5931fb1c04d5cd598c491c85bb097c195a7f60c8
[linux-3.10.git] / security / tomoyo / domain.c
1 /*
2  * security/tomoyo/domain.c
3  *
4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
5  */
6
7 #include "common.h"
8 #include <linux/binfmts.h>
9 #include <linux/slab.h>
10
11 /* Variables definitions.*/
12
13 /* The initial domain. */
14 struct tomoyo_domain_info tomoyo_kernel_domain;
15
16 /**
17  * tomoyo_update_policy - Update an entry for exception policy.
18  *
19  * @new_entry:       Pointer to "struct tomoyo_acl_info".
20  * @size:            Size of @new_entry in bytes.
21  * @param:           Pointer to "struct tomoyo_acl_param".
22  * @check_duplicate: Callback function to find duplicated entry.
23  *
24  * Returns 0 on success, negative value otherwise.
25  *
26  * Caller holds tomoyo_read_lock().
27  */
28 int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
29                          struct tomoyo_acl_param *param,
30                          bool (*check_duplicate) (const struct tomoyo_acl_head
31                                                   *,
32                                                   const struct tomoyo_acl_head
33                                                   *))
34 {
35         int error = param->is_delete ? -ENOENT : -ENOMEM;
36         struct tomoyo_acl_head *entry;
37         struct list_head *list = param->list;
38
39         if (mutex_lock_interruptible(&tomoyo_policy_lock))
40                 return -ENOMEM;
41         list_for_each_entry_rcu(entry, list, list) {
42                 if (!check_duplicate(entry, new_entry))
43                         continue;
44                 entry->is_deleted = param->is_delete;
45                 error = 0;
46                 break;
47         }
48         if (error && !param->is_delete) {
49                 entry = tomoyo_commit_ok(new_entry, size);
50                 if (entry) {
51                         list_add_tail_rcu(&entry->list, list);
52                         error = 0;
53                 }
54         }
55         mutex_unlock(&tomoyo_policy_lock);
56         return error;
57 }
58
59 /**
60  * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry.
61  *
62  * @a: Pointer to "struct tomoyo_acl_info".
63  * @b: Pointer to "struct tomoyo_acl_info".
64  *
65  * Returns true if @a == @b, false otherwise.
66  */
67 static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
68                                         const struct tomoyo_acl_info *b)
69 {
70         return a->type == b->type && a->cond == b->cond;
71 }
72
73 /**
74  * tomoyo_update_domain - Update an entry for domain policy.
75  *
76  * @new_entry:       Pointer to "struct tomoyo_acl_info".
77  * @size:            Size of @new_entry in bytes.
78  * @param:           Pointer to "struct tomoyo_acl_param".
79  * @check_duplicate: Callback function to find duplicated entry.
80  * @merge_duplicate: Callback function to merge duplicated entry.
81  *
82  * Returns 0 on success, negative value otherwise.
83  *
84  * Caller holds tomoyo_read_lock().
85  */
86 int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
87                          struct tomoyo_acl_param *param,
88                          bool (*check_duplicate) (const struct tomoyo_acl_info
89                                                   *,
90                                                   const struct tomoyo_acl_info
91                                                   *),
92                          bool (*merge_duplicate) (struct tomoyo_acl_info *,
93                                                   struct tomoyo_acl_info *,
94                                                   const bool))
95 {
96         const bool is_delete = param->is_delete;
97         int error = is_delete ? -ENOENT : -ENOMEM;
98         struct tomoyo_acl_info *entry;
99         struct list_head * const list = param->list;
100
101         if (param->data[0]) {
102                 new_entry->cond = tomoyo_get_condition(param);
103                 if (!new_entry->cond)
104                         return -EINVAL;
105         }
106         if (mutex_lock_interruptible(&tomoyo_policy_lock))
107                 goto out;
108         list_for_each_entry_rcu(entry, list, list) {
109                 if (!tomoyo_same_acl_head(entry, new_entry) ||
110                     !check_duplicate(entry, new_entry))
111                         continue;
112                 if (merge_duplicate)
113                         entry->is_deleted = merge_duplicate(entry, new_entry,
114                                                             is_delete);
115                 else
116                         entry->is_deleted = is_delete;
117                 error = 0;
118                 break;
119         }
120         if (error && !is_delete) {
121                 entry = tomoyo_commit_ok(new_entry, size);
122                 if (entry) {
123                         list_add_tail_rcu(&entry->list, list);
124                         error = 0;
125                 }
126         }
127         mutex_unlock(&tomoyo_policy_lock);
128 out:
129         tomoyo_put_condition(new_entry->cond);
130         return error;
131 }
132
133 /**
134  * tomoyo_check_acl - Do permission check.
