Commit | Line | Data |
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b886d83c | 1 | // SPDX-License-Identifier: GPL-2.0-only |
898127c3 JJ |
2 | /* |
3 | * AppArmor security module | |
4 | * | |
5 | * This file contains AppArmor policy attachment and domain transitions | |
6 | * | |
7 | * Copyright (C) 2002-2008 Novell/SUSE | |
8 | * Copyright 2009-2010 Canonical Ltd. | |
898127c3 JJ |
9 | */ |
10 | ||
11 | #include <linux/errno.h> | |
12 | #include <linux/fdtable.h> | |
13 | #include <linux/file.h> | |
14 | #include <linux/mount.h> | |
15 | #include <linux/syscalls.h> | |
16 | #include <linux/tracehook.h> | |
17 | #include <linux/personality.h> | |
8e51f908 | 18 | #include <linux/xattr.h> |
898127c3 JJ |
19 | |
20 | #include "include/audit.h" | |
21 | #include "include/apparmorfs.h" | |
d8889d49 | 22 | #include "include/cred.h" |
898127c3 JJ |
23 | #include "include/domain.h" |
24 | #include "include/file.h" | |
25 | #include "include/ipc.h" | |
26 | #include "include/match.h" | |
27 | #include "include/path.h" | |
28 | #include "include/policy.h" | |
cff281f6 | 29 | #include "include/policy_ns.h" |
898127c3 JJ |
30 | |
31 | /** | |
32 | * aa_free_domain_entries - free entries in a domain table | |
33 | * @domain: the domain table to free (MAYBE NULL) | |
34 | */ | |
35 | void aa_free_domain_entries(struct aa_domain *domain) | |
36 | { | |
37 | int i; | |
38 | if (domain) { | |
39 | if (!domain->table) | |
40 | return; | |
41 | ||
42 | for (i = 0; i < domain->size; i++) | |
43 | kzfree(domain->table[i]); | |
44 | kzfree(domain->table); | |
45 | domain->table = NULL; | |
46 | } | |
47 | } | |
48 | ||
49 | /** | |
50 | * may_change_ptraced_domain - check if can change profile on ptraced task | |
b2d09ae4 JJ |
51 | * @to_label: profile to change to (NOT NULL) |
52 | * @info: message if there is an error | |
898127c3 | 53 | * |
51775fe7 | 54 | * Check if current is ptraced and if so if the tracing task is allowed |
898127c3 JJ |
55 | * to trace the new domain |
56 | * | |
57 | * Returns: %0 or error if change not allowed | |
58 | */ | |
b2d09ae4 JJ |
59 | static int may_change_ptraced_domain(struct aa_label *to_label, |
60 | const char **info) | |
898127c3 JJ |
61 | { |
62 | struct task_struct *tracer; | |
637f688d | 63 | struct aa_label *tracerl = NULL; |
898127c3 JJ |
64 | int error = 0; |
65 | ||
66 | rcu_read_lock(); | |
51775fe7 | 67 | tracer = ptrace_parent(current); |
3cfcc19e | 68 | if (tracer) |
898127c3 | 69 | /* released below */ |
637f688d | 70 | tracerl = aa_get_task_label(tracer); |
898127c3 JJ |
71 | |
72 | /* not ptraced */ | |
637f688d | 73 | if (!tracer || unconfined(tracerl)) |
898127c3 JJ |
74 | goto out; |
75 | ||
b2d09ae4 | 76 | error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); |
898127c3 JJ |
77 | |
78 | out: | |
04fdc099 | 79 | rcu_read_unlock(); |
637f688d | 80 | aa_put_label(tracerl); |
898127c3 | 81 | |
b2d09ae4 JJ |
82 | if (error) |
83 | *info = "ptrace prevents transition"; | |
898127c3 JJ |
84 | return error; |
85 | } | |
86 | ||
93c98a48 JJ |
87 | /**** TODO: dedup to aa_label_match - needs perm and dfa, merging |
88 | * specifically this is an exact copy of aa_label_match except | |
89 | * aa_compute_perms is replaced with aa_compute_fperms | |
90 | * and policy.dfa with file.dfa | |
91 | ****/ | |
92 | /* match a profile and its associated ns component if needed | |
93 | * Assumes visibility test has already been done. | |
94 | * If a subns profile is not to be matched should be prescreened with | |
95 | * visibility test. | |
96 | */ | |
97 | static inline unsigned int match_component(struct aa_profile *profile, | |
98 | struct aa_profile *tp, | |
99 | bool stack, unsigned int state) | |
100 | { | |
101 | const char *ns_name; | |
102 | ||
103 | if (stack) | |
104 | state = aa_dfa_match(profile->file.dfa, state, "&"); | |
105 | if (profile->ns == tp->ns) | |
106 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
107 | ||
108 | /* try matching with namespace name and then profile */ | |
109 | ns_name = aa_ns_name(profile->ns, tp->ns, true); | |
110 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
111 | state = aa_dfa_match(profile->file.dfa, state, ns_name); | |
112 | state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); | |
113 | return aa_dfa_match(profile->file.dfa, state, tp->base.hname); | |
114 | } | |
115 | ||
116 | /** | |
117 | * label_compound_match - find perms for full compound label | |
118 | * @profile: profile to find perms for | |
119 | * @label: label to check access permissions for | |
120 | * @stack: whether this is a stacking request | |
121 | * @start: state to start match in | |
122 | * @subns: whether to do permission checks on components in a subns | |
123 | * @request: permissions to request | |
124 | * @perms: perms struct to set | |
125 | * | |
126 | * Returns: 0 on success else ERROR | |
127 | * | |
128 | * For the label A//&B//&C this does the perm match for A//&B//&C | |
129 | * @perms should be preinitialized with allperms OR a previous permission | |
130 | * check to be stacked. | |
131 | */ | |
132 | static int label_compound_match(struct aa_profile *profile, | |
133 | struct aa_label *label, bool stack, | |
134 | unsigned int state, bool subns, u32 request, | |
135 | struct aa_perms *perms) | |
136 | { | |
137 | struct aa_profile *tp; | |
138 | struct label_it i; | |
139 | struct path_cond cond = { }; | |
140 | ||
141 | /* find first subcomponent that is visible */ | |
142 | label_for_each(i, label, tp) { | |
143 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
144 | continue; | |
145 | state = match_component(profile, tp, stack, state); | |
146 | if (!state) | |
147 | goto fail; | |
148 | goto next; | |
149 | } | |
150 | ||
151 | /* no component visible */ | |
152 | *perms = allperms; | |
153 | return 0; | |
154 | ||
155 | next: | |
156 | label_for_each_cont(i, label, tp) { | |
157 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
158 | continue; | |
159 | state = aa_dfa_match(profile->file.dfa, state, "//&"); | |
160 | state = match_component(profile, tp, false, state); | |
161 | if (!state) | |
162 | goto fail; | |
163 | } | |
164 | *perms = aa_compute_fperms(profile->file.dfa, state, &cond); | |
165 | aa_apply_modes_to_perms(profile, perms); | |
166 | if ((perms->allow & request) != request) | |
167 | return -EACCES; | |
168 | ||
169 | return 0; | |
170 | ||
171 | fail: | |
172 | *perms = nullperms; | |
173 | return -EACCES; | |
174 | } | |
175 | ||
176 | /** | |
177 | * label_components_match - find perms for all subcomponents of a label | |
178 | * @profile: profile to find perms for | |
179 | * @label: label to check access permissions for | |
180 | * @stack: whether this is a stacking request | |
181 | * @start: state to start match in | |
182 | * @subns: whether to do permission checks on components in a subns | |
183 | * @request: permissions to request | |
