xref: /linux/security/tomoyo/file.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * security/tomoyo/file.c
4  *
5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
6  */
7 
8 #include "common.h"
9 #include <linux/slab.h>
10 
11 /*
12  * Mapping table from "enum tomoyo_path_acl_index" to "enum tomoyo_mac_index".
13  */
14 static const u8 tomoyo_p2mac[TOMOYO_MAX_PATH_OPERATION] = {
15 	[TOMOYO_TYPE_EXECUTE]    = TOMOYO_MAC_FILE_EXECUTE,
16 	[TOMOYO_TYPE_READ]       = TOMOYO_MAC_FILE_OPEN,
17 	[TOMOYO_TYPE_WRITE]      = TOMOYO_MAC_FILE_OPEN,
18 	[TOMOYO_TYPE_APPEND]     = TOMOYO_MAC_FILE_OPEN,
19 	[TOMOYO_TYPE_UNLINK]     = TOMOYO_MAC_FILE_UNLINK,
20 	[TOMOYO_TYPE_GETATTR]    = TOMOYO_MAC_FILE_GETATTR,
21 	[TOMOYO_TYPE_RMDIR]      = TOMOYO_MAC_FILE_RMDIR,
22 	[TOMOYO_TYPE_TRUNCATE]   = TOMOYO_MAC_FILE_TRUNCATE,
23 	[TOMOYO_TYPE_SYMLINK]    = TOMOYO_MAC_FILE_SYMLINK,
24 	[TOMOYO_TYPE_CHROOT]     = TOMOYO_MAC_FILE_CHROOT,
25 	[TOMOYO_TYPE_UMOUNT]     = TOMOYO_MAC_FILE_UMOUNT,
26 };
27 
28 /*
29  * Mapping table from "enum tomoyo_mkdev_acl_index" to "enum tomoyo_mac_index".
30  */
31 const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION] = {
32 	[TOMOYO_TYPE_MKBLOCK] = TOMOYO_MAC_FILE_MKBLOCK,
33 	[TOMOYO_TYPE_MKCHAR]  = TOMOYO_MAC_FILE_MKCHAR,
34 };
35 
36 /*
37  * Mapping table from "enum tomoyo_path2_acl_index" to "enum tomoyo_mac_index".
38  */
39 const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION] = {
40 	[TOMOYO_TYPE_LINK]       = TOMOYO_MAC_FILE_LINK,
41 	[TOMOYO_TYPE_RENAME]     = TOMOYO_MAC_FILE_RENAME,
42 	[TOMOYO_TYPE_PIVOT_ROOT] = TOMOYO_MAC_FILE_PIVOT_ROOT,
43 };
44 
45 /*
46  * Mapping table from "enum tomoyo_path_number_acl_index" to
47  * "enum tomoyo_mac_index".
48  */
49 const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
50 	[TOMOYO_TYPE_CREATE] = TOMOYO_MAC_FILE_CREATE,
51 	[TOMOYO_TYPE_MKDIR]  = TOMOYO_MAC_FILE_MKDIR,
52 	[TOMOYO_TYPE_MKFIFO] = TOMOYO_MAC_FILE_MKFIFO,
53 	[TOMOYO_TYPE_MKSOCK] = TOMOYO_MAC_FILE_MKSOCK,
54 	[TOMOYO_TYPE_IOCTL]  = TOMOYO_MAC_FILE_IOCTL,
55 	[TOMOYO_TYPE_CHMOD]  = TOMOYO_MAC_FILE_CHMOD,
56 	[TOMOYO_TYPE_CHOWN]  = TOMOYO_MAC_FILE_CHOWN,
57 	[TOMOYO_TYPE_CHGRP]  = TOMOYO_MAC_FILE_CHGRP,
58 };
59 
60 /**
61  * tomoyo_put_name_union - Drop reference on "struct tomoyo_name_union".
62  *
63  * @ptr: Pointer to "struct tomoyo_name_union".
64  *
65  * Returns nothing.
66  */
tomoyo_put_name_union(struct tomoyo_name_union * ptr)67 void tomoyo_put_name_union(struct tomoyo_name_union *ptr)
68 {
69 	tomoyo_put_group(ptr->group);
70 	tomoyo_put_name(ptr->filename);
71 }
72 
73 /**
74  * tomoyo_compare_name_union - Check whether a name matches "struct tomoyo_name_union" or not.
75  *
76  * @name: Pointer to "struct tomoyo_path_info".
77  * @ptr:  Pointer to "struct tomoyo_name_union".
78  *
79  * Returns "struct tomoyo_path_info" if @name matches @ptr, NULL otherwise.
80  */
81 const struct tomoyo_path_info *
tomoyo_compare_name_union(const struct tomoyo_path_info * name,const struct tomoyo_name_union * ptr)82 tomoyo_compare_name_union(const struct tomoyo_path_info *name,
83 			  const struct tomoyo_name_union *ptr)
84 {
85 	if (ptr->group)
86 		return tomoyo_path_matches_group(name, ptr->group);
87 	if (tomoyo_path_matches_pattern(name, ptr->filename))
88 		return ptr->filename;
89 	return NULL;
90 }
91 
92 /**
93  * tomoyo_put_number_union - Drop reference on "struct tomoyo_number_union".
94  *
95  * @ptr: Pointer to "struct tomoyo_number_union".
96  *
97  * Returns nothing.
98  */
tomoyo_put_number_union(struct tomoyo_number_union * ptr)99 void tomoyo_put_number_union(struct tomoyo_number_union *ptr)
100 {
101 	tomoyo_put_group(ptr->group);
102 }
103 
104 /**
105  * tomoyo_compare_number_union - Check whether a value matches "struct tomoyo_number_union" or not.
106  *
107  * @value: Number to check.
108  * @ptr:   Pointer to "struct tomoyo_number_union".
109  *
110  * Returns true if @value matches @ptr, false otherwise.