135  *
136  * @r:           Pointer to "struct tomoyo_request_info".
137  * @check_entry: Callback function to check type specific parameters.
138  *
139  * Returns 0 on success, negative value otherwise.
140  *
141  * Caller holds tomoyo_read_lock().
142  */
143 void tomoyo_check_acl(struct tomoyo_request_info *r,
144                       bool (*check_entry) (struct tomoyo_request_info *,
145                                            const struct tomoyo_acl_info *))
146 {
147         const struct tomoyo_domain_info *domain = r->domain;
148         struct tomoyo_acl_info *ptr;
149         bool retried = false;
150         const struct list_head *list = &domain->acl_info_list;
151
152 retry:
153         list_for_each_entry_rcu(ptr, list, list) {
154                 if (ptr->is_deleted || ptr->type != r->param_type)
155                         continue;
156                 if (!check_entry(r, ptr))
157                         continue;
158                 if (!tomoyo_condition(r, ptr->cond))
159                         continue;
160                 r->granted = true;
161                 return;
162         }
163         if (!retried) {
164                 retried = true;
165                 list = &domain->ns->acl_group[domain->group];
166                 goto retry;
167         }
168         r->granted = false;
169 }
170
171 /* The list for "struct tomoyo_domain_info". */
172 LIST_HEAD(tomoyo_domain_list);
173
174 /**
175  * tomoyo_last_word - Get last component of a domainname.
176  *
177  * @name: Domainname to check.
178  *
179  * Returns the last word of @domainname.
180  */
181 static const char *tomoyo_last_word(const char *name)
182 {
183         const char *cp = strrchr(name, ' ');
184         if (cp)
185                 return cp + 1;
186         return name;
187 }
188
189 /**
190  * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
191  *
192  * @a: Pointer to "struct tomoyo_acl_head".
193  * @b: Pointer to "struct tomoyo_acl_head".
194  *
195  * Returns true if @a == @b, false otherwise.
196  */
197 static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
198                                            const struct tomoyo_acl_head *b)
199 {
200         const struct tomoyo_transition_control *p1 = container_of(a,
201                                                                   typeof(*p1),
202                                                                   head);
203         const struct tomoyo_transition_control *p2 = container_of(b,
204                                                                   typeof(*p2),
205                                                                   head);
206         return p1->type == p2->type && p1->is_last_name == p2->is_last_name
207                 && p1->domainname == p2->domainname
208                 && p1->program == p2->program;
209 }
210
211 /**
212  * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
213  *
214  * @param: Pointer to "struct tomoyo_acl_param".
215  * @type:  Type of this entry.
216  *
217  * Returns 0 on success, negative value otherwise.
218  */
219 int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
220                                     const u8 type)
221 {
222         struct tomoyo_transition_control e = { .type = type };
223         int error = param->is_delete ? -ENOENT : -ENOMEM;
224         char *program = param->data;
225         char *domainname = strstr(program, " from ");
226         if (domainname) {
227                 *domainname = '\0';
228                 domainname += 6;
229         } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
230                    type == TOMOYO_TRANSITION_CONTROL_KEEP) {
231                 domainname = program;
232                 program = NULL;
233         }
234         if (program && strcmp(program, "any")) {
235                 if (!tomoyo_correct_path(program))
236                         return -EINVAL;
237                 e.program = tomoyo_get_name(program);
238                 if (!e.program)
239                         goto out;
240         }
241         if (domainname && strcmp(domainname, "any")) {
242                 if (!tomoyo_correct_domain(domainname)) {
243                         if (!tomoyo_correct_path(domainname))
244                                 goto out;
245                         e.is_last_name = true;
246                 }
247                 e.domainname = tomoyo_get_name(domainname);
248                 if (!e.domainname)
249                         goto out;
250         }
251         param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
252         error = tomoyo_update_policy(&e.head, sizeof(e), param,
253                                      tomoyo_same_transition_control);
254 out:
255         tomoyo_put_name(e.domainname);
256         tomoyo_put_name(e.program);
257         return error;
258 }
259
260 /**
261  * tomoyo_scan_transition - Try to find specific domain transition type.
