498fea732f4843f537fa3c66b5b1a96006a4d8e5
[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->matched_acl = ptr;
161                 r->granted = true;
162                 return;
163         }
164         if (!retried) {
165                 retried = true;
166                 list = &domain->ns->acl_group[domain->group];
167                 goto retry;
168         }
169         r->granted = false;
170 }
171
172 /* The list for "struct tomoyo_domain_info". */
173 LIST_HEAD(tomoyo_domain_list);
174
175 /**
176  * tomoyo_last_word - Get last component of a domainname.
177  *
178  * @name: Domainname to check.
179  *
180  * Returns the last word of @domainname.
181  */
182 static const char *tomoyo_last_word(const char *name)
183 {
184         const char *cp = strrchr(name, ' ');
185         if (cp)
186                 return cp + 1;
187         return name;
188 }
189
190 /**
191  * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
192  *
193  * @a: Pointer to "struct tomoyo_acl_head".
194  * @b: Pointer to "struct tomoyo_acl_head".
195  *
196  * Returns true if @a == @b, false otherwise.
197  */
198 static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
199                                            const struct tomoyo_acl_head *b)
200 {
201         const struct tomoyo_transition_control *p1 = container_of(a,
202                                                                   typeof(*p1),
203                                                                   head);
204         const struct tomoyo_transition_control *p2 = container_of(b,
205                                                                   typeof(*p2),
206                                                                   head);
207         return p1->type == p2->type && p1->is_last_name == p2->is_last_name
208                 && p1->domainname == p2->domainname
209                 && p1->program == p2->program;
210 }
211
212 /**
213  * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
214  *
215  * @param: Pointer to "struct tomoyo_acl_param".
216  * @type:  Type of this entry.
217  *
218  * Returns 0 on success, negative value otherwise.
219  */
220 int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
221                                     const u8 type)
222 {
223         struct tomoyo_transition_control e = { .type = type };
224         int error = param->is_delete ? -ENOENT : -ENOMEM;
225         char *program = param->data;
226         char *domainname = strstr(program, " from ");
227         if (domainname) {
228                 *domainname = '\0';
229                 domainname += 6;
230         } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
231                    type == TOMOYO_TRANSITION_CONTROL_KEEP) {
232                 domainname = program;
233                 program = NULL;
234         }
235         if (program && strcmp(program, "any")) {
236                 if (!tomoyo_correct_path(program))
237                         return -EINVAL;
238                 e.program = tomoyo_get_name(program);
239                 if (!e.program)
240                         goto out;
241         }
242         if (domainname && strcmp(domainname, "any")) {
243                 if (!tomoyo_correct_domain(domainname)) {
244                         if (!tomoyo_correct_path(domainname))
245                                 goto out;
246                         e.is_last_name = true;
247                 }
248                 e.domainname = tomoyo_get_name(domainname);
249                 if (!e.domainname)
250                         goto out;
251         }
252         param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
253         error = tomoyo_update_policy(&e.head, sizeof(e), param,
254                                      tomoyo_same_transition_control);
255 out:
256         tomoyo_put_name(e.domainname);
257         tomoyo_put_name(e.program);
258         return error;
259 }
260
261 /**
262  * tomoyo_scan_transition - Try to find specific domain transition type.
263  *
264  * @list:       Pointer to "struct list_head".
265  * @domainname: The name of current domain.
266  * @program:    The name of requested program.
267  * @last_name:  The last component of @domainname.
268  * @type:       One of values in "enum tomoyo_transition_type".
269  *
270  * Returns true if found one, false otherwise.
271  *
272  * Caller holds tomoyo_read_lock().
273  */
274 static inline bool tomoyo_scan_transition
275 (const struct list_head *list, const struct tomoyo_path_info *domainname,
276  const struct tomoyo_path_info *program, const char *last_name,
277  const enum tomoyo_transition_type type)
278 {
279         const struct tomoyo_transition_control *ptr;
280         list_for_each_entry_rcu(ptr, list, head.list) {
281                 if (ptr->head.is_deleted || ptr->type != type)
282                         continue;
283                 if (ptr->domainname) {
284                         if (!ptr->is_last_name) {
285                                 if (ptr->domainname != domainname)
286                                         continue;
287                         } else {
288                                 /*
289                                  * Use direct strcmp() since this is
290                                  * unlikely used.
291                                  */
292                                 if (strcmp(ptr->domainname->name, last_name))
293                                         continue;
294                         }
295                 }
296                 if (ptr->program && tomoyo_pathcmp(ptr->program, program))
297                         continue;
298                 return true;
299         }
300         return false;
301 }
302
303 /**
304  * tomoyo_transition_type - Get domain transition type.
