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TOMOYO Linux Cross Reference
Linux/security/tomoyo/domain.c

Version: ~ [ linux-5.3 ] ~ [ linux-5.2.14 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.72 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.143 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.192 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.192 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.73 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * security/tomoyo/domain.c
  4  *
  5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
  6  */
  7 
  8 #include "common.h"
  9 
 10 #include <linux/binfmts.h>
 11 #include <linux/slab.h>
 12 #include <linux/rculist.h>
 13 
 14 /* Variables definitions.*/
 15 
 16 /* The initial domain. */
 17 struct tomoyo_domain_info tomoyo_kernel_domain;
 18 
 19 /**
 20  * tomoyo_update_policy - Update an entry for exception policy.
 21  *
 22  * @new_entry:       Pointer to "struct tomoyo_acl_info".
 23  * @size:            Size of @new_entry in bytes.
 24  * @param:           Pointer to "struct tomoyo_acl_param".
 25  * @check_duplicate: Callback function to find duplicated entry.
 26  *
 27  * Returns 0 on success, negative value otherwise.
 28  *
 29  * Caller holds tomoyo_read_lock().
 30  */
 31 int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
 32                          struct tomoyo_acl_param *param,
 33                          bool (*check_duplicate) (const struct tomoyo_acl_head
 34                                                   *,
 35                                                   const struct tomoyo_acl_head
 36                                                   *))
 37 {
 38         int error = param->is_delete ? -ENOENT : -ENOMEM;
 39         struct tomoyo_acl_head *entry;
 40         struct list_head *list = param->list;
 41 
 42         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 43                 return -ENOMEM;
 44         list_for_each_entry_rcu(entry, list, list) {
 45                 if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
 46                         continue;
 47                 if (!check_duplicate(entry, new_entry))
 48                         continue;
 49                 entry->is_deleted = param->is_delete;
 50                 error = 0;
 51                 break;
 52         }
 53         if (error && !param->is_delete) {
 54                 entry = tomoyo_commit_ok(new_entry, size);
 55                 if (entry) {
 56                         list_add_tail_rcu(&entry->list, list);
 57                         error = 0;
 58                 }
 59         }
 60         mutex_unlock(&tomoyo_policy_lock);
 61         return error;
 62 }
 63 
 64 /**
 65  * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry.
 66  *
 67  * @a: Pointer to "struct tomoyo_acl_info".
 68  * @b: Pointer to "struct tomoyo_acl_info".
 69  *
 70  * Returns true if @a == @b, false otherwise.
 71  */
 72 static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
 73                                         const struct tomoyo_acl_info *b)
 74 {
 75         return a->type == b->type && a->cond == b->cond;
 76 }
 77 
 78 /**
 79  * tomoyo_update_domain - Update an entry for domain policy.
 80  *
 81  * @new_entry:       Pointer to "struct tomoyo_acl_info".
 82  * @size:            Size of @new_entry in bytes.
 83  * @param:           Pointer to "struct tomoyo_acl_param".
 84  * @check_duplicate: Callback function to find duplicated entry.
 85  * @merge_duplicate: Callback function to merge duplicated entry.
 86  *
 87  * Returns 0 on success, negative value otherwise.
 88  *
 89  * Caller holds tomoyo_read_lock().
 90  */
 91 int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
 92                          struct tomoyo_acl_param *param,
 93                          bool (*check_duplicate) (const struct tomoyo_acl_info
 94                                                   *,
 95                                                   const struct tomoyo_acl_info
 96                                                   *),
 97                          bool (*merge_duplicate) (struct tomoyo_acl_info *,
 98                                                   struct tomoyo_acl_info *,
 99                                                   const bool))
100 {
101         const bool is_delete = param->is_delete;
102         int error = is_delete ? -ENOENT : -ENOMEM;
103         struct tomoyo_acl_info *entry;
104         struct list_head * const list = param->list;
105 
106         if (param->data[0]) {
107                 new_entry->cond = tomoyo_get_condition(param);
108                 if (!new_entry->cond)
109                         return -EINVAL;
110                 /*
111                  * Domain transition preference is allowed for only
112                  * "file execute" entries.