111  */
tomoyo_compare_number_union(const unsigned long value,const struct tomoyo_number_union * ptr)112 bool tomoyo_compare_number_union(const unsigned long value,
113 				 const struct tomoyo_number_union *ptr)
114 {
115 	if (ptr->group)
116 		return tomoyo_number_matches_group(value, value, ptr->group);
117 	return value >= ptr->values[0] && value <= ptr->values[1];
118 }
119 
120 /**
121  * tomoyo_add_slash - Add trailing '/' if needed.
122  *
123  * @buf: Pointer to "struct tomoyo_path_info".
124  *
125  * Returns nothing.
126  *
127  * @buf must be generated by tomoyo_encode() because this function does not
128  * allocate memory for adding '/'.
129  */
tomoyo_add_slash(struct tomoyo_path_info * buf)130 static void tomoyo_add_slash(struct tomoyo_path_info *buf)
131 {
132 	if (buf->is_dir)
133 		return;
134 	/*
135 	 * This is OK because tomoyo_encode() reserves space for appending "/".
136 	 */
137 	strcat((char *) buf->name, "/");
138 	tomoyo_fill_path_info(buf);
139 }
140 
141 /**
142  * tomoyo_get_realpath - Get realpath.
143  *
144  * @buf:  Pointer to "struct tomoyo_path_info".
145  * @path: Pointer to "struct path".
146  *
147  * Returns true on success, false otherwise.
148  */
tomoyo_get_realpath(struct tomoyo_path_info * buf,const struct path * path)149 static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, const struct path *path)
150 {
151 	buf->name = tomoyo_realpath_from_path(path);
152 	if (buf->name) {
153 		tomoyo_fill_path_info(buf);
154 		return true;
155 	}
156 	return false;
157 }
158 
159 /**
160  * tomoyo_audit_path_log - Audit path request log.
161  *
162  * @r: Pointer to "struct tomoyo_request_info".
163  *
164  * Returns 0 on success, negative value otherwise.
165  */
tomoyo_audit_path_log(struct tomoyo_request_info * r)166 static int tomoyo_audit_path_log(struct tomoyo_request_info *r)
167 {
168 	return tomoyo_supervisor(r, "file %s %s\n", tomoyo_path_keyword
169 				 [r->param.path.operation],
170 				 r->param.path.filename->name);
171 }
172 
173 /**
174  * tomoyo_audit_path2_log - Audit path/path request log.
175  *
176  * @r: Pointer to "struct tomoyo_request_info".
177  *
178  * Returns 0 on success, negative value otherwise.
179  */
tomoyo_audit_path2_log(struct tomoyo_request_info * r)180 static int tomoyo_audit_path2_log(struct tomoyo_request_info *r)
181 {
182 	return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords
183 				 [tomoyo_pp2mac[r->param.path2.operation]],
184 				 r->param.path2.filename1->name,
185 				 r->param.path2.filename2->name);
186 }
187 
188 /**
189  * tomoyo_audit_mkdev_log - Audit path/number/number/number request log.
190  *
191  * @r: Pointer to "struct tomoyo_request_info".
192  *
193  * Returns 0 on success, negative value otherwise.
194  */
tomoyo_audit_mkdev_log(struct tomoyo_request_info * r)195 static int tomoyo_audit_mkdev_log(struct tomoyo_request_info *r)
196 {
197 	return tomoyo_supervisor(r, "file %s %s 0%o %u %u\n",
198 				 tomoyo_mac_keywords
199 				 [tomoyo_pnnn2mac[r->param.mkdev.operation]],
200 				 r->param.mkdev.filename->name,
201 				 r->param.mkdev.mode, r->param.mkdev.major,
202 				 r->param.mkdev.minor);
203 }
204 
205 /**
206  * tomoyo_audit_path_number_log - Audit path/number request log.
207  *
208  * @r: Pointer to "struct tomoyo_request_info".
209  *
210  * Returns 0 on success, negative value otherwise.
211  */
tomoyo_audit_path_number_log(struct tomoyo_request_info * r)212 static int tomoyo_audit_path_number_log(struct tomoyo_request_info *r)
213 {
214 	const u8 type = r->param.path_number.operation;
215 	u8 radix;
216 	char buffer[64];
217 
218 	switch (type) {
219 	case TOMOYO_TYPE_CREATE:
220 	case TOMOYO_TYPE_MKDIR:
221 	case TOMOYO_TYPE_MKFIFO:
222 	case TOMOYO_TYPE_MKSOCK:
223 	case TOMOYO_TYPE_CHMOD:
224 		radix = TOMOYO_VALUE_TYPE_OCTAL;
225 		break;
226 	case TOMOYO_TYPE_IOCTL:
227 		radix = TOMOYO_VALUE_TYPE_HEXADECIMAL;
228 		break;
229 	default:
230 		radix = TOMOYO_VALUE_TYPE_DECIMAL;
231 		break;
232 	}
233 	tomoyo_print_ulong(buffer, sizeof(buffer), r->param.path_number.number,
234 			   radix);
235 	return tomoyo_supervisor(r, "file %s %s %s\n", tomoyo_mac_keywords
236 				 [tomoyo_pn2mac[type]],
237 				 r->param.path_number.filename->name, buffer);
238 }
239 
240 /**
241  * tomoyo_check_path_acl - Check permission for path operation.
242  *
243  * @r:   Pointer to "struct tomoyo_request_info".
244  * @ptr: Pointer to "struct tomoyo_acl_info".
245  *
246  * Returns true if granted, false otherwise.
247  *
248  * To be able to use wildcard for domain transition, this function sets
249  * matching entry on success. Since the caller holds tomoyo_read_lock(),
250  * it is safe to set matching entry.