184 | * @perms: an initialized perms struct to add accumulation to | |
185 | * | |
186 | * Returns: 0 on success else ERROR | |
187 | * | |
188 | * For the label A//&B//&C this does the perm match for each of A and B and C | |
189 | * @perms should be preinitialized with allperms OR a previous permission | |
190 | * check to be stacked. | |
191 | */ | |
192 | static int label_components_match(struct aa_profile *profile, | |
193 | struct aa_label *label, bool stack, | |
194 | unsigned int start, bool subns, u32 request, | |
195 | struct aa_perms *perms) | |
196 | { | |
197 | struct aa_profile *tp; | |
198 | struct label_it i; | |
199 | struct aa_perms tmp; | |
200 | struct path_cond cond = { }; | |
201 | unsigned int state = 0; | |
202 | ||
203 | /* find first subcomponent to test */ | |
204 | label_for_each(i, label, tp) { | |
205 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
206 | continue; | |
207 | state = match_component(profile, tp, stack, start); | |
208 | if (!state) | |
209 | goto fail; | |
210 | goto next; | |
211 | } | |
212 | ||
213 | /* no subcomponents visible - no change in perms */ | |
214 | return 0; | |
215 | ||
216 | next: | |
217 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
218 | aa_apply_modes_to_perms(profile, &tmp); | |
219 | aa_perms_accum(perms, &tmp); | |
220 | label_for_each_cont(i, label, tp) { | |
221 | if (!aa_ns_visible(profile->ns, tp->ns, subns)) | |
222 | continue; | |
223 | state = match_component(profile, tp, stack, start); | |
224 | if (!state) | |
225 | goto fail; | |
226 | tmp = aa_compute_fperms(profile->file.dfa, state, &cond); | |
227 | aa_apply_modes_to_perms(profile, &tmp); | |
228 | aa_perms_accum(perms, &tmp); | |
229 | } | |
230 | ||
231 | if ((perms->allow & request) != request) | |
232 | return -EACCES; | |
233 | ||
234 | return 0; | |
235 | ||
236 | fail: | |
237 | *perms = nullperms; | |
238 | return -EACCES; | |
239 | } | |
240 | ||
241 | /** | |
242 | * label_match - do a multi-component label match | |
243 | * @profile: profile to match against (NOT NULL) | |
244 | * @label: label to match (NOT NULL) | |
245 | * @stack: whether this is a stacking request | |
246 | * @state: state to start in | |
247 | * @subns: whether to match subns components | |
248 | * @request: permission request | |
249 | * @perms: Returns computed perms (NOT NULL) | |
250 | * | |
251 | * Returns: the state the match finished in, may be the none matching state | |
252 | */ | |
253 | static int label_match(struct aa_profile *profile, struct aa_label *label, | |
254 | bool stack, unsigned int state, bool subns, u32 request, | |
255 | struct aa_perms *perms) | |
256 | { | |
257 | int error; | |
258 | ||
259 | *perms = nullperms; | |
260 | error = label_compound_match(profile, label, stack, state, subns, | |
261 | request, perms); | |
262 | if (!error) | |
263 | return error; | |
264 | ||
265 | *perms = allperms; | |
266 | return label_components_match(profile, label, stack, state, subns, | |
267 | request, perms); | |
268 | } | |
269 | ||
270 | /******* end TODO: dedup *****/ | |
271 | ||
898127c3 JJ |
272 | /** |
273 | * change_profile_perms - find permissions for change_profile | |
274 | * @profile: the current profile (NOT NULL) | |
93c98a48 JJ |
275 | * @target: label to transition to (NOT NULL) |
276 | * @stack: whether this is a stacking request | |
898127c3 JJ |
277 | * @request: requested perms |
278 | * @start: state to start matching in | |
279 | * | |
93c98a48 | 280 | * |
898127c3 | 281 | * Returns: permission set |
93c98a48 JJ |
282 | * |
283 | * currently only matches full label A//&B//&C or individual components A, B, C | |
284 | * not arbitrary combinations. Eg. A//&B, C | |
898127c3 | 285 | */ |
93c98a48 JJ |
286 | static int change_profile_perms(struct aa_profile *profile, |
287 | struct aa_label *target, bool stack, | |
288 | u32 request, unsigned int start, | |
289 | struct aa_perms *perms) | |
290 | { | |
291 | if (profile_unconfined(profile)) { | |
292 | perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; | |
293 | perms->audit = perms->quiet = perms->kill = 0; | |
294 | return 0; | |
295 | } | |
296 | ||
297 | /* TODO: add profile in ns screening */ | |
298 | return label_match(profile, target, stack, start, true, request, perms); | |
299 | } | |
300 | ||
8e51f908 MG |
301 | /** |
302 | * aa_xattrs_match - check whether a file matches the xattrs defined in profile | |
303 | * @bprm: binprm struct for the process to validate | |
304 | * @profile: profile to match against (NOT NULL) | |
73f488cd | 305 | * @state: state to start match in |
8e51f908 MG |
306 | * |
307 | * Returns: number of extended attributes that matched, or < 0 on error | |
308 | */ | |
309 | static int aa_xattrs_match(const struct linux_binprm *bprm, | |
73f488cd | 310 | struct aa_profile *profile, unsigned int state) |
8e51f908 MG |
311 | { |
312 | int i; | |
a61ecd32 | 313 | ssize_t size; |
8e51f908 MG |
314 | struct dentry *d; |
315 | char *value = NULL; | |
316 | int value_size = 0, ret = profile->xattr_count; | |
317 | ||
318 | if (!bprm || !profile->xattr_count) | |
319 | return 0; | |
320 | ||
73f488cd JJ |
321 | /* transition from exec match to xattr set */ |
322 | state = aa_dfa_null_transition(profile->xmatch, state); | |
323 | ||
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 | |
73f488cd JJ |
332 | /* Check the xattr value, not just presence */ |
333 | state = aa_dfa_match_len(profile->xmatch, state, value, | |
334 | size); | |
335 | perm = dfa_user_allow(profile->xmatch, state); | |
336 | if (!(perm & MAY_EXEC)) { | |
8e51f908 MG |
337 | ret = -EINVAL; |
338 | goto out; | |
339 | } | |
73f488cd JJ |
340 | } |
341 | /* transition to next element */ | |
342 | state = aa_dfa_null_transition(profile->xmatch, state); | |
343 | if (size < 0) { | |
344 | /* | |
345 | * No xattr match, so verify if transition to | |
346 | * next element was valid. IFF so the xattr | |
347 | * was optional. | |
348 | */ | |
349 | if (!state) { | |
8e51f908 MG |
350 | ret = -EINVAL; |
351 | goto out; | |
352 | } | |
73f488cd JJ |
353 | /* don't count missing optional xattr as matched */ |
354 | ret--; | |
8e51f908 MG |
355 | } |
356 | } | |
357 | ||
358 | out: | |
359 | kfree(value); | |
360 | return ret; | |
361 | } | |
362 | ||
898127c3 JJ |
363 | /** |
364 | * __attach_match_ - find an attachment match | |
8e51f908 | 365 | * @bprm - binprm structure of transitioning task |
898127c3 JJ |
366 | * @name - to match against (NOT NULL) |
367 | * @head - profile list to walk (NOT NULL) | |
844b8292 | 368 | * @info - info message if there was an error (NOT NULL) |
898127c3 JJ |
369 | * |
370 | * Do a linear search on the profiles in the list. There is a matching | |
371 | * preference where an exact match is preferred over a name which uses | |
372 | * expressions to match, and matching expressions with the greatest | |
