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
|
/*
* Copyright (C) 2014-2020 Firejail Authors
*
* This file is part of firejail project
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "firejail.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <sys/mount.h>
#include <dirent.h>
#include <errno.h>
#include <sys/wait.h>
#include <fcntl.h>
#ifndef O_PATH
#define O_PATH 010000000
#endif
#define PULSE_CLIENT_SYSCONF "/etc/pulse/client.conf"
// disable pulseaudio socket
void pulseaudio_disable(void) {
if (arg_debug)
printf("disable pulseaudio\n");
// blacklist user config directory
disable_file_path(cfg.homedir, ".config/pulse");
// blacklist pulseaudio socket in XDG_RUNTIME_DIR
char *name = getenv("XDG_RUNTIME_DIR");
if (name)
disable_file_path(name, "pulse/native");
// try the default location anyway
char *path;
if (asprintf(&path, "/run/user/%d", getuid()) == -1)
errExit("asprintf");
disable_file_path(path, "pulse");
free(path);
// blacklist any pulse* file in /tmp directory
DIR *dir;
if (!(dir = opendir("/tmp"))) {
// sleep 2 seconds and try again
sleep(2);
if (!(dir = opendir("/tmp"))) {
return;
}
}
struct dirent *entry;
while ((entry = readdir(dir))) {
if (strncmp(entry->d_name, "pulse-", 6) == 0) {
disable_file_path("/tmp", entry->d_name);
}
}
closedir(dir);
}
static void pulseaudio_fallback(const char *path) {
fmessage("Cannot mount tmpfs on %s/.config/pulse\n", cfg.homedir);
if (setenv("PULSE_CLIENTCONFIG", path, 1) < 0)
errExit("setenv");
}
// disable shm in pulseaudio (issue #69)
void pulseaudio_init(void) {
struct stat s;
// do we have pulseaudio in the system?
if (stat(PULSE_CLIENT_SYSCONF, &s) == -1) {
if (arg_debug)
printf("%s not found\n", PULSE_CLIENT_SYSCONF);
return;
}
// create the new user pulseaudio directory
if (mkdir(RUN_PULSE_DIR, 0700) == -1)
errExit("mkdir");
selinux_relabel_path(RUN_PULSE_DIR, RUN_PULSE_DIR);
// mount it nosuid, noexec, nodev
fs_remount(RUN_PULSE_DIR, MOUNT_NOEXEC, 0);
// create the new client.conf file
char *pulsecfg = NULL;
if (asprintf(&pulsecfg, "%s/client.conf", RUN_PULSE_DIR) == -1)
errExit("asprintf");
if (copy_file(PULSE_CLIENT_SYSCONF, pulsecfg, -1, -1, 0644)) // root needed
errExit("copy_file");
FILE *fp = fopen(pulsecfg, "a");
if (!fp)
errExit("fopen");
fprintf(fp, "%s", "\nenable-shm = no\n");
SET_PERMS_STREAM(fp, getuid(), getgid(), 0644);
fclose(fp);
// hand over the directory to the user
if (set_perms(RUN_PULSE_DIR, getuid(), getgid(), 0700))
errExit("set_perms");
// create ~/.config/pulse directory if not present
char *homeusercfg = NULL;
if (asprintf(&homeusercfg, "%s/.config", cfg.homedir) == -1)
errExit("asprintf");
if (create_empty_dir_as_user(homeusercfg, 0700))
fs_logger2("create", homeusercfg);
free(homeusercfg);
if (asprintf(&homeusercfg, "%s/.config/pulse", cfg.homedir) == -1)
errExit("asprintf");
if (create_empty_dir_as_user(homeusercfg, 0700))
fs_logger2("create", homeusercfg);
// if ~/.config/pulse exists and there are no symbolic links, mount the new directory
// else set environment variable
int fd = safe_fd(homeusercfg, O_PATH|O_DIRECTORY|O_NOFOLLOW|O_CLOEXEC);
if (fd == -1) {
pulseaudio_fallback(pulsecfg);
goto out;
}
// confirm the actual mount destination is owned by the user
if (fstat(fd, &s) == -1) { // FUSE
if (errno != EACCES)
errExit("fstat");
close(fd);
pulseaudio_fallback(pulsecfg);
goto out;
}
if (s.st_uid != getuid()) {
close(fd);
pulseaudio_fallback(pulsecfg);
goto out;
}
// preserve a read-only mount
struct statvfs vfs;
if (fstatvfs(fd, &vfs) == -1)
errExit("fstatvfs");
if ((vfs.f_flag & MS_RDONLY) == MS_RDONLY)
fs_remount(RUN_PULSE_DIR, MOUNT_READONLY, 0);
// mount via the link in /proc/self/fd
if (arg_debug)
printf("Mounting %s on %s\n", RUN_PULSE_DIR, homeusercfg);
char *proc;
if (asprintf(&proc, "/proc/self/fd/%d", fd) == -1)
errExit("asprintf");
if (mount(RUN_PULSE_DIR, proc, "none", MS_BIND, NULL) < 0)
errExit("mount pulseaudio");
// check /proc/self/mountinfo to confirm the mount is ok
MountData *mptr = get_last_mount();
if (strcmp(mptr->dir, homeusercfg) != 0 || strcmp(mptr->fstype, "tmpfs") != 0)
errLogExit("invalid pulseaudio mount");
fs_logger2("tmpfs", homeusercfg);
free(proc);
close(fd);
char *p;
if (asprintf(&p, "%s/client.conf", homeusercfg) == -1)
errExit("asprintf");
if (setenv("PULSE_CLIENTCONFIG", p, 1) < 0)
errExit("setenv");
fs_logger2("create", p);
free(p);
// RUN_PULSE_DIR not needed anymore, mask it
if (mount("tmpfs", RUN_PULSE_DIR, "tmpfs", MS_NOSUID | MS_NODEV | MS_STRICTATIME, "mode=755,gid=0") < 0)
errExit("mount pulseaudio");
fs_logger2("tmpfs", RUN_PULSE_DIR);
out:
free(pulsecfg);
free(homeusercfg);
}
|