251  */
tomoyo_check_path_acl(struct tomoyo_request_info * r,const struct tomoyo_acl_info * ptr)252 static bool tomoyo_check_path_acl(struct tomoyo_request_info *r,
253 				  const struct tomoyo_acl_info *ptr)
254 {
255 	const struct tomoyo_path_acl *acl = container_of(ptr, typeof(*acl),
256 							 head);
257 
258 	if (acl->perm & (1 << r->param.path.operation)) {
259 		r->param.path.matched_path =
260 			tomoyo_compare_name_union(r->param.path.filename,
261 						  &acl->name);
262 		return r->param.path.matched_path != NULL;
263 	}
264 	return false;
265 }
266 
267 /**
268  * tomoyo_check_path_number_acl - Check permission for path number operation.
269  *
270  * @r:   Pointer to "struct tomoyo_request_info".
271  * @ptr: Pointer to "struct tomoyo_acl_info".
272  *
273  * Returns true if granted, false otherwise.
274  */
tomoyo_check_path_number_acl(struct tomoyo_request_info * r,const struct tomoyo_acl_info * ptr)275 static bool tomoyo_check_path_number_acl(struct tomoyo_request_info *r,
276 					 const struct tomoyo_acl_info *ptr)
277 {
278 	const struct tomoyo_path_number_acl *acl =
279 		container_of(ptr, typeof(*acl), head);
280 
281 	return (acl->perm & (1 << r->param.path_number.operation)) &&
282 		tomoyo_compare_number_union(r->param.path_number.number,
283 					    &acl->number) &&
284 		tomoyo_compare_name_union(r->param.path_number.filename,
285 					  &acl->name);
286 }
287 
288 /**
289  * tomoyo_check_path2_acl - Check permission for path path operation.
290  *
291  * @r:   Pointer to "struct tomoyo_request_info".
292  * @ptr: Pointer to "struct tomoyo_acl_info".
293  *
294  * Returns true if granted, false otherwise.
295  */
tomoyo_check_path2_acl(struct tomoyo_request_info * r,const struct tomoyo_acl_info * ptr)296 static bool tomoyo_check_path2_acl(struct tomoyo_request_info *r,
297 				   const struct tomoyo_acl_info *ptr)
298 {
299 	const struct tomoyo_path2_acl *acl =
300 		container_of(ptr, typeof(*acl), head);
301 
302 	return (acl->perm & (1 << r->param.path2.operation)) &&
303 		tomoyo_compare_name_union(r->param.path2.filename1, &acl->name1)
304 		&& tomoyo_compare_name_union(r->param.path2.filename2,
305 					     &acl->name2);
306 }
307 
308 /**
309  * tomoyo_check_mkdev_acl - Check permission for path number number number operation.
310  *
311  * @r:   Pointer to "struct tomoyo_request_info".
312  * @ptr: Pointer to "struct tomoyo_acl_info".
313  *
314  * Returns true if granted, false otherwise.
315  */
tomoyo_check_mkdev_acl(struct tomoyo_request_info * r,const struct tomoyo_acl_info * ptr)316 static bool tomoyo_check_mkdev_acl(struct tomoyo_request_info *r,
317 				   const struct tomoyo_acl_info *ptr)
318 {
319 	const struct tomoyo_mkdev_acl *acl =
320 		container_of(ptr, typeof(*acl), head);
321 
322 	return (acl->perm & (1 << r->param.mkdev.operation)) &&
323 		tomoyo_compare_number_union(r->param.mkdev.mode,
324 					    &acl->mode) &&
325 		tomoyo_compare_number_union(r->param.mkdev.major,
326 					    &acl->major) &&
327 		tomoyo_compare_number_union(r->param.mkdev.minor,
328 					    &acl->minor) &&
329 		tomoyo_compare_name_union(r->param.mkdev.filename,
330 					  &acl->name);
331 }
332 
333 /**
334  * tomoyo_same_path_acl - Check for duplicated "struct tomoyo_path_acl" entry.
335  *
336  * @a: Pointer to "struct tomoyo_acl_info".
337  * @b: Pointer to "struct tomoyo_acl_info".
338  *
339  * Returns true if @a == @b except permission bits, false otherwise.
340  */
tomoyo_same_path_acl(const struct tomoyo_acl_info * a,const struct tomoyo_acl_info * b)341 static bool tomoyo_same_path_acl(const struct tomoyo_acl_info *a,
342 				 const struct tomoyo_acl_info *b)
343 {
344 	const struct tomoyo_path_acl *p1 = container_of(a, typeof(*p1), head);
345 	const struct tomoyo_path_acl *p2 = container_of(b, typeof(*p2), head);
346 
347 	return tomoyo_same_name_union(&p1->name, &p2->name);
348 }
349 
350 /**
351  * tomoyo_merge_path_acl - Merge duplicated "struct tomoyo_path_acl" entry.
352  *
353  * @a:         Pointer to "struct tomoyo_acl_info".
354  * @b:         Pointer to "struct tomoyo_acl_info".
355  * @is_delete: True for @a &= ~@b, false for @a |= @b.
356  *
357  * Returns true if @a is empty, false otherwise.
358  */
tomoyo_merge_path_acl(struct tomoyo_acl_info * a,struct tomoyo_acl_info * b,const bool is_delete)359 static bool tomoyo_merge_path_acl(struct tomoyo_acl_info *a,
360 				  struct tomoyo_acl_info *b,
361 				  const bool is_delete)
362 {
363 	u16 * const a_perm = &container_of(a, struct tomoyo_path_acl, head)
364 		->perm;
365 	u16 perm = READ_ONCE(*a_perm);
366 	const u16 b_perm = container_of(b, struct tomoyo_path_acl, head)->perm;
367 
368 	if (is_delete)
369 		perm &= ~b_perm;
370 	else
371 		perm |= b_perm;
372 	WRITE_ONCE(*a_perm, perm);
373 	return !perm;
374 }
375 
376 /**
377  * tomoyo_update_path_acl - Update "struct tomoyo_path_acl" list.
378  *
379  * @perm:  Permission.
380  * @param: Pointer to "struct tomoyo_acl_param".
381  *
382  * Returns 0 on success, negative value otherwise.
