1 |
/* |
2 |
* security/ccsecurity/domain.c |
3 |
* |
4 |
* Copyright (C) 2005-2010 NTT DATA CORPORATION |
5 |
* |
6 |
* Version: 1.8.0-pre 2010/08/01 |
7 |
* |
8 |
* This file is applicable to both 2.4.30 and 2.6.11 and later. |
9 |
* See README.ccs for ChangeLog. |
10 |
* |
11 |
*/ |
12 |
|
13 |
#include <linux/slab.h> |
14 |
#include <linux/highmem.h> |
15 |
#include <linux/version.h> |
16 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 0) |
17 |
#include <linux/namei.h> |
18 |
#include <linux/mount.h> |
19 |
#endif |
20 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 30) |
21 |
#include <linux/fs_struct.h> |
22 |
#endif |
23 |
#include "internal.h" |
24 |
|
25 |
/* Variables definitions.*/ |
26 |
|
27 |
/* The global domain. */ |
28 |
struct ccs_domain_info ccs_acl_group[CCS_MAX_ACL_GROUPS]; |
29 |
|
30 |
/* The initial domain. */ |
31 |
struct ccs_domain_info ccs_kernel_domain; |
32 |
|
33 |
/* The list for "struct ccs_domain_info". */ |
34 |
LIST_HEAD(ccs_domain_list); |
35 |
|
36 |
struct list_head ccs_policy_list[CCS_MAX_POLICY]; |
37 |
struct list_head ccs_group_list[CCS_MAX_GROUP]; |
38 |
struct list_head ccs_shared_list[CCS_MAX_LIST]; |
39 |
|
40 |
/** |
41 |
* ccs_update_policy - Update an entry for exception policy. |
42 |
* |
43 |
* @new_entry: Pointer to "struct ccs_acl_info". |
44 |
* @size: Size of @new_entry in bytes. |
45 |
* @is_delete: True if it is a delete request. |
46 |
* @list: Pointer to "struct list_head". |
47 |
* @check_duplicate: Callback function to find duplicated entry. |
48 |
* |
49 |
* Returns 0 on success, negative value otherwise. |
50 |
* |
51 |
* Caller holds ccs_read_lock(). |
52 |
*/ |
53 |
int ccs_update_policy(struct ccs_acl_head *new_entry, const int size, |
54 |
bool is_delete, struct list_head *list, |
55 |
bool (*check_duplicate) (const struct ccs_acl_head *, |
56 |
const struct ccs_acl_head *)) |
57 |
{ |
58 |
int error = is_delete ? -ENOENT : -ENOMEM; |
59 |
struct ccs_acl_head *entry; |
60 |
if (mutex_lock_interruptible(&ccs_policy_lock)) |
61 |
return -ENOMEM; |
62 |
list_for_each_entry_rcu(entry, list, list) { |
63 |
if (!check_duplicate(entry, new_entry)) |
64 |
continue; |
65 |
entry->is_deleted = is_delete; |
66 |
error = 0; |
67 |
break; |
68 |
} |
69 |
if (error && !is_delete) { |
70 |
entry = ccs_commit_ok(new_entry, size); |
71 |
if (entry) { |
72 |
list_add_tail_rcu(&entry->list, list); |
73 |
error = 0; |
74 |
} |
75 |
} |
76 |
mutex_unlock(&ccs_policy_lock); |
77 |
return error; |
78 |
} |
79 |
|
80 |
/** |
81 |
* ccs_update_domain - Update an entry for domain policy. |
82 |
* |
83 |
* @new_entry: Pointer to "struct ccs_acl_info". |
84 |
* @size: Size of @new_entry in bytes. |
85 |
* @is_delete: True if it is a delete request. |
86 |
* @domain: Pointer to "struct ccs_domain_info". |
87 |
* @check_duplicate: Callback function to find duplicated entry. |
88 |
* @merge_duplicate: Callback function to merge duplicated entry. |
89 |
* |
90 |
* Returns 0 on success, negative value otherwise. |
91 |
* |
92 |
* Caller holds ccs_read_lock(). |
93 |
*/ |
94 |
int ccs_update_domain(struct ccs_acl_info *new_entry, const int size, |
95 |
bool is_delete, struct ccs_domain_info *domain, |
96 |
bool (*check_duplicate) (const struct ccs_acl_info *, |
97 |
const struct ccs_acl_info *), |
98 |
bool (*merge_duplicate) (struct ccs_acl_info *, |
99 |
struct ccs_acl_info *, |
100 |
const bool)) |
101 |
{ |
102 |
int error = is_delete ? -ENOENT : -ENOMEM; |
103 |
struct ccs_acl_info *entry; |
104 |
const u8 type = new_entry->type; |
105 |
const u8 i = type == CCS_TYPE_AUTO_EXECUTE_HANDLER || |
106 |
type == CCS_TYPE_DENIED_EXECUTE_HANDLER || |
107 |
type == CCS_TYPE_AUTO_TASK_ACL; |
108 |
if (mutex_lock_interruptible(&ccs_policy_lock)) |
109 |
return error; |
110 |
list_for_each_entry_rcu(entry, &domain->acl_info_list[i], list) { |
111 |
if (!check_duplicate(entry, new_entry)) |
112 |
continue; |
113 |
if (merge_duplicate) |
114 |
entry->is_deleted = merge_duplicate(entry, new_entry, |
115 |
is_delete); |
116 |
else |
117 |
entry->is_deleted = is_delete; |
118 |
error = 0; |
119 |
break; |
120 |
} |
121 |
if (error && !is_delete) { |
122 |
entry = ccs_commit_ok(new_entry, size); |
123 |
if (entry) { |
124 |
if (entry->cond) |
125 |
atomic_inc(&entry->cond->head.users); |
126 |
list_add_tail_rcu(&entry->list, |
127 |
&domain->acl_info_list[i]); |
128 |
error = 0; |
129 |
} |
130 |
} |
131 |
mutex_unlock(&ccs_policy_lock); |
132 |
return error; |
133 |
} |
134 |
|
135 |
void ccs_check_acl(struct ccs_request_info *r, |
136 |
