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
|
/*
* Copyright (C) 2016, Red Hat Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "tracker-seccomp.h"
#ifdef HAVE_LIBSECCOMP
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <seccomp.h>
#define ALLOW_RULE(call) G_STMT_START { if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(call), 0) < 0) goto out; } G_STMT_END
gboolean
tracker_seccomp_init (void)
{
scmp_filter_ctx ctx;
ctx = seccomp_init (SCMP_ACT_TRAP);
if (ctx == NULL)
return FALSE;
/* Memory management */
ALLOW_RULE (brk);
ALLOW_RULE (mmap);
ALLOW_RULE (munmap);
ALLOW_RULE (mremap);
ALLOW_RULE (mprotect);
ALLOW_RULE (madvise);
/* Process management */
ALLOW_RULE (exit_group);
ALLOW_RULE (getuid);
ALLOW_RULE (geteuid);
ALLOW_RULE (getppid);
ALLOW_RULE (gettid);
ALLOW_RULE (exit);
/* Basic filesystem access */
ALLOW_RULE (fstat);
ALLOW_RULE (fstat64);
ALLOW_RULE (stat);
ALLOW_RULE (stat64);
ALLOW_RULE (statfs);
ALLOW_RULE (statfs64);
ALLOW_RULE (lstat);
ALLOW_RULE (lstat64);
ALLOW_RULE (access);
ALLOW_RULE (getdents);
ALLOW_RULE (getdents64);
ALLOW_RULE (readlink);
ALLOW_RULE (readlinkat);
ALLOW_RULE (utime);
ALLOW_RULE (fsync);
/* Processes and threads */
ALLOW_RULE (clone);
ALLOW_RULE (futex);
ALLOW_RULE (set_robust_list);
ALLOW_RULE (rt_sigaction);
ALLOW_RULE (rt_sigprocmask);
ALLOW_RULE (sched_yield);
ALLOW_RULE (sched_getaffinity);
ALLOW_RULE (nanosleep);
/* Main loops */
ALLOW_RULE (poll);
ALLOW_RULE (ppoll);
ALLOW_RULE (fcntl);
ALLOW_RULE (eventfd2);
ALLOW_RULE (pipe);
ALLOW_RULE (pipe2);
/* System */
ALLOW_RULE (uname);
ALLOW_RULE (sysinfo);
ALLOW_RULE (prctl);
ALLOW_RULE (getrandom);
/* Descriptors */
ALLOW_RULE (close);
ALLOW_RULE (read);
ALLOW_RULE (pread64);
ALLOW_RULE (lseek);
ALLOW_RULE (fadvise64);
ALLOW_RULE (write);
ALLOW_RULE (writev);
/* Needed by some GStreamer modules doing crazy stuff, less
* scary thanks to the restriction below about sockets being
* local.
*/
ALLOW_RULE (connect);
ALLOW_RULE (send);
ALLOW_RULE (sendto);
ALLOW_RULE (sendmsg);
ALLOW_RULE (recv);
ALLOW_RULE (recvmsg);
ALLOW_RULE (recvfrom);
ALLOW_RULE (getsockname);
ALLOW_RULE (getpeername);
ALLOW_RULE (shutdown);
/* Special requirements for socket/socketpair, only on AF_UNIX/AF_LOCAL */
if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(socket), 1,
SCMP_CMP(0, SCMP_CMP_EQ, AF_UNIX)) < 0)
goto out;
if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(socket), 1,
SCMP_CMP(0, SCMP_CMP_EQ, AF_LOCAL)) < 0)
goto out;
if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(socketpair), 1,
SCMP_CMP(0, SCMP_CMP_EQ, AF_UNIX)) < 0)
goto out;
if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(socketpair), 1,
SCMP_CMP(0, SCMP_CMP_EQ, AF_LOCAL)) < 0)
goto out;
/* Special requirements for ioctl, allowed on stdout/stderr */
if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(ioctl), 1,
SCMP_CMP(0, SCMP_CMP_EQ, 1)) < 0)
goto out;
if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(ioctl), 1,
SCMP_CMP(0, SCMP_CMP_EQ, 2)) < 0)
goto out;
/* Special requirements for open, allow O_RDONLY calls, but fail
* if write permissions are requested.
*/
if (seccomp_rule_add (ctx, SCMP_ACT_ALLOW, SCMP_SYS(open), 1,
SCMP_CMP(1, SCMP_CMP_MASKED_EQ, O_WRONLY | O_RDWR, 0)) < 0)
goto out;
if (seccomp_rule_add (ctx, SCMP_ACT_ERRNO (EACCES), SCMP_SYS(open), 1,
SCMP_CMP(1, SCMP_CMP_MASKED_EQ, O_WRONLY, O_WRONLY)) < 0)
goto out;
if (seccomp_rule_add (ctx, SCMP_ACT_ERRNO (EACCES), SCMP_SYS(open), 1,
SCMP_CMP(1, SCMP_CMP_MASKED_EQ, O_RDWR, O_RDWR)) < 0)
goto out;
g_debug ("Loading seccomp rules.");
if (seccomp_load (ctx) >= 0)
return TRUE;
out:
g_critical ("Failed to load seccomp rules.");
seccomp_release (ctx);
return FALSE;
}
#else /* HAVE_LIBSECCOMP */
gboolean
tracker_seccomp_init (void)
{
g_warning ("No seccomp support compiled-in.");
return TRUE;
}
#endif /* HAVE_LIBSECCOMP */
|