113                  */
114                 if (new_entry->cond->transit &&
115                     !(new_entry->type == TOMOYO_TYPE_PATH_ACL &&
116                       container_of(new_entry, struct tomoyo_path_acl, head)
117                       ->perm == 1 << TOMOYO_TYPE_EXECUTE))
118                         goto out;
119         }
120         if (mutex_lock_interruptible(&tomoyo_policy_lock))
121                 goto out;
122         list_for_each_entry_rcu(entry, list, list) {
123                 if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
124                         continue;
125                 if (!tomoyo_same_acl_head(entry, new_entry) ||
126                     !check_duplicate(entry, new_entry))
127                         continue;
128                 if (merge_duplicate)
129                         entry->is_deleted = merge_duplicate(entry, new_entry,
130                                                             is_delete);
131                 else
132                         entry->is_deleted = is_delete;
133                 error = 0;
134                 break;
135         }
136         if (error && !is_delete) {
137                 entry = tomoyo_commit_ok(new_entry, size);
138                 if (entry) {
139                         list_add_tail_rcu(&entry->list, list);
140                         error = 0;
141                 }
142         }
143         mutex_unlock(&tomoyo_policy_lock);
144 out:
145         tomoyo_put_condition(new_entry->cond);
146         return error;
147 }
148 
149 /**
150  * tomoyo_check_acl - Do permission check.
151  *
152  * @r:           Pointer to "struct tomoyo_request_info".
153  * @check_entry: Callback function to check type specific parameters.
154  *
155  * Returns 0 on success, negative value otherwise.
156  *
157  * Caller holds tomoyo_read_lock().
158  */
159 void tomoyo_check_acl(struct tomoyo_request_info *r,
160                       bool (*check_entry) (struct tomoyo_request_info *,
161                                            const struct tomoyo_acl_info *))
162 {
163         const struct tomoyo_domain_info *domain = r->domain;
164         struct tomoyo_acl_info *ptr;
165         bool retried = false;
166         const struct list_head *list = &domain->acl_info_list;
167 
168 retry:
169         list_for_each_entry_rcu(ptr, list, list) {
170                 if (ptr->is_deleted || ptr->type != r->param_type)
171                         continue;
172                 if (!check_entry(r, ptr))
173                         continue;
174                 if (!tomoyo_condition(r, ptr->cond))
175                         continue;
176                 r->matched_acl = ptr;
177                 r->granted = true;
178                 return;
179         }
180         if (!retried) {
181                 retried = true;
182                 list = &domain->ns->acl_group[domain->group];
183                 goto retry;
184         }
185         r->granted = false;
186 }
187 
188 /* The list for "struct tomoyo_domain_info". */
189 LIST_HEAD(tomoyo_domain_list);
190 
191 /**
192  * tomoyo_last_word - Get last component of a domainname.
193  *
194  * @name: Domainname to check.
195  *
196  * Returns the last word of @domainname.
197  */
198 static const char *tomoyo_last_word(const char *name)
199 {
200         const char *cp = strrchr(name, ' ');
201         if (cp)
202                 return cp + 1;
203         return name;
204 }
205 
206 /**
207  * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
208  *
209  * @a: Pointer to "struct tomoyo_acl_head".
210  * @b: Pointer to "struct tomoyo_acl_head".
211  *
212  * Returns true if @a == @b, false otherwise.
213  */
214 static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
215                                            const struct tomoyo_acl_head *b)
216 {
217         const struct tomoyo_transition_control *p1 = container_of(a,
218                                                                   typeof(*p1),
219                                                                   head);
220         const struct tomoyo_transition_control *p2 = container_of(b,
221                                                                   typeof(*p2),
222                                                                   head);
223         return p1->type == p2->type && p1->is_last_name == p2->is_last_name
224                 && p1->domainname == p2->domainname
225                 && p1->program == p2->program;
226 }
227 
228 /**
229  * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
230  *
231  * @param: Pointer to "struct tomoyo_acl_param".
232  * @type:  Type of this entry.
233  *
234  * Returns 0 on success, negative value otherwise.