bool (*check_entry) (struct ccs_request_info *, |
137 |
const struct ccs_acl_info *)) |
138 |
{ |
139 |
const struct ccs_domain_info *domain = ccs_current_domain(); |
140 |
struct ccs_acl_info *ptr; |
141 |
bool retried = false; |
142 |
const u8 i = !check_entry; |
143 |
retry: |
144 |
list_for_each_entry_rcu(ptr, &domain->acl_info_list[i], list) { |
145 |
if (ptr->is_deleted) |
146 |
continue; |
147 |
if (ptr->type != r->param_type) |
148 |
continue; |
149 |
if (check_entry && !check_entry(r, ptr)) |
150 |
continue; |
151 |
if (!ccs_condition(r, ptr->cond)) |
152 |
continue; |
153 |
r->matched_acl = ptr; |
154 |
r->granted = true; |
155 |
return; |
156 |
} |
157 |
if (!retried) { |
158 |
retried = true; |
159 |
domain = &ccs_acl_group[domain->group]; |
160 |
goto retry; |
161 |
} |
162 |
r->granted = false; |
163 |
} |
164 |
|
165 |
static bool ccs_same_transition_control(const struct ccs_acl_head *a, |
166 |
const struct ccs_acl_head *b) |
167 |
{ |
168 |
const struct ccs_transition_control *p1 = container_of(a, typeof(*p1), |
169 |
head); |
170 |
const struct ccs_transition_control *p2 = container_of(b, typeof(*p2), |
171 |
head); |
172 |
return p1->type == p2->type && p1->is_last_name == p2->is_last_name |
173 |
&& p1->domainname == p2->domainname |
174 |
&& p1->program == p2->program; |
175 |
} |
176 |
|
177 |
/** |
178 |
* ccs_update_transition_control_entry - Update "struct ccs_transition_control" list. |
179 |
* |
180 |
* @domainname: The name of domain. Maybe NULL. |
181 |
* @program: The name of program. Maybe NULL. |
182 |
* @type: Type of transition. |
183 |
* @is_delete: True if it is a delete request. |
184 |
* |
185 |
* Returns 0 on success, negative value otherwise. |
186 |
*/ |
187 |
static int ccs_update_transition_control_entry(const char *domainname, |
188 |
const char *program, |
189 |
const u8 type, |
190 |
const bool is_delete) |
191 |
{ |
192 |
struct ccs_transition_control e = { .type = type }; |
193 |
int error = is_delete ? -ENOENT : -ENOMEM; |
194 |
if (program && strcmp(program, "any")) { |
195 |
if (!ccs_correct_path(program)) |
196 |
return -EINVAL; |
197 |
e.program = ccs_get_name(program); |
198 |
if (!e.program) |
199 |
goto out; |
200 |
} |
201 |
if (domainname && strcmp(domainname, "any")) { |
202 |
if (!ccs_correct_domain(domainname)) { |
203 |
if (!ccs_correct_path(domainname)) |
204 |
goto out; |
205 |
e.is_last_name = true; |
206 |
} |
207 |
e.domainname = ccs_get_name(domainname); |
208 |
if (!e.domainname) |
209 |
goto out; |
210 |
} |
211 |
error = ccs_update_policy(&e.head, sizeof(e), is_delete, |
212 |
&ccs_policy_list[CCS_ID_TRANSITION_CONTROL], |
213 |
ccs_same_transition_control); |
214 |
out: |
215 |
ccs_put_name(e.domainname); |
216 |
ccs_put_name(e.program); |
217 |
return error; |
218 |
} |
219 |
|
220 |
/** |
221 |
* ccs_write_transition_control - Write "struct ccs_transition_control" list. |
222 |
* |
223 |
* @data: String to parse. |
224 |
* @is_delete: True if it is a delete request. |
225 |
* @type: Type of this entry. |
226 |
* |
227 |
* Returns 0 on success, negative value otherwise. |
228 |
*/ |
229 |
int ccs_write_transition_control(char *data, const bool is_delete, |
230 |
const u8 type) |
231 |
{ |
232 |
char *domainname = strstr(data, " from "); |
233 |
if (domainname) { |
234 |
*domainname = '\0'; |
235 |
domainname += 6; |
236 |
} else if (type == CCS_TRANSITION_CONTROL_NO_KEEP || |
237 |
type == CCS_TRANSITION_CONTROL_KEEP) { |
238 |
domainname = data; |
239 |
data = NULL; |
240 |
} |
241 |
return ccs_update_transition_control_entry(domainname, data, type, |
242 |
is_delete); |
243 |
} |
244 |
|
245 |
/** |
246 |
* ccs_transition_type - Get domain transition type. |
247 |
* |
248 |
* @domainname: The name of domain. |
249 |
* @program: The name of program. |
250 |
* |
251 |
* Returns CCS_TRANSITION_CONTROL_INITIALIZE if executing @program |
252 |
* reinitializes domain transition, CCS_TRANSITION_CONTROL_KEEP if executing |
253 |
* @program suppresses domain transition, others otherwise. |
254 |
* |
255 |
* Caller holds ccs_read_lock(). |
256 |
*/ |
257 |
static u8 ccs_transition_type(const struct ccs_path_info *domainname, |
258 |
const struct ccs_path_info *program) |
259 |
{ |
260 |
const struct ccs_transition_control *ptr; |
261 |
const char *last_name = ccs_last_word(domainname->name); |
262 |
u8 type; |
263 |
for (type = 0; type < CCS_MAX_TRANSITION_TYPE; type++) { |
264 |
next: |
265 |
list_for_each_entry_rcu(ptr, &ccs_policy_list |
266 |
[CCS_ID_TRANSITION_CONTROL], |
267 |
head.list) { |
268 |
if (ptr->head.is_deleted || ptr->type != type) |