383  *
384  * Caller holds tomoyo_read_lock().
385  */
tomoyo_update_path_acl(const u16 perm,struct tomoyo_acl_param * param)386 static int tomoyo_update_path_acl(const u16 perm,
387 				  struct tomoyo_acl_param *param)
388 {
389 	struct tomoyo_path_acl e = {
390 		.head.type = TOMOYO_TYPE_PATH_ACL,
391 		.perm = perm
392 	};
393 	int error;
394 
395 	if (!tomoyo_parse_name_union(param, &e.name))
396 		error = -EINVAL;
397 	else
398 		error = tomoyo_update_domain(&e.head, sizeof(e), param,
399 					     tomoyo_same_path_acl,
400 					     tomoyo_merge_path_acl);
401 	tomoyo_put_name_union(&e.name);
402 	return error;
403 }
404 
405 /**
406  * tomoyo_same_mkdev_acl - Check for duplicated "struct tomoyo_mkdev_acl" entry.
407  *
408  * @a: Pointer to "struct tomoyo_acl_info".
409  * @b: Pointer to "struct tomoyo_acl_info".
410  *
411  * Returns true if @a == @b except permission bits, false otherwise.
412  */
tomoyo_same_mkdev_acl(const struct tomoyo_acl_info * a,const struct tomoyo_acl_info * b)413 static bool tomoyo_same_mkdev_acl(const struct tomoyo_acl_info *a,
414 					 const struct tomoyo_acl_info *b)
415 {
416 	const struct tomoyo_mkdev_acl *p1 = container_of(a, typeof(*p1), head);
417 	const struct tomoyo_mkdev_acl *p2 = container_of(b, typeof(*p2), head);
418 
419 	return tomoyo_same_name_union(&p1->name, &p2->name) &&
420 		tomoyo_same_number_union(&p1->mode, &p2->mode) &&
421 		tomoyo_same_number_union(&p1->major, &p2->major) &&
422 		tomoyo_same_number_union(&p1->minor, &p2->minor);
423 }
424 
425 /**
426  * tomoyo_merge_mkdev_acl - Merge duplicated "struct tomoyo_mkdev_acl" entry.
427  *
428  * @a:         Pointer to "struct tomoyo_acl_info".
429  * @b:         Pointer to "struct tomoyo_acl_info".
430  * @is_delete: True for @a &= ~@b, false for @a |= @b.
431  *
432  * Returns true if @a is empty, false otherwise.
433  */
tomoyo_merge_mkdev_acl(struct tomoyo_acl_info * a,struct tomoyo_acl_info * b,const bool is_delete)434 static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a,
435 				   struct tomoyo_acl_info *b,
436 				   const bool is_delete)
437 {
438 	u8 *const a_perm = &container_of(a, struct tomoyo_mkdev_acl,
439 					 head)->perm;
440 	u8 perm = READ_ONCE(*a_perm);
441 	const u8 b_perm = container_of(b, struct tomoyo_mkdev_acl, head)
442 		->perm;
443 
444 	if (is_delete)
445 		perm &= ~b_perm;
446 	else
447 		perm |= b_perm;
448 	WRITE_ONCE(*a_perm, perm);
449 	return !perm;
450 }
451 
452 /**
453  * tomoyo_update_mkdev_acl - Update "struct tomoyo_mkdev_acl" list.
454  *
455  * @perm:  Permission.
456  * @param: Pointer to "struct tomoyo_acl_param".
457  *
458  * Returns 0 on success, negative value otherwise.
459  *
460  * Caller holds tomoyo_read_lock().
461  */
tomoyo_update_mkdev_acl(const u8 perm,struct tomoyo_acl_param * param)462 static int tomoyo_update_mkdev_acl(const u8 perm,
463 				   struct tomoyo_acl_param *param)
464 {
465 	struct tomoyo_mkdev_acl e = {
466 		.head.type = TOMOYO_TYPE_MKDEV_ACL,
467 		.perm = perm
468 	};
469 	int error;
470 
471 	if (!tomoyo_parse_name_union(param, &e.name) ||
472 	    !tomoyo_parse_number_union(param, &e.mode) ||
473 	    !tomoyo_parse_number_union(param, &e.major) ||
474 	    !tomoyo_parse_number_union(param, &e.minor))
475 		error = -EINVAL;
476 	else
477 		error = tomoyo_update_domain(&e.head, sizeof(e), param,
478 					     tomoyo_same_mkdev_acl,
479 					     tomoyo_merge_mkdev_acl);
480 	tomoyo_put_name_union(&e.name);
481 	tomoyo_put_number_union(&e.mode);
482 	tomoyo_put_number_union(&e.major);
483 	tomoyo_put_number_union(&e.minor);
484 	return error;
485 }
486 
487 /**
488  * tomoyo_same_path2_acl - Check for duplicated "struct tomoyo_path2_acl" entry.
489  *
490  * @a: Pointer to "struct tomoyo_acl_info".
491  * @b: Pointer to "struct tomoyo_acl_info".
492  *
493  * Returns true if @a == @b except permission bits, false otherwise.
494  */
tomoyo_same_path2_acl(const struct tomoyo_acl_info * a,const struct tomoyo_acl_info * b)495 static bool tomoyo_same_path2_acl(const struct tomoyo_acl_info *a,
496 				  const struct tomoyo_acl_info *b)
497 {
498 	const struct tomoyo_path2_acl *p1 = container_of(a, typeof(*p1), head);
499 	const struct tomoyo_path2_acl *p2 = container_of(b, typeof(*p2), head);
500 
501 	return tomoyo_same_name_union(&p1->name1, &p2->name1) &&
502 		tomoyo_same_name_union(&p1->name2, &p2->name2);
503 }
504 
505 /**
506  * tomoyo_merge_path2_acl - Merge duplicated "struct tomoyo_path2_acl" entry.
507  *
508  * @a:         Pointer to "struct tomoyo_acl_info".
509  * @b:         Pointer to "struct tomoyo_acl_info".