235  */
236 int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
237                                     const u8 type)
238 {
239         struct tomoyo_transition_control e = { .type = type };
240         int error = param->is_delete ? -ENOENT : -ENOMEM;
241         char *program = param->data;
242         char *domainname = strstr(program, " from ");
243         if (domainname) {
244                 *domainname = '\0';
245                 domainname += 6;
246         } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
247                    type == TOMOYO_TRANSITION_CONTROL_KEEP) {
248                 domainname = program;
249                 program = NULL;
250         }
251         if (program && strcmp(program, "any")) {
252                 if (!tomoyo_correct_path(program))
253                         return -EINVAL;
254                 e.program = tomoyo_get_name(program);
255                 if (!e.program)
256                         goto out;
257         }
258         if (domainname && strcmp(domainname, "any")) {
259                 if (!tomoyo_correct_domain(domainname)) {
260                         if (!tomoyo_correct_path(domainname))
261                                 goto out;
262                         e.is_last_name = true;
263                 }
264                 e.domainname = tomoyo_get_name(domainname);
265                 if (!e.domainname)
266                         goto out;
267         }
268         param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
269         error = tomoyo_update_policy(&e.head, sizeof(e), param,
270                                      tomoyo_same_transition_control);
271 out:
272         tomoyo_put_name(e.domainname);
273         tomoyo_put_name(e.program);
274         return error;
275 }
276 
277 /**
278  * tomoyo_scan_transition - Try to find specific domain transition type.
279  *
280  * @list:       Pointer to "struct list_head".
281  * @domainname: The name of current domain.
282  * @program:    The name of requested program.
283  * @last_name:  The last component of @domainname.
284  * @type:       One of values in "enum tomoyo_transition_type".
285  *
286  * Returns true if found one, false otherwise.
287  *
288  * Caller holds tomoyo_read_lock().
289  */
290 static inline bool tomoyo_scan_transition
291 (const struct list_head *list, const struct tomoyo_path_info *domainname,
292  const struct tomoyo_path_info *program, const char *last_name,
293  const enum tomoyo_transition_type type)
294 {
295         const struct tomoyo_transition_control *ptr;
296         list_for_each_entry_rcu(ptr, list, head.list) {
297                 if (ptr->head.is_deleted || ptr->type != type)
298                         continue;
299                 if (ptr->domainname) {
300                         if (!ptr->is_last_name) {
301                                 if (ptr->domainname != domainname)
302                                         continue;
303                         } else {
304                                 /*
305                                  * Use direct strcmp() since this is
306                                  * unlikely used.
307                                  */
308                                 if (strcmp(ptr->domainname->name, last_name))
309                                         continue;
310                         }
311                 }
312                 if (ptr->program && tomoyo_pathcmp(ptr->program, program))
313                         continue;
314                 return true;
315         }
316         return false;
317 }
318 
319 /**
320  * tomoyo_transition_type - Get domain transition type.
321  *
322  * @ns:         Pointer to "struct tomoyo_policy_namespace".
323  * @domainname: The name of current domain.
324  * @program:    The name of requested program.
325  *
326  * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
327  * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
328  * executing @program reinitializes domain transition within that namespace,
329  * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
330  * others otherwise.
331  *
332  * Caller holds tomoyo_read_lock().
333  */
334 static enum tomoyo_transition_type tomoyo_transition_type
335 (const struct tomoyo_policy_namespace *ns,
336  const struct tomoyo_path_info *domainname,
337  const struct tomoyo_path_info *program)
338 {
339         const char *last_name = tomoyo_last_word(domainname->name);
340         enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
341         while (type < TOMOYO_MAX_TRANSITION_TYPE) {
342                 const struct list_head * const list =
343                         &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
344                 if (!tomoyo_scan_transition(list, domainname, program,
345                                             last_name, type)) {
346                         type++;
347                         continue;
348                 }
349                 if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
350                     type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
351                         break;
352                 /*
353                  * Do not check for reset_domain if no_reset_domain matched.
354                  * Do not check for initialize_domain if no_initialize_domain
355                  * matched.
356                  */
357                 type++;
358                 type++;
359         }
360         return type;
361 }
362 
363 /**
364  * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
365  *
366  * @a: Pointer to "struct tomoyo_acl_head".
367  * @b: Pointer to "struct tomoyo_acl_head".
368  *
369  * Returns true if @a == @b, false otherwise.
370  */
371 static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
372                                    const struct tomoyo_acl_head *b)
373 {
374         const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
375                                                           head);
376         const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
377                                                           head);
378         return p1->original_name == p2->original_name &&
379                 p1->aggregated_name == p2->aggregated_name;
380 }
381 
382 /**
383  * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
384  *
385  * @param: Pointer to "struct tomoyo_acl_param".
386  *
387  * Returns 0 on success, negative value otherwise.
388  *
389  * Caller holds tomoyo_read_lock().