269 |
continue; |
270 |
if (ptr->domainname) { |
271 |
if (!ptr->is_last_name) { |
272 |
if (ptr->domainname != domainname) |
273 |
continue; |
274 |
} else { |
275 |
/* |
276 |
* Use direct strcmp() since this is |
277 |
* unlikely used. |
278 |
*/ |
279 |
if (strcmp(ptr->domainname->name, |
280 |
last_name)) |
281 |
continue; |
282 |
} |
283 |
} |
284 |
if (ptr->program && ccs_pathcmp(ptr->program, program)) |
285 |
continue; |
286 |
if (type == CCS_TRANSITION_CONTROL_NO_INITIALIZE) { |
287 |
/* |
288 |
* Do not check for initialize_domain if |
289 |
* no_initialize_domain matched. |
290 |
*/ |
291 |
type = CCS_TRANSITION_CONTROL_NO_KEEP; |
292 |
goto next; |
293 |
} |
294 |
goto done; |
295 |
} |
296 |
} |
297 |
done: |
298 |
return type; |
299 |
} |
300 |
|
301 |
static bool ccs_same_aggregator(const struct ccs_acl_head *a, |
302 |
const struct ccs_acl_head *b) |
303 |
{ |
304 |
const struct ccs_aggregator *p1 = container_of(a, typeof(*p1), head); |
305 |
const struct ccs_aggregator *p2 = container_of(b, typeof(*p2), head); |
306 |
return p1->original_name == p2->original_name && |
307 |
p1->aggregated_name == p2->aggregated_name; |
308 |
} |
309 |
|
310 |
/** |
311 |
* ccs_update_aggregator_entry - Update "struct ccs_aggregator" list. |
312 |
* |
313 |
* @original_name: The original program's name. |
314 |
* @aggregated_name: The aggregated program's name. |
315 |
* @is_delete: True if it is a delete request. |
316 |
* |
317 |
* Returns 0 on success, negative value otherwise. |
318 |
*/ |
319 |
static int ccs_update_aggregator_entry(const char *original_name, |
320 |
const char *aggregated_name, |
321 |
const bool is_delete) |
322 |
{ |
323 |
struct ccs_aggregator e = { }; |
324 |
int error = is_delete ? -ENOENT : -ENOMEM; |
325 |
if (!ccs_correct_word(original_name) || |
326 |
!ccs_correct_path(aggregated_name)) |
327 |
return -EINVAL; |
328 |
e.original_name = ccs_get_name(original_name); |
329 |
e.aggregated_name = ccs_get_name(aggregated_name); |
330 |
if (!e.original_name || !e.aggregated_name || |
331 |
e.aggregated_name->is_patterned) /* No patterns allowed. */ |
332 |
goto out; |
333 |
error = ccs_update_policy(&e.head, sizeof(e), is_delete, |
334 |
&ccs_policy_list[CCS_ID_AGGREGATOR], |
335 |
ccs_same_aggregator); |
336 |
out: |
337 |
ccs_put_name(e.original_name); |
338 |
ccs_put_name(e.aggregated_name); |
339 |
return error; |
340 |
} |
341 |
|
342 |
/** |
343 |
* ccs_write_aggregator - Write "struct ccs_aggregator" list. |
344 |
* |
345 |
* @data: String to parse. |
346 |
* @is_delete: True if it is a delete request. |
347 |
* |
348 |
* Returns 0 on success, negative value otherwise. |
349 |
*/ |
350 |
int ccs_write_aggregator(char *data, const bool is_delete) |
351 |
{ |
352 |
char *w[2]; |
353 |
if (!ccs_tokenize(data, w, sizeof(w)) || !w[1][0]) |
354 |
return -EINVAL; |
355 |
return ccs_update_aggregator_entry(w[0], w[1], is_delete); |
356 |
} |
357 |
|
358 |
/* Domain create/delete handler. */ |
359 |
|
360 |
/** |
361 |
* ccs_delete_domain - Delete a domain. |
362 |
* |
363 |
* @domainname: The name of domain. |
364 |
* |
365 |
* Returns 0. |
366 |
*/ |
367 |
int ccs_delete_domain(char *domainname) |
368 |
{ |
369 |
struct ccs_domain_info *domain; |
370 |
struct ccs_path_info name; |
371 |
name.name = domainname; |
372 |
ccs_fill_path_info(&name); |
373 |
if (mutex_lock_interruptible(&ccs_policy_lock)) |
374 |
return 0; |
375 |
/* Is there an active domain? */ |
376 |
list_for_each_entry_rcu(domain, &ccs_domain_list, list) { |
377 |
/* Never delete ccs_kernel_domain */ |
378 |
if (domain == &ccs_kernel_domain) |
379 |
continue; |
380 |
if (domain->is_deleted || |
381 |
ccs_pathcmp(domain->domainname, &name)) |
382 |
continue; |
383 |
domain->is_deleted = true; |
384 |
break; |
385 |
} |
386 |
mutex_unlock(&ccs_policy_lock); |
387 |
return 0; |
388 |
} |
389 |
|
390 |
/** |
391 |
* ccs_assign_domain - Create a domain. |
392 |
* |
393 |
* @domainname: The name of domain. |
394 |
* @profile: Profile number to assign if the domain was newly created. |
395 |
* @group: Group number to assign if the domain was newly created. |
396 |
* @transit: True if transit to domain found or created. |
397 |
* |
398 |
* Returns pointer to "struct ccs_domain_info" on success, NULL otherwise. |
399 |
* |
400 |
* Caller holds ccs_read_lock(). |
401 |
*/ |
402 |
struct ccs_domain_info *ccs_assign_domain(const char *domainname, |
403 |
const u8 profile, const u8 group, |
404 |
const bool transit) |
405 |
{ |
406 |
struct ccs_domain_info e = { }; |
407 |
