2 * security/tomoyo/mount.c
4 * Copyright (C) 2005-2010 NTT DATA CORPORATION
7 #include <linux/slab.h>
10 /* Keywords for mount restrictions. */
12 /* Allow to call 'mount --bind /source_dir /dest_dir' */
13 #define TOMOYO_MOUNT_BIND_KEYWORD "--bind"
14 /* Allow to call 'mount --move /old_dir /new_dir ' */
15 #define TOMOYO_MOUNT_MOVE_KEYWORD "--move"
16 /* Allow to call 'mount -o remount /dir ' */
17 #define TOMOYO_MOUNT_REMOUNT_KEYWORD "--remount"
18 /* Allow to call 'mount --make-unbindable /dir' */
19 #define TOMOYO_MOUNT_MAKE_UNBINDABLE_KEYWORD "--make-unbindable"
20 /* Allow to call 'mount --make-private /dir' */
21 #define TOMOYO_MOUNT_MAKE_PRIVATE_KEYWORD "--make-private"
22 /* Allow to call 'mount --make-slave /dir' */
23 #define TOMOYO_MOUNT_MAKE_SLAVE_KEYWORD "--make-slave"
24 /* Allow to call 'mount --make-shared /dir' */
25 #define TOMOYO_MOUNT_MAKE_SHARED_KEYWORD "--make-shared"
28 * tomoyo_mount_acl2 - Check permission for mount() operation.
30 * @r: Pointer to "struct tomoyo_request_info".
31 * @dev_name: Name of device file.
32 * @dir: Pointer to "struct path".
33 * @type: Name of filesystem type.
34 * @flags: Mount options.
36 * Returns 0 on success, negative value otherwise.
38 * Caller holds tomoyo_read_lock().
40 static int tomoyo_mount_acl2(struct tomoyo_request_info *r, char *dev_name,
41 struct path *dir, char *type, unsigned long flags)
44 struct tomoyo_acl_info *ptr;
45 struct file_system_type *fstype = NULL;
46 const char *requested_type = NULL;
47 const char *requested_dir_name = NULL;
48 const char *requested_dev_name = NULL;
49 struct tomoyo_path_info rtype;
50 struct tomoyo_path_info rdev;
51 struct tomoyo_path_info rdir;
56 requested_type = tomoyo_encode(type);
59 rtype.name = requested_type;
60 tomoyo_fill_path_info(&rtype);
62 /* Get mount point. */
63 requested_dir_name = tomoyo_realpath_from_path(dir);
64 if (!requested_dir_name) {
68 rdir.name = requested_dir_name;
69 tomoyo_fill_path_info(&rdir);
71 /* Compare fs name. */
72 if (!strcmp(type, TOMOYO_MOUNT_REMOUNT_KEYWORD)) {
73 /* dev_name is ignored. */
74 } else if (!strcmp(type, TOMOYO_MOUNT_MAKE_UNBINDABLE_KEYWORD) ||
75 !strcmp(type, TOMOYO_MOUNT_MAKE_PRIVATE_KEYWORD) ||
76 !strcmp(type, TOMOYO_MOUNT_MAKE_SLAVE_KEYWORD) ||
77 !strcmp(type, TOMOYO_MOUNT_MAKE_SHARED_KEYWORD)) {
78 /* dev_name is ignored. */
79 } else if (!strcmp(type, TOMOYO_MOUNT_BIND_KEYWORD) ||
80 !strcmp(type, TOMOYO_MOUNT_MOVE_KEYWORD)) {
81 need_dev = -1; /* dev_name is a directory */
83 fstype = get_fs_type(type);
88 if (fstype->fs_flags & FS_REQUIRES_DEV)
89 /* dev_name is a block device file. */
93 /* Get mount point or device file. */
94 if (kern_path(dev_name, LOOKUP_FOLLOW, &path)) {
98 requested_dev_name = tomoyo_realpath_from_path(&path);
99 if (!requested_dev_name) {
104 /* Map dev_name to "<NULL>" if no dev_name given. */
107 requested_dev_name = tomoyo_encode(dev_name);
108 if (!requested_dev_name) {
113 rdev.name = requested_dev_name;
114 tomoyo_fill_path_info(&rdev);
115 list_for_each_entry_rcu(ptr, &r->domain->acl_info_list, list) {
116 struct tomoyo_mount_acl *acl;
117 if (ptr->type != TOMOYO_TYPE_MOUNT_ACL)
119 acl = container_of(ptr, struct tomoyo_mount_acl, head);
120 if (acl->is_deleted ||
121 !tomoyo_compare_number_union(flags, &acl->flags) ||
122 !tomoyo_compare_name_union(&rtype, &acl->fs_type) ||
123 !tomoyo_compare_name_union(&rdir, &acl->dir_name) ||
125 !tomoyo_compare_name_union(&rdev, &acl->dev_name)))
131 error = tomoyo_supervisor(r, TOMOYO_KEYWORD_ALLOW_MOUNT
133 tomoyo_file_pattern(&rdev),
134 tomoyo_file_pattern(&rdir),
135 requested_type, flags);
137 kfree(requested_dev_name);
138 kfree(requested_dir_name);
140 put_filesystem(fstype);
141 kfree(requested_type);
146 * tomoyo_mount_acl - Check permission for mount() operation.
148 * @r: Pointer to "struct tomoyo_request_info".
149 * @dev_name: Name of device file.
150 * @dir: Pointer to "struct path".
151 * @type: Name of filesystem type.
152 * @flags: Mount options.