262  *
263  * @list:       Pointer to "struct list_head".
264  * @domainname: The name of current domain.
265  * @program:    The name of requested program.
266  * @last_name:  The last component of @domainname.
267  * @type:       One of values in "enum tomoyo_transition_type".
268  *
269  * Returns true if found one, false otherwise.
270  *
271  * Caller holds tomoyo_read_lock().
272  */
273 static inline bool tomoyo_scan_transition
274 (const struct list_head *list, const struct tomoyo_path_info *domainname,
275  const struct tomoyo_path_info *program, const char *last_name,
276  const enum tomoyo_transition_type type)
277 {
278         const struct tomoyo_transition_control *ptr;
279         list_for_each_entry_rcu(ptr, list, head.list) {
280                 if (ptr->head.is_deleted || ptr->type != type)
281                         continue;
282                 if (ptr->domainname) {
283                         if (!ptr->is_last_name) {
284                                 if (ptr->domainname != domainname)
285                                         continue;
286                         } else {
287                                 /*
288                                  * Use direct strcmp() since this is
289                                  * unlikely used.
290                                  */
291                                 if (strcmp(ptr->domainname->name, last_name))
292                                         continue;
293                         }
294                 }
295                 if (ptr->program && tomoyo_pathcmp(ptr->program, program))
296                         continue;
297                 return true;
298         }
299         return false;
300 }
301
302 /**
303  * tomoyo_transition_type - Get domain transition type.
304  *
305  * @ns:         Pointer to "struct tomoyo_policy_namespace".
306  * @domainname: The name of current domain.
307  * @program:    The name of requested program.
308  *
309  * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
310  * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
311  * executing @program reinitializes domain transition within that namespace,
312  * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
313  * others otherwise.
314  *
315  * Caller holds tomoyo_read_lock().
316  */
317 static enum tomoyo_transition_type tomoyo_transition_type
318 (const struct tomoyo_policy_namespace *ns,
319  const struct tomoyo_path_info *domainname,
320  const struct tomoyo_path_info *program)
321 {
322         const char *last_name = tomoyo_last_word(domainname->name);
323         enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
324         while (type < TOMOYO_MAX_TRANSITION_TYPE) {
325                 const struct list_head * const list =
326                         &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
327                 if (!tomoyo_scan_transition(list, domainname, program,
328                                             last_name, type)) {
329                         type++;
330                         continue;
331                 }
332                 if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
333                     type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
334                         break;
335                 /*
336                  * Do not check for reset_domain if no_reset_domain matched.
337                  * Do not check for initialize_domain if no_initialize_domain
338                  * matched.
339                  */
340                 type++;
341                 type++;
342         }
343         return type;
344 }
345
346 /**
347  * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
348  *
349  * @a: Pointer to "struct tomoyo_acl_head".
350  * @b: Pointer to "struct tomoyo_acl_head".
351  *
352  * Returns true if @a == @b, false otherwise.
353  */
354 static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
355                                    const struct tomoyo_acl_head *b)
356 {
357         const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
358                                                           head);
359         const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
360                                                           head);
361         return p1->original_name == p2->original_name &&
362                 p1->aggregated_name == p2->aggregated_name;
363 }
364
365 /**
366  * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
367  *
368  * @param: Pointer to "struct tomoyo_acl_param".
369  *
370  * Returns 0 on success, negative value otherwise.
371  *
372  * Caller holds tomoyo_read_lock().
