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
|
// SPDX-License-Identifier: GPL-2.0
/* Test triggering of loading of firmware from different mount
* namespaces. Expect firmware to be always loaded from the mount
* namespace of PID 1. */
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#ifndef CLONE_NEWNS
# define CLONE_NEWNS 0x00020000
#endif
static char *fw_path = NULL;
static void die(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
if (fw_path)
unlink(fw_path);
umount("/lib/firmware");
exit(EXIT_FAILURE);
}
static void trigger_fw(const char *fw_name, const char *sys_path)
{
int fd;
fd = open(sys_path, O_WRONLY);
if (fd < 0)
die("open failed: %s\n",
strerror(errno));
if (write(fd, fw_name, strlen(fw_name)) != strlen(fw_name))
exit(EXIT_FAILURE);
close(fd);
}
static void setup_fw(const char *fw_path)
{
int fd;
const char fw[] = "ABCD0123";
fd = open(fw_path, O_WRONLY | O_CREAT, 0600);
if (fd < 0)
die("open failed: %s\n",
strerror(errno));
if (write(fd, fw, sizeof(fw) -1) != sizeof(fw) -1)
die("write failed: %s\n",
strerror(errno));
close(fd);
}
static bool test_fw_in_ns(const char *fw_name, const char *sys_path, bool block_fw_in_parent_ns)
{
pid_t child;
if (block_fw_in_parent_ns)
if (mount("test", "/lib/firmware", "tmpfs", MS_RDONLY, NULL) == -1)
die("blocking firmware in parent ns failed\n");
child = fork();
if (child == -1) {
die("fork failed: %s\n",
strerror(errno));
}
if (child != 0) { /* parent */
pid_t pid;
int status;
pid = waitpid(child, &status, 0);
if (pid == -1) {
die("waitpid failed: %s\n",
strerror(errno));
}
if (pid != child) {
die("waited for %d got %d\n",
child, pid);
}
if (!WIFEXITED(status)) {
die("child did not terminate cleanly\n");
}
if (block_fw_in_parent_ns)
umount("/lib/firmware");
return WEXITSTATUS(status) == EXIT_SUCCESS;
}
if (unshare(CLONE_NEWNS) != 0) {
die("unshare(CLONE_NEWNS) failed: %s\n",
strerror(errno));
}
if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) == -1)
die("remount root in child ns failed\n");
if (!block_fw_in_parent_ns) {
if (mount("test", "/lib/firmware", "tmpfs", MS_RDONLY, NULL) == -1)
die("blocking firmware in child ns failed\n");
} else
umount("/lib/firmware");
trigger_fw(fw_name, sys_path);
exit(EXIT_SUCCESS);
}
int main(int argc, char **argv)
{
const char *fw_name = "test-firmware.bin";
char *sys_path;
if (argc != 2)
die("usage: %s sys_path\n", argv[0]);
/* Mount tmpfs to /lib/firmware so we don't have to assume
that it is writable for us.*/
if (mount("test", "/lib/firmware", "tmpfs", 0, NULL) == -1)
die("mounting tmpfs to /lib/firmware failed\n");
sys_path = argv[1];
asprintf(&fw_path, "/lib/firmware/%s", fw_name);
setup_fw(fw_path);
setvbuf(stdout, NULL, _IONBF, 0);
/* Positive case: firmware in PID1 mount namespace */
printf("Testing with firmware in parent namespace (assumed to be same file system as PID1)\n");
if (!test_fw_in_ns(fw_name, sys_path, false))
die("error: failed to access firmware\n");
/* Negative case: firmware in child mount namespace, expected to fail */
printf("Testing with firmware in child namespace\n");
if (test_fw_in_ns(fw_name, sys_path, true))
die("error: firmware access did not fail\n");
unlink(fw_path);
free(fw_path);
umount("/lib/firmware");
exit(EXIT_SUCCESS);
}
|