struct ccs_domain_info *entry = ccs_find_domain(domainname); |
408 |
bool created = false; |
409 |
if (entry) |
410 |
goto out; |
411 |
if (strlen(domainname) >= CCS_EXEC_TMPSIZE - 10 || |
412 |
!ccs_correct_domain(domainname)) |
413 |
return NULL; |
414 |
e.profile = profile; |
415 |
e.group = group; |
416 |
e.domainname = ccs_get_name(domainname); |
417 |
if (!e.domainname) |
418 |
return NULL; |
419 |
if (mutex_lock_interruptible(&ccs_policy_lock)) |
420 |
goto out; |
421 |
entry = ccs_find_domain(domainname); |
422 |
if (!entry) { |
423 |
entry = ccs_commit_ok(&e, sizeof(e)); |
424 |
if (entry) { |
425 |
INIT_LIST_HEAD(&entry->acl_info_list[0]); |
426 |
INIT_LIST_HEAD(&entry->acl_info_list[1]); |
427 |
list_add_tail_rcu(&entry->list, &ccs_domain_list); |
428 |
created = true; |
429 |
} |
430 |
} |
431 |
mutex_unlock(&ccs_policy_lock); |
432 |
out: |
433 |
ccs_put_name(e.domainname); |
434 |
if (entry && transit) { |
435 |
current->ccs_domain_info = entry; |
436 |
if (created) { |
437 |
struct ccs_request_info r; |
438 |
ccs_init_request_info(&r, CCS_MAC_FILE_EXECUTE); |
439 |
r.granted = false; |
440 |
ccs_write_log(&r, "use_profile %u\n", r.profile); |
441 |
} |
442 |
} |
443 |
return entry; |
444 |
} |
445 |
|
446 |
/** |
447 |
* ccs_find_next_domain - Find a domain. |
448 |
* |
449 |
* @ee: Pointer to "struct ccs_execve". |
450 |
* |
451 |
* Returns 0 on success, negative value otherwise. |
452 |
* |
453 |
* Caller holds ccs_read_lock(). |
454 |
*/ |
455 |
static int ccs_find_next_domain(struct ccs_execve *ee) |
456 |
{ |
457 |
struct ccs_request_info *r = &ee->r; |
458 |
const struct ccs_path_info *handler = ee->handler; |
459 |
struct ccs_domain_info *domain = NULL; |
460 |
struct ccs_domain_info * const old_domain = ccs_current_domain(); |
461 |
struct linux_binprm *bprm = ee->bprm; |
462 |
struct task_struct *task = current; |
463 |
struct ccs_path_info rn = { }; /* real name */ |
464 |
int retval; |
465 |
bool need_kfree = false; |
466 |
retry: |
467 |
r->matched_acl = NULL; |
468 |
if (need_kfree) { |
469 |
kfree(rn.name); |
470 |
need_kfree = false; |
471 |
} |
472 |
|
473 |
/* Get symlink's pathname of program. */ |
474 |
retval = ccs_symlink_path(bprm->filename, &rn); |
475 |
if (retval < 0) |
476 |
goto out; |
477 |
need_kfree = true; |
478 |
|
479 |
if (handler) { |
480 |
if (ccs_pathcmp(&rn, handler)) { |
481 |
/* Failed to verify execute handler. */ |
482 |
static u8 counter = 20; |
483 |
if (counter) { |
484 |
counter--; |
485 |
printk(KERN_WARNING "Failed to verify: %s\n", |
486 |
handler->name); |
487 |
} |
488 |
goto out; |
489 |
} |
490 |
} else { |
491 |
struct ccs_aggregator *ptr; |
492 |
/* Check 'aggregator' directive. */ |
493 |
list_for_each_entry_rcu(ptr, |
494 |
&ccs_policy_list[CCS_ID_AGGREGATOR], |
495 |
head.list) { |
496 |
if (ptr->head.is_deleted || |
497 |
!ccs_path_matches_pattern(&rn, ptr->original_name)) |
498 |
continue; |
499 |
kfree(rn.name); |
500 |
need_kfree = false; |
501 |
/* This is OK because it is read only. */ |
502 |
rn = *ptr->aggregated_name; |
503 |
break; |
504 |
} |
505 |
|
506 |
/* Check execute permission. */ |
507 |
retval = ccs_path_permission(r, CCS_TYPE_EXECUTE, &rn); |
508 |
if (retval == CCS_RETRY_REQUEST) |
509 |
goto retry; |
510 |
if (retval < 0) |
511 |
goto out; |
512 |
/* |
513 |
* To be able to specify domainnames with wildcards, use the |
514 |
* pathname specified in the policy (which may contain |
515 |
* wildcard) rather than the pathname passed to execve() |
516 |
* (which never contains wildcard). |
517 |
*/ |
518 |
if (r->param.path.matched_path) { |
519 |
if (need_kfree) |
520 |
kfree(rn.name); |
521 |
need_kfree = false; |
522 |
/* This is OK because it is read only. */ |
523 |
rn = *r->param.path.matched_path; |
524 |
} |
525 |
} |
526 |
|
527 |
/* Calculate domain to transit to. */ |
528 |
switch (ccs_transition_type(old_domain->domainname, &rn)) { |
529 |
case CCS_TRANSITION_CONTROL_INITIALIZE: |
530 |
/* Transit to the child of ccs_kernel_domain domain. */ |
531 |
snprintf(ee->tmp, CCS_EXEC_TMPSIZE - 1, CCS_ROOT_NAME " " "%s", |
532 |
rn.name); |
533 |
break; |
534 |
case CCS_TRANSITION_CONTROL_KEEP: |
535 |
/* Keep current domain. */ |
536 |
domain = old_domain; |
537 |
break; |
538 |
default: |
539 |
if (old_domain == &ccs_kernel_domain && !ccs_policy_loaded) { |
540 |
/* |
541 |
* Needn't to transit from kernel domain before |
542 |
* starting /sbin/init. But transit from kernel domain |
543 |
* if executing initializers because they might start |
544 |
* before /sbin/init. |
545 |
*/ |
546 |
