Commit | Line | Data |
---|---|---|
2106ccd9 TH |
1 | /* |
2 | * security/tomoyo/mount.c | |
3 | * | |
0f2a55d5 | 4 | * Copyright (C) 2005-2011 NTT DATA CORPORATION |
2106ccd9 TH |
5 | */ |
6 | ||
7 | #include <linux/slab.h> | |
8 | #include "common.h" | |
9 | ||
b5bc60b4 TH |
10 | /* String table for special mount operations. */ |
11 | static const char * const tomoyo_mounts[TOMOYO_MAX_SPECIAL_MOUNT] = { | |
12 | [TOMOYO_MOUNT_BIND] = "--bind", | |
13 | [TOMOYO_MOUNT_MOVE] = "--move", | |
14 | [TOMOYO_MOUNT_REMOUNT] = "--remount", | |
15 | [TOMOYO_MOUNT_MAKE_UNBINDABLE] = "--make-unbindable", | |
16 | [TOMOYO_MOUNT_MAKE_PRIVATE] = "--make-private", | |
17 | [TOMOYO_MOUNT_MAKE_SLAVE] = "--make-slave", | |
18 | [TOMOYO_MOUNT_MAKE_SHARED] = "--make-shared", | |
19 | }; | |
2106ccd9 | 20 | |
99a85259 TH |
21 | /** |
22 | * tomoyo_audit_mount_log - Audit mount log. | |
23 | * | |
24 | * @r: Pointer to "struct tomoyo_request_info". | |
25 | * | |
26 | * Returns 0 on success, negative value otherwise. | |
27 | */ | |
28 | static int tomoyo_audit_mount_log(struct tomoyo_request_info *r) | |
29 | { | |
eadd99cc | 30 | return tomoyo_supervisor(r, "file mount %s %s %s 0x%lX\n", |
7c75964f | 31 | r->param.mount.dev->name, |
eadd99cc TH |
32 | r->param.mount.dir->name, |
33 | r->param.mount.type->name, | |
34 | r->param.mount.flags); | |
99a85259 TH |
35 | } |
36 | ||
0df7e8b8 TH |
37 | /** |
38 | * tomoyo_check_mount_acl - Check permission for path path path number operation. | |
39 | * | |
40 | * @r: Pointer to "struct tomoyo_request_info". | |
41 | * @ptr: Pointer to "struct tomoyo_acl_info". | |
42 | * | |
43 | * Returns true if granted, false otherwise. | |
44 | */ | |
484ca79c | 45 | static bool tomoyo_check_mount_acl(struct tomoyo_request_info *r, |
99a85259 TH |
46 | const struct tomoyo_acl_info *ptr) |
47 | { | |
48 | const struct tomoyo_mount_acl *acl = | |
49 | container_of(ptr, typeof(*acl), head); | |
0df7e8b8 TH |
50 | return tomoyo_compare_number_union(r->param.mount.flags, |
51 | &acl->flags) && | |
52 | tomoyo_compare_name_union(r->param.mount.type, | |
53 | &acl->fs_type) && | |
54 | tomoyo_compare_name_union(r->param.mount.dir, | |
55 | &acl->dir_name) && | |
99a85259 | 56 | (!r->param.mount.need_dev || |
0df7e8b8 TH |
57 | tomoyo_compare_name_union(r->param.mount.dev, |
58 | &acl->dev_name)); | |
99a85259 TH |
59 | } |
60 | ||
2106ccd9 | 61 | /** |
d795ef9e | 62 | * tomoyo_mount_acl - Check permission for mount() operation. |
2106ccd9 TH |
63 | * |
64 | * @r: Pointer to "struct tomoyo_request_info". | |
0f2a55d5 | 65 | * @dev_name: Name of device file. Maybe NULL. |
2106ccd9 TH |
66 | * @dir: Pointer to "struct path". |
67 | * @type: Name of filesystem type. | |
68 | * @flags: Mount options. | |
69 | * | |
70 | * Returns 0 on success, negative value otherwise. | |
71 | * | |
72 | * Caller holds tomoyo_read_lock(). | |
73 | */ | |
d795ef9e | 74 | static int tomoyo_mount_acl(struct tomoyo_request_info *r, char *dev_name, |
b5bc60b4 TH |
75 | struct path *dir, const char *type, |
76 | unsigned long flags) | |
2106ccd9 | 77 | { |
97fb35e4 | 78 | struct tomoyo_obj_info obj = { }; |
2106ccd9 | 79 | struct path path; |