373  */
374 int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
375 {
376         struct tomoyo_aggregator e = { };
377         int error = param->is_delete ? -ENOENT : -ENOMEM;
378         const char *original_name = tomoyo_read_token(param);
379         const char *aggregated_name = tomoyo_read_token(param);
380         if (!tomoyo_correct_word(original_name) ||
381             !tomoyo_correct_path(aggregated_name))
382                 return -EINVAL;
383         e.original_name = tomoyo_get_name(original_name);
384         e.aggregated_name = tomoyo_get_name(aggregated_name);
385         if (!e.original_name || !e.aggregated_name ||
386             e.aggregated_name->is_patterned) /* No patterns allowed. */
387                 goto out;
388         param->list = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
389         error = tomoyo_update_policy(&e.head, sizeof(e), param,
390                                      tomoyo_same_aggregator);
391 out:
392         tomoyo_put_name(e.original_name);
393         tomoyo_put_name(e.aggregated_name);
394         return error;
395 }
396
397 /**
398  * tomoyo_find_namespace - Find specified namespace.
399  *
400  * @name: Name of namespace to find.
401  * @len:  Length of @name.
402  *
403  * Returns pointer to "struct tomoyo_policy_namespace" if found,
404  * NULL otherwise.
405  *
406  * Caller holds tomoyo_read_lock().
407  */
408 static struct tomoyo_policy_namespace *tomoyo_find_namespace
409 (const char *name, const unsigned int len)
410 {
411         struct tomoyo_policy_namespace *ns;
412         list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
413                 if (strncmp(name, ns->name, len) ||
414                     (name[len] && name[len] != ' '))
415                         continue;
416                 return ns;
417         }
418         return NULL;
419 }
420
421 /**
422  * tomoyo_assign_namespace - Create a new namespace.
423  *
424  * @domainname: Name of namespace to create.
425  *
426  * Returns pointer to "struct tomoyo_policy_namespace" on success,
427  * NULL otherwise.
428  *
429  * Caller holds tomoyo_read_lock().
430  */
431 struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
432 {
433         struct tomoyo_policy_namespace *ptr;
434         struct tomoyo_policy_namespace *entry;
435         const char *cp = domainname;
436         unsigned int len = 0;
437         while (*cp && *cp++ != ' ')
438                 len++;
439         ptr = tomoyo_find_namespace(domainname, len);
440         if (ptr)
441                 return ptr;
442         if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
443                 return NULL;
444         entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS);
445         if (!entry)
446                 return NULL;
447         if (mutex_lock_interruptible(&tomoyo_policy_lock))
448                 goto out;
449         ptr = tomoyo_find_namespace(domainname, len);
450         if (!ptr && tomoyo_memory_ok(entry)) {
451                 char *name = (char *) (entry + 1);
452                 ptr = entry;
453                 memmove(name, domainname, len);
454                 name[len] = '\0';
455                 entry->name = name;
456                 tomoyo_init_policy_namespace(entry);
457                 entry = NULL;
458         }
459         mutex_unlock(&tomoyo_policy_lock);
460 out:
461         kfree(entry);
462         return ptr;
463 }
464
465 /**
466  * tomoyo_namespace_jump - Check for namespace jump.
467  *
468  * @domainname: Name of domain.
469  *
470  * Returns true if namespace differs, false otherwise.
471  */
472 static bool tomoyo_namespace_jump(const char *domainname)
473 {
474         const char *namespace = tomoyo_current_namespace()->name;
475         const int len = strlen(namespace);
476         return strncmp(domainname, namespace, len) ||
477                 (domainname[len] && domainname[len] != ' ');
478 }
479
480 /**
481  * tomoyo_assign_domain - Create a domain or a namespace.
482  *
483  * @domainname: The name of domain.
484  * @transit:    True if transit to domain found or created.
485  *
486  * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
487  *
488  * Caller holds tomoyo_read_lock().
489  */
490 struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
491                                                 const bool transit)
492 {
493         struct tomoyo_domain_info e = { };
494         struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
495         bool created = false;
496         if (entry) {
497                 if (transit) {
498                         /*
499                          * Since namespace is created at runtime, profiles may
500                          * not be created by the moment the process transits to
501                          * that domain. Do not perform domain transition if
502                          * profile for that domain is not yet created.