305  *
306  * @ns:         Pointer to "struct tomoyo_policy_namespace".
307  * @domainname: The name of current domain.
308  * @program:    The name of requested program.
309  *
310  * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
311  * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
312  * executing @program reinitializes domain transition within that namespace,
313  * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
314  * others otherwise.
315  *
316  * Caller holds tomoyo_read_lock().
317  */
318 static enum tomoyo_transition_type tomoyo_transition_type
319 (const struct tomoyo_policy_namespace *ns,
320  const struct tomoyo_path_info *domainname,
321  const struct tomoyo_path_info *program)
322 {
323         const char *last_name = tomoyo_last_word(domainname->name);
324         enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
325         while (type < TOMOYO_MAX_TRANSITION_TYPE) {
326                 const struct list_head * const list =
327                         &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
328                 if (!tomoyo_scan_transition(list, domainname, program,
329                                             last_name, type)) {
330                         type++;
331                         continue;
332                 }
333                 if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
334                     type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
335                         break;
336                 /*
337                  * Do not check for reset_domain if no_reset_domain matched.
338                  * Do not check for initialize_domain if no_initialize_domain
339                  * matched.
340                  */
341                 type++;
342                 type++;
343         }
344         return type;
345 }
346
347 /**
348  * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
349  *
350  * @a: Pointer to "struct tomoyo_acl_head".
351  * @b: Pointer to "struct tomoyo_acl_head".
352  *
353  * Returns true if @a == @b, false otherwise.
354  */
355 static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
356                                    const struct tomoyo_acl_head *b)
357 {
358         const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
359                                                           head);
360         const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
361                                                           head);
362         return p1->original_name == p2->original_name &&
363                 p1->aggregated_name == p2->aggregated_name;
364 }
365
366 /**
367  * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
368  *
369  * @param: Pointer to "struct tomoyo_acl_param".
370  *
371  * Returns 0 on success, negative value otherwise.
372  *
373  * Caller holds tomoyo_read_lock().
374  */
375 int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
376 {
377         struct tomoyo_aggregator e = { };
378         int error = param->is_delete ? -ENOENT : -ENOMEM;
379         const char *original_name = tomoyo_read_token(param);
380         const char *aggregated_name = tomoyo_read_token(param);
381         if (!tomoyo_correct_word(original_name) ||
382             !tomoyo_correct_path(aggregated_name))
383                 return -EINVAL;
384         e.original_name = tomoyo_get_name(original_name);
385         e.aggregated_name = tomoyo_get_name(aggregated_name);
386         if (!e.original_name || !e.aggregated_name ||
387             e.aggregated_name->is_patterned) /* No patterns allowed. */
388                 goto out;
389         param->list = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
390         error = tomoyo_update_policy(&e.head, sizeof(e), param,
391                                      tomoyo_same_aggregator);
392 out:
393         tomoyo_put_name(e.original_name);
394         tomoyo_put_name(e.aggregated_name);
395         return error;
396 }
397
398 /**
399  * tomoyo_find_namespace - Find specified namespace.
400  *
401  * @name: Name of namespace to find.
402  * @len:  Length of @name.
403  *
404  * Returns pointer to "struct tomoyo_policy_namespace" if found,
405  * NULL otherwise.
406  *
407  * Caller holds tomoyo_read_lock().
408  */
409 static struct tomoyo_policy_namespace *tomoyo_find_namespace
410 (const char *name, const unsigned int len)
411 {
412         struct tomoyo_policy_namespace *ns;
413         list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
414                 if (strncmp(name, ns->name, len) ||
415                     (name[len] && name[len] != ' '))
416                         continue;
417                 return ns;
418         }
419         return NULL;
420 }
421
422 /**
423  * tomoyo_assign_namespace - Create a new namespace.
424  *
425  * @domainname: Name of namespace to create.
426  *
427  * Returns pointer to "struct tomoyo_policy_namespace" on success,
428  * NULL otherwise.
429  *
430  * Caller holds tomoyo_read_lock().
