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v6.2
  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. */
 17struct 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 */
 31int 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				srcu_read_lock_held(&tomoyo_ss)) {
 46		if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
 47			continue;
 48		if (!check_duplicate(entry, new_entry))
 49			continue;
 50		entry->is_deleted = param->is_delete;
 51		error = 0;
 52		break;
 53	}
 54	if (error && !param->is_delete) {
 55		entry = tomoyo_commit_ok(new_entry, size);
 56		if (entry) {
 57			list_add_tail_rcu(&entry->list, list);
 58			error = 0;
 59		}
 60	}
 61	mutex_unlock(&tomoyo_policy_lock);
 62	return error;
 63}
 64
 65/**
 66 * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry.
 67 *
 68 * @a: Pointer to "struct tomoyo_acl_info".
 69 * @b: Pointer to "struct tomoyo_acl_info".
 70 *
 71 * Returns true if @a == @b, false otherwise.
 72 */
 73static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
 74					const struct tomoyo_acl_info *b)
 75{
 76	return a->type == b->type && a->cond == b->cond;
 77}
 78
 79/**
 80 * tomoyo_update_domain - Update an entry for domain policy.
 81 *
 82 * @new_entry:       Pointer to "struct tomoyo_acl_info".
 83 * @size:            Size of @new_entry in bytes.
 84 * @param:           Pointer to "struct tomoyo_acl_param".
 85 * @check_duplicate: Callback function to find duplicated entry.
 86 * @merge_duplicate: Callback function to merge duplicated entry.
 87 *
 88 * Returns 0 on success, negative value otherwise.
 89 *
 90 * Caller holds tomoyo_read_lock().
 91 */
 92int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
 93			 struct tomoyo_acl_param *param,
 94			 bool (*check_duplicate)(const struct tomoyo_acl_info
 95						 *,
 96						 const struct tomoyo_acl_info
 97						 *),
 98			 bool (*merge_duplicate)(struct tomoyo_acl_info *,
 99						 struct tomoyo_acl_info *,
100						 const bool))
101{
102	const bool is_delete = param->is_delete;
103	int error = is_delete ? -ENOENT : -ENOMEM;
104	struct tomoyo_acl_info *entry;
105	struct list_head * const list = param->list;
106
107	if (param->data[0]) {
108		new_entry->cond = tomoyo_get_condition(param);
109		if (!new_entry->cond)
110			return -EINVAL;
111		/*
112		 * Domain transition preference is allowed for only
113		 * "file execute" entries.
114		 */
115		if (new_entry->cond->transit &&
116		    !(new_entry->type == TOMOYO_TYPE_PATH_ACL &&
117		      container_of(new_entry, struct tomoyo_path_acl, head)
118		      ->perm == 1 << TOMOYO_TYPE_EXECUTE))
119			goto out;
120	}
121	if (mutex_lock_interruptible(&tomoyo_policy_lock))
122		goto out;
123	list_for_each_entry_rcu(entry, list, list,
124				srcu_read_lock_held(&tomoyo_ss)) {
125		if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
126			continue;
127		if (!tomoyo_same_acl_head(entry, new_entry) ||
128		    !check_duplicate(entry, new_entry))
129			continue;
130		if (merge_duplicate)
131			entry->is_deleted = merge_duplicate(entry, new_entry,
132							    is_delete);
133		else
134			entry->is_deleted = is_delete;
135		error = 0;
136		break;
137	}
138	if (error && !is_delete) {
139		entry = tomoyo_commit_ok(new_entry, size);
140		if (entry) {
141			list_add_tail_rcu(&entry->list, list);
142			error = 0;
143		}
144	}
145	mutex_unlock(&tomoyo_policy_lock);
146out:
147	tomoyo_put_condition(new_entry->cond);
148	return error;
149}
150
151/**
152 * tomoyo_check_acl - Do permission check.
153 *
154 * @r:           Pointer to "struct tomoyo_request_info".
155 * @check_entry: Callback function to check type specific parameters.
156 *
157 * Returns 0 on success, negative value otherwise.
158 *
159 * Caller holds tomoyo_read_lock().
