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
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/***
Copyright © 2013 Intel Corporation
Author: Auke Kok <auke-jan.h.kok@intel.com>
***/
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/xattr.h>
#include <unistd.h>
#include "alloc-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "log.h"
#include "macro.h"
#include "path-util.h"
#include "process-util.h"
#include "smack-util.h"
#include "stdio-util.h"
#include "string-table.h"
#include "xattr-util.h"
#if ENABLE_SMACK
bool mac_smack_use(void) {
static int cached_use = -1;
if (cached_use < 0)
cached_use = access("/sys/fs/smackfs/", F_OK) >= 0;
return cached_use;
}
static const char* const smack_attr_table[_SMACK_ATTR_MAX] = {
[SMACK_ATTR_ACCESS] = "security.SMACK64",
[SMACK_ATTR_EXEC] = "security.SMACK64EXEC",
[SMACK_ATTR_MMAP] = "security.SMACK64MMAP",
[SMACK_ATTR_TRANSMUTE] = "security.SMACK64TRANSMUTE",
[SMACK_ATTR_IPIN] = "security.SMACK64IPIN",
[SMACK_ATTR_IPOUT] = "security.SMACK64IPOUT",
};
DEFINE_STRING_TABLE_LOOKUP(smack_attr, SmackAttr);
int mac_smack_read(const char *path, SmackAttr attr, char **label) {
assert(path);
assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
assert(label);
if (!mac_smack_use())
return 0;
return getxattr_malloc(path, smack_attr_to_string(attr), label);
}
int mac_smack_read_fd(int fd, SmackAttr attr, char **label) {
assert(fd >= 0);
assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
assert(label);
if (!mac_smack_use())
return 0;
return fgetxattr_malloc(fd, smack_attr_to_string(attr), label);
}
int mac_smack_apply(const char *path, SmackAttr attr, const char *label) {
int r;
assert(path);
assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
if (!mac_smack_use())
return 0;
if (label)
r = lsetxattr(path, smack_attr_to_string(attr), label, strlen(label), 0);
else
r = lremovexattr(path, smack_attr_to_string(attr));
if (r < 0)
return -errno;
return 0;
}
int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) {
int r;
assert(fd >= 0);
assert(attr >= 0 && attr < _SMACK_ATTR_MAX);
if (!mac_smack_use())
return 0;
if (label)
r = setxattr(FORMAT_PROC_FD_PATH(fd), smack_attr_to_string(attr), label, strlen(label), 0);
else
r = removexattr(FORMAT_PROC_FD_PATH(fd), smack_attr_to_string(attr));
if (r < 0)
return -errno;
return 0;
}
int mac_smack_apply_pid(pid_t pid, const char *label) {
const char *p;
int r;
assert(label);
if (!mac_smack_use())
return 0;
p = procfs_file_alloca(pid, "attr/current");
r = write_string_file(p, label, WRITE_STRING_FILE_DISABLE_BUFFER);
if (r < 0)
return r;
return r;
}
static int smack_fix_fd(int fd, const char *abspath, LabelFixFlags flags) {
const char *label;
struct stat st;
int r;
/* The caller should have done the sanity checks. */
assert(abspath);
assert(path_is_absolute(abspath));
/* Path must be in /dev. */
if (!path_startswith(abspath, "/dev"))
return 0;
if (fstat(fd, &st) < 0)
return -errno;
/*
* Label directories and character devices "*".
* Label symlinks "_".
* Don't change anything else.
*/
if (S_ISDIR(st.st_mode))
label = SMACK_STAR_LABEL;
else if (S_ISLNK(st.st_mode))
label = SMACK_FLOOR_LABEL;
else if (S_ISCHR(st.st_mode))
label = SMACK_STAR_LABEL;
else
return 0;
if (setxattr(FORMAT_PROC_FD_PATH(fd), "security.SMACK64", label, strlen(label), 0) < 0) {
_cleanup_free_ char *old_label = NULL;
r = -errno;
/* If the FS doesn't support labels, then exit without warning */
if (r == -EOPNOTSUPP)
return 0;
/* It the FS is read-only and we were told to ignore failures caused by that, suppress error */
if (r == -EROFS && (flags & LABEL_IGNORE_EROFS))
return 0;
/* If the old label is identical to the new one, suppress any kind of error */
if (lgetxattr_malloc(FORMAT_PROC_FD_PATH(fd), "security.SMACK64", &old_label) >= 0 &&
streq(old_label, label))
return 0;
return log_debug_errno(r, "Unable to fix SMACK label of %s: %m", abspath);
}
return 0;
}
int mac_smack_fix_at(int dir_fd, const char *path, LabelFixFlags flags) {
_cleanup_free_ char *p = NULL;
_cleanup_close_ int fd = -1;
int r;
assert(path);
if (!mac_smack_use())
return 0;
if (dir_fd < 0) {
if (dir_fd != AT_FDCWD)
return -EBADF;
return mac_smack_fix(path, flags);
}
fd = openat(dir_fd, path, O_NOFOLLOW|O_CLOEXEC|O_PATH);
if (fd < 0) {
if ((flags & LABEL_IGNORE_ENOENT) && errno == ENOENT)
return 0;
return -errno;
}
if (!path_is_absolute(path)) {
r = fd_get_path(fd, &p);
if (r < 0)
return r;
path = p;
}
return smack_fix_fd(fd, path, flags);
}
int mac_smack_fix_container(const char *path, const char *inside_path, LabelFixFlags flags) {
_cleanup_free_ char *abspath = NULL;
_cleanup_close_ int fd = -1;
int r;
assert(path);
if (!mac_smack_use())
return 0;
r = path_make_absolute_cwd(path, &abspath);
if (r < 0)
return r;
fd = open(abspath, O_NOFOLLOW|O_CLOEXEC|O_PATH);
if (fd < 0) {
if ((flags & LABEL_IGNORE_ENOENT) && errno == ENOENT)
return 0;
return -errno;
}
return smack_fix_fd(fd, inside_path, flags);
}
int mac_smack_copy(const char *dest, const char *src) {
int r;
_cleanup_free_ char *label = NULL;
assert(dest);
assert(src);
r = mac_smack_read(src, SMACK_ATTR_ACCESS, &label);
if (r < 0)
return r;
r = mac_smack_apply(dest, SMACK_ATTR_ACCESS, label);
if (r < 0)
return r;
return r;
}
#else
bool mac_smack_use(void) {
return false;
}
int mac_smack_read(const char *path, SmackAttr attr, char **label) {
return -EOPNOTSUPP;
}
int mac_smack_read_fd(int fd, SmackAttr attr, char **label) {
return -EOPNOTSUPP;
}
int mac_smack_apply(const char *path, SmackAttr attr, const char *label) {
return 0;
}
int mac_smack_apply_fd(int fd, SmackAttr attr, const char *label) {
return 0;
}
int mac_smack_apply_pid(pid_t pid, const char *label) {
return 0;
}
int mac_smack_fix_container(const char *path, const char *inside_path, LabelFixFlags flags) {
return 0;
}
int mac_smack_fix_at(int dirfd, const char *path, LabelFixFlags flags) {
return 0;
}
int mac_smack_copy(const char *dest, const char *src) {
return 0;
}
#endif
int rename_and_apply_smack_floor_label(const char *from, const char *to) {
if (rename(from, to) < 0)
return -errno;
#if HAVE_SMACK_RUN_LABEL
return mac_smack_apply(to, SMACK_ATTR_ACCESS, SMACK_FLOOR_LABEL);
#else
return 0;
#endif
}
|