373 | * xmatch_len are preferred. | |
374 | * | |
375 | * Requires: @head not be shared or have appropriate locks held | |
376 | * | |
377 | * Returns: profile or NULL if no match found | |
378 | */ | |
8e51f908 MG |
379 | static struct aa_profile *__attach_match(const struct linux_binprm *bprm, |
380 | const char *name, | |
844b8292 JJ |
381 | struct list_head *head, |
382 | const char **info) | |
898127c3 | 383 | { |
21f60661 | 384 | int candidate_len = 0, candidate_xattrs = 0; |
844b8292 | 385 | bool conflict = false; |
898127c3 JJ |
386 | struct aa_profile *profile, *candidate = NULL; |
387 | ||
21f60661 JJ |
388 | AA_BUG(!name); |
389 | AA_BUG(!head); | |
390 | ||
01e2b670 | 391 | list_for_each_entry_rcu(profile, head, base.list) { |
06d426d1 JJ |
392 | if (profile->label.flags & FLAG_NULL && |
393 | &profile->label == ns_unconfined(profile->ns)) | |
898127c3 | 394 | continue; |
06d426d1 | 395 | |
8e51f908 MG |
396 | /* Find the "best" matching profile. Profiles must |
397 | * match the path and extended attributes (if any) | |
398 | * associated with the file. A more specific path | |
399 | * match will be preferred over a less specific one, | |
400 | * and a match with more matching extended attributes | |
401 | * will be preferred over one with fewer. If the best | |
402 | * match has both the same level of path specificity | |
403 | * and the same number of matching extended attributes | |
404 | * as another profile, signal a conflict and refuse to | |
405 | * match. | |
406 | */ | |
844b8292 | 407 | if (profile->xmatch) { |
21f60661 | 408 | unsigned int state, count; |
8e51f908 MG |
409 | u32 perm; |
410 | ||
21f60661 JJ |
411 | state = aa_dfa_leftmatch(profile->xmatch, DFA_START, |
412 | name, &count); | |
8e51f908 MG |
413 | perm = dfa_user_allow(profile->xmatch, state); |
414 | /* any accepting state means a valid match. */ | |
415 | if (perm & MAY_EXEC) { | |
21f60661 JJ |
416 | int ret; |
417 | ||
418 | if (count < candidate_len) | |
419 | continue; | |
8e51f908 | 420 | |
21f60661 | 421 | ret = aa_xattrs_match(bprm, profile, state); |
8e51f908 MG |
422 | /* Fail matching if the xattrs don't match */ |
423 | if (ret < 0) | |
424 | continue; | |
425 | ||
73f488cd JJ |
426 | /* |
427 | * TODO: allow for more flexible best match | |
428 | * | |
429 | * The new match isn't more specific | |
8e51f908 MG |
430 | * than the current best match |
431 | */ | |
21f60661 JJ |
432 | if (count == candidate_len && |
433 | ret <= candidate_xattrs) { | |
8e51f908 | 434 | /* Match is equivalent, so conflict */ |
21f60661 | 435 | if (ret == candidate_xattrs) |
1a3881d3 | 436 | conflict = true; |
8e51f908 | 437 | continue; |
844b8292 | 438 | } |
8e51f908 MG |
439 | |
440 | /* Either the same length with more matching | |
441 | * xattrs, or a longer match | |
442 | */ | |
443 | candidate = profile; | |
21f60661 JJ |
444 | candidate_len = profile->xmatch_len; |
445 | candidate_xattrs = ret; | |
8e51f908 | 446 | conflict = false; |
898127c3 | 447 | } |
73f488cd JJ |
448 | } else if (!strcmp(profile->base.name, name)) |
449 | /* | |
450 | * old exact non-re match, without conditionals such | |
451 | * as xattrs. no more searching required | |
452 | */ | |
898127c3 JJ |
453 | return profile; |
454 | } | |
455 | ||
844b8292 JJ |
456 | if (conflict) { |
457 | *info = "conflicting profile attachments"; | |
458 | return NULL; | |
459 | } | |
460 | ||
898127c3 JJ |
461 | return candidate; |
462 | } | |
463 | ||
464 | /** | |
465 | * find_attach - do attachment search for unconfined processes | |
8e51f908 | 466 | * @bprm - binprm structure of transitioning task |
898127c3 JJ |
467 | * @ns: the current namespace (NOT NULL) |
468 | * @list: list to search (NOT NULL) | |
469 | * @name: the executable name to match against (NOT NULL) | |
844b8292 | 470 | * @info: info message if there was an error |
898127c3 | 471 | * |
93c98a48 | 472 | * Returns: label or NULL if no match found |
898127c3 | 473 | */ |
8e51f908 MG |
474 | static struct aa_label *find_attach(const struct linux_binprm *bprm, |
475 | struct aa_ns *ns, struct list_head *list, | |
844b8292 | 476 | const char *name, const char **info) |
898127c3 JJ |
477 | { |
478 | struct aa_profile *profile; | |
479 | ||
01e2b670 | 480 | rcu_read_lock(); |
8e51f908 | 481 | profile = aa_get_profile(__attach_match(bprm, name, list, info)); |
01e2b670 | 482 | rcu_read_unlock(); |
898127c3 | 483 | |
93c98a48 | 484 | return profile ? &profile->label : NULL; |
898127c3 JJ |
485 | } |
486 | ||
487 | static const char *next_name(int xtype, const char *name) | |
488 | { | |
489 | return NULL; | |
490 | } | |
491 | ||
492 | /** | |
493 | * x_table_lookup - lookup an x transition name via transition table | |
494 | * @profile: current profile (NOT NULL) | |
495 | * @xindex: index into x transition table | |
93c98a48 | 496 | * @name: returns: name tested to find label (NOT NULL) |
898127c3 | 497 | * |
93c98a48 | 498 | * Returns: refcounted label, or NULL on failure (MAYBE NULL) |
898127c3 | 499 | */ |
2ea3ffb7 JJ |
500 | struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, |
501 | const char **name) | |
898127c3 | 502 | { |
93c98a48 | 503 | struct aa_label *label = NULL; |
898127c3 JJ |
504 | u32 xtype = xindex & AA_X_TYPE_MASK; |
505 | int index = xindex & AA_X_INDEX_MASK; | |
898127c3 | 506 | |
93c98a48 | 507 | AA_BUG(!name); |
898127c3 | 508 | |
93c98a48 JJ |
509 | /* index is guaranteed to be in range, validated at load time */ |
510 | /* TODO: move lookup parsing to unpack time so this is a straight | |
511 | * index into the resultant label | |
512 | */ | |
513 | for (*name = profile->file.trans.table[index]; !label && *name; | |
514 | *name = next_name(xtype, *name)) { | |
898127c3 | 515 | if (xindex & AA_X_CHILD) { |
93c98a48 | 516 | struct aa_profile *new_profile; |
898127c3 | 517 | /* release by caller */ |
93c98a48 JJ |
518 | new_profile = aa_find_child(profile, *name); |
519 | if (new_profile) | |
520 | label = &new_profile->label; | |
898127c3 | 521 | continue; |
898127c3 | 522 | } |
93c98a48 JJ |
523 | label = aa_label_parse(&profile->label, *name, GFP_ATOMIC, |
524 | true, false); | |
525 | if (IS_ERR(label)) | |
526 | label = NULL; | |
898127c3 JJ |
527 | } |
528 | ||
529 | /* released by caller */ | |
93c98a48 JJ |
530 | |
531 | return label; | |
898127c3 JJ |
532 | } |
533 | ||
534 | /** | |
93c98a48 | 535 | * x_to_label - get target label for a given xindex |
898127c3 | 536 | * @profile: current profile (NOT NULL) |
8e51f908 | 537 | * @bprm: binprm structure of transitioning task |
898127c3 JJ |
538 | * @name: name to lookup (NOT NULL) |
539 | * @xindex: index into x transition table | |
93c98a48 | 540 | * @lookupname: returns: name used in lookup if one was specified (NOT NULL) |
898127c3 | 541 | * |
93c98a48 | 542 | * find label for a transition index |
898127c3 | 543 | * |
93c98a48 | 544 | * Returns: refcounted label or NULL if not found available |