160 */
161void tomoyo_check_acl(struct tomoyo_request_info *r,
162		      bool (*check_entry)(struct tomoyo_request_info *,
163					  const struct tomoyo_acl_info *))
164{
165	const struct tomoyo_domain_info *domain = r->domain;
166	struct tomoyo_acl_info *ptr;
 
167	const struct list_head *list = &domain->acl_info_list;
168	u16 i = 0;
169
170retry:
171	list_for_each_entry_rcu(ptr, list, list,
172				srcu_read_lock_held(&tomoyo_ss)) {
173		if (ptr->is_deleted || ptr->type != r->param_type)
174			continue;
175		if (!check_entry(r, ptr))
176			continue;
177		if (!tomoyo_condition(r, ptr->cond))
178			continue;
179		r->matched_acl = ptr;
180		r->granted = true;
181		return;
182	}
183	for (; i < TOMOYO_MAX_ACL_GROUPS; i++) {
184		if (!test_bit(i, domain->group))
185			continue;
186		list = &domain->ns->acl_group[i++];
187		goto retry;
188	}
189	r->granted = false;
190}
191
192/* The list for "struct tomoyo_domain_info". */
193LIST_HEAD(tomoyo_domain_list);
194
195/**
196 * tomoyo_last_word - Get last component of a domainname.
197 *
198 * @name: Domainname to check.
199 *
200 * Returns the last word of @domainname.
201 */
202static const char *tomoyo_last_word(const char *name)
203{
204	const char *cp = strrchr(name, ' ');
205
206	if (cp)
207		return cp + 1;
208	return name;
209}
210
211/**
212 * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
213 *
214 * @a: Pointer to "struct tomoyo_acl_head".
215 * @b: Pointer to "struct tomoyo_acl_head".
216 *
217 * Returns true if @a == @b, false otherwise.
218 */
219static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
220					   const struct tomoyo_acl_head *b)
221{
222	const struct tomoyo_transition_control *p1 = container_of(a,
223								  typeof(*p1),
224								  head);
225	const struct tomoyo_transition_control *p2 = container_of(b,
226								  typeof(*p2),
227								  head);
228
229	return p1->type == p2->type && p1->is_last_name == p2->is_last_name
230		&& p1->domainname == p2->domainname
231		&& p1->program == p2->program;
232}
233
234/**
235 * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
236 *
237 * @param: Pointer to "struct tomoyo_acl_param".
238 * @type:  Type of this entry.
239 *
240 * Returns 0 on success, negative value otherwise.
241 */
242int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
243				    const u8 type)
244{
245	struct tomoyo_transition_control e = { .type = type };
246	int error = param->is_delete ? -ENOENT : -ENOMEM;
247	char *program = param->data;
248	char *domainname = strstr(program, " from ");
249
250	if (domainname) {
251		*domainname = '\0';
252		domainname += 6;
253	} else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
254		   type == TOMOYO_TRANSITION_CONTROL_KEEP) {
255		domainname = program;
256		program = NULL;
257	}
258	if (program && strcmp(program, "any")) {
259		if (!tomoyo_correct_path(program))
260			return -EINVAL;
261		e.program = tomoyo_get_name(program);
262		if (!e.program)
263			goto out;
264	}
265	if (domainname && strcmp(domainname, "any")) {
266		if (!tomoyo_correct_domain(domainname)) {
267			if (!tomoyo_correct_path(domainname))
268				goto out;
269			e.is_last_name = true;
270		}
271		e.domainname = tomoyo_get_name(domainname);
272		if (!e.domainname)
273			goto out;
274	}
275	param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
276	error = tomoyo_update_policy(&e.head, sizeof(e), param,
277				     tomoyo_same_transition_control);
278out:
279	tomoyo_put_name(e.domainname);
280	tomoyo_put_name(e.program);
281	return error;
282}
283
284/**
285 * tomoyo_scan_transition - Try to find specific domain transition type.
286 *
287 * @list:       Pointer to "struct list_head".
288 * @domainname: The name of current domain.
289 * @program:    The name of requested program.
290 * @last_name:  The last component of @domainname.
291 * @type:       One of values in "enum tomoyo_transition_type".
292 *
293 * Returns true if found one, false otherwise.
294 *
295 * Caller holds tomoyo_read_lock().
