | aa_get_label(&profile->label)); | |
1407 | /* | |
1408 | * no new privs prevents domain transitions that would | |
1409 | * reduce restrictions. | |
1410 | */ | |
1411 | if (task_no_new_privs(current) && !unconfined(label) && | |
3ed4aaa9 | 1412 | !aa_label_is_unconfined_subset(new, ctx->nnp)) { |
9fcf78cc JJ |
1413 | /* not an apparmor denial per se, so don't log it */ |
1414 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1415 | error = -EPERM; | |
1416 | goto out; | |
1417 | } | |
1418 | } | |
1419 | ||
e00b02bb JJ |
1420 | if (!(flags & AA_CHANGE_ONEXEC)) { |
1421 | /* only transition profiles in the current ns */ | |
1422 | if (stack) | |
1423 | new = aa_label_merge(label, target, GFP_KERNEL); | |
e00b02bb JJ |
1424 | if (IS_ERR_OR_NULL(new)) { |
1425 | info = "failed to build target label"; | |
d6d478ae JJ |
1426 | if (!new) |
1427 | error = -ENOMEM; | |
1428 | else | |
1429 | error = PTR_ERR(new); | |
e00b02bb JJ |
1430 | new = NULL; |
1431 | perms.allow = 0; | |
1432 | goto audit; | |
1433 | } | |
1434 | error = aa_replace_current_label(new); | |
9fcf78cc JJ |
1435 | } else { |
1436 | if (new) { | |
1437 | aa_put_label(new); | |
1438 | new = NULL; | |
1439 | } | |
1440 | ||
e00b02bb JJ |
1441 | /* full transition will be built in exec path */ |
1442 | error = aa_set_current_onexec(target, stack); | |
9fcf78cc | 1443 | } |
898127c3 JJ |
1444 | |
1445 | audit: | |
e00b02bb JJ |
1446 | error = fn_for_each_in_ns(label, profile, |
1447 | aa_audit_file(profile, &perms, op, request, auditname, | |
1448 | NULL, new ? new : target, | |
1449 | GLOBAL_ROOT_UID, info, error)); | |
898127c3 | 1450 | |
e00b02bb JJ |
1451 | out: |
1452 | aa_put_label(new); | |
1453 | aa_put_label(target); | |
637f688d | 1454 | aa_put_label(label); |
898127c3 JJ |
1455 | |
1456 | return error; | |
1457 | } |