510  * @is_delete: True for @a &= ~@b, false for @a |= @b.
511  *
512  * Returns true if @a is empty, false otherwise.
513  */
tomoyo_merge_path2_acl(struct tomoyo_acl_info * a,struct tomoyo_acl_info * b,const bool is_delete)514 static bool tomoyo_merge_path2_acl(struct tomoyo_acl_info *a,
515 				   struct tomoyo_acl_info *b,
516 				   const bool is_delete)
517 {
518 	u8 * const a_perm = &container_of(a, struct tomoyo_path2_acl, head)
519 		->perm;
520 	u8 perm = READ_ONCE(*a_perm);
521 	const u8 b_perm = container_of(b, struct tomoyo_path2_acl, head)->perm;
522 
523 	if (is_delete)
524 		perm &= ~b_perm;
525 	else
526 		perm |= b_perm;
527 	WRITE_ONCE(*a_perm, perm);
528 	return !perm;
529 }
530 
531 /**
532  * tomoyo_update_path2_acl - Update "struct tomoyo_path2_acl" list.
533  *
534  * @perm:  Permission.
535  * @param: Pointer to "struct tomoyo_acl_param".
536  *
537  * Returns 0 on success, negative value otherwise.
538  *
539  * Caller holds tomoyo_read_lock().
540  */
tomoyo_update_path2_acl(const u8 perm,struct tomoyo_acl_param * param)541 static int tomoyo_update_path2_acl(const u8 perm,
542 				   struct tomoyo_acl_param *param)
543 {
544 	struct tomoyo_path2_acl e = {
545 		.head.type = TOMOYO_TYPE_PATH2_ACL,
546 		.perm = perm
547 	};
548 	int error;
549 
550 	if (!tomoyo_parse_name_union(param, &e.name1) ||
551 	    !tomoyo_parse_name_union(param, &e.name2))
552 		error = -EINVAL;
553 	else
554 		error = tomoyo_update_domain(&e.head, sizeof(e), param,
555 					     tomoyo_same_path2_acl,
556 					     tomoyo_merge_path2_acl);
557 	tomoyo_put_name_union(&e.name1);
558 	tomoyo_put_name_union(&e.name2);
559 	return error;
560 }
561 
562 /**
563  * tomoyo_path_permission - Check permission for single path operation.
564  *
565  * @r:         Pointer to "struct tomoyo_request_info".
566  * @operation: Type of operation.
567  * @filename:  Filename to check.
568  *
569  * Returns 0 on success, negative value otherwise.
570  *
571  * Caller holds tomoyo_read_lock().
572  */
tomoyo_path_permission(struct tomoyo_request_info * r,u8 operation,const struct tomoyo_path_info * filename)573 static int tomoyo_path_permission(struct tomoyo_request_info *r, u8 operation,
574 				  const struct tomoyo_path_info *filename)
575 {
576 	int error;
577 
578 	r->type = tomoyo_p2mac[operation];
579 	r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type);
580 	if (r->mode == TOMOYO_CONFIG_DISABLED)
581 		return 0;
582 	r->param_type = TOMOYO_TYPE_PATH_ACL;
583 	r->param.path.filename = filename;
584 	r->param.path.operation = operation;
585 	do {
586 		tomoyo_check_acl(r, tomoyo_check_path_acl);
587 		error = tomoyo_audit_path_log(r);
588 	} while (error == TOMOYO_RETRY_REQUEST);
589 	return error;
590 }
591 
592 /**
593  * tomoyo_execute_permission - Check permission for execute operation.
594  *
595  * @r:         Pointer to "struct tomoyo_request_info".
596  * @filename:  Filename to check.
597  *
598  * Returns 0 on success, negative value otherwise.
599  *
600  * Caller holds tomoyo_read_lock().
601  */
tomoyo_execute_permission(struct tomoyo_request_info * r,const struct tomoyo_path_info * filename)602 int tomoyo_execute_permission(struct tomoyo_request_info *r,
603 			      const struct tomoyo_path_info *filename)
604 {
605 	/*
606 	 * Unlike other permission checks, this check is done regardless of
607 	 * profile mode settings in order to check for domain transition
608 	 * preference.
609 	 */
610 	r->type = TOMOYO_MAC_FILE_EXECUTE;
611 	r->mode = tomoyo_get_mode(r->domain->ns, r->profile, r->type);
612 	r->param_type = TOMOYO_TYPE_PATH_ACL;
613 	r->param.path.filename = filename;
614 	r->param.path.operation = TOMOYO_TYPE_EXECUTE;
615 	tomoyo_check_acl(r, tomoyo_check_path_acl);
616 	r->ee->transition = r->matched_acl && r->matched_acl->cond ?
617 		r->matched_acl->cond->transit : NULL;
618 	if (r->mode != TOMOYO_CONFIG_DISABLED)
619 		return tomoyo_audit_path_log(r);
620 	return 0;
621 }
622 
623 /**
624  * tomoyo_same_path_number_acl - Check for duplicated "struct tomoyo_path_number_acl" entry.
625  *
626  * @a: Pointer to "struct tomoyo_acl_info".
627  * @b: Pointer to "struct tomoyo_acl_info".
628  *
629  * Returns true if @a == @b except permission bits, false otherwise.
630  */
tomoyo_same_path_number_acl(const struct tomoyo_acl_info * a,const struct tomoyo_acl_info * b)631 static bool tomoyo_same_path_number_acl(const struct tomoyo_acl_info *a,
632 					const struct tomoyo_acl_info *b)
633 {
634 	const struct tomoyo_path_number_acl *p1 = container_of(a, typeof(*p1),
635 							       head);
636 	const struct tomoyo_path_number_acl *p2 = container_of(b, typeof(*p2),
637 							       head);
638 
639 	return tomoyo_same_name_union(&p1->name, &p2->name) &&
640 		tomoyo_same_number_union(&p1->number, &p2->number);
641 }
642 
643 /**
644  * tomoyo_merge_path_number_acl - Merge duplicated "struct tomoyo_path_number_acl" entry.