154 * Returns 0 on success, negative value otherwise.
156 * Caller holds tomoyo_read_lock().
158 static int tomoyo_mount_acl(struct tomoyo_request_info *r, char *dev_name,
159 struct path *dir, char *type, unsigned long flags)
163 if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
164 flags &= ~MS_MGC_MSK;
165 switch (flags & (MS_REMOUNT | MS_MOVE | MS_BIND)) {
172 printk(KERN_WARNING "ERROR: "
173 "%s%s%sare given for single mount operation.\n",
174 flags & MS_REMOUNT ? "'remount' " : "",
175 flags & MS_MOVE ? "'move' " : "",
176 flags & MS_BIND ? "'bind' " : "");
179 switch (flags & (MS_UNBINDABLE | MS_PRIVATE | MS_SLAVE | MS_SHARED)) {
187 printk(KERN_WARNING "ERROR: "
188 "%s%s%s%sare given for single mount operation.\n",
189 flags & MS_UNBINDABLE ? "'unbindable' " : "",
190 flags & MS_PRIVATE ? "'private' " : "",
191 flags & MS_SLAVE ? "'slave' " : "",
192 flags & MS_SHARED ? "'shared' " : "");
195 if (flags & MS_REMOUNT)
196 error = tomoyo_mount_acl(r, dev_name, dir,
197 TOMOYO_MOUNT_REMOUNT_KEYWORD,
198 flags & ~MS_REMOUNT);
199 else if (flags & MS_MOVE)
200 error = tomoyo_mount_acl(r, dev_name, dir,
201 TOMOYO_MOUNT_MOVE_KEYWORD,
203 else if (flags & MS_BIND)
204 error = tomoyo_mount_acl(r, dev_name, dir,
205 TOMOYO_MOUNT_BIND_KEYWORD,
207 else if (flags & MS_UNBINDABLE)
208 error = tomoyo_mount_acl(r, dev_name, dir,
209 TOMOYO_MOUNT_MAKE_UNBINDABLE_KEYWORD,
210 flags & ~MS_UNBINDABLE);
211 else if (flags & MS_PRIVATE)
212 error = tomoyo_mount_acl(r, dev_name, dir,
213 TOMOYO_MOUNT_MAKE_PRIVATE_KEYWORD,
214 flags & ~MS_PRIVATE);
215 else if (flags & MS_SLAVE)
216 error = tomoyo_mount_acl(r, dev_name, dir,
217 TOMOYO_MOUNT_MAKE_SLAVE_KEYWORD,
219 else if (flags & MS_SHARED)
220 error = tomoyo_mount_acl(r, dev_name, dir,
221 TOMOYO_MOUNT_MAKE_SHARED_KEYWORD,
225 error = tomoyo_mount_acl2(r, dev_name, dir, type,
227 } while (error == TOMOYO_RETRY_REQUEST);
228 if (r->mode != TOMOYO_CONFIG_ENFORCING)
234 * tomoyo_mount_permission - Check permission for mount() operation.
236 * @dev_name: Name of device file.
237 * @path: Pointer to "struct path".
238 * @type: Name of filesystem type. May be NULL.
239 * @flags: Mount options.
240 * @data_page: Optional data. May be NULL.
242 * Returns 0 on success, negative value otherwise.
244 int tomoyo_mount_permission(char *dev_name, struct path *path, char *type,
245 unsigned long flags, void *data_page)
247 struct tomoyo_request_info r;
251 if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED)
255 idx = tomoyo_read_lock();
256 error = tomoyo_mount_acl(&r, dev_name, path, type, flags);
257 tomoyo_read_unlock(idx);
262 * tomoyo_write_mount_policy - Write "struct tomoyo_mount_acl" list.
264 * @data: String to parse.
265 * @domain: Pointer to "struct tomoyo_domain_info".
266 * @is_delete: True if it is a delete request.
268 * Returns 0 on success, negative value otherwise.
270 int tomoyo_write_mount_policy(char *data, struct tomoyo_domain_info *domain,
271 const bool is_delete)
273 struct tomoyo_acl_info *ptr;
274 struct tomoyo_mount_acl e = { .head.type = TOMOYO_TYPE_MOUNT_ACL };
275 int error = is_delete ? -ENOENT : -ENOMEM;
277 if (!tomoyo_tokenize(data, w, sizeof(w)) || !w[3][0])
279 if (!tomoyo_parse_name_union(w[0], &e.dev_name) ||
280 !tomoyo_parse_name_union(w[1], &e.dir_name) ||
281 !tomoyo_parse_name_union(w[2], &e.fs_type) ||
282 !tomoyo_parse_number_union(w[3], &e.flags))
284 if (mutex_lock_interruptible(&tomoyo_policy_lock))
286 list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
287 struct tomoyo_mount_acl *acl =
288 container_of(ptr, struct tomoyo_mount_acl, head);
289 if (!tomoyo_is_same_mount_acl(acl, &e))
291 acl->is_deleted = is_delete;
295 if (!is_delete && error) {
296 struct tomoyo_mount_acl *entry =
297 tomoyo_commit_ok(&e, sizeof(e));
299 list_add_tail_rcu(&entry->head.list,
300 &domain->acl_info_list);
304 mutex_unlock(&tomoyo_policy_lock);
306 tomoyo_put_name_union(&e.dev_name);
307 tomoyo_put_name_union(&e.dir_name);
308 tomoyo_put_name_union(&e.fs_type);
309 tomoyo_put_number_union(&e.flags);