296 */
297static inline bool tomoyo_scan_transition
298(const struct list_head *list, const struct tomoyo_path_info *domainname,
299 const struct tomoyo_path_info *program, const char *last_name,
300 const enum tomoyo_transition_type type)
301{
302	const struct tomoyo_transition_control *ptr;
303
304	list_for_each_entry_rcu(ptr, list, head.list,
305				srcu_read_lock_held(&tomoyo_ss)) {
306		if (ptr->head.is_deleted || ptr->type != type)
307			continue;
308		if (ptr->domainname) {
309			if (!ptr->is_last_name) {
310				if (ptr->domainname != domainname)
311					continue;
312			} else {
313				/*
314				 * Use direct strcmp() since this is
315				 * unlikely used.
316				 */
317				if (strcmp(ptr->domainname->name, last_name))
318					continue;
319			}
320		}
321		if (ptr->program && tomoyo_pathcmp(ptr->program, program))
322			continue;
323		return true;
324	}
325	return false;
326}
327
328/**
329 * tomoyo_transition_type - Get domain transition type.
330 *
331 * @ns:         Pointer to "struct tomoyo_policy_namespace".
332 * @domainname: The name of current domain.
333 * @program:    The name of requested program.
334 *
335 * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
336 * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
337 * executing @program reinitializes domain transition within that namespace,
338 * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
339 * others otherwise.
340 *
341 * Caller holds tomoyo_read_lock().
342 */
343static enum tomoyo_transition_type tomoyo_transition_type
344(const struct tomoyo_policy_namespace *ns,
345 const struct tomoyo_path_info *domainname,
346 const struct tomoyo_path_info *program)
347{
348	const char *last_name = tomoyo_last_word(domainname->name);
349	enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
350
351	while (type < TOMOYO_MAX_TRANSITION_TYPE) {
352		const struct list_head * const list =
353			&ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
354
355		if (!tomoyo_scan_transition(list, domainname, program,
356					    last_name, type)) {
357			type++;
358			continue;
359		}
360		if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
361		    type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
362			break;
363		/*
364		 * Do not check for reset_domain if no_reset_domain matched.
365		 * Do not check for initialize_domain if no_initialize_domain
366		 * matched.
367		 */
368		type++;
369		type++;
370	}
371	return type;
372}
373
374/**
375 * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
376 *
377 * @a: Pointer to "struct tomoyo_acl_head".
378 * @b: Pointer to "struct tomoyo_acl_head".
379 *
380 * Returns true if @a == @b, false otherwise.
381 */
382static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
383				   const struct tomoyo_acl_head *b)
384{
385	const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
386							  head);
387	const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
388							  head);
389
390	return p1->original_name == p2->original_name &&
391		p1->aggregated_name == p2->aggregated_name;
392}
393
394/**
395 * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
396 *
397 * @param: Pointer to "struct tomoyo_acl_param".
398 *
399 * Returns 0 on success, negative value otherwise.
400 *
401 * Caller holds tomoyo_read_lock().
402 */
403int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
404{
405	struct tomoyo_aggregator e = { };
406	int error = param->is_delete ? -ENOENT : -ENOMEM;
407	const char *original_name = tomoyo_read_token(param);
408	const char *aggregated_name = tomoyo_read_token(param);
409
410	if (!tomoyo_correct_word(original_name) ||
411	    !tomoyo_correct_path(aggregated_name))
412		return -EINVAL;
413	e.original_name = tomoyo_get_name(original_name);
414	e.aggregated_name = tomoyo_get_name(aggregated_name);
415	if (!e.original_name || !e.aggregated_name ||
416	    e.aggregated_name->is_patterned) /* No patterns allowed. */
417		goto out;
418	param->list = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
419	error = tomoyo_update_policy(&e.head, sizeof(e), param,
420				     tomoyo_same_aggregator);
421out:
422	tomoyo_put_name(e.original_name);
423	tomoyo_put_name(e.aggregated_name);
424	return error;
425}
426
427/**
428 * tomoyo_find_namespace - Find specified namespace.
429 *
430 * @name: Name of namespace to find.
431 * @len:  Length of @name.
432 *
433 * Returns pointer to "struct tomoyo_policy_namespace" if found,
434 * NULL otherwise.
435 *
436 * Caller holds tomoyo_read_lock().