898127c3 | 545 | */ |
93c98a48 | 546 | static struct aa_label *x_to_label(struct aa_profile *profile, |
8e51f908 | 547 | const struct linux_binprm *bprm, |
93c98a48 JJ |
548 | const char *name, u32 xindex, |
549 | const char **lookupname, | |
550 | const char **info) | |
898127c3 | 551 | { |
93c98a48 | 552 | struct aa_label *new = NULL; |
98849dff | 553 | struct aa_ns *ns = profile->ns; |
898127c3 | 554 | u32 xtype = xindex & AA_X_TYPE_MASK; |
93c98a48 | 555 | const char *stack = NULL; |
898127c3 JJ |
556 | |
557 | switch (xtype) { | |
558 | case AA_X_NONE: | |
559 | /* fail exec unless ix || ux fallback - handled by caller */ | |
93c98a48 JJ |
560 | *lookupname = NULL; |
561 | break; | |
562 | case AA_X_TABLE: | |
563 | /* TODO: fix when perm mapping done at unload */ | |
564 | stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; | |
565 | if (*stack != '&') { | |
566 | /* released by caller */ | |
567 | new = x_table_lookup(profile, xindex, lookupname); | |
568 | stack = NULL; | |
569 | break; | |
570 | } | |
09186e50 | 571 | /* fall through - to X_NAME */ |
898127c3 JJ |
572 | case AA_X_NAME: |
573 | if (xindex & AA_X_CHILD) | |
574 | /* released by caller */ | |
8e51f908 | 575 | new = find_attach(bprm, ns, &profile->base.profiles, |
844b8292 | 576 | name, info); |
898127c3 JJ |
577 | else |
578 | /* released by caller */ | |
8e51f908 | 579 | new = find_attach(bprm, ns, &ns->base.profiles, |
844b8292 | 580 | name, info); |
93c98a48 | 581 | *lookupname = name; |
898127c3 JJ |
582 | break; |
583 | } | |
584 | ||
93c98a48 JJ |
585 | if (!new) { |
586 | if (xindex & AA_X_INHERIT) { | |
587 | /* (p|c|n)ix - don't change profile but do | |
588 | * use the newest version | |
589 | */ | |
590 | *info = "ix fallback"; | |
591 | /* no profile && no error */ | |
592 | new = aa_get_newest_label(&profile->label); | |
593 | } else if (xindex & AA_X_UNCONFINED) { | |
594 | new = aa_get_newest_label(ns_unconfined(profile->ns)); | |
595 | *info = "ux fallback"; | |
596 | } | |
597 | } | |
598 | ||
599 | if (new && stack) { | |
600 | /* base the stack on post domain transition */ | |
601 | struct aa_label *base = new; | |
602 | ||
603 | new = aa_label_parse(base, stack, GFP_ATOMIC, true, false); | |
604 | if (IS_ERR(new)) | |
605 | new = NULL; | |
606 | aa_put_label(base); | |
607 | } | |
608 | ||
898127c3 | 609 | /* released by caller */ |
93c98a48 | 610 | return new; |
898127c3 JJ |
611 | } |
612 | ||
93c98a48 JJ |
613 | static struct aa_label *profile_transition(struct aa_profile *profile, |
614 | const struct linux_binprm *bprm, | |
615 | char *buffer, struct path_cond *cond, | |
616 | bool *secure_exec) | |
898127c3 | 617 | { |
93c98a48 | 618 | struct aa_label *new = NULL; |
8e51f908 MG |
619 | struct aa_profile *component; |
620 | struct label_it i; | |
93c98a48 JJ |
621 | const char *info = NULL, *name = NULL, *target = NULL; |
622 | unsigned int state = profile->file.start; | |
2d679f3c | 623 | struct aa_perms perms = {}; |
93c98a48 | 624 | bool nonewprivs = false; |
b1d9e6b0 | 625 | int error = 0; |
898127c3 | 626 | |
93c98a48 JJ |
627 | AA_BUG(!profile); |
628 | AA_BUG(!bprm); | |
629 | AA_BUG(!buffer); | |
898127c3 | 630 | |
4227c333 | 631 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, |
72c8a768 | 632 | &name, &info, profile->disconnected); |
898127c3 | 633 | if (error) { |
637f688d | 634 | if (profile_unconfined(profile) || |
93c98a48 JJ |
635 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { |
636 | AA_DEBUG("name lookup ix on error"); | |
898127c3 | 637 | error = 0; |
93c98a48 JJ |
638 | new = aa_get_newest_label(&profile->label); |
639 | } | |
898127c3 JJ |
640 | name = bprm->filename; |
641 | goto audit; | |
642 | } | |
643 | ||
637f688d | 644 | if (profile_unconfined(profile)) { |
8e51f908 MG |
645 | new = find_attach(bprm, profile->ns, |
646 | &profile->ns->base.profiles, name, &info); | |
93c98a48 JJ |
647 | if (new) { |
648 | AA_DEBUG("unconfined attached to new label"); | |
649 | return new; | |
650 | } | |
651 | AA_DEBUG("unconfined exec no attachment"); | |
652 | return aa_get_newest_label(&profile->label); | |
898127c3 JJ |
653 | } |
654 | ||
655 | /* find exec permissions for name */ | |
93c98a48 | 656 | state = aa_str_perms(profile->file.dfa, state, name, cond, &perms); |
898127c3 JJ |
657 | if (perms.allow & MAY_EXEC) { |
658 | /* exec permission determine how to transition */ | |
8e51f908 MG |
659 | new = x_to_label(profile, bprm, name, perms.xindex, &target, |
660 | &info); | |
93c98a48 JJ |
661 | if (new && new->proxy == profile->label.proxy && info) { |
662 | /* hack ix fallback - improve how this is detected */ | |
663 | goto audit; | |
664 | } else if (!new) { | |
665 | error = -EACCES; | |
666 | info = "profile transition not found"; | |
667 | /* remove MAY_EXEC to audit as failure */ | |
668 | perms.allow &= ~MAY_EXEC; | |
8e51f908 MG |
669 | } else { |
670 | /* verify that each component's xattr requirements are | |
671 | * met, and fail execution otherwise | |
672 | */ | |
673 | label_for_each(i, new, component) { | |
73f488cd JJ |
674 | if (aa_xattrs_match(bprm, component, state) < |
675 | 0) { | |
8e51f908 MG |
676 | error = -EACCES; |
677 | info = "required xattrs not present"; | |
678 | perms.allow &= ~MAY_EXEC; | |
679 | aa_put_label(new); | |
680 | new = NULL; | |
681 | goto audit; | |
682 | } | |
683 | } | |
898127c3 JJ |
684 | } |
685 | } else if (COMPLAIN_MODE(profile)) { | |
93c98a48 | 686 | /* no exec permission - learning mode */ |
5d7c44ef JJ |
687 | struct aa_profile *new_profile = NULL; |
688 | char *n = kstrdup(name, GFP_ATOMIC); | |
689 | ||
690 | if (n) { | |
691 | /* name is ptr into buffer */ | |
692 | long pos = name - buffer; | |
693 | /* break per cpu buffer hold */ | |
694 | put_buffers(buffer); | |
695 | new_profile = aa_new_null_profile(profile, false, n, | |
696 | GFP_KERNEL); | |
697 | get_buffers(buffer); | |
698 | name = buffer + pos; | |
699 | strcpy((char *)name, n); | |
700 | kfree(n); | |
701 | } | |
898127c3 JJ |
702 | if (!new_profile) { |
703 | error = -ENOMEM; | |
704 | info = "could not create null profile"; | |
93c98a48 | 705 | } else { |
898127c3 | 706 | error = -EACCES; |
93c98a48 JJ |
707 | new = &new_profile->label; |
708 | } | |
898127c3 JJ |
709 | perms.xindex |= AA_X_UNSAFE; |
710 | } else | |
711 | /* fail exec */ | |
712 | error = -EACCES; | |
713 | ||
93c98a48 JJ |
714 | if (!new) |
715 | goto audit; | |
716 | ||
93c98a48 JJ |
717 | |
718 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
719 | if (DEBUG_ON) { | |
720 | dbg_printk("apparmor: scrubbing environment variables" | |
721 | " for %s profile=", name); | |
722 | aa_label_printk(new, GFP_ATOMIC); | |
723 | dbg_printk("\n"); | |
724 | } | |
725 | *secure_exec = true; | |
c29bceb3 JJ |
726 | } |
727 | ||
93c98a48 JJ |
728 | audit: |
729 | aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, | |