645  *
646  * @a:         Pointer to "struct tomoyo_acl_info".
647  * @b:         Pointer to "struct tomoyo_acl_info".
648  * @is_delete: True for @a &= ~@b, false for @a |= @b.
649  *
650  * Returns true if @a is empty, false otherwise.
651  */
tomoyo_merge_path_number_acl(struct tomoyo_acl_info * a,struct tomoyo_acl_info * b,const bool is_delete)652 static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a,
653 					 struct tomoyo_acl_info *b,
654 					 const bool is_delete)
655 {
656 	u8 * const a_perm = &container_of(a, struct tomoyo_path_number_acl,
657 					  head)->perm;
658 	u8 perm = READ_ONCE(*a_perm);
659 	const u8 b_perm = container_of(b, struct tomoyo_path_number_acl, head)
660 		->perm;
661 
662 	if (is_delete)
663 		perm &= ~b_perm;
664 	else
665 		perm |= b_perm;
666 	WRITE_ONCE(*a_perm, perm);
667 	return !perm;
668 }
669 
670 /**
671  * tomoyo_update_path_number_acl - Update ioctl/chmod/chown/chgrp ACL.
672  *
673  * @perm:  Permission.
674  * @param: Pointer to "struct tomoyo_acl_param".
675  *
676  * Returns 0 on success, negative value otherwise.
677  */
tomoyo_update_path_number_acl(const u8 perm,struct tomoyo_acl_param * param)678 static int tomoyo_update_path_number_acl(const u8 perm,
679 					 struct tomoyo_acl_param *param)
680 {
681 	struct tomoyo_path_number_acl e = {
682 		.head.type = TOMOYO_TYPE_PATH_NUMBER_ACL,
683 		.perm = perm
684 	};
685 	int error;
686 
687 	if (!tomoyo_parse_name_union(param, &e.name) ||
688 	    !tomoyo_parse_number_union(param, &e.number))
689 		error = -EINVAL;
690 	else
691 		error = tomoyo_update_domain(&e.head, sizeof(e), param,
692 					     tomoyo_same_path_number_acl,
693 					     tomoyo_merge_path_number_acl);
694 	tomoyo_put_name_union(&e.name);
695 	tomoyo_put_number_union(&e.number);
696 	return error;
697 }
698 
699 /**
700  * tomoyo_path_number_perm - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp".
701  *
702  * @type:   Type of operation.
703  * @path:   Pointer to "struct path".
704  * @number: Number.
705  *
706  * Returns 0 on success, negative value otherwise.
707  */
tomoyo_path_number_perm(const u8 type,const struct path * path,unsigned long number)708 int tomoyo_path_number_perm(const u8 type, const struct path *path,
709 			    unsigned long number)
710 {
711 	struct tomoyo_request_info r;
712 	struct tomoyo_obj_info obj = {
713 		.path1 = { .mnt = path->mnt, .dentry = path->dentry },
714 	};
715 	int error = -ENOMEM;
716 	struct tomoyo_path_info buf;
717 	int idx;
718 
719 	if (tomoyo_init_request_info(&r, NULL, tomoyo_pn2mac[type])
720 	    == TOMOYO_CONFIG_DISABLED)
721 		return 0;
722 	idx = tomoyo_read_lock();
723 	if (!tomoyo_get_realpath(&buf, path))
724 		goto out;
725 	r.obj = &obj;
726 	if (type == TOMOYO_TYPE_MKDIR)
727 		tomoyo_add_slash(&buf);
728 	r.param_type = TOMOYO_TYPE_PATH_NUMBER_ACL;
729 	r.param.path_number.operation = type;
730 	r.param.path_number.filename = &buf;
731 	r.param.path_number.number = number;
732 	do {
733 		tomoyo_check_acl(&r, tomoyo_check_path_number_acl);
734 		error = tomoyo_audit_path_number_log(&r);
735 	} while (error == TOMOYO_RETRY_REQUEST);
736 	kfree(buf.name);
737  out:
738 	tomoyo_read_unlock(idx);
739 	if (r.mode != TOMOYO_CONFIG_ENFORCING)
740 		error = 0;
741 	return error;
742 }
743 
744 /**
745  * tomoyo_check_open_permission - Check permission for "read" and "write".
746  *
747  * @domain: Pointer to "struct tomoyo_domain_info".
748  * @path:   Pointer to "struct path".
749  * @flag:   Flags for open().
750  *
751  * Returns 0 on success, negative value otherwise.
752  */
tomoyo_check_open_permission(struct tomoyo_domain_info * domain,const struct path * path,const int flag)753 int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
754 				 const struct path *path, const int flag)
755 {
756 	const u8 acc_mode = ACC_MODE(flag);
757 	int error = 0;
758 	struct tomoyo_path_info buf;
759 	struct tomoyo_request_info r;
760 	struct tomoyo_obj_info obj = {
761 		.path1 = { .mnt = path->mnt, .dentry = path->dentry },
762 	};
763 	int idx;
764 
765 	buf.name = NULL;
766 	r.mode = TOMOYO_CONFIG_DISABLED;
767 	idx = tomoyo_read_lock();
768 	if (acc_mode &&
769 	    tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_OPEN)
770 	    != TOMOYO_CONFIG_DISABLED) {
771 		if (!tomoyo_get_realpath(&buf, path)) {
772 			error = -ENOMEM;
773 			goto out;
774 		}
775 		r.obj = &obj;
776 		if (acc_mode & MAY_READ)
777 			error = tomoyo_path_permission(&r, TOMOYO_TYPE_READ,
778 						       &buf);
779 		if (!error && (acc_mode & MAY_WRITE))
780 			error = tomoyo_path_permission(&r, (flag & O_APPEND) ?