domain = old_domain; |
547 |
} else { |
548 |
/* Normal domain transition. */ |
549 |
snprintf(ee->tmp, CCS_EXEC_TMPSIZE - 1, "%s %s", |
550 |
old_domain->domainname->name, rn.name); |
551 |
} |
552 |
break; |
553 |
} |
554 |
/* |
555 |
* Tell GC that I started execve(). |
556 |
* Also, tell open_exec() to check read permission. |
557 |
*/ |
558 |
task->ccs_flags |= CCS_TASK_IS_IN_EXECVE; |
559 |
/* |
560 |
* Make task->ccs_flags visible to GC before changing |
561 |
* task->ccs_domain_info . |
562 |
*/ |
563 |
smp_mb(); |
564 |
/* |
565 |
* Proceed to the next domain in order to allow reaching via PID. |
566 |
* It will be reverted if execve() failed. Reverting is not good. |
567 |
* But it is better than being unable to reach via PID in interactive |
568 |
* enforcing mode. |
569 |
*/ |
570 |
if (!domain) |
571 |
domain = ccs_assign_domain(ee->tmp, r->profile, |
572 |
old_domain->group, true); |
573 |
if (domain) |
574 |
retval = 0; |
575 |
else if (r->mode == CCS_CONFIG_ENFORCING) |
576 |
retval = -ENOMEM; |
577 |
else { |
578 |
retval = 0; |
579 |
if (!old_domain->flags[CCS_DIF_TRANSITION_FAILED]) { |
580 |
old_domain->flags[CCS_DIF_TRANSITION_FAILED] = true; |
581 |
r->granted = false; |
582 |
ccs_write_log(r, CCS_KEYWORD_TRANSITION_FAILED "\n"); |
583 |
printk(KERN_WARNING |
584 |
"ERROR: Domain '%s' not defined.\n", ee->tmp); |
585 |
} |
586 |
} |
587 |
out: |
588 |
if (need_kfree) |
589 |
kfree(rn.name); |
590 |
return retval; |
591 |
} |
592 |
|
593 |
/** |
594 |
* ccs_environ - Check permission for environment variable names. |
595 |
* |
596 |
* @ee: Pointer to "struct ccs_execve". |
597 |
* |
598 |
* Returns 0 on success, negative value otherwise. |
599 |
*/ |
600 |
static int ccs_environ(struct ccs_execve *ee) |
601 |
{ |
602 |
struct ccs_request_info *r = &ee->r; |
603 |
struct linux_binprm *bprm = ee->bprm; |
604 |
/* env_page->data is allocated by ccs_dump_page(). */ |
605 |
struct ccs_page_dump env_page = { }; |
606 |
char *arg_ptr; /* Size is CCS_EXEC_TMPSIZE bytes */ |
607 |
int arg_len = 0; |
608 |
unsigned long pos = bprm->p; |
609 |
int offset = pos % PAGE_SIZE; |
610 |
int argv_count = bprm->argc; |
611 |
int envp_count = bprm->envc; |
612 |
/* printk(KERN_DEBUG "start %d %d\n", argv_count, envp_count); */ |
613 |
int error = -ENOMEM; |
614 |
ee->r.type = CCS_MAC_ENVIRON; |
615 |
ee->r.mode = ccs_get_mode(ccs_current_domain()->profile, |
616 |
CCS_MAC_ENVIRON); |
617 |
if (!r->mode || !envp_count) |
618 |
return 0; |
619 |
arg_ptr = kzalloc(CCS_EXEC_TMPSIZE, CCS_GFP_FLAGS); |
620 |
if (!arg_ptr) |
621 |
goto out; |
622 |
while (error == -ENOMEM) { |
623 |
if (!ccs_dump_page(bprm, pos, &env_page)) |
624 |
goto out; |
625 |
pos += PAGE_SIZE - offset; |
626 |
/* Read. */ |
627 |
while (argv_count && offset < PAGE_SIZE) { |
628 |
if (!env_page.data[offset++]) |
629 |
argv_count--; |
630 |
} |
631 |
if (argv_count) { |
632 |
offset = 0; |
633 |
continue; |
634 |
} |
635 |
while (offset < PAGE_SIZE) { |
636 |
const unsigned char c = env_page.data[offset++]; |
637 |
if (c && arg_len < CCS_EXEC_TMPSIZE - 10) { |
638 |
if (c == '=') { |
639 |
arg_ptr[arg_len++] = '\0'; |
640 |
} else if (c == '\\') { |
641 |
arg_ptr[arg_len++] = '\\'; |
642 |
arg_ptr[arg_len++] = '\\'; |
643 |
} else if (c > ' ' && c < 127) { |
644 |
arg_ptr[arg_len++] = c; |
645 |
} else { |
646 |
arg_ptr[arg_len++] = '\\'; |
647 |
arg_ptr[arg_len++] = (c >> 6) + '0'; |
648 |
arg_ptr[arg_len++] |
649 |
= ((c >> 3) & 7) + '0'; |
650 |
arg_ptr[arg_len++] = (c & 7) + '0'; |
651 |
} |
652 |
} else { |
653 |
arg_ptr[arg_len] = '\0'; |
654 |
} |
655 |
if (c) |
656 |
continue; |
657 |
if (ccs_env_perm(r, arg_ptr)) { |
658 |
error = -EPERM; |
659 |
break; |
660 |
} |
661 |
if (!--envp_count) { |
662 |
error = 0; |
663 |
break; |
664 |
} |
665 |
arg_len = 0; |
666 |
} |
667 |
offset = 0; |
668 |
} |
669 |
out: |
670 |
if (r->mode != 3) |
671 |
error = 0; |
672 |
kfree(env_page.data); |
673 |
kfree(arg_ptr); |
674 |
return error; |
675 |
} |
676 |
|
677 |
/** |
678 |
* ccs_unescape - Unescape escaped string. |
679 |
* |
680 |
* @dest: String to unescape. |
681 |
* |
682 |
* Returns nothing. |
683 |
*/ |
684 |
static void ccs_unescape(unsigned char *dest) |
685 |
{ |
686 |
unsigned char *src = dest; |
687 |
unsigned char c; |
688 |
unsigned char d; |
689 |
unsigned char e; |
690 |
while (1) { |
691 |
c = *src++; |
692 |
if (!c) |
693 |
break; |
694 |
if (c != '\\') { |
695 |
*dest++ = c; |
696 |
continue; |
697 |
} |
698 |
c = *src++; |
699 |
if (c == '\\') { |
700 |
*dest++ = c; |
701 |
continue; |
702 |
} |
703 |