730 | cond->uid, info, error); | |
731 | if (!new || nonewprivs) { | |
732 | aa_put_label(new); | |
733 | return ERR_PTR(error); | |
734 | } | |
735 | ||
736 | return new; | |
737 | } | |
738 | ||
739 | static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, | |
740 | bool stack, const struct linux_binprm *bprm, | |
741 | char *buffer, struct path_cond *cond, | |
742 | bool *secure_exec) | |
743 | { | |
744 | unsigned int state = profile->file.start; | |
745 | struct aa_perms perms = {}; | |
746 | const char *xname = NULL, *info = "change_profile onexec"; | |
747 | int error = -EACCES; | |
748 | ||
749 | AA_BUG(!profile); | |
750 | AA_BUG(!onexec); | |
751 | AA_BUG(!bprm); | |
752 | AA_BUG(!buffer); | |
753 | ||
754 | if (profile_unconfined(profile)) { | |
755 | /* change_profile on exec already granted */ | |
756 | /* | |
757 | * NOTE: Domain transitions from unconfined are allowed | |
758 | * even when no_new_privs is set because this aways results | |
759 | * in a further reduction of permissions. | |
760 | */ | |
761 | return 0; | |
762 | } | |
763 | ||
764 | error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, | |
765 | &xname, &info, profile->disconnected); | |
766 | if (error) { | |
767 | if (profile_unconfined(profile) || | |
768 | (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { | |
769 | AA_DEBUG("name lookup ix on error"); | |
770 | error = 0; | |
771 | } | |
772 | xname = bprm->filename; | |
898127c3 | 773 | goto audit; |
93c98a48 JJ |
774 | } |
775 | ||
776 | /* find exec permissions for name */ | |
777 | state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms); | |
778 | if (!(perms.allow & AA_MAY_ONEXEC)) { | |
779 | info = "no change_onexec valid for executable"; | |
780 | goto audit; | |
781 | } | |
782 | /* test if this exec can be paired with change_profile onexec. | |
783 | * onexec permission is linked to exec with a standard pairing | |
784 | * exec\0change_profile | |
785 | */ | |
786 | state = aa_dfa_null_transition(profile->file.dfa, state); | |
787 | error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, | |
788 | state, &perms); | |
789 | if (error) { | |
790 | perms.allow &= ~AA_MAY_ONEXEC; | |
791 | goto audit; | |
792 | } | |
93c98a48 JJ |
793 | |
794 | if (!(perms.xindex & AA_X_UNSAFE)) { | |
795 | if (DEBUG_ON) { | |
796 | dbg_printk("apparmor: scrubbing environment " | |
797 | "variables for %s label=", xname); | |
798 | aa_label_printk(onexec, GFP_ATOMIC); | |
799 | dbg_printk("\n"); | |
800 | } | |
801 | *secure_exec = true; | |
802 | } | |
803 | ||
804 | audit: | |
805 | return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, | |
806 | NULL, onexec, cond->uid, info, error); | |
807 | } | |
808 | ||
809 | /* ensure none ns domain transitions are correctly applied with onexec */ | |
810 | ||
811 | static struct aa_label *handle_onexec(struct aa_label *label, | |
812 | struct aa_label *onexec, bool stack, | |
813 | const struct linux_binprm *bprm, | |
814 | char *buffer, struct path_cond *cond, | |
815 | bool *unsafe) | |
816 | { | |
817 | struct aa_profile *profile; | |
818 | struct aa_label *new; | |
819 | int error; | |
820 | ||
821 | AA_BUG(!label); | |
822 | AA_BUG(!onexec); | |
823 | AA_BUG(!bprm); | |
824 | AA_BUG(!buffer); | |
825 | ||
826 | if (!stack) { | |
827 | error = fn_for_each_in_ns(label, profile, | |
828 | profile_onexec(profile, onexec, stack, | |
829 | bprm, buffer, cond, unsafe)); | |
830 | if (error) | |
831 | return ERR_PTR(error); | |
832 | new = fn_label_build_in_ns(label, profile, GFP_ATOMIC, | |
833 | aa_get_newest_label(onexec), | |
834 | profile_transition(profile, bprm, buffer, | |
835 | cond, unsafe)); | |
836 | ||
837 | } else { | |
b2c2086c | 838 | /* TODO: determine how much we want to loosen this */ |
93c98a48 JJ |
839 | error = fn_for_each_in_ns(label, profile, |
840 | profile_onexec(profile, onexec, stack, bprm, | |
841 | buffer, cond, unsafe)); | |
842 | if (error) | |
843 | return ERR_PTR(error); | |
844 | new = fn_label_build_in_ns(label, profile, GFP_ATOMIC, | |
845 | aa_label_merge(&profile->label, onexec, | |
846 | GFP_ATOMIC), | |
847 | profile_transition(profile, bprm, buffer, | |
848 | cond, unsafe)); | |
849 | } | |
850 | ||
851 | if (new) | |
852 | return new; | |
853 | ||
854 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
855 | error = fn_for_each_in_ns(label, profile, | |
856 | aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, | |
857 | AA_MAY_ONEXEC, bprm->filename, NULL, | |
858 | onexec, GLOBAL_ROOT_UID, | |
859 | "failed to build target label", -ENOMEM)); | |
860 | return ERR_PTR(error); | |
861 | } | |
862 | ||
863 | /** | |
864 | * apparmor_bprm_set_creds - set the new creds on the bprm struct | |
865 | * @bprm: binprm for the exec (NOT NULL) | |
866 | * | |
867 | * Returns: %0 or error on failure | |
868 | * | |
869 | * TODO: once the other paths are done see if we can't refactor into a fn | |
870 | */ | |
871 | int apparmor_bprm_set_creds(struct linux_binprm *bprm) | |
872 | { | |
f175221a | 873 | struct aa_task_ctx *ctx; |
93c98a48 JJ |
874 | struct aa_label *label, *new = NULL; |
875 | struct aa_profile *profile; | |
876 | char *buffer = NULL; | |
877 | const char *info = NULL; | |
878 | int error = 0; | |
879 | bool unsafe = false; | |
880 | struct path_cond cond = { | |
881 | file_inode(bprm->file)->i_uid, | |
882 | file_inode(bprm->file)->i_mode | |
883 | }; | |
884 | ||
ddb4a144 | 885 | if (bprm->called_set_creds) |
93c98a48 JJ |
886 | return 0; |
887 | ||
de62de59 | 888 | ctx = task_ctx(current); |
d9087c49 | 889 | AA_BUG(!cred_label(bprm->cred)); |
f175221a | 890 | AA_BUG(!ctx); |
93c98a48 | 891 | |
d9087c49 | 892 | label = aa_get_newest_label(cred_label(bprm->cred)); |
93c98a48 | 893 | |
9fcf78cc JJ |
894 | /* |
895 | * Detect no new privs being set, and store the label it | |
896 | * occurred under. Ideally this would happen when nnp | |
897 | * is set but there isn't a good way to do that yet. | |
898 | * | |
899 | * Testing for unconfined must be done before the subset test | |
900 | */ | |
901 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) && | |
902 | !ctx->nnp) | |
903 | ctx->nnp = aa_get_label(label); | |
904 | ||
93c98a48 JJ |
905 | /* buffer freed below, name is pointer into buffer */ |
906 | get_buffers(buffer); | |
907 | /* Test for onexec first as onexec override other x transitions. */ | |
f175221a JJ |
908 | if (ctx->onexec) |
909 | new = handle_onexec(label, ctx->onexec, ctx->token, | |
93c98a48 JJ |
910 | bprm, buffer, &cond, &unsafe); |
911 | else | |
912 | new = fn_label_build(label, profile, GFP_ATOMIC, | |
913 | profile_transition(profile, bprm, buffer, | |
914 | &cond, &unsafe)); | |
915 | ||
916 | AA_BUG(!new); | |
917 | if (IS_ERR(new)) { | |
918 | error = PTR_ERR(new); | |
919 | goto done; | |
920 | } else if (!new) { | |
921 | error = -ENOMEM; | |
922 | goto done; | |