437 */
438static struct tomoyo_policy_namespace *tomoyo_find_namespace
439(const char *name, const unsigned int len)
440{
441	struct tomoyo_policy_namespace *ns;
442
443	list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
444		if (strncmp(name, ns->name, len) ||
445		    (name[len] && name[len] != ' '))
446			continue;
447		return ns;
448	}
449	return NULL;
450}
451
452/**
453 * tomoyo_assign_namespace - Create a new namespace.
454 *
455 * @domainname: Name of namespace to create.
456 *
457 * Returns pointer to "struct tomoyo_policy_namespace" on success,
458 * NULL otherwise.
459 *
460 * Caller holds tomoyo_read_lock().
461 */
462struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
463{
464	struct tomoyo_policy_namespace *ptr;
465	struct tomoyo_policy_namespace *entry;
466	const char *cp = domainname;
467	unsigned int len = 0;
468
469	while (*cp && *cp++ != ' ')
470		len++;
471	ptr = tomoyo_find_namespace(domainname, len);
472	if (ptr)
473		return ptr;
474	if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
475		return NULL;
476	entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS | __GFP_NOWARN);
 
 
477	if (mutex_lock_interruptible(&tomoyo_policy_lock))
478		goto out;
479	ptr = tomoyo_find_namespace(domainname, len);
480	if (!ptr && tomoyo_memory_ok(entry)) {
481		char *name = (char *) (entry + 1);
482
483		ptr = entry;
484		memmove(name, domainname, len);
485		name[len] = '\0';
486		entry->name = name;
487		tomoyo_init_policy_namespace(entry);
488		entry = NULL;
489	}
490	mutex_unlock(&tomoyo_policy_lock);
491out:
492	kfree(entry);
493	return ptr;
494}
495
496/**
497 * tomoyo_namespace_jump - Check for namespace jump.
498 *
499 * @domainname: Name of domain.
500 *
501 * Returns true if namespace differs, false otherwise.
502 */
503static bool tomoyo_namespace_jump(const char *domainname)
504{
505	const char *namespace = tomoyo_current_namespace()->name;
506	const int len = strlen(namespace);
507
508	return strncmp(domainname, namespace, len) ||
509		(domainname[len] && domainname[len] != ' ');
510}
511
512/**
513 * tomoyo_assign_domain - Create a domain or a namespace.
514 *
515 * @domainname: The name of domain.
516 * @transit:    True if transit to domain found or created.
517 *
518 * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
519 *
520 * Caller holds tomoyo_read_lock().
521 */
522struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
523						const bool transit)
524{
525	struct tomoyo_domain_info e = { };
526	struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
527	bool created = false;
528
529	if (entry) {
530		if (transit) {
531			/*
532			 * Since namespace is created at runtime, profiles may
533			 * not be created by the moment the process transits to
534			 * that domain. Do not perform domain transition if
535			 * profile for that domain is not yet created.
536			 */
537			if (tomoyo_policy_loaded &&
538			    !entry->ns->profile_ptr[entry->profile])
539				return NULL;
540		}
541		return entry;
542	}
543	/* Requested domain does not exist. */
544	/* Don't create requested domain if domainname is invalid. */
545	if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
546	    !tomoyo_correct_domain(domainname))
547		return NULL;
548	/*
549	 * Since definition of profiles and acl_groups may differ across
550	 * namespaces, do not inherit "use_profile" and "use_group" settings
551	 * by automatically creating requested domain upon domain transition.
552	 */
553	if (transit && tomoyo_namespace_jump(domainname))
554		return NULL;
555	e.ns = tomoyo_assign_namespace(domainname);
556	if (!e.ns)
557		return NULL;
558	/*
559	 * "use_profile" and "use_group" settings for automatically created
560	 * domains are inherited from current domain. These are 0 for manually
561	 * created domains.