390  */
391 int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
392 {
393         struct tomoyo_aggregator e = { };
394         int error = param->is_delete ? -ENOENT : -ENOMEM;
395         const char *original_name = tomoyo_read_token(param);
396         const char *aggregated_name = tomoyo_read_token(param);
397         if (!tomoyo_correct_word(original_name) ||
398             !tomoyo_correct_path(aggregated_name))
399                 return -EINVAL;
400         e.original_name = tomoyo_get_name(original_name);
401         e.aggregated_name = tomoyo_get_name(aggregated_name);
402         if (!e.original_name || !e.aggregated_name ||
403             e.aggregated_name->is_patterned) /* No patterns allowed. */
404                 goto out;
405         param->list = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
406         error = tomoyo_update_policy(&e.head, sizeof(e), param,
407                                      tomoyo_same_aggregator);
408 out:
409         tomoyo_put_name(e.original_name);
410         tomoyo_put_name(e.aggregated_name);
411         return error;
412 }
413 
414 /**
415  * tomoyo_find_namespace - Find specified namespace.
416  *
417  * @name: Name of namespace to find.
418  * @len:  Length of @name.
419  *
420  * Returns pointer to "struct tomoyo_policy_namespace" if found,
421  * NULL otherwise.
422  *
423  * Caller holds tomoyo_read_lock().
424  */
425 static struct tomoyo_policy_namespace *tomoyo_find_namespace
426 (const char *name, const unsigned int len)
427 {
428         struct tomoyo_policy_namespace *ns;
429         list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
430                 if (strncmp(name, ns->name, len) ||
431                     (name[len] && name[len] != ' '))
432                         continue;
433                 return ns;
434         }
435         return NULL;
436 }
437 
438 /**
439  * tomoyo_assign_namespace - Create a new namespace.
440  *
441  * @domainname: Name of namespace to create.
442  *
443  * Returns pointer to "struct tomoyo_policy_namespace" on success,
444  * NULL otherwise.
445  *
446  * Caller holds tomoyo_read_lock().
447  */
448 struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
449 {
450         struct tomoyo_policy_namespace *ptr;
451         struct tomoyo_policy_namespace *entry;
452         const char *cp = domainname;
453         unsigned int len = 0;
454         while (*cp && *cp++ != ' ')
455                 len++;
456         ptr = tomoyo_find_namespace(domainname, len);
457         if (ptr)
458                 return ptr;
459         if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
460                 return NULL;
461         entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS);
462         if (!entry)
463                 return NULL;
464         if (mutex_lock_interruptible(&tomoyo_policy_lock))
465                 goto out;
466         ptr = tomoyo_find_namespace(domainname, len);
467         if (!ptr && tomoyo_memory_ok(entry)) {
468                 char *name = (char *) (entry + 1);
469                 ptr = entry;
470                 memmove(name, domainname, len);
471                 name[len] = '\0';
472                 entry->name = name;
473                 tomoyo_init_policy_namespace(entry);
474                 entry = NULL;
475         }
476         mutex_unlock(&tomoyo_policy_lock);
477 out:
478         kfree(entry);
479         return ptr;
480 }
481 
482 /**
483  * tomoyo_namespace_jump - Check for namespace jump.
484  *
485  * @domainname: Name of domain.
486  *
487  * Returns true if namespace differs, false otherwise.
488  */
489 static bool tomoyo_namespace_jump(const char *domainname)
490 {
491         const char *namespace = tomoyo_current_namespace()->name;
492         const int len = strlen(namespace);
493         return strncmp(domainname, namespace, len) ||
494                 (domainname[len] && domainname[len] != ' ');
495 }
496 
497 /**
498  * tomoyo_assign_domain - Create a domain or a namespace.
499  *
500  * @domainname: The name of domain.
501  * @transit:    True if transit to domain found or created.
502  *
503  * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
504  *
505  * Caller holds tomoyo_read_lock().
506  */
507 struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
508                                                 const bool transit)
509 {
510         struct tomoyo_domain_info e = { };
511         struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
512         bool created = false;
513         if (entry) {
514                 if (transit) {
515                         /*
516                          * Since namespace is created at runtime, profiles may
517                          * not be created by the moment the process transits to
518                          * that domain. Do not perform domain transition if
519                          * profile for that domain is not yet created.