431  */
432 struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
433 {
434         struct tomoyo_policy_namespace *ptr;
435         struct tomoyo_policy_namespace *entry;
436         const char *cp = domainname;
437         unsigned int len = 0;
438         while (*cp && *cp++ != ' ')
439                 len++;
440         ptr = tomoyo_find_namespace(domainname, len);
441         if (ptr)
442                 return ptr;
443         if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
444                 return NULL;
445         entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS);
446         if (!entry)
447                 return NULL;
448         if (mutex_lock_interruptible(&tomoyo_policy_lock))
449                 goto out;
450         ptr = tomoyo_find_namespace(domainname, len);
451         if (!ptr && tomoyo_memory_ok(entry)) {
452                 char *name = (char *) (entry + 1);
453                 ptr = entry;
454                 memmove(name, domainname, len);
455                 name[len] = '\0';
456                 entry->name = name;
457                 tomoyo_init_policy_namespace(entry);
458                 entry = NULL;
459         }
460         mutex_unlock(&tomoyo_policy_lock);
461 out:
462         kfree(entry);
463         return ptr;
464 }
465
466 /**
467  * tomoyo_namespace_jump - Check for namespace jump.
468  *
469  * @domainname: Name of domain.
470  *
471  * Returns true if namespace differs, false otherwise.
472  */
473 static bool tomoyo_namespace_jump(const char *domainname)
474 {
475         const char *namespace = tomoyo_current_namespace()->name;
476         const int len = strlen(namespace);
477         return strncmp(domainname, namespace, len) ||
478                 (domainname[len] && domainname[len] != ' ');
479 }
480
481 /**
482  * tomoyo_assign_domain - Create a domain or a namespace.
483  *
484  * @domainname: The name of domain.
485  * @transit:    True if transit to domain found or created.
486  *
487  * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
488  *
489  * Caller holds tomoyo_read_lock().
490  */
491 struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
492                                                 const bool transit)
493 {
494         struct tomoyo_domain_info e = { };
495         struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
496         bool created = false;
497         if (entry) {
498                 if (transit) {
499                         /*
500                          * Since namespace is created at runtime, profiles may
501                          * not be created by the moment the process transits to
502                          * that domain. Do not perform domain transition if
503                          * profile for that domain is not yet created.
504                          */
505                         if (!entry->ns->profile_ptr[entry->profile])
506                                 return NULL;
507                 }
508                 return entry;
509         }
510         /* Requested domain does not exist. */
511         /* Don't create requested domain if domainname is invalid. */
512         if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
513             !tomoyo_correct_domain(domainname))
514                 return NULL;
515         /*
516          * Since definition of profiles and acl_groups may differ across
517          * namespaces, do not inherit "use_profile" and "use_group" settings
518          * by automatically creating requested domain upon domain transition.
519          */
520         if (transit && tomoyo_namespace_jump(domainname))
521                 return NULL;
522         e.ns = tomoyo_assign_namespace(domainname);
523         if (!e.ns)
524                 return NULL;
525         /*
526          * "use_profile" and "use_group" settings for automatically created
527          * domains are inherited from current domain. These are 0 for manually
528          * created domains.
529          */
530         if (transit) {
531                 const struct tomoyo_domain_info *domain = tomoyo_domain();
532                 e.profile = domain->profile;
533                 e.group = domain->group;
534         }
535         e.domainname = tomoyo_get_name(domainname);
536         if (!e.domainname)
537                 return NULL;
538         if (mutex_lock_interruptible(&tomoyo_policy_lock))
539                 goto out;
540         entry = tomoyo_find_domain(domainname);
541         if (!entry) {
542                 entry = tomoyo_commit_ok(&e, sizeof(e));
543                 if (entry) {
544                         INIT_LIST_HEAD(&entry->acl_info_list);
545                         list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
546                         created = true;
547                 }
548         }
549         mutex_unlock(&tomoyo_policy_lock);
550 out:
551         tomoyo_put_name(e.domainname);
552         if (entry && transit) {
553                 if (created) {
554                         struct tomoyo_request_info r;
555                         tomoyo_init_request_info(&r, entry,
556                                                  TOMOYO_MAC_FILE_EXECUTE);
557                         r.granted = false;
558                         tomoyo_write_log(&r, "use_profile %u\n",
559                                          entry->profile);
560                         tomoyo_write_log(&r, "use_group %u\n", entry->group);
561                 }
562         }
563         return entry;
564 }
565
566 /**
567  * tomoyo_environ - Check permission for environment variable names.
568  *
569  * @ee: Pointer to "struct tomoyo_execve".
570  *
571  * Returns 0 on success, negative value otherwise.
