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