520                          */
521                         if (tomoyo_policy_loaded &&
522                             !entry->ns->profile_ptr[entry->profile])
523                                 return NULL;
524                 }
525                 return entry;
526         }
527         /* Requested domain does not exist. */
528         /* Don't create requested domain if domainname is invalid. */
529         if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
530             !tomoyo_correct_domain(domainname))
531                 return NULL;
532         /*
533          * Since definition of profiles and acl_groups may differ across
534          * namespaces, do not inherit "use_profile" and "use_group" settings
535          * by automatically creating requested domain upon domain transition.
536          */
537         if (transit && tomoyo_namespace_jump(domainname))
538                 return NULL;
539         e.ns = tomoyo_assign_namespace(domainname);
540         if (!e.ns)
541                 return NULL;
542         /*
543          * "use_profile" and "use_group" settings for automatically created
544          * domains are inherited from current domain. These are 0 for manually
545          * created domains.
546          */
547         if (transit) {
548                 const struct tomoyo_domain_info *domain = tomoyo_domain();
549                 e.profile = domain->profile;
550                 e.group = domain->group;
551         }
552         e.domainname = tomoyo_get_name(domainname);
553         if (!e.domainname)
554                 return NULL;
555         if (mutex_lock_interruptible(&tomoyo_policy_lock))
556                 goto out;
557         entry = tomoyo_find_domain(domainname);
558         if (!entry) {
559                 entry = tomoyo_commit_ok(&e, sizeof(e));
560                 if (entry) {
561                         INIT_LIST_HEAD(&entry->acl_info_list);
562                         list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
563                         created = true;
564                 }
565         }
566         mutex_unlock(&tomoyo_policy_lock);
567 out:
568         tomoyo_put_name(e.domainname);
569         if (entry && transit) {
570                 if (created) {
571                         struct tomoyo_request_info r;
572                         tomoyo_init_request_info(&r, entry,
573                                                  TOMOYO_MAC_FILE_EXECUTE);
574                         r.granted = false;
575                         tomoyo_write_log(&r, "use_profile %u\n",
576                                          entry->profile);
577                         tomoyo_write_log(&r, "use_group %u\n", entry->group);
578                         tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
579                 }
580         }
581         return entry;
582 }
583 
584 /**
585  * tomoyo_environ - Check permission for environment variable names.
586  *
587  * @ee: Pointer to "struct tomoyo_execve".
588  *
589  * Returns 0 on success, negative value otherwise.
590  */
591 static int tomoyo_environ(struct tomoyo_execve *ee)
592 {
593         struct tomoyo_request_info *r = &ee->r;
594         struct linux_binprm *bprm = ee->bprm;
595         /* env_page.data is allocated by tomoyo_dump_page(). */
596         struct tomoyo_page_dump env_page = { };
597         char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
598         int arg_len = 0;
599         unsigned long pos = bprm->p;
600         int offset = pos % PAGE_SIZE;
601         int argv_count = bprm->argc;
602         int envp_count = bprm->envc;
603         int error = -ENOMEM;
604 
605         ee->r.type = TOMOYO_MAC_ENVIRON;
606         ee->r.profile = r->domain->profile;
607         ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
608                                      TOMOYO_MAC_ENVIRON);
609         if (!r->mode || !envp_count)
610                 return 0;
611         arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
612         if (!arg_ptr)
613                 goto out;
614         while (error == -ENOMEM) {
615                 if (!tomoyo_dump_page(bprm, pos, &env_page))
616                         goto out;
617                 pos += PAGE_SIZE - offset;
618                 /* Read. */
619                 while (argv_count && offset < PAGE_SIZE) {
620                         if (!env_page.data[offset++])
621                                 argv_count--;
622                 }
623                 if (argv_count) {
624                         offset = 0;
625                         continue;
626                 }
627                 while (offset < PAGE_SIZE) {
628                         const unsigned char c = env_page.data[offset++];
629 
630                         if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
631                                 if (c == '=') {
632                                         arg_ptr[arg_len++] = '\0';
633                                 } else if (c == '\\') {
634                                         arg_ptr[arg_len++] = '\\';
635                                         arg_ptr[arg_len++] = '\\';
636                                 } else if (c > ' ' && c < 127) {
637                                         arg_ptr[arg_len++] = c;
638                                 } else {
639                                         arg_ptr[arg_len++] = '\\';
640                                         arg_ptr[arg_len++] = (c >> 6) + '';
641                                         arg_ptr[arg_len++]
642                                                 = ((c >> 3) & 7) + '';
643                                         arg_ptr[arg_len++] = (c & 7) + '';
644                                 }
645                         } else {
646                                 arg_ptr[arg_len] = '\0';
647                         }
648                         if (c)
649                                 continue;
650                         if (tomoyo_env_perm(r, arg_ptr)) {
651                                 error = -EPERM;
652                                 break;
653                         }
654                         if (!--envp_count) {
655                                 error = 0;
656                                 break;
657                         }
658                         arg_len = 0;
659                 }
660                 offset = 0;
661         }
662 out:
663         if (r->mode != TOMOYO_CONFIG_ENFORCING)
664                 error = 0;
665         kfree(env_page.data);
666         kfree(arg_ptr);
667         return error;
668 }
669 
670 /**
671  * tomoyo_find_next_domain - Find a domain.