562	 */
563	if (transit) {
564		const struct tomoyo_domain_info *domain = tomoyo_domain();
565
566		e.profile = domain->profile;
567		memcpy(e.group, domain->group, sizeof(e.group));
568	}
569	e.domainname = tomoyo_get_name(domainname);
570	if (!e.domainname)
571		return NULL;
572	if (mutex_lock_interruptible(&tomoyo_policy_lock))
573		goto out;
574	entry = tomoyo_find_domain(domainname);
575	if (!entry) {
576		entry = tomoyo_commit_ok(&e, sizeof(e));
577		if (entry) {
578			INIT_LIST_HEAD(&entry->acl_info_list);
579			list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
580			created = true;
581		}
582	}
583	mutex_unlock(&tomoyo_policy_lock);
584out:
585	tomoyo_put_name(e.domainname);
586	if (entry && transit) {
587		if (created) {
588			struct tomoyo_request_info r;
589			int i;
590
591			tomoyo_init_request_info(&r, entry,
592						 TOMOYO_MAC_FILE_EXECUTE);
593			r.granted = false;
594			tomoyo_write_log(&r, "use_profile %u\n",
595					 entry->profile);
596			for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++)
597				if (test_bit(i, entry->group))
598					tomoyo_write_log(&r, "use_group %u\n",
599							 i);
600			tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
601		}
602	}
603	return entry;
604}
605
606/**
607 * tomoyo_environ - Check permission for environment variable names.
608 *
609 * @ee: Pointer to "struct tomoyo_execve".
610 *
611 * Returns 0 on success, negative value otherwise.
612 */
613static int tomoyo_environ(struct tomoyo_execve *ee)
614{
615	struct tomoyo_request_info *r = &ee->r;
616	struct linux_binprm *bprm = ee->bprm;
617	/* env_page.data is allocated by tomoyo_dump_page(). */
618	struct tomoyo_page_dump env_page = { };
619	char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
620	int arg_len = 0;
621	unsigned long pos = bprm->p;
622	int offset = pos % PAGE_SIZE;
623	int argv_count = bprm->argc;
624	int envp_count = bprm->envc;
625	int error = -ENOMEM;
626
627	ee->r.type = TOMOYO_MAC_ENVIRON;
628	ee->r.profile = r->domain->profile;
629	ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
630				     TOMOYO_MAC_ENVIRON);
631	if (!r->mode || !envp_count)
632		return 0;
633	arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
634	if (!arg_ptr)
635		goto out;
636	while (error == -ENOMEM) {
637		if (!tomoyo_dump_page(bprm, pos, &env_page))
638			goto out;
639		pos += PAGE_SIZE - offset;
640		/* Read. */
641		while (argv_count && offset < PAGE_SIZE) {
642			if (!env_page.data[offset++])
643				argv_count--;
644		}
645		if (argv_count) {
646			offset = 0;
647			continue;
648		}
649		while (offset < PAGE_SIZE) {
650			const unsigned char c = env_page.data[offset++];
651
652			if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
653				if (c == '=') {
654					arg_ptr[arg_len++] = '\0';
655				} else if (c == '\\') {
656					arg_ptr[arg_len++] = '\\';
657					arg_ptr[arg_len++] = '\\';
658				} else if (c > ' ' && c < 127) {
659					arg_ptr[arg_len++] = c;
660				} else {
661					arg_ptr[arg_len++] = '\\';
662					arg_ptr[arg_len++] = (c >> 6) + '0';
663					arg_ptr[arg_len++]
664						= ((c >> 3) & 7) + '0';
665					arg_ptr[arg_len++] = (c & 7) + '0';
666				}
667			} else {
668				arg_ptr[arg_len] = '\0';
669			}
670			if (c)
671				continue;
672			if (tomoyo_env_perm(r, arg_ptr)) {
673				error = -EPERM;
674				break;
675			}
676			if (!--envp_count) {
677				error = 0;
678				break;
679			}
680			arg_len = 0;
681		}
682		offset = 0;
683	}
684out:
685	if (r->mode != TOMOYO_CONFIG_ENFORCING)
686		error = 0;
687	kfree(env_page.data);
688	kfree(arg_ptr);
689	return error;
690}
691
692/**
693 * tomoyo_find_next_domain - Find a domain.
694 *
695 * @bprm: Pointer to "struct linux_binprm".
696 *
697 * Returns 0 on success, negative value otherwise.
698 *
699 * Caller holds tomoyo_read_lock().