if (c < '0' || c > '3') |
704 |
break; |
705 |
d = *src++; |
706 |
if (d < '0' || d > '7') |
707 |
break; |
708 |
e = *src++; |
709 |
if (e < '0' || e > '7') |
710 |
break; |
711 |
*dest++ = ((c - '0') << 6) + ((d - '0') << 3) + (e - '0'); |
712 |
} |
713 |
*dest = '\0'; |
714 |
} |
715 |
|
716 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 36) |
717 |
static int ccs_copy_argv(const char *arg, struct linux_binprm *bprm) |
718 |
{ |
719 |
const int ret = copy_strings_kernel(1, &arg, bprm); |
720 |
if (ret >= 0) |
721 |
bprm->argc++; |
722 |
return ret; |
723 |
} |
724 |
#else |
725 |
static int ccs_copy_argv(char *arg, struct linux_binprm *bprm) |
726 |
{ |
727 |
const int ret = copy_strings_kernel(1, &arg, bprm); |
728 |
if (ret >= 0) |
729 |
bprm->argc++; |
730 |
return ret; |
731 |
} |
732 |
#endif |
733 |
|
734 |
/** |
735 |
* ccs_try_alt_exec - Try to start execute handler. |
736 |
* |
737 |
* @ee: Pointer to "struct ccs_execve". |
738 |
* |
739 |
* Returns 0 on success, negative value otherwise. |
740 |
*/ |
741 |
static int ccs_try_alt_exec(struct ccs_execve *ee) |
742 |
{ |
743 |
/* |
744 |
* Contents of modified bprm. |
745 |
* The envp[] in original bprm is moved to argv[] so that |
746 |
* the alternatively executed program won't be affected by |
747 |
* some dangerous environment variables like LD_PRELOAD. |
748 |
* |
749 |
* modified bprm->argc |
750 |
* = original bprm->argc + original bprm->envc + 7 |
751 |
* modified bprm->envc |
752 |
* = 0 |
753 |
* |
754 |
* modified bprm->argv[0] |
755 |
* = the program's name specified by *_execute_handler |
756 |
* modified bprm->argv[1] |
757 |
* = ccs_current_domain()->domainname->name |
758 |
* modified bprm->argv[2] |
759 |
* = the current process's name |
760 |
* modified bprm->argv[3] |
761 |
* = the current process's information (e.g. uid/gid). |
762 |
* modified bprm->argv[4] |
763 |
* = original bprm->filename |
764 |
* modified bprm->argv[5] |
765 |
* = original bprm->argc in string expression |
766 |
* modified bprm->argv[6] |
767 |
* = original bprm->envc in string expression |
768 |
* modified bprm->argv[7] |
769 |
* = original bprm->argv[0] |
770 |
* ... |
771 |
* modified bprm->argv[bprm->argc + 6] |
772 |
* = original bprm->argv[bprm->argc - 1] |
773 |
* modified bprm->argv[bprm->argc + 7] |
774 |
* = original bprm->envp[0] |
775 |
* ... |
776 |
* modified bprm->argv[bprm->envc + bprm->argc + 6] |
777 |
* = original bprm->envp[bprm->envc - 1] |
778 |
*/ |
779 |
struct linux_binprm *bprm = ee->bprm; |
780 |
struct file *filp; |
781 |
int retval; |
782 |
const int original_argc = bprm->argc; |
783 |
const int original_envc = bprm->envc; |
784 |
struct task_struct *task = current; |
785 |
|
786 |
/* Close the requested program's dentry. */ |
787 |
ee->obj.path1.dentry = NULL; |
788 |
ee->obj.path1.mnt = NULL; |
789 |
ee->obj.validate_done = false; |
790 |
allow_write_access(bprm->file); |
791 |
fput(bprm->file); |
792 |
bprm->file = NULL; |
793 |
|
794 |
/* Invalidate page dump cache. */ |
795 |
ee->dump.page = NULL; |
796 |
|
797 |
/* Move envp[] to argv[] */ |
798 |
bprm->argc += bprm->envc; |
799 |
bprm->envc = 0; |
800 |
|
801 |
/* Set argv[6] */ |
802 |
{ |
803 |
snprintf(ee->tmp, CCS_EXEC_TMPSIZE - 1, "%d", original_envc); |
804 |
retval = ccs_copy_argv(ee->tmp, bprm); |
805 |
if (retval < 0) |
806 |
goto out; |
807 |
} |
808 |
|
809 |
/* Set argv[5] */ |
810 |
{ |
811 |
snprintf(ee->tmp, CCS_EXEC_TMPSIZE - 1, "%d", original_argc); |
812 |
retval = ccs_copy_argv(ee->tmp, bprm); |
813 |
if (retval < 0) |
814 |
goto out; |
815 |
} |
816 |
|
817 |
/* Set argv[4] */ |
818 |
{ |
819 |
retval = ccs_copy_argv(bprm->filename, bprm); |
820 |
if (retval < 0) |
821 |
goto out; |
822 |
} |
823 |
|
824 |
/* Set argv[3] */ |
825 |
{ |
826 |
snprintf(ee->tmp, CCS_EXEC_TMPSIZE - 1, |
827 |
"pid=%d uid=%d gid=%d euid=%d egid=%d suid=%d " |
828 |
"sgid=%d fsuid=%d fsgid=%d", |
829 |
(pid_t) ccsecurity_exports.sys_getpid(), |
830 |
current_uid(), current_gid(), current_euid(), |
831 |
current_egid(), current_suid(), current_sgid(), |
832 |
current_fsuid(), current_fsgid()); |
833 |
retval = ccs_copy_argv(ee->tmp, bprm); |
834 |
if (retval < 0) |
835 |
goto out; |
836 |
} |
837 |
|
838 |
/* Set argv[2] */ |
839 |
{ |
840 |
char *exe = (char *) ccs_get_exe(); |
841 |
if (exe) { |
842 |
retval = ccs_copy_argv(exe, bprm); |
843 |
kfree(exe); |
844 |
} else { |
845 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 36) |
846 |
retval = ccs_copy_argv("<unknown>", bprm); |
847 |
#else |
848 |
snprintf(ee->tmp, CCS_EXEC_TMPSIZE - 1, "<unknown>"); |