672  *
673  * @bprm: Pointer to "struct linux_binprm".
674  *
675  * Returns 0 on success, negative value otherwise.
676  *
677  * Caller holds tomoyo_read_lock().
678  */
679 int tomoyo_find_next_domain(struct linux_binprm *bprm)
680 {
681         struct tomoyo_domain_info *old_domain = tomoyo_domain();
682         struct tomoyo_domain_info *domain = NULL;
683         const char *original_name = bprm->filename;
684         int retval = -ENOMEM;
685         bool reject_on_transition_failure = false;
686         const struct tomoyo_path_info *candidate;
687         struct tomoyo_path_info exename;
688         struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
689 
690         if (!ee)
691                 return -ENOMEM;
692         ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
693         if (!ee->tmp) {
694                 kfree(ee);
695                 return -ENOMEM;
696         }
697         /* ee->dump->data is allocated by tomoyo_dump_page(). */
698         tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
699         ee->r.ee = ee;
700         ee->bprm = bprm;
701         ee->r.obj = &ee->obj;
702         ee->obj.path1 = bprm->file->f_path;
703         /* Get symlink's pathname of program. */
704         retval = -ENOENT;
705         exename.name = tomoyo_realpath_nofollow(original_name);
706         if (!exename.name)
707                 goto out;
708         tomoyo_fill_path_info(&exename);
709 retry:
710         /* Check 'aggregator' directive. */
711         {
712                 struct tomoyo_aggregator *ptr;
713                 struct list_head *list =
714                         &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
715                 /* Check 'aggregator' directive. */
716                 candidate = &exename;
717                 list_for_each_entry_rcu(ptr, list, head.list) {
718                         if (ptr->head.is_deleted ||
719                             !tomoyo_path_matches_pattern(&exename,
720                                                          ptr->original_name))
721                                 continue;
722                         candidate = ptr->aggregated_name;
723                         break;
724                 }
725         }
726 
727         /* Check execute permission. */
728         retval = tomoyo_execute_permission(&ee->r, candidate);
729         if (retval == TOMOYO_RETRY_REQUEST)
730                 goto retry;
731         if (retval < 0)
732                 goto out;
733         /*
734          * To be able to specify domainnames with wildcards, use the
735          * pathname specified in the policy (which may contain
736          * wildcard) rather than the pathname passed to execve()
737          * (which never contains wildcard).
738          */
739         if (ee->r.param.path.matched_path)
740                 candidate = ee->r.param.path.matched_path;
741 
742         /*
743          * Check for domain transition preference if "file execute" matched.
744          * If preference is given, make do_execve() fail if domain transition
745          * has failed, for domain transition preference should be used with
746          * destination domain defined.
747          */
748         if (ee->transition) {
749                 const char *domainname = ee->transition->name;
750                 reject_on_transition_failure = true;
751                 if (!strcmp(domainname, "keep"))
752                         goto force_keep_domain;
753                 if (!strcmp(domainname, "child"))
754                         goto force_child_domain;
755                 if (!strcmp(domainname, "reset"))
756                         goto force_reset_domain;
757                 if (!strcmp(domainname, "initialize"))
758                         goto force_initialize_domain;
759                 if (!strcmp(domainname, "parent")) {
760                         char *cp;
761                         strncpy(ee->tmp, old_domain->domainname->name,
762                                 TOMOYO_EXEC_TMPSIZE - 1);
763                         cp = strrchr(ee->tmp, ' ');
764                         if (cp)
765                                 *cp = '\0';
766                 } else if (*domainname == '<')
767                         strncpy(ee->tmp, domainname, TOMOYO_EXEC_TMPSIZE - 1);
768                 else
769                         snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
770                                  old_domain->domainname->name, domainname);
771                 goto force_jump_domain;
772         }
773         /*
774          * No domain transition preference specified.