781 						       TOMOYO_TYPE_APPEND :
782 						       TOMOYO_TYPE_WRITE,
783 						       &buf);
784 	}
785  out:
786 	kfree(buf.name);
787 	tomoyo_read_unlock(idx);
788 	if (r.mode != TOMOYO_CONFIG_ENFORCING)
789 		error = 0;
790 	return error;
791 }
792 
793 /**
794  * tomoyo_path_perm - Check permission for "unlink", "rmdir", "truncate", "symlink", "append", "chroot" and "unmount".
795  *
796  * @operation: Type of operation.
797  * @path:      Pointer to "struct path".
798  * @target:    Symlink's target if @operation is TOMOYO_TYPE_SYMLINK,
799  *             NULL otherwise.
800  *
801  * Returns 0 on success, negative value otherwise.
802  */
tomoyo_path_perm(const u8 operation,const struct path * path,const char * target)803 int tomoyo_path_perm(const u8 operation, const struct path *path, const char *target)
804 {
805 	struct tomoyo_request_info r;
806 	struct tomoyo_obj_info obj = {
807 		.path1 = { .mnt = path->mnt, .dentry = path->dentry },
808 	};
809 	int error;
810 	struct tomoyo_path_info buf;
811 	bool is_enforce;
812 	struct tomoyo_path_info symlink_target;
813 	int idx;
814 
815 	if (tomoyo_init_request_info(&r, NULL, tomoyo_p2mac[operation])
816 	    == TOMOYO_CONFIG_DISABLED)
817 		return 0;
818 	is_enforce = (r.mode == TOMOYO_CONFIG_ENFORCING);
819 	error = -ENOMEM;
820 	buf.name = NULL;
821 	idx = tomoyo_read_lock();
822 	if (!tomoyo_get_realpath(&buf, path))
823 		goto out;
824 	r.obj = &obj;
825 	switch (operation) {
826 	case TOMOYO_TYPE_RMDIR:
827 	case TOMOYO_TYPE_CHROOT:
828 		tomoyo_add_slash(&buf);
829 		break;
830 	case TOMOYO_TYPE_SYMLINK:
831 		symlink_target.name = tomoyo_encode(target);
832 		if (!symlink_target.name)
833 			goto out;
834 		tomoyo_fill_path_info(&symlink_target);
835 		obj.symlink_target = &symlink_target;
836 		break;
837 	}
838 	error = tomoyo_path_permission(&r, operation, &buf);
839 	if (operation == TOMOYO_TYPE_SYMLINK)
840 		kfree(symlink_target.name);
841  out:
842 	kfree(buf.name);
843 	tomoyo_read_unlock(idx);
844 	if (!is_enforce)
845 		error = 0;
846 	return error;
847 }
848 
849 /**
850  * tomoyo_mkdev_perm - Check permission for "mkblock" and "mkchar".
851  *
852  * @operation: Type of operation. (TOMOYO_TYPE_MKCHAR or TOMOYO_TYPE_MKBLOCK)
853  * @path:      Pointer to "struct path".
854  * @mode:      Create mode.
855  * @dev:       Device number.
856  *
857  * Returns 0 on success, negative value otherwise.
858  */
tomoyo_mkdev_perm(const u8 operation,const struct path * path,const unsigned int mode,unsigned int dev)859 int tomoyo_mkdev_perm(const u8 operation, const struct path *path,
860 		      const unsigned int mode, unsigned int dev)
861 {
862 	struct tomoyo_request_info r;
863 	struct tomoyo_obj_info obj = {
864 		.path1 = { .mnt = path->mnt, .dentry = path->dentry },
865 	};
866 	int error = -ENOMEM;
867 	struct tomoyo_path_info buf;
868 	int idx;
869 
870 	if (tomoyo_init_request_info(&r, NULL, tomoyo_pnnn2mac[operation])
871 	    == TOMOYO_CONFIG_DISABLED)
872 		return 0;
873 	idx = tomoyo_read_lock();
874 	error = -ENOMEM;
875 	if (tomoyo_get_realpath(&buf, path)) {
876 		r.obj = &obj;
877 		dev = new_decode_dev(dev);
878 		r.param_type = TOMOYO_TYPE_MKDEV_ACL;
879 		r.param.mkdev.filename = &buf;
880 		r.param.mkdev.operation = operation;
881 		r.param.mkdev.mode = mode;
882 		r.param.mkdev.major = MAJOR(dev);
883 		r.param.mkdev.minor = MINOR(dev);
884 		tomoyo_check_acl(&r, tomoyo_check_mkdev_acl);
885 		error = tomoyo_audit_mkdev_log(&r);
886 		kfree(buf.name);
887 	}
888 	tomoyo_read_unlock(idx);
889 	if (r.mode != TOMOYO_CONFIG_ENFORCING)
890 		error = 0;
891 	return error;
892 }
893 
894 /**
895  * tomoyo_path2_perm - Check permission for "rename", "link" and "pivot_root".
896  *
897  * @operation: Type of operation.
898  * @path1:      Pointer to "struct path".
899  * @path2:      Pointer to "struct path".
900  *
901  * Returns 0 on success, negative value otherwise.