849 |
retval = ccs_copy_argv(ee->tmp, bprm); |
850 |
#endif |
851 |
} |
852 |
if (retval < 0) |
853 |
goto out; |
854 |
} |
855 |
|
856 |
/* Set argv[1] */ |
857 |
{ |
858 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 36) |
859 |
retval = ccs_copy_argv(ccs_current_domain()->domainname->name, |
860 |
bprm); |
861 |
#else |
862 |
snprintf(ee->tmp, CCS_EXEC_TMPSIZE - 1, "%s", |
863 |
ccs_current_domain()->domainname->name); |
864 |
retval = ccs_copy_argv(ee->tmp, bprm); |
865 |
#endif |
866 |
if (retval < 0) |
867 |
goto out; |
868 |
} |
869 |
|
870 |
/* Set argv[0] */ |
871 |
{ |
872 |
struct path root; |
873 |
char *cp; |
874 |
int root_len; |
875 |
int handler_len; |
876 |
get_fs_root(current->fs, &root); |
877 |
cp = ccs_realpath_from_path(&root); |
878 |
path_put(&root); |
879 |
if (!cp) { |
880 |
retval = -ENOMEM; |
881 |
goto out; |
882 |
} |
883 |
root_len = strlen(cp); |
884 |
retval = strncmp(ee->handler->name, cp, root_len); |
885 |
root_len--; |
886 |
kfree(cp); |
887 |
if (retval) { |
888 |
retval = -ENOENT; |
889 |
goto out; |
890 |
} |
891 |
handler_len = ee->handler->total_len + 1; |
892 |
cp = kmalloc(handler_len, CCS_GFP_FLAGS); |
893 |
if (!cp) { |
894 |
retval = -ENOMEM; |
895 |
goto out; |
896 |
} |
897 |
ee->handler_path = cp; |
898 |
/* Adjust root directory for open_exec(). */ |
899 |
memmove(cp, ee->handler->name + root_len, |
900 |
handler_len - root_len); |
901 |
ccs_unescape(cp); |
902 |
retval = -ENOENT; |
903 |
if (!*cp || *cp != '/') |
904 |
goto out; |
905 |
retval = ccs_copy_argv(cp, bprm); |
906 |
if (retval < 0) |
907 |
goto out; |
908 |
} |
909 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 23) |
910 |
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 24) |
911 |
bprm->argv_len = bprm->exec - bprm->p; |
912 |
#endif |
913 |
#endif |
914 |
|
915 |
/* |
916 |
* OK, now restart the process with execute handler program's dentry. |
917 |
*/ |
918 |
filp = open_exec(ee->handler_path); |
919 |
if (IS_ERR(filp)) { |
920 |
retval = PTR_ERR(filp); |
921 |
goto out; |
922 |
} |
923 |
ee->obj.path1.dentry = filp->f_dentry; |
924 |
ee->obj.path1.mnt = filp->f_vfsmnt; |
925 |
bprm->file = filp; |
926 |
bprm->filename = ee->handler_path; |
927 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 0) |
928 |
bprm->interp = bprm->filename; |
929 |
#endif |
930 |
retval = prepare_binprm(bprm); |
931 |
if (retval < 0) |
932 |
goto out; |
933 |
task->ccs_flags |= CCS_DONT_SLEEP_ON_ENFORCE_ERROR; |
934 |
retval = ccs_find_next_domain(ee); |
935 |
task->ccs_flags &= ~CCS_DONT_SLEEP_ON_ENFORCE_ERROR; |
936 |
out: |
937 |
return retval; |
938 |
} |
939 |
|
940 |
/** |
941 |
* ccs_find_execute_handler - Find an execute handler. |
942 |
* |
943 |
* @ee: Pointer to "struct ccs_execve". |
944 |
* @type: Type of execute handler. |
945 |
* |
946 |
* Returns true if found, false otherwise. |
947 |
* |
948 |
* Caller holds ccs_read_lock(). |
949 |
*/ |
950 |
static bool ccs_find_execute_handler(struct ccs_execve *ee, const u8 type) |
951 |
{ |
952 |
struct ccs_request_info *r = &ee->r; |
953 |
/* |
954 |
* To avoid infinite execute handler loop, don't use execute handler |
955 |
* if the current process is marked as execute handler . |
956 |
*/ |
957 |
if (current->ccs_flags & CCS_TASK_IS_EXECUTE_HANDLER) |
958 |
return false; |
959 |
r->param_type = type; |
960 |
ccs_check_acl(r, NULL); |
961 |
if (!r->granted) |
962 |
return false; |
963 |
ee->handler = container_of(r->matched_acl, struct ccs_handler_acl, |
964 |
head)->handler; |
965 |
return true; |
966 |
} |
967 |
|
968 |
#ifdef CONFIG_MMU |
969 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 23) |
970 |
#define CCS_BPRM_MMU |
971 |
#elif defined(RHEL_MAJOR) && RHEL_MAJOR == 5 && defined(RHEL_MINOR) && RHEL_MINOR >= 3 |
972 |
#define CCS_BPRM_MMU |
973 |
#elif defined(AX_MAJOR) && AX_MAJOR == 3 && defined(AX_MINOR) && AX_MINOR >= 2 |
974 |
#define CCS_BPRM_MMU |
975 |
#endif |
976 |
#endif |
977 |
|
978 |
/** |
979 |
* ccs_dump_page - Dump a page to buffer. |
980 |
* |
981 |
* @bprm: Pointer to "struct linux_binprm". |
982 |
* @pos: Location to dump. |
983 |
* @dump: Poiner to "struct ccs_page_dump". |
984 |
* |
985 |
* Returns true on success, false otherwise. |
986 |
*/ |
987 |
bool ccs_dump_page(struct linux_binprm *bprm, unsigned long pos, |
988 |
struct ccs_page_dump *dump) |
989 |
{ |
990 |
struct page *page; |
991 |
/* dump->data is released by ccs_finish_execve(). */ |
992 |
if (!dump->data) { |
993 |
dump->data = kzalloc(PAGE_SIZE, CCS_GFP_FLAGS); |
994 |
if (!dump->data) |
995 |