775          * Calculate domain to transit to.
776          */
777         switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
778                                        candidate)) {
779         case TOMOYO_TRANSITION_CONTROL_RESET:
780 force_reset_domain:
781                 /* Transit to the root of specified namespace. */
782                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>",
783                          candidate->name);
784                 /*
785                  * Make do_execve() fail if domain transition across namespaces
786                  * has failed.
787                  */
788                 reject_on_transition_failure = true;
789                 break;
790         case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
791 force_initialize_domain:
792                 /* Transit to the child of current namespace's root. */
793                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
794                          old_domain->ns->name, candidate->name);
795                 break;
796         case TOMOYO_TRANSITION_CONTROL_KEEP:
797 force_keep_domain:
798                 /* Keep current domain. */
799                 domain = old_domain;
800                 break;
801         default:
802                 if (old_domain == &tomoyo_kernel_domain &&
803                     !tomoyo_policy_loaded) {
804                         /*
805                          * Needn't to transit from kernel domain before
806                          * starting /sbin/init. But transit from kernel domain
807                          * if executing initializers because they might start
808                          * before /sbin/init.
809                          */
810                         domain = old_domain;
811                         break;
812                 }
813 force_child_domain:
814                 /* Normal domain transition. */
815                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
816                          old_domain->domainname->name, candidate->name);
817                 break;
818         }
819 force_jump_domain:
820         if (!domain)
821                 domain = tomoyo_assign_domain(ee->tmp, true);
822         if (domain)
823                 retval = 0;
824         else if (reject_on_transition_failure) {
825                 printk(KERN_WARNING "ERROR: Domain '%s' not ready.\n",
826                        ee->tmp);
827                 retval = -ENOMEM;
828         } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
829                 retval = -ENOMEM;
830         else {
831                 retval = 0;
832                 if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
833                         old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
834                         ee->r.granted = false;
835                         tomoyo_write_log(&ee->r, "%s", tomoyo_dif
836                                          [TOMOYO_DIF_TRANSITION_FAILED]);
837                         printk(KERN_WARNING
838                                "ERROR: Domain '%s' not defined.\n", ee->tmp);
839                 }
840         }
841  out:
842         if (!domain)
843                 domain = old_domain;
844         /* Update reference count on "struct tomoyo_domain_info". */
845         atomic_inc(&domain->users);
846         bprm->cred->security = domain;
847         kfree(exename.name);
848         if (!retval) {
849                 ee->r.domain = domain;
850                 retval = tomoyo_environ(ee);
851         }
852         kfree(ee->tmp);
853         kfree(ee->dump.data);
854         kfree(ee);
855         return retval;
856 }
857 
858 /**
859  * tomoyo_dump_page - Dump a page to buffer.
860  *
861  * @bprm: Pointer to "struct linux_binprm".
862  * @pos:  Location to dump.
863  * @dump: Poiner to "struct tomoyo_page_dump".
864  *
865  * Returns true on success, false otherwise.
866  */
867 bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
868                       struct tomoyo_page_dump *dump)
869 {
870         struct page *page;
871 
872         /* dump->data is released by tomoyo_find_next_domain(). */
873         if (!dump->data) {
874                 dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
875                 if (!dump->data)
876                         return false;
877         }
878         /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
879 #ifdef CONFIG_MMU
880         /*
881          * This is called at execve() time in order to dig around
882          * in the argv/environment of the new proceess
883          * (represented by bprm).  'current' is the process doing
884          * the execve().
885          */
886         if (get_user_pages_remote(current, bprm->mm, pos, 1,
887                                 FOLL_FORCE, &page, NULL, NULL) <= 0)
888                 return false;
889 #else
890         page = bprm->page[pos / PAGE_SIZE];
891 #endif
892         if (page != dump->page) {
893                 const unsigned int offset = pos % PAGE_SIZE;
894                 /*
895                  * Maybe kmap()/kunmap() should be used here.
896                  * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
897                  * So do I.
898                  */
899                 char *kaddr = kmap_atomic(page);
900 
901                 dump->page = page;
902                 memcpy(dump->data + offset, kaddr + offset,
903                        PAGE_SIZE - offset);
904                 kunmap_atomic(kaddr);
905         }
906         /* Same with put_arg_page(page) in fs/exec.c */
907 #ifdef CONFIG_MMU
908         put_page(page);
909 #endif
910         return true;
911 }
912 

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