700 */
701int tomoyo_find_next_domain(struct linux_binprm *bprm)
702{
703	struct tomoyo_domain_info *old_domain = tomoyo_domain();
704	struct tomoyo_domain_info *domain = NULL;
705	const char *original_name = bprm->filename;
706	int retval = -ENOMEM;
707	bool reject_on_transition_failure = false;
708	const struct tomoyo_path_info *candidate;
709	struct tomoyo_path_info exename;
710	struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
711
712	if (!ee)
713		return -ENOMEM;
714	ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
715	if (!ee->tmp) {
716		kfree(ee);
717		return -ENOMEM;
718	}
719	/* ee->dump->data is allocated by tomoyo_dump_page(). */
720	tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
721	ee->r.ee = ee;
722	ee->bprm = bprm;
723	ee->r.obj = &ee->obj;
724	ee->obj.path1 = bprm->file->f_path;
725	/* Get symlink's pathname of program. */
726	retval = -ENOENT;
727	exename.name = tomoyo_realpath_nofollow(original_name);
728	if (!exename.name)
729		goto out;
730	tomoyo_fill_path_info(&exename);
731retry:
732	/* Check 'aggregator' directive. */
733	{
734		struct tomoyo_aggregator *ptr;
735		struct list_head *list =
736			&old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
737
738		/* Check 'aggregator' directive. */
739		candidate = &exename;
740		list_for_each_entry_rcu(ptr, list, head.list,
741					srcu_read_lock_held(&tomoyo_ss)) {
742			if (ptr->head.is_deleted ||
743			    !tomoyo_path_matches_pattern(&exename,
744							 ptr->original_name))
745				continue;
746			candidate = ptr->aggregated_name;
747			break;
748		}
749	}
750
751	/* Check execute permission. */
752	retval = tomoyo_execute_permission(&ee->r, candidate);
753	if (retval == TOMOYO_RETRY_REQUEST)
754		goto retry;
755	if (retval < 0)
756		goto out;
757	/*
758	 * To be able to specify domainnames with wildcards, use the
759	 * pathname specified in the policy (which may contain
760	 * wildcard) rather than the pathname passed to execve()
761	 * (which never contains wildcard).
762	 */
763	if (ee->r.param.path.matched_path)
764		candidate = ee->r.param.path.matched_path;
765
766	/*
767	 * Check for domain transition preference if "file execute" matched.
768	 * If preference is given, make execve() fail if domain transition
769	 * has failed, for domain transition preference should be used with
770	 * destination domain defined.
771	 */
772	if (ee->transition) {
773		const char *domainname = ee->transition->name;
774
775		reject_on_transition_failure = true;
776		if (!strcmp(domainname, "keep"))
777			goto force_keep_domain;
778		if (!strcmp(domainname, "child"))
779			goto force_child_domain;
780		if (!strcmp(domainname, "reset"))
781			goto force_reset_domain;
782		if (!strcmp(domainname, "initialize"))
783			goto force_initialize_domain;
784		if (!strcmp(domainname, "parent")) {
785			char *cp;
786
787			strncpy(ee->tmp, old_domain->domainname->name,
788				TOMOYO_EXEC_TMPSIZE - 1);
789			cp = strrchr(ee->tmp, ' ');
790			if (cp)
791				*cp = '\0';
792		} else if (*domainname == '<')
793			strncpy(ee->tmp, domainname, TOMOYO_EXEC_TMPSIZE - 1);
794		else
795			snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
796				 old_domain->domainname->name, domainname);
797		goto force_jump_domain;
798	}
799	/*
800	 * No domain transition preference specified.
801	 * Calculate domain to transit to.
802	 */
803	switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
804				       candidate)) {
805	case TOMOYO_TRANSITION_CONTROL_RESET:
806force_reset_domain:
807		/* Transit to the root of specified namespace. */
808		snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>",
809			 candidate->name);
810		/*
811		 * Make execve() fail if domain transition across namespaces
812		 * has failed.
813		 */
814		reject_on_transition_failure = true;
815		break;
816	case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
817force_initialize_domain:
818		/* Transit to the child of current namespace's root. */
819		snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
820			 old_domain->ns->name, candidate->name);
821		break;
822	case TOMOYO_TRANSITION_CONTROL_KEEP:
823force_keep_domain:
824		/* Keep current domain. */
825		domain = old_domain;
826		break;
827	default:
828		if (old_domain == &tomoyo_kernel_domain &&
829		    !tomoyo_policy_loaded) {
830			/*
831			 * Needn't to transit from kernel domain before
832			 * starting /sbin/init. But transit from kernel domain
833			 * if executing initializers because they might start
834			 * before /sbin/init.