923 | } | |
924 | ||
9fcf78cc JJ |
925 | /* Policy has specified a domain transitions. If no_new_privs and |
926 | * confined ensure the transition is to confinement that is subset | |
927 | * of the confinement when the task entered no new privs. | |
928 | * | |
929 | * NOTE: Domain transitions from unconfined and to stacked | |
930 | * subsets are allowed even when no_new_privs is set because this | |
931 | * aways results in a further reduction of permissions. | |
932 | */ | |
933 | if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && | |
934 | !unconfined(label) && !aa_label_is_subset(new, ctx->nnp)) { | |
935 | error = -EPERM; | |
936 | info = "no new privs"; | |
937 | goto audit; | |
938 | } | |
898127c3 JJ |
939 | |
940 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
941 | /* FIXME: currently don't mediate shared state */ | |
942 | ; | |
943 | } | |
944 | ||
93c98a48 JJ |
945 | if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { |
946 | /* TODO: test needs to be profile of label to new */ | |
947 | error = may_change_ptraced_domain(new, &info); | |
f7da2de0 | 948 | if (error) |
898127c3 | 949 | goto audit; |
898127c3 JJ |
950 | } |
951 | ||
93c98a48 JJ |
952 | if (unsafe) { |
953 | if (DEBUG_ON) { | |
954 | dbg_printk("scrubbing environment variables for %s " | |
955 | "label=", bprm->filename); | |
956 | aa_label_printk(new, GFP_ATOMIC); | |
957 | dbg_printk("\n"); | |
958 | } | |
993b3ab0 | 959 | bprm->secureexec = 1; |
898127c3 | 960 | } |
898127c3 | 961 | |
93c98a48 JJ |
962 | if (label->proxy != new->proxy) { |
963 | /* when transitioning clear unsafe personality bits */ | |
964 | if (DEBUG_ON) { | |
965 | dbg_printk("apparmor: clearing unsafe personality " | |
966 | "bits. %s label=", bprm->filename); | |
967 | aa_label_printk(new, GFP_ATOMIC); | |
968 | dbg_printk("\n"); | |
969 | } | |
970 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
971 | } | |
d9087c49 JJ |
972 | aa_put_label(cred_label(bprm->cred)); |
973 | /* transfer reference, released when cred is freed */ | |
69b5a44a | 974 | set_cred_label(bprm->cred, new); |
898127c3 | 975 | |
93c98a48 | 976 | done: |
637f688d | 977 | aa_put_label(label); |
4227c333 | 978 | put_buffers(buffer); |
898127c3 JJ |
979 | |
980 | return error; | |
93c98a48 JJ |
981 | |
982 | audit: | |
983 | error = fn_for_each(label, profile, | |
984 | aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, | |
985 | bprm->filename, NULL, new, | |
986 | file_inode(bprm->file)->i_uid, info, | |
987 | error)); | |
988 | aa_put_label(new); | |
989 | goto done; | |
898127c3 JJ |
990 | } |
991 | ||
898127c3 JJ |
992 | /* |
993 | * Functions for self directed profile change | |
994 | */ | |
995 | ||
89dbf196 JJ |
996 | |
997 | /* helper fn for change_hat | |
898127c3 | 998 | * |
89dbf196 | 999 | * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL |
898127c3 | 1000 | */ |
89dbf196 JJ |
1001 | static struct aa_label *build_change_hat(struct aa_profile *profile, |
1002 | const char *name, bool sibling) | |
898127c3 | 1003 | { |
89dbf196 JJ |
1004 | struct aa_profile *root, *hat = NULL; |
1005 | const char *info = NULL; | |
1006 | int error = 0; | |
1007 | ||
1008 | if (sibling && PROFILE_IS_HAT(profile)) { | |
1009 | root = aa_get_profile_rcu(&profile->parent); | |
1010 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1011 | root = aa_get_profile(profile); | |
1012 | } else { | |
1013 | info = "conflicting target types"; | |
1014 | error = -EPERM; | |
1015 | goto audit; | |
1016 | } | |
1017 | ||
1018 | hat = aa_find_child(root, name); | |
1019 | if (!hat) { | |
1020 | error = -ENOENT; | |
1021 | if (COMPLAIN_MODE(profile)) { | |
1022 | hat = aa_new_null_profile(profile, true, name, | |
1023 | GFP_KERNEL); | |
1024 | if (!hat) { | |
1025 | info = "failed null profile create"; | |
1026 | error = -ENOMEM; | |
1027 | } | |
1028 | } | |
1029 | } | |
1030 | aa_put_profile(root); | |
1031 | ||
1032 | audit: | |
1033 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, | |
1034 | name, hat ? hat->base.hname : NULL, | |
24b87a16 | 1035 | hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, |
89dbf196 JJ |
1036 | error); |
1037 | if (!hat || (error && error != -ENOENT)) | |
1038 | return ERR_PTR(error); | |
1039 | /* if hat && error - complain mode, already audited and we adjust for | |
1040 | * complain mode allow by returning hat->label | |
1041 | */ | |
1042 | return &hat->label; | |
1043 | } | |
1044 | ||
1045 | /* helper fn for changing into a hat | |
1046 | * | |
1047 | * Returns: label for hat transition or ERR_PTR. Does not return NULL | |
1048 | */ | |
1049 | static struct aa_label *change_hat(struct aa_label *label, const char *hats[], | |
1050 | int count, int flags) | |
1051 | { | |
1052 | struct aa_profile *profile, *root, *hat = NULL; | |
1053 | struct aa_label *new; | |
1054 | struct label_it it; | |
1055 | bool sibling = false; | |
1056 | const char *name, *info = NULL; | |
1057 | int i, error; | |
1058 | ||
1059 | AA_BUG(!label); | |
1060 | AA_BUG(!hats); | |
1061 | AA_BUG(count < 1); | |
1062 | ||
1063 | if (PROFILE_IS_HAT(labels_profile(label))) | |
1064 | sibling = true; | |
1065 | ||
1066 | /*find first matching hat */ | |
1067 | for (i = 0; i < count && !hat; i++) { | |
1068 | name = hats[i]; | |
1069 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1070 | if (sibling && PROFILE_IS_HAT(profile)) { | |
1071 | root = aa_get_profile_rcu(&profile->parent); | |
1072 | } else if (!sibling && !PROFILE_IS_HAT(profile)) { | |
1073 | root = aa_get_profile(profile); | |
1074 | } else { /* conflicting change type */ | |
1075 | info = "conflicting targets types"; | |
1076 | error = -EPERM; | |
1077 | goto fail; | |
1078 | } | |
1079 | hat = aa_find_child(root, name); | |
1080 | aa_put_profile(root); | |
1081 | if (!hat) { | |
1082 | if (!COMPLAIN_MODE(profile)) | |
1083 | goto outer_continue; | |
1084 | /* complain mode succeed as if hat */ | |
1085 | } else if (!PROFILE_IS_HAT(hat)) { | |
1086 | info = "target not hat"; | |
1087 | error = -EPERM; | |
1088 | aa_put_profile(hat); | |
1089 | goto fail; | |
1090 | } | |
1091 | aa_put_profile(hat); | |
1092 | } | |
1093 | /* found a hat for all profiles in ns */ | |
1094 | goto build; | |
1095 | outer_continue: | |
1096 | ; | |
1097 | } | |
1098 | /* no hats that match, find appropriate error | |
1099 | * | |
1100 | * In complain mode audit of the failure is based off of the first | |
1101 | * hat supplied. This is done due how userspace interacts with | |
1102 | * change_hat. | |
1103 | */ | |
1104 | name = NULL; | |
1105 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1106 | if (!list_empty(&profile->base.profiles)) { | |
1107 | info = "hat not found"; | |
1108 | error = -ENOENT; | |
1109 | goto fail; | |
1110 | } | |
1111 | } | |
1112 | info = "no hats defined"; | |
1113 | error = -ECHILD; | |
1114 | ||
1115 | fail: | |