return false; |
996 |
} |
997 |
/* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */ |
998 |
#ifdef CCS_BPRM_MMU |
999 |
if (get_user_pages(current, bprm->mm, pos, 1, 0, 1, &page, NULL) <= 0) |
1000 |
return false; |
1001 |
#else |
1002 |
page = bprm->page[pos / PAGE_SIZE]; |
1003 |
#endif |
1004 |
if (page != dump->page) { |
1005 |
const unsigned int offset = pos % PAGE_SIZE; |
1006 |
/* |
1007 |
* Maybe kmap()/kunmap() should be used here. |
1008 |
* But remove_arg_zero() uses kmap_atomic()/kunmap_atomic(). |
1009 |
* So do I. |
1010 |
*/ |
1011 |
char *kaddr = kmap_atomic(page, KM_USER0); |
1012 |
dump->page = page; |
1013 |
memcpy(dump->data + offset, kaddr + offset, |
1014 |
PAGE_SIZE - offset); |
1015 |
kunmap_atomic(kaddr, KM_USER0); |
1016 |
} |
1017 |
/* Same with put_arg_page(page) in fs/exec.c */ |
1018 |
#ifdef CCS_BPRM_MMU |
1019 |
put_page(page); |
1020 |
#endif |
1021 |
return true; |
1022 |
} |
1023 |
|
1024 |
/** |
1025 |
* ccs_start_execve - Prepare for execve() operation. |
1026 |
* |
1027 |
* @bprm: Pointer to "struct linux_binprm". |
1028 |
* @eep: Pointer to "struct ccs_execve *". |
1029 |
* |
1030 |
* Returns 0 on success, negative value otherwise. |
1031 |
*/ |
1032 |
static int ccs_start_execve(struct linux_binprm *bprm, |
1033 |
struct ccs_execve **eep) |
1034 |
{ |
1035 |
int retval; |
1036 |
struct task_struct *task = current; |
1037 |
struct ccs_execve *ee; |
1038 |
*eep = NULL; |
1039 |
ee = kzalloc(sizeof(*ee), CCS_GFP_FLAGS); |
1040 |
if (!ee) |
1041 |
return -ENOMEM; |
1042 |
ee->tmp = kzalloc(CCS_EXEC_TMPSIZE, CCS_GFP_FLAGS); |
1043 |
if (!ee->tmp) { |
1044 |
kfree(ee); |
1045 |
return -ENOMEM; |
1046 |
} |
1047 |
ee->reader_idx = ccs_read_lock(); |
1048 |
/* ee->dump->data is allocated by ccs_dump_page(). */ |
1049 |
ee->previous_domain = task->ccs_domain_info; |
1050 |
/* Clear manager flag. */ |
1051 |
task->ccs_flags &= ~CCS_TASK_IS_MANAGER; |
1052 |
*eep = ee; |
1053 |
ccs_init_request_info(&ee->r, CCS_MAC_FILE_EXECUTE); |
1054 |
ee->r.ee = ee; |
1055 |
ee->bprm = bprm; |
1056 |
ee->r.obj = &ee->obj; |
1057 |
ee->obj.path1.dentry = bprm->file->f_dentry; |
1058 |
ee->obj.path1.mnt = bprm->file->f_vfsmnt; |
1059 |
/* |
1060 |
* No need to call ccs_environ() for execute handler because envp[] is |
1061 |
* moved to argv[]. |
1062 |
*/ |
1063 |
if (ccs_find_execute_handler(ee, CCS_TYPE_AUTO_EXECUTE_HANDLER)) |
1064 |
return ccs_try_alt_exec(ee); |
1065 |
retval = ccs_find_next_domain(ee); |
1066 |
if (retval == -EPERM) { |
1067 |
if (ccs_find_execute_handler(ee, |
1068 |
CCS_TYPE_DENIED_EXECUTE_HANDLER)) |
1069 |
return ccs_try_alt_exec(ee); |
1070 |
} |
1071 |
if (!retval) |
1072 |
retval = ccs_environ(ee); |
1073 |
return retval; |
1074 |
} |
1075 |
|
1076 |
/** |
1077 |
* ccs_finish_execve - Clean up execve() operation. |
1078 |
* |
1079 |
* @retval: Return code of an execve() operation. |
1080 |
* @ee: Pointer to "struct ccs_execve". |
1081 |
* |
1082 |
* Caller holds ccs_read_lock(). |
1083 |
*/ |
1084 |
static void ccs_finish_execve(int retval, struct ccs_execve *ee) |
1085 |
{ |
1086 |
struct task_struct *task = current; |
1087 |
if (!ee) |
1088 |
return; |
1089 |
if (retval < 0) { |
1090 |
task->ccs_domain_info = ee->previous_domain; |
1091 |
/* |
1092 |
* Make task->ccs_domain_info visible to GC before changing |
1093 |
* task->ccs_flags . |
1094 |
*/ |
1095 |
smp_mb(); |
1096 |
} else { |
1097 |
/* Mark the current process as execute handler. */ |
1098 |
if (ee->handler) |
1099 |
task->ccs_flags |= CCS_TASK_IS_EXECUTE_HANDLER; |
1100 |
/* Mark the current process as normal process. */ |
1101 |
else |
1102 |
task->ccs_flags &= ~CCS_TASK_IS_EXECUTE_HANDLER; |
1103 |
} |
1104 |
/* Tell GC that I finished execve(). */ |
1105 |
task->ccs_flags &= ~CCS_TASK_IS_IN_EXECVE; |
1106 |
ccs_read_unlock(ee->reader_idx); |
1107 |
kfree(ee->handler_path); |
1108 |
kfree(ee->tmp); |
1109 |
kfree(ee->dump.data); |
1110 |
kfree(ee); |
1111 |
} |
1112 |
|
1113 |
static int __ccs_search_binary_handler(struct linux_binprm *bprm, |
1114 |
struct pt_regs *regs) |
1115 |
{ |
1116 |
struct ccs_execve *ee; |
1117 |
int retval; |
1118 |
if (!ccs_policy_loaded) |
1119 |
ccsecurity_exports.load_policy(bprm->filename); |
1120 |
retval = ccs_start_execve(bprm, &ee); |
1121 |
if (!retval) |
1122 |
retval = search_binary_handler(bprm, regs); |
1123 |
ccs_finish_execve(retval, ee); |
1124 |
return retval; |
1125 |
} |
1126 |
|
1127 |
void __init ccs_domain_init(void) |
1128 |
{ |
1129 |
ccsecurity_ops.search_binary_handler = __ccs_search_binary_handler; |
1130 |
} |