835			 */
836			domain = old_domain;
837			break;
838		}
839force_child_domain:
840		/* Normal domain transition. */
841		snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
842			 old_domain->domainname->name, candidate->name);
843		break;
844	}
845force_jump_domain:
846	if (!domain)
847		domain = tomoyo_assign_domain(ee->tmp, true);
848	if (domain)
849		retval = 0;
850	else if (reject_on_transition_failure) {
851		pr_warn("ERROR: Domain '%s' not ready.\n", ee->tmp);
 
852		retval = -ENOMEM;
853	} else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
854		retval = -ENOMEM;
855	else {
856		retval = 0;
857		if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
858			old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
859			ee->r.granted = false;
860			tomoyo_write_log(&ee->r, "%s", tomoyo_dif
861					 [TOMOYO_DIF_TRANSITION_FAILED]);
862			pr_warn("ERROR: Domain '%s' not defined.\n", ee->tmp);
 
863		}
864	}
865 out:
866	if (!domain)
867		domain = old_domain;
868	/* Update reference count on "struct tomoyo_domain_info". */
869	{
870		struct tomoyo_task *s = tomoyo_task(current);
871
872		s->old_domain_info = s->domain_info;
873		s->domain_info = domain;
874		atomic_inc(&domain->users);
875	}
876	kfree(exename.name);
877	if (!retval) {
878		ee->r.domain = domain;
879		retval = tomoyo_environ(ee);
880	}
881	kfree(ee->tmp);
882	kfree(ee->dump.data);
883	kfree(ee);
884	return retval;
885}
886
887/**
888 * tomoyo_dump_page - Dump a page to buffer.
889 *
890 * @bprm: Pointer to "struct linux_binprm".
891 * @pos:  Location to dump.
892 * @dump: Pointer to "struct tomoyo_page_dump".
893 *
894 * Returns true on success, false otherwise.
895 */
896bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
897		      struct tomoyo_page_dump *dump)
898{
899	struct page *page;
900#ifdef CONFIG_MMU
901	int ret;
902#endif
903
904	/* dump->data is released by tomoyo_find_next_domain(). */
905	if (!dump->data) {
906		dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
907		if (!dump->data)
908			return false;
909	}
910	/* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
911#ifdef CONFIG_MMU
912	/*
913	 * This is called at execve() time in order to dig around
914	 * in the argv/environment of the new proceess
915	 * (represented by bprm).
 
916	 */
917	mmap_read_lock(bprm->mm);
918	ret = get_user_pages_remote(bprm->mm, pos, 1,
919				    FOLL_FORCE, &page, NULL, NULL);
920	mmap_read_unlock(bprm->mm);
921	if (ret <= 0)
922		return false;
923#else
924	page = bprm->page[pos / PAGE_SIZE];
925#endif
926	if (page != dump->page) {
927		const unsigned int offset = pos % PAGE_SIZE;
928		/*
929		 * Maybe kmap()/kunmap() should be used here.
930		 * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
931		 * So do I.
932		 */
933		char *kaddr = kmap_atomic(page);
934
935		dump->page = page;
936		memcpy(dump->data + offset, kaddr + offset,
937		       PAGE_SIZE - offset);
938		kunmap_atomic(kaddr);
939	}
940	/* Same with put_arg_page(page) in fs/exec.c */
941#ifdef CONFIG_MMU
942	put_page(page);
943#endif
944	return true;
945}
v4.17
  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. */
 17struct 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 */
 31int 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 */
 72static 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 */
 91int 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);
144out:
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 */
159void 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
168retry:
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". */
189LIST_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 */
198static 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 */
214static 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 */
236int 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);
271out:
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 */
290static 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 */
334static 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 */
371static 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 */
391int 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);
408out:
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 */
425static 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 */
448struct 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);
477out:
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 */
489static 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 */
507struct 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);
567out:
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 */
591static 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) + '0';
641					arg_ptr[arg_len++]
642						= ((c >> 3) & 7) + '0';
643					arg_ptr[arg_len++] = (c & 7) + '0';
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	}
662out:
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 */
679int 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);
709retry:
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:
780force_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:
791force_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:
797force_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		}
813force_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	}
819force_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 */
867bool 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}