1116 | label_for_each_in_ns(it, labels_ns(label), label, profile) { | |
1117 | /* | |
1118 | * no target as it has failed to be found or built | |
1119 | * | |
1120 | * change_hat uses probing and should not log failures | |
1121 | * related to missing hats | |
1122 | */ | |
1123 | /* TODO: get rid of GLOBAL_ROOT_UID */ | |
1124 | if (count > 1 || COMPLAIN_MODE(profile)) { | |
1125 | aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, | |
1126 | AA_MAY_CHANGEHAT, name, NULL, NULL, | |
1127 | GLOBAL_ROOT_UID, info, error); | |
1128 | } | |
1129 | } | |
1130 | return ERR_PTR(error); | |
1131 | ||
1132 | build: | |
1133 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1134 | build_change_hat(profile, name, sibling), | |
1135 | aa_get_label(&profile->label)); | |
1136 | if (!new) { | |
1137 | info = "label build failed"; | |
1138 | error = -ENOMEM; | |
1139 | goto fail; | |
1140 | } /* else if (IS_ERR) build_change_hat has logged error so return new */ | |
1141 | ||
1142 | return new; | |
898127c3 JJ |
1143 | } |
1144 | ||
1145 | /** | |
1146 | * aa_change_hat - change hat to/from subprofile | |
1147 | * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) | |
1148 | * @count: number of hat names in @hats | |
1149 | * @token: magic value to validate the hat change | |
df8073c6 | 1150 | * @flags: flags affecting behavior of the change |
898127c3 | 1151 | * |
89dbf196 JJ |
1152 | * Returns %0 on success, error otherwise. |
1153 | * | |
898127c3 JJ |
1154 | * Change to the first profile specified in @hats that exists, and store |
1155 | * the @hat_magic in the current task context. If the count == 0 and the | |
1156 | * @token matches that stored in the current task context, return to the | |
1157 | * top level profile. | |
1158 | * | |
89dbf196 JJ |
1159 | * change_hat only applies to profiles in the current ns, and each profile |
1160 | * in the ns must make the same transition otherwise change_hat will fail. | |
898127c3 | 1161 | */ |
df8073c6 | 1162 | int aa_change_hat(const char *hats[], int count, u64 token, int flags) |
898127c3 JJ |
1163 | { |
1164 | const struct cred *cred; | |
9fcf78cc | 1165 | struct aa_task_ctx *ctx = task_ctx(current); |
89dbf196 JJ |
1166 | struct aa_label *label, *previous, *new = NULL, *target = NULL; |
1167 | struct aa_profile *profile; | |
2d679f3c | 1168 | struct aa_perms perms = {}; |
89dbf196 | 1169 | const char *info = NULL; |
898127c3 JJ |
1170 | int error = 0; |
1171 | ||
1172 | /* released below */ | |
1173 | cred = get_current_cred(); | |
637f688d | 1174 | label = aa_get_newest_cred_label(cred); |
f175221a | 1175 | previous = aa_get_newest_label(ctx->previous); |
898127c3 | 1176 | |
9fcf78cc JJ |
1177 | /* |
1178 | * Detect no new privs being set, and store the label it | |
1179 | * occurred under. Ideally this would happen when nnp | |
1180 | * is set but there isn't a good way to do that yet. | |
1181 | * | |
1182 | * Testing for unconfined must be done before the subset test | |
1183 | */ | |
1184 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1185 | ctx->nnp = aa_get_label(label); | |
1186 | ||
637f688d | 1187 | if (unconfined(label)) { |
89dbf196 | 1188 | info = "unconfined can not change_hat"; |
898127c3 | 1189 | error = -EPERM; |
89dbf196 | 1190 | goto fail; |
898127c3 JJ |
1191 | } |
1192 | ||
1193 | if (count) { | |
89dbf196 JJ |
1194 | new = change_hat(label, hats, count, flags); |
1195 | AA_BUG(!new); | |
1196 | if (IS_ERR(new)) { | |
1197 | error = PTR_ERR(new); | |
1198 | new = NULL; | |
1199 | /* already audited */ | |
1200 | goto out; | |
898127c3 JJ |
1201 | } |
1202 | ||
89dbf196 JJ |
1203 | error = may_change_ptraced_domain(new, &info); |
1204 | if (error) | |
1205 | goto fail; | |
898127c3 | 1206 | |
9fcf78cc JJ |
1207 | /* |
1208 | * no new privs prevents domain transitions that would | |
1209 | * reduce restrictions. | |
1210 | */ | |
1211 | if (task_no_new_privs(current) && !unconfined(label) && | |
1212 | !aa_label_is_subset(new, ctx->nnp)) { | |
1213 | /* not an apparmor denial per se, so don't log it */ | |
1214 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1215 | error = -EPERM; | |
1216 | goto out; | |
1217 | } | |
1218 | ||
89dbf196 JJ |
1219 | if (flags & AA_CHANGE_TEST) |
1220 | goto out; | |
1221 | ||
1222 | target = new; | |
1223 | error = aa_set_current_hat(new, token); | |
1224 | if (error == -EACCES) | |
1225 | /* kill task in case of brute force attacks */ | |
1226 | goto kill; | |
1227 | } else if (previous && !(flags & AA_CHANGE_TEST)) { | |
9fcf78cc JJ |
1228 | /* |
1229 | * no new privs prevents domain transitions that would | |
1230 | * reduce restrictions. | |
1231 | */ | |
1232 | if (task_no_new_privs(current) && !unconfined(label) && | |
1233 | !aa_label_is_subset(previous, ctx->nnp)) { | |
1234 | /* not an apparmor denial per se, so don't log it */ | |
1235 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1236 | error = -EPERM; | |
1237 | goto out; | |
1238 | } | |
1239 | ||
89dbf196 | 1240 | /* Return to saved label. Kill task if restore fails |
898127c3 JJ |
1241 | * to avoid brute force attacks |
1242 | */ | |
89dbf196 | 1243 | target = previous; |
637f688d | 1244 | error = aa_restore_previous_label(token); |
89dbf196 JJ |
1245 | if (error) { |
1246 | if (error == -EACCES) | |
1247 | goto kill; | |
1248 | goto fail; | |
1249 | } | |
1250 | } /* else ignore @flags && restores when there is no saved profile */ | |
898127c3 JJ |
1251 | |
1252 | out: | |
89dbf196 JJ |
1253 | aa_put_label(new); |
1254 | aa_put_label(previous); | |
637f688d | 1255 | aa_put_label(label); |
898127c3 JJ |
1256 | put_cred(cred); |
1257 | ||
1258 | return error; | |
89dbf196 JJ |
1259 | |
1260 | kill: | |
1261 | info = "failed token match"; | |
1262 | perms.kill = AA_MAY_CHANGEHAT; | |
1263 | ||
1264 | fail: | |
1265 | fn_for_each_in_ns(label, profile, | |
1266 | aa_audit_file(profile, &perms, OP_CHANGE_HAT, | |
1267 | AA_MAY_CHANGEHAT, NULL, NULL, target, | |
1268 | GLOBAL_ROOT_UID, info, error)); | |
1269 | ||
1270 | goto out; | |
898127c3 JJ |
1271 | } |
1272 | ||
89dbf196 | 1273 | |
e00b02bb JJ |
1274 | static int change_profile_perms_wrapper(const char *op, const char *name, |
1275 | struct aa_profile *profile, | |
1276 | struct aa_label *target, bool stack, | |
1277 | u32 request, struct aa_perms *perms) | |
1278 | { | |
1279 | const char *info = NULL; | |
1280 | int error = 0; | |
1281 | ||
e00b02bb JJ |
1282 | if (!error) |
1283 | error = change_profile_perms(profile, target, stack, request, | |
1284 | profile->file.start, perms); | |
1285 | if (error) | |
1286 | error = aa_audit_file(profile, perms, op, request, name, | |
1287 | NULL, target, GLOBAL_ROOT_UID, info, | |
1288 | error); | |
1289 | ||
1290 | return error; | |
1291 | } | |
89dbf196 | 1292 | |
898127c3 JJ |
1293 | /** |
1294 | * aa_change_profile - perform a one-way profile transition | |