902  */
tomoyo_path2_perm(const u8 operation,const struct path * path1,const struct path * path2)903 int tomoyo_path2_perm(const u8 operation, const struct path *path1,
904 		      const struct path *path2)
905 {
906 	int error = -ENOMEM;
907 	struct tomoyo_path_info buf1;
908 	struct tomoyo_path_info buf2;
909 	struct tomoyo_request_info r;
910 	struct tomoyo_obj_info obj = {
911 		.path1 = { .mnt = path1->mnt, .dentry = path1->dentry },
912 		.path2 = { .mnt = path2->mnt, .dentry = path2->dentry }
913 	};
914 	int idx;
915 
916 	if (tomoyo_init_request_info(&r, NULL, tomoyo_pp2mac[operation])
917 	    == TOMOYO_CONFIG_DISABLED)
918 		return 0;
919 	buf1.name = NULL;
920 	buf2.name = NULL;
921 	idx = tomoyo_read_lock();
922 	if (!tomoyo_get_realpath(&buf1, path1) ||
923 	    !tomoyo_get_realpath(&buf2, path2))
924 		goto out;
925 	switch (operation) {
926 	case TOMOYO_TYPE_RENAME:
927 	case TOMOYO_TYPE_LINK:
928 		if (!d_is_dir(path1->dentry))
929 			break;
930 		fallthrough;
931 	case TOMOYO_TYPE_PIVOT_ROOT:
932 		tomoyo_add_slash(&buf1);
933 		tomoyo_add_slash(&buf2);
934 		break;
935 	}
936 	r.obj = &obj;
937 	r.param_type = TOMOYO_TYPE_PATH2_ACL;
938 	r.param.path2.operation = operation;
939 	r.param.path2.filename1 = &buf1;
940 	r.param.path2.filename2 = &buf2;
941 	do {
942 		tomoyo_check_acl(&r, tomoyo_check_path2_acl);
943 		error = tomoyo_audit_path2_log(&r);
944 	} while (error == TOMOYO_RETRY_REQUEST);
945  out:
946 	kfree(buf1.name);
947 	kfree(buf2.name);
948 	tomoyo_read_unlock(idx);
949 	if (r.mode != TOMOYO_CONFIG_ENFORCING)
950 		error = 0;
951 	return error;
952 }
953 
954 /**
955  * tomoyo_same_mount_acl - Check for duplicated "struct tomoyo_mount_acl" entry.
956  *
957  * @a: Pointer to "struct tomoyo_acl_info".
958  * @b: Pointer to "struct tomoyo_acl_info".
959  *
960  * Returns true if @a == @b, false otherwise.
961  */
tomoyo_same_mount_acl(const struct tomoyo_acl_info * a,const struct tomoyo_acl_info * b)962 static bool tomoyo_same_mount_acl(const struct tomoyo_acl_info *a,
963 				  const struct tomoyo_acl_info *b)
964 {
965 	const struct tomoyo_mount_acl *p1 = container_of(a, typeof(*p1), head);
966 	const struct tomoyo_mount_acl *p2 = container_of(b, typeof(*p2), head);
967 
968 	return tomoyo_same_name_union(&p1->dev_name, &p2->dev_name) &&
969 		tomoyo_same_name_union(&p1->dir_name, &p2->dir_name) &&
970 		tomoyo_same_name_union(&p1->fs_type, &p2->fs_type) &&
971 		tomoyo_same_number_union(&p1->flags, &p2->flags);
972 }
973 
974 /**
975  * tomoyo_update_mount_acl - Write "struct tomoyo_mount_acl" list.
976  *
977  * @param: Pointer to "struct tomoyo_acl_param".
978  *
979  * Returns 0 on success, negative value otherwise.
980  *
981  * Caller holds tomoyo_read_lock().
982  */
tomoyo_update_mount_acl(struct tomoyo_acl_param * param)983 static int tomoyo_update_mount_acl(struct tomoyo_acl_param *param)
984 {
985 	struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL };
986 	int error;
987 
988 	if (!tomoyo_parse_name_union(param, &e.dev_name) ||
989 	    !tomoyo_parse_name_union(param, &e.dir_name) ||
990 	    !tomoyo_parse_name_union(param, &e.fs_type) ||
991 	    !tomoyo_parse_number_union(param, &e.flags))
992 		error = -EINVAL;
993 	else
994 		error = tomoyo_update_domain(&e.head, sizeof(e), param,
995 					     tomoyo_same_mount_acl, NULL);
996 	tomoyo_put_name_union(&e.dev_name);
997 	tomoyo_put_name_union(&e.dir_name);
998 	tomoyo_put_name_union(&e.fs_type);
999 	tomoyo_put_number_union(&e.flags);
1000 	return error;
1001 }
1002 
1003 /**
1004  * tomoyo_write_file - Update file related list.
1005  *
1006  * @param: Pointer to "struct tomoyo_acl_param".
1007  *
1008  * Returns 0 on success, negative value otherwise.
1009  *
1010  * Caller holds tomoyo_read_lock().
1011  */
tomoyo_write_file(struct tomoyo_acl_param * param)1012 int tomoyo_write_file(struct tomoyo_acl_param *param)
1013 {
1014 	u16 perm = 0;
1015 	u8 type;
1016 	const char *operation = tomoyo_read_token(param);
1017 
1018 	for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++)
1019 		if (tomoyo_permstr(operation, tomoyo_path_keyword[type]))
1020 			perm |= 1 << type;
1021 	if (perm)
1022 		return tomoyo_update_path_acl(perm, param);
1023 	for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++)
1024 		if (tomoyo_permstr(operation,
1025 				   tomoyo_mac_keywords[tomoyo_pp2mac[type]]))
1026 			perm |= 1 << type;
1027 	if (perm)
1028 		return tomoyo_update_path2_acl(perm, param);
1029 	for (type = 0; type < TOMOYO_MAX_PATH_NUMBER_OPERATION; type++)
1030 		if (tomoyo_permstr(operation,
1031 				   tomoyo_mac_keywords[tomoyo_pn2mac[type]]))
1032 			perm |= 1 << type;
1033 	if (perm)
1034 		return tomoyo_update_path_number_acl(perm, param);
1035 	for (type = 0; type < TOMOYO_MAX_MKDEV_OPERATION; type++)
1036 		if (tomoyo_permstr(operation,
1037 				   tomoyo_mac_keywords[tomoyo_pnnn2mac[type]]))
1038 			perm |= 1 << type;
1039 	if (perm)
1040 		return tomoyo_update_mkdev_acl(perm, param);
1041 	if (tomoyo_permstr(operation,
1042 			   tomoyo_mac_keywords[TOMOYO_MAC_FILE_MOUNT]))
1043 		return tomoyo_update_mount_acl(param);
1044 	return -EINVAL;
1045 }
1046