572  */
573 static int tomoyo_environ(struct tomoyo_execve *ee)
574 {
575         struct tomoyo_request_info *r = &ee->r;
576         struct linux_binprm *bprm = ee->bprm;
577         /* env_page.data is allocated by tomoyo_dump_page(). */
578         struct tomoyo_page_dump env_page = { };
579         char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
580         int arg_len = 0;
581         unsigned long pos = bprm->p;
582         int offset = pos % PAGE_SIZE;
583         int argv_count = bprm->argc;
584         int envp_count = bprm->envc;
585         int error = -ENOMEM;
586
587         ee->r.type = TOMOYO_MAC_ENVIRON;
588         ee->r.profile = r->domain->profile;
589         ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
590                                      TOMOYO_MAC_ENVIRON);
591         if (!r->mode || !envp_count)
592                 return 0;
593         arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
594         if (!arg_ptr)
595                 goto out;
596         while (error == -ENOMEM) {
597                 if (!tomoyo_dump_page(bprm, pos, &env_page))
598                         goto out;
599                 pos += PAGE_SIZE - offset;
600                 /* Read. */
601                 while (argv_count && offset < PAGE_SIZE) {
602                         if (!env_page.data[offset++])
603                                 argv_count--;
604                 }
605                 if (argv_count) {
606                         offset = 0;
607                         continue;
608                 }
609                 while (offset < PAGE_SIZE) {
610                         const unsigned char c = env_page.data[offset++];
611
612                         if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
613                                 if (c == '=') {
614                                         arg_ptr[arg_len++] = '\0';
615                                 } else if (c == '\\') {
616                                         arg_ptr[arg_len++] = '\\';
617                                         arg_ptr[arg_len++] = '\\';
618                                 } else if (c > ' ' && c < 127) {
619                                         arg_ptr[arg_len++] = c;
620                                 } else {
621                                         arg_ptr[arg_len++] = '\\';
622                                         arg_ptr[arg_len++] = (c >> 6) + '0';
623                                         arg_ptr[arg_len++]
624                                                 = ((c >> 3) & 7) + '0';
625                                         arg_ptr[arg_len++] = (c & 7) + '0';
626                                 }
627                         } else {
628                                 arg_ptr[arg_len] = '\0';
629                         }
630                         if (c)
631                                 continue;
632                         if (tomoyo_env_perm(r, arg_ptr)) {
633                                 error = -EPERM;
634                                 break;
635                         }
636                         if (!--envp_count) {
637                                 error = 0;
638                                 break;
639                         }
640                         arg_len = 0;
641                 }
642                 offset = 0;
643         }
644 out:
645         if (r->mode != TOMOYO_CONFIG_ENFORCING)
646                 error = 0;
647         kfree(env_page.data);
648         kfree(arg_ptr);
649         return error;
650 }
651
652 /**
653  * tomoyo_find_next_domain - Find a domain.
654  *
655  * @bprm: Pointer to "struct linux_binprm".
656  *
657  * Returns 0 on success, negative value otherwise.
658  *
659  * Caller holds tomoyo_read_lock().
660  */
661 int tomoyo_find_next_domain(struct linux_binprm *bprm)
662 {
663         struct tomoyo_domain_info *old_domain = tomoyo_domain();
664         struct tomoyo_domain_info *domain = NULL;
665         const char *original_name = bprm->filename;
666         int retval = -ENOMEM;
667         bool need_kfree = false;
668         bool reject_on_transition_failure = false;
669         struct tomoyo_path_info rn = { }; /* real name */
670         struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
671
672         if (!ee)
673                 return -ENOMEM;
674         ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
675         if (!ee->tmp) {
676                 kfree(ee);
677                 return -ENOMEM;
678         }
679         /* ee->dump->data is allocated by tomoyo_dump_page(). */
680         tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
681         ee->r.ee = ee;
682         ee->bprm = bprm;
683         ee->r.obj = &ee->obj;
684         ee->obj.path1 = bprm->file->f_path;
685  retry:
686         if (need_kfree) {
687                 kfree(rn.name);
688                 need_kfree = false;
689         }
690         /* Get symlink's pathname of program. */
691         retval = -ENOENT;
692         rn.name = tomoyo_realpath_nofollow(original_name);
693         if (!rn.name)
694                 goto out;
695         tomoyo_fill_path_info(&rn);
696         need_kfree = true;
697
698         /* Check 'aggregator' directive. */
699         {
700                 struct tomoyo_aggregator *ptr;
701                 struct list_head *list =
702                         &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
703                 /* Check 'aggregator' directive. */
704                 list_for_each_entry_rcu(ptr, list, head.list) {
705                         if (ptr->head.is_deleted ||
706                             !tomoyo_path_matches_pattern(&rn,
707                                                          ptr->original_name))
708                                 continue;
709                         kfree(rn.name);
710                         need_kfree = false;
711                         /* This is OK because it is read only. */
712                         rn = *ptr->aggregated_name;
713                         break;
714                 }
715         }
716
717         /* Check execute permission. */
718         retval = tomoyo_path_permission(&ee->r, TOMOYO_TYPE_EXECUTE, &rn);
719         if (retval == TOMOYO_RETRY_REQUEST)
720                 goto retry;
721         if (retval < 0)
722                 goto out;
723         /*
724          * To be able to specify domainnames with wildcards, use the
725          * pathname specified in the policy (which may contain
726          * wildcard) rather than the pathname passed to execve()
727          * (which never contains wildcard).