aa9a39ad | 1295 | * @fqname: name of profile may include namespace (NOT NULL) |
898127c3 | 1296 | * @onexec: whether this transition is to take place immediately or at exec |
df8073c6 | 1297 | * @flags: flags affecting change behavior |
898127c3 JJ |
1298 | * |
1299 | * Change to new profile @name. Unlike with hats, there is no way | |
1300 | * to change back. If @name isn't specified the current profile name is | |
1301 | * used. | |
1302 | * If @onexec then the transition is delayed until | |
1303 | * the next exec. | |
1304 | * | |
1305 | * Returns %0 on success, error otherwise. | |
1306 | */ | |
df8073c6 | 1307 | int aa_change_profile(const char *fqname, int flags) |
898127c3 | 1308 | { |
e00b02bb JJ |
1309 | struct aa_label *label, *new = NULL, *target = NULL; |
1310 | struct aa_profile *profile; | |
2d679f3c | 1311 | struct aa_perms perms = {}; |
e00b02bb JJ |
1312 | const char *info = NULL; |
1313 | const char *auditname = fqname; /* retain leading & if stack */ | |
1314 | bool stack = flags & AA_CHANGE_STACK; | |
9fcf78cc | 1315 | struct aa_task_ctx *ctx = task_ctx(current); |
47f6e5cc | 1316 | int error = 0; |
e00b02bb | 1317 | char *op; |
898127c3 JJ |
1318 | u32 request; |
1319 | ||
9fcf78cc JJ |
1320 | label = aa_get_current_label(); |
1321 | ||
1322 | /* | |
1323 | * Detect no new privs being set, and store the label it | |
1324 | * occurred under. Ideally this would happen when nnp | |
1325 | * is set but there isn't a good way to do that yet. | |
1326 | * | |
1327 | * Testing for unconfined must be done before the subset test | |
1328 | */ | |
1329 | if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) | |
1330 | ctx->nnp = aa_get_label(label); | |
1331 | ||
aa9a39ad JJ |
1332 | if (!fqname || !*fqname) { |
1333 | AA_DEBUG("no profile name"); | |
898127c3 | 1334 | return -EINVAL; |
aa9a39ad | 1335 | } |
898127c3 | 1336 | |
df8073c6 | 1337 | if (flags & AA_CHANGE_ONEXEC) { |
898127c3 | 1338 | request = AA_MAY_ONEXEC; |
e00b02bb JJ |
1339 | if (stack) |
1340 | op = OP_STACK_ONEXEC; | |
1341 | else | |
1342 | op = OP_CHANGE_ONEXEC; | |
898127c3 JJ |
1343 | } else { |
1344 | request = AA_MAY_CHANGE_PROFILE; | |
e00b02bb JJ |
1345 | if (stack) |
1346 | op = OP_STACK; | |
1347 | else | |
1348 | op = OP_CHANGE_PROFILE; | |
898127c3 JJ |
1349 | } |
1350 | ||
e00b02bb | 1351 | label = aa_get_current_label(); |
898127c3 | 1352 | |
e00b02bb JJ |
1353 | if (*fqname == '&') { |
1354 | stack = true; | |
1355 | /* don't have label_parse() do stacking */ | |
1356 | fqname++; | |
c29bceb3 | 1357 | } |
e00b02bb JJ |
1358 | target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); |
1359 | if (IS_ERR(target)) { | |
1360 | struct aa_profile *tprofile; | |
c29bceb3 | 1361 | |
e00b02bb JJ |
1362 | info = "label not found"; |
1363 | error = PTR_ERR(target); | |
1364 | target = NULL; | |
1365 | /* | |
1366 | * TODO: fixme using labels_profile is not right - do profile | |
1367 | * per complain profile | |
1368 | */ | |
df8073c6 | 1369 | if ((flags & AA_CHANGE_TEST) || |
e00b02bb | 1370 | !COMPLAIN_MODE(labels_profile(label))) |
898127c3 JJ |
1371 | goto audit; |
1372 | /* released below */ | |
e00b02bb JJ |
1373 | tprofile = aa_new_null_profile(labels_profile(label), false, |
1374 | fqname, GFP_KERNEL); | |
1375 | if (!tprofile) { | |
898127c3 JJ |
1376 | info = "failed null profile create"; |
1377 | error = -ENOMEM; | |
1378 | goto audit; | |
1379 | } | |
e00b02bb JJ |
1380 | target = &tprofile->label; |
1381 | goto check; | |
898127c3 JJ |
1382 | } |
1383 | ||
e00b02bb JJ |
1384 | /* |
1385 | * self directed transitions only apply to current policy ns | |
1386 | * TODO: currently requiring perms for stacking and straight change | |
1387 | * stacking doesn't strictly need this. Determine how much | |
1388 | * we want to loosen this restriction for stacking | |
1389 | * | |
1390 | * if (!stack) { | |
1391 | */ | |
1392 | error = fn_for_each_in_ns(label, profile, | |
1393 | change_profile_perms_wrapper(op, auditname, | |
1394 | profile, target, stack, | |
1395 | request, &perms)); | |
1396 | if (error) | |
1397 | /* auditing done in change_profile_perms_wrapper */ | |
1398 | goto out; | |
aa9a39ad | 1399 | |
e00b02bb JJ |
1400 | /* } */ |
1401 | ||
1402 | check: | |
898127c3 | 1403 | /* check if tracing task is allowed to trace target domain */ |
e00b02bb JJ |
1404 | error = may_change_ptraced_domain(target, &info); |
1405 | if (error && !fn_for_each_in_ns(label, profile, | |
1406 | COMPLAIN_MODE(profile))) | |
898127c3 | 1407 | goto audit; |
898127c3 | 1408 | |
e00b02bb JJ |
1409 | /* TODO: add permission check to allow this |
1410 | * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { | |
1411 | * info = "not a single threaded task"; | |
1412 | * error = -EACCES; | |
1413 | * goto audit; | |
1414 | * } | |
1415 | */ | |
df8073c6 | 1416 | if (flags & AA_CHANGE_TEST) |
e00b02bb | 1417 | goto out; |
898127c3 | 1418 | |
9fcf78cc JJ |
1419 | /* stacking is always a subset, so only check the nonstack case */ |
1420 | if (!stack) { | |
1421 | new = fn_label_build_in_ns(label, profile, GFP_KERNEL, | |
1422 | aa_get_label(target), | |
1423 | aa_get_label(&profile->label)); | |
1424 | /* | |
1425 | * no new privs prevents domain transitions that would | |
1426 | * reduce restrictions. | |
1427 | */ | |
1428 | if (task_no_new_privs(current) && !unconfined(label) && | |
1429 | !aa_label_is_subset(new, ctx->nnp)) { | |
1430 | /* not an apparmor denial per se, so don't log it */ | |
1431 | AA_DEBUG("no_new_privs - change_hat denied"); | |
1432 | error = -EPERM; | |
1433 | goto out; | |
1434 | } | |
1435 | } | |
1436 | ||
e00b02bb JJ |
1437 | if (!(flags & AA_CHANGE_ONEXEC)) { |
1438 | /* only transition profiles in the current ns */ | |
1439 | if (stack) | |
1440 | new = aa_label_merge(label, target, GFP_KERNEL); | |
e00b02bb JJ |
1441 | if (IS_ERR_OR_NULL(new)) { |
1442 | info = "failed to build target label"; | |
d6d478ae JJ |
1443 | if (!new) |
1444 | error = -ENOMEM; | |
1445 | else | |
1446 | error = PTR_ERR(new); | |
e00b02bb JJ |
1447 | new = NULL; |
1448 | perms.allow = 0; | |
1449 | goto audit; | |
1450 | } | |
1451 | error = aa_replace_current_label(new); | |
9fcf78cc JJ |
1452 | } else { |
1453 | if (new) { | |
1454 | aa_put_label(new); | |
1455 | new = NULL; | |
1456 | } | |
1457 | ||
e00b02bb JJ |
1458 | /* full transition will be built in exec path */ |
1459 | error = aa_set_current_onexec(target, stack); | |
9fcf78cc | 1460 | } |
898127c3 JJ |
1461 | |
1462 | audit: | |
e00b02bb JJ |
1463 | error = fn_for_each_in_ns(label, profile, |
1464 | aa_audit_file(profile, &perms, op, request, auditname, | |
1465 | NULL, new ? new : target, | |
1466 | GLOBAL_ROOT_UID, info, error)); | |
898127c3 | 1467 | |
e00b02bb JJ |
1468 | out: |
1469 | aa_put_label(new); | |
1470 | aa_put_label(target); | |
637f688d | 1471 | aa_put_label(label); |
898127c3 JJ |
1472 | |
1473 | return error; | |
1474 | } |