503                          */
504                         if (!entry->ns->profile_ptr[entry->profile])
505                                 return NULL;
506                 }
507                 return entry;
508         }
509         /* Requested domain does not exist. */
510         /* Don't create requested domain if domainname is invalid. */
511         if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
512             !tomoyo_correct_domain(domainname))
513                 return NULL;
514         /*
515          * Since definition of profiles and acl_groups may differ across
516          * namespaces, do not inherit "use_profile" and "use_group" settings
517          * by automatically creating requested domain upon domain transition.
518          */
519         if (transit && tomoyo_namespace_jump(domainname))
520                 return NULL;
521         e.ns = tomoyo_assign_namespace(domainname);
522         if (!e.ns)
523                 return NULL;
524         /*
525          * "use_profile" and "use_group" settings for automatically created
526          * domains are inherited from current domain. These are 0 for manually
527          * created domains.
528          */
529         if (transit) {
530                 const struct tomoyo_domain_info *domain = tomoyo_domain();
531                 e.profile = domain->profile;
532                 e.group = domain->group;
533         }
534         e.domainname = tomoyo_get_name(domainname);
535         if (!e.domainname)
536                 return NULL;
537         if (mutex_lock_interruptible(&tomoyo_policy_lock))
538                 goto out;
539         entry = tomoyo_find_domain(domainname);
540         if (!entry) {
541                 entry = tomoyo_commit_ok(&e, sizeof(e));
542                 if (entry) {
543                         INIT_LIST_HEAD(&entry->acl_info_list);
544                         list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
545                         created = true;
546                 }
547         }
548         mutex_unlock(&tomoyo_policy_lock);
549 out:
550         tomoyo_put_name(e.domainname);
551         if (entry && transit) {
552                 if (created) {
553                         struct tomoyo_request_info r;
554                         tomoyo_init_request_info(&r, entry,
555                                                  TOMOYO_MAC_FILE_EXECUTE);
556                         r.granted = false;
557                         tomoyo_write_log(&r, "use_profile %u\n",
558                                          entry->profile);
559                         tomoyo_write_log(&r, "use_group %u\n", entry->group);
560                 }
561         }
562         return entry;
563 }
564
565 /**
566  * tomoyo_environ - Check permission for environment variable names.
567  *
568  * @ee: Pointer to "struct tomoyo_execve".
569  *
570  * Returns 0 on success, negative value otherwise.
571  */
572 static int tomoyo_environ(struct tomoyo_execve *ee)
573 {
574         struct tomoyo_request_info *r = &ee->r;
575         struct linux_binprm *bprm = ee->bprm;
576         /* env_page.data is allocated by tomoyo_dump_page(). */
577         struct tomoyo_page_dump env_page = { };
578         char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
579         int arg_len = 0;
580         unsigned long pos = bprm->p;
581         int offset = pos % PAGE_SIZE;
582         int argv_count = bprm->argc;
583         int envp_count = bprm->envc;
584         int error = -ENOMEM;
585
586         ee->r.type = TOMOYO_MAC_ENVIRON;
587         ee->r.profile = r->domain->profile;
588         ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
589                                      TOMOYO_MAC_ENVIRON);
590         if (!r->mode || !envp_count)
591                 return 0;
592         arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
593         if (!arg_ptr)
594                 goto out;
595         while (error == -ENOMEM) {
596                 if (!tomoyo_dump_page(bprm, pos, &env_page))
597                         goto out;
598                 pos += PAGE_SIZE - offset;
599                 /* Read. */
600                 while (argv_count && offset < PAGE_SIZE) {
601                         if (!env_page.data[offset++])
602                                 argv_count--;
603                 }
604                 if (argv_count) {
605                         offset = 0;
606                         continue;
607                 }
608                 while (offset < PAGE_SIZE) {
609                         const unsigned char c = env_page.data[offset++];
610
611                         if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
612                                 if (c == '=') {