2106ccd9 TH |
80 | struct file_system_type *fstype = NULL; |
81 | const char *requested_type = NULL; | |
82 | const char *requested_dir_name = NULL; | |
83 | const char *requested_dev_name = NULL; | |
84 | struct tomoyo_path_info rtype; | |
85 | struct tomoyo_path_info rdev; | |
86 | struct tomoyo_path_info rdir; | |
87 | int need_dev = 0; | |
88 | int error = -ENOMEM; | |
97fb35e4 | 89 | r->obj = &obj; |
2106ccd9 TH |
90 | |
91 | /* Get fstype. */ | |
c8c57e84 | 92 | requested_type = tomoyo_encode(type); |
2106ccd9 TH |
93 | if (!requested_type) |
94 | goto out; | |
95 | rtype.name = requested_type; | |
96 | tomoyo_fill_path_info(&rtype); | |
97 | ||
98 | /* Get mount point. */ | |
97fb35e4 | 99 | obj.path2 = *dir; |
2106ccd9 TH |
100 | requested_dir_name = tomoyo_realpath_from_path(dir); |
101 | if (!requested_dir_name) { | |
102 | error = -ENOMEM; | |
103 | goto out; | |
104 | } | |
105 | rdir.name = requested_dir_name; | |
106 | tomoyo_fill_path_info(&rdir); | |
107 | ||
108 | /* Compare fs name. */ | |
b5bc60b4 | 109 | if (type == tomoyo_mounts[TOMOYO_MOUNT_REMOUNT]) { |
2106ccd9 | 110 | /* dev_name is ignored. */ |
b5bc60b4 TH |
111 | } else if (type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE] || |
112 | type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE] || | |
113 | type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE] || | |
114 | type == tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED]) { | |
2106ccd9 | 115 | /* dev_name is ignored. */ |
b5bc60b4 TH |
116 | } else if (type == tomoyo_mounts[TOMOYO_MOUNT_BIND] || |
117 | type == tomoyo_mounts[TOMOYO_MOUNT_MOVE]) { | |
2106ccd9 TH |
118 | need_dev = -1; /* dev_name is a directory */ |
119 | } else { | |
120 | fstype = get_fs_type(type); | |
121 | if (!fstype) { | |
122 | error = -ENODEV; | |
123 | goto out; | |
124 | } | |
125 | if (fstype->fs_flags & FS_REQUIRES_DEV) | |
126 | /* dev_name is a block device file. */ | |
127 | need_dev = 1; | |
128 | } | |
129 | if (need_dev) { | |
130 | /* Get mount point or device file. */ | |
4e78c724 | 131 | if (!dev_name || kern_path(dev_name, LOOKUP_FOLLOW, &path)) { |
2106ccd9 TH |
132 | error = -ENOENT; |
133 | goto out; | |
134 | } | |
97fb35e4 | 135 | obj.path1 = path; |
2106ccd9 TH |
136 | requested_dev_name = tomoyo_realpath_from_path(&path); |
137 | if (!requested_dev_name) { | |
138 | error = -ENOENT; | |
139 | goto out; | |
140 | } | |
141 | } else { | |
142 | /* Map dev_name to "<NULL>" if no dev_name given. */ | |
143 | if (!dev_name) | |
144 | dev_name = "<NULL>"; | |
c8c57e84 | 145 | requested_dev_name = tomoyo_encode(dev_name); |
2106ccd9 TH |
146 | if (!requested_dev_name) { |
147 | error = -ENOMEM; | |
148 | goto out; | |
149 | } | |
150 | } | |
151 | rdev.name = requested_dev_name; | |
152 | tomoyo_fill_path_info(&rdev); | |
cf6e9a64 TH |
153 | r->param_type = TOMOYO_TYPE_MOUNT_ACL; |
154 | r->param.mount.need_dev = need_dev; | |
155 | r->param.mount.dev = &rdev; | |
156 | r->param.mount.dir = &rdir; | |
157 | r->param.mount.type = &rtype; | |
158 | r->param.mount.flags = flags; | |
99a85259 TH |
159 | do { |
160 | tomoyo_check_acl(r, tomoyo_check_mount_acl); | |