728          */
729         if (ee->r.param.path.matched_path) {
730                 if (need_kfree)
731                         kfree(rn.name);
732                 need_kfree = false;
733                 /* This is OK because it is read only. */
734                 rn = *ee->r.param.path.matched_path;
735         }
736
737         /* Calculate domain to transit to. */
738         switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
739                                        &rn)) {
740         case TOMOYO_TRANSITION_CONTROL_RESET:
741                 /* Transit to the root of specified namespace. */
742                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>", rn.name);
743                 /*
744                  * Make do_execve() fail if domain transition across namespaces
745                  * has failed.
746                  */
747                 reject_on_transition_failure = true;
748                 break;
749         case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
750                 /* Transit to the child of current namespace's root. */
751                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
752                          old_domain->ns->name, rn.name);
753                 break;
754         case TOMOYO_TRANSITION_CONTROL_KEEP:
755                 /* Keep current domain. */
756                 domain = old_domain;
757                 break;
758         default:
759                 if (old_domain == &tomoyo_kernel_domain &&
760                     !tomoyo_policy_loaded) {
761                         /*
762                          * Needn't to transit from kernel domain before
763                          * starting /sbin/init. But transit from kernel domain
764                          * if executing initializers because they might start
765                          * before /sbin/init.
766                          */
767                         domain = old_domain;
768                 } else {
769                         /* Normal domain transition. */
770                         snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
771                                  old_domain->domainname->name, rn.name);
772                 }
773                 break;
774         }
775         if (!domain)
776                 domain = tomoyo_assign_domain(ee->tmp, true);
777         if (domain)
778                 retval = 0;
779         else if (reject_on_transition_failure) {
780                 printk(KERN_WARNING "ERROR: Domain '%s' not ready.\n",
781                        ee->tmp);
782                 retval = -ENOMEM;
783         } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
784                 retval = -ENOMEM;
785         else {
786                 retval = 0;
787                 if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
788                         old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
789                         ee->r.granted = false;
790                         tomoyo_write_log(&ee->r, "%s", tomoyo_dif
791                                          [TOMOYO_DIF_TRANSITION_FAILED]);
792                         printk(KERN_WARNING
793                                "ERROR: Domain '%s' not defined.\n", ee->tmp);
794                 }
795         }
796  out:
797         if (!domain)
798                 domain = old_domain;
799         /* Update reference count on "struct tomoyo_domain_info". */
800         atomic_inc(&domain->users);
801         bprm->cred->security = domain;
802         if (need_kfree)
803                 kfree(rn.name);
804         if (!retval) {
805                 ee->r.domain = domain;
806                 retval = tomoyo_environ(ee);
807         }
808         kfree(ee->tmp);
809         kfree(ee->dump.data);
810         kfree(ee);
811         return retval;
812 }
813
814 /**
815  * tomoyo_dump_page - Dump a page to buffer.
816  *
817  * @bprm: Pointer to "struct linux_binprm".
818  * @pos:  Location to dump.
819  * @dump: Poiner to "struct tomoyo_page_dump".
820  *
821  * Returns true on success, false otherwise.
822  */
823 bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
824                       struct tomoyo_page_dump *dump)
825 {
826         struct page *page;
827
828         /* dump->data is released by tomoyo_find_next_domain(). */
829         if (!dump->data) {
830                 dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
831                 if (!dump->data)
832                         return false;
833         }
834         /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
835 #ifdef CONFIG_MMU
836         if (get_user_pages(current, bprm->mm, pos, 1, 0, 1, &page, NULL) <= 0)
837                 return false;
838 #else
839         page = bprm->page[pos / PAGE_SIZE];
840 #endif
841         if (page != dump->page) {
842                 const unsigned int offset = pos % PAGE_SIZE;
843                 /*
844                  * Maybe kmap()/kunmap() should be used here.
845                  * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
846                  * So do I.
847                  */
848                 char *kaddr = kmap_atomic(page, KM_USER0);
849
850                 dump->page = page;
851                 memcpy(dump->data + offset, kaddr + offset,
852                        PAGE_SIZE - offset);
853                 kunmap_atomic(kaddr, KM_USER0);
854         }
855         /* Same with put_arg_page(page) in fs/exec.c */
856 #ifdef CONFIG_MMU
857         put_page(page);
858 #endif
859         return true;
860 }