613                                         arg_ptr[arg_len++] = '\0';
614                                 } else if (c == '\\') {
615                                         arg_ptr[arg_len++] = '\\';
616                                         arg_ptr[arg_len++] = '\\';
617                                 } else if (c > ' ' && c < 127) {
618                                         arg_ptr[arg_len++] = c;
619                                 } else {
620                                         arg_ptr[arg_len++] = '\\';
621                                         arg_ptr[arg_len++] = (c >> 6) + '0';
622                                         arg_ptr[arg_len++]
623                                                 = ((c >> 3) & 7) + '0';
624                                         arg_ptr[arg_len++] = (c & 7) + '0';
625                                 }
626                         } else {
627                                 arg_ptr[arg_len] = '\0';
628                         }
629                         if (c)
630                                 continue;
631                         if (tomoyo_env_perm(r, arg_ptr)) {
632                                 error = -EPERM;
633                                 break;
634                         }
635                         if (!--envp_count) {
636                                 error = 0;
637                                 break;
638                         }
639                         arg_len = 0;
640                 }
641                 offset = 0;
642         }
643 out:
644         if (r->mode != TOMOYO_CONFIG_ENFORCING)
645                 error = 0;
646         kfree(env_page.data);
647         kfree(arg_ptr);
648         return error;
649 }
650
651 /**
652  * tomoyo_find_next_domain - Find a domain.
653  *
654  * @bprm: Pointer to "struct linux_binprm".
655  *
656  * Returns 0 on success, negative value otherwise.
657  *
658  * Caller holds tomoyo_read_lock().
659  */
660 int tomoyo_find_next_domain(struct linux_binprm *bprm)
661 {
662         struct tomoyo_domain_info *old_domain = tomoyo_domain();
663         struct tomoyo_domain_info *domain = NULL;
664         const char *original_name = bprm->filename;
665         int retval = -ENOMEM;
666         bool need_kfree = false;
667         bool reject_on_transition_failure = false;
668         struct tomoyo_path_info rn = { }; /* real name */
669         struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
670
671         if (!ee)
672                 return -ENOMEM;
673         ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
674         if (!ee->tmp) {
675                 kfree(ee);
676                 return -ENOMEM;
677         }
678         /* ee->dump->data is allocated by tomoyo_dump_page(). */
679         tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
680         ee->r.ee = ee;
681         ee->bprm = bprm;
682         ee->r.obj = &ee->obj;
683         ee->obj.path1 = bprm->file->f_path;
684  retry:
685         if (need_kfree) {
686                 kfree(rn.name);
687                 need_kfree = false;
688         }
689         /* Get symlink's pathname of program. */
690         retval = -ENOENT;
691         rn.name = tomoyo_realpath_nofollow(original_name);
692         if (!rn.name)
693                 goto out;
694         tomoyo_fill_path_info(&rn);
695         need_kfree = true;
696
697         /* Check 'aggregator' directive. */
698         {
699                 struct tomoyo_aggregator *ptr;
700                 struct list_head *list =
701                         &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
702                 /* Check 'aggregator' directive. */
703                 list_for_each_entry_rcu(ptr, list, head.list) {
704                         if (ptr->head.is_deleted ||
705                             !tomoyo_path_matches_pattern(&rn,
706                                                          ptr->original_name))
707                                 continue;
708                         kfree(rn.name);
709                         need_kfree = false;
710                         /* This is OK because it is read only. */
711                         rn = *ptr->aggregated_name;
712                         break;
713                 }
714         }
715
716         /* Check execute permission. */
717         retval = tomoyo_path_permission(&ee->r, TOMOYO_TYPE_EXECUTE, &rn);
718         if (retval == TOMOYO_RETRY_REQUEST)
719                 goto retry;
720         if (retval < 0)
721                 goto out;
722         /*
723          * To be able to specify domainnames with wildcards, use the
724          * pathname specified in the policy (which may contain
725          * wildcard) rather than the pathname passed to execve()
726          * (which never contains wildcard).