161 | error = tomoyo_audit_mount_log(r); | |
162 | } while (error == TOMOYO_RETRY_REQUEST); | |
2106ccd9 TH |
163 | out: |
164 | kfree(requested_dev_name); | |
165 | kfree(requested_dir_name); | |
166 | if (fstype) | |
167 | put_filesystem(fstype); | |
168 | kfree(requested_type); | |
97fb35e4 TH |
169 | /* Drop refcount obtained by kern_path(). */ |
170 | if (obj.path1.dentry) | |
171 | path_put(&obj.path1); | |
2106ccd9 TH |
172 | return error; |
173 | } | |
174 | ||
2106ccd9 TH |
175 | /** |
176 | * tomoyo_mount_permission - Check permission for mount() operation. | |
177 | * | |
0f2a55d5 | 178 | * @dev_name: Name of device file. Maybe NULL. |
2106ccd9 | 179 | * @path: Pointer to "struct path". |
0f2a55d5 | 180 | * @type: Name of filesystem type. Maybe NULL. |
2106ccd9 | 181 | * @flags: Mount options. |
0f2a55d5 | 182 | * @data_page: Optional data. Maybe NULL. |
2106ccd9 TH |
183 | * |
184 | * Returns 0 on success, negative value otherwise. | |
185 | */ | |
b5bc60b4 TH |
186 | int tomoyo_mount_permission(char *dev_name, struct path *path, |
187 | const char *type, unsigned long flags, | |
188 | void *data_page) | |
2106ccd9 TH |
189 | { |
190 | struct tomoyo_request_info r; | |
191 | int error; | |
192 | int idx; | |
193 | ||
57c2590f TH |
194 | if (tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_MOUNT) |
195 | == TOMOYO_CONFIG_DISABLED) | |
2106ccd9 | 196 | return 0; |
d795ef9e TH |
197 | if ((flags & MS_MGC_MSK) == MS_MGC_VAL) |
198 | flags &= ~MS_MGC_MSK; | |
199 | if (flags & MS_REMOUNT) { | |
b5bc60b4 | 200 | type = tomoyo_mounts[TOMOYO_MOUNT_REMOUNT]; |
d795ef9e | 201 | flags &= ~MS_REMOUNT; |
df91e494 | 202 | } else if (flags & MS_BIND) { |
b5bc60b4 | 203 | type = tomoyo_mounts[TOMOYO_MOUNT_BIND]; |
d795ef9e | 204 | flags &= ~MS_BIND; |
df91e494 TH |
205 | } else if (flags & MS_SHARED) { |
206 | if (flags & (MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) | |
207 | return -EINVAL; | |
208 | type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SHARED]; | |
209 | flags &= ~MS_SHARED; | |
210 | } else if (flags & MS_PRIVATE) { | |
211 | if (flags & (MS_SHARED | MS_SLAVE | MS_UNBINDABLE)) | |
212 | return -EINVAL; | |
b5bc60b4 | 213 | type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_PRIVATE]; |
d795ef9e | 214 | flags &= ~MS_PRIVATE; |
df91e494 TH |
215 | } else if (flags & MS_SLAVE) { |
216 | if (flags & (MS_SHARED | MS_PRIVATE | MS_UNBINDABLE)) | |
217 | return -EINVAL; | |
b5bc60b4 | 218 | type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_SLAVE]; |
d795ef9e | 219 | flags &= ~MS_SLAVE; |
df91e494 TH |
220 | } else if (flags & MS_UNBINDABLE) { |
221 | if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE)) | |
222 | return -EINVAL; | |
223 | type = tomoyo_mounts[TOMOYO_MOUNT_MAKE_UNBINDABLE]; | |
224 | flags &= ~MS_UNBINDABLE; | |
225 | } else if (flags & MS_MOVE) { | |
226 | type = tomoyo_mounts[TOMOYO_MOUNT_MOVE]; | |
227 | flags &= ~MS_MOVE; | |
d795ef9e | 228 | } |
2106ccd9 TH |
229 | if (!type) |
230 | type = "<NULL>"; | |
231 | idx = tomoyo_read_lock(); | |
232 | error = tomoyo_mount_acl(&r, dev_name, path, type, flags); | |
233 | tomoyo_read_unlock(idx); | |
234 | return error; | |
235 | } |