727          */
728         if (ee->r.param.path.matched_path) {
729                 if (need_kfree)
730                         kfree(rn.name);
731                 need_kfree = false;
732                 /* This is OK because it is read only. */
733                 rn = *ee->r.param.path.matched_path;
734         }
735
736         /* Calculate domain to transit to. */
737         switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
738                                        &rn)) {
739         case TOMOYO_TRANSITION_CONTROL_RESET:
740                 /* Transit to the root of specified namespace. */
741                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>", rn.name);
742                 /*
743                  * Make do_execve() fail if domain transition across namespaces
744                  * has failed.
745                  */
746                 reject_on_transition_failure = true;
747                 break;
748         case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
749                 /* Transit to the child of current namespace's root. */
750                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
751                          old_domain->ns->name, rn.name);
752                 break;
753         case TOMOYO_TRANSITION_CONTROL_KEEP:
754                 /* Keep current domain. */
755                 domain = old_domain;
756                 break;
757         default:
758                 if (old_domain == &tomoyo_kernel_domain &&
759                     !tomoyo_policy_loaded) {
760                         /*
761                          * Needn't to transit from kernel domain before
762                          * starting /sbin/init. But transit from kernel domain
763                          * if executing initializers because they might start
764                          * before /sbin/init.
765                          */
766                         domain = old_domain;
767                 } else {
768                         /* Normal domain transition. */
769                         snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
770                                  old_domain->domainname->name, rn.name);
771                 }
772                 break;
773         }
774         if (!domain)
775                 domain = tomoyo_assign_domain(ee->tmp, true);
776         if (domain)
777                 retval = 0;
778         else if (reject_on_transition_failure) {
779                 printk(KERN_WARNING "ERROR: Domain '%s' not ready.\n",
780                        ee->tmp);
781                 retval = -ENOMEM;
782         } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
783                 retval = -ENOMEM;
784         else {
785                 retval = 0;
786                 if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
787                         old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
788                         ee->r.granted = false;
789                         tomoyo_write_log(&ee->r, "%s", tomoyo_dif
790                                          [TOMOYO_DIF_TRANSITION_FAILED]);
791                         printk(KERN_WARNING
792                                "ERROR: Domain '%s' not defined.\n", ee->tmp);
793                 }
794         }
795  out:
796         if (!domain)
797                 domain = old_domain;
798         /* Update reference count on "struct tomoyo_domain_info". */
799         atomic_inc(&domain->users);
800         bprm->cred->security = domain;
801         if (need_kfree)
802                 kfree(rn.name);
803         if (!retval) {
804                 ee->r.domain = domain;
805                 retval = tomoyo_environ(ee);
806         }
807         kfree(ee->tmp);
808         kfree(ee->dump.data);
809         kfree(ee);
810         return retval;
811 }
812
813 /**
814  * tomoyo_dump_page - Dump a page to buffer.
815  *
816  * @bprm: Pointer to "struct linux_binprm".
817  * @pos:  Location to dump.
818  * @dump: Poiner to "struct tomoyo_page_dump".
819  *
820  * Returns true on success, false otherwise.
821  */
822 bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
823                       struct tomoyo_page_dump *dump)
824 {
825         struct page *page;
826
827         /* dump->data is released by tomoyo_find_next_domain(). */
828         if (!dump->data) {
829                 dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
830                 if (!dump->data)
831                         return false;
832         }
833         /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
834 #ifdef CONFIG_MMU
835         if (get_user_pages(current, bprm->mm, pos, 1, 0, 1, &page, NULL) <= 0)
836                 return false;
837 #else
838         page = bprm->page[pos / PAGE_SIZE];
839 #endif
840         if (page != dump->page) {
841                 const unsigned int offset = pos % PAGE_SIZE;
842                 /*
843                  * Maybe kmap()/kunmap() should be used here.
844                  * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
845                  * So do I.
846                  */
847                 char *kaddr = kmap_atomic(page, KM_USER0);
848
849                 dump->page = page;
850                 memcpy(dump->data + offset, kaddr + offset,
851                        PAGE_SIZE - offset);
852                 kunmap_atomic(kaddr, KM_USER0);
853         }
854         /* Same with put_arg_page(page) in fs/exec.c */
855 #ifdef CONFIG_MMU
856         put_page(page);
857 #endif
858         return true;
859 }