rcu_queue: remove barrier from QLIST_EMPTY_RCU
[qemu/ar7.git] / qemu-seccomp.c
blob9cd8eb949989e67d4cc4e495d611de95df98a162
1 /*
2 * QEMU seccomp mode 2 support with libseccomp
4 * Copyright IBM, Corp. 2012
6 * Authors:
7 * Eduardo Otubo <eotubo@br.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
12 * Contributions after 2012-01-13 are licensed under the terms of the
13 * GNU GPL, version 2 or (at your option) any later version.
15 #include "qemu/osdep.h"
16 #include "qemu/config-file.h"
17 #include "qemu/option.h"
18 #include "qemu/module.h"
19 #include "qemu/error-report.h"
20 #include <sys/prctl.h>
21 #include <seccomp.h>
22 #include "sysemu/seccomp.h"
24 /* For some architectures (notably ARM) cacheflush is not supported until
25 * libseccomp 2.2.3, but configure enforces that we are using a more recent
26 * version on those hosts, so it is OK for this check to be less strict.
28 #if SCMP_VER_MAJOR >= 3
29 #define HAVE_CACHEFLUSH
30 #elif SCMP_VER_MAJOR == 2 && SCMP_VER_MINOR >= 2
31 #define HAVE_CACHEFLUSH
32 #endif
34 struct QemuSeccompSyscall {
35 int32_t num;
36 uint8_t set;
37 uint8_t narg;
38 const struct scmp_arg_cmp *arg_cmp;
41 const struct scmp_arg_cmp sched_setscheduler_arg[] = {
42 SCMP_A1(SCMP_CMP_NE, SCHED_IDLE)
45 static const struct QemuSeccompSyscall blacklist[] = {
46 /* default set of syscalls to blacklist */
47 { SCMP_SYS(reboot), QEMU_SECCOMP_SET_DEFAULT },
48 { SCMP_SYS(swapon), QEMU_SECCOMP_SET_DEFAULT },
49 { SCMP_SYS(swapoff), QEMU_SECCOMP_SET_DEFAULT },
50 { SCMP_SYS(syslog), QEMU_SECCOMP_SET_DEFAULT },
51 { SCMP_SYS(mount), QEMU_SECCOMP_SET_DEFAULT },
52 { SCMP_SYS(umount), QEMU_SECCOMP_SET_DEFAULT },
53 { SCMP_SYS(kexec_load), QEMU_SECCOMP_SET_DEFAULT },
54 { SCMP_SYS(afs_syscall), QEMU_SECCOMP_SET_DEFAULT },
55 { SCMP_SYS(break), QEMU_SECCOMP_SET_DEFAULT },
56 { SCMP_SYS(ftime), QEMU_SECCOMP_SET_DEFAULT },
57 { SCMP_SYS(getpmsg), QEMU_SECCOMP_SET_DEFAULT },
58 { SCMP_SYS(gtty), QEMU_SECCOMP_SET_DEFAULT },
59 { SCMP_SYS(lock), QEMU_SECCOMP_SET_DEFAULT },
60 { SCMP_SYS(mpx), QEMU_SECCOMP_SET_DEFAULT },
61 { SCMP_SYS(prof), QEMU_SECCOMP_SET_DEFAULT },
62 { SCMP_SYS(profil), QEMU_SECCOMP_SET_DEFAULT },
63 { SCMP_SYS(putpmsg), QEMU_SECCOMP_SET_DEFAULT },
64 { SCMP_SYS(security), QEMU_SECCOMP_SET_DEFAULT },
65 { SCMP_SYS(stty), QEMU_SECCOMP_SET_DEFAULT },
66 { SCMP_SYS(tuxcall), QEMU_SECCOMP_SET_DEFAULT },
67 { SCMP_SYS(ulimit), QEMU_SECCOMP_SET_DEFAULT },
68 { SCMP_SYS(vserver), QEMU_SECCOMP_SET_DEFAULT },
69 /* obsolete */
70 { SCMP_SYS(readdir), QEMU_SECCOMP_SET_OBSOLETE },
71 { SCMP_SYS(_sysctl), QEMU_SECCOMP_SET_OBSOLETE },
72 { SCMP_SYS(bdflush), QEMU_SECCOMP_SET_OBSOLETE },
73 { SCMP_SYS(create_module), QEMU_SECCOMP_SET_OBSOLETE },
74 { SCMP_SYS(get_kernel_syms), QEMU_SECCOMP_SET_OBSOLETE },
75 { SCMP_SYS(query_module), QEMU_SECCOMP_SET_OBSOLETE },
76 { SCMP_SYS(sgetmask), QEMU_SECCOMP_SET_OBSOLETE },
77 { SCMP_SYS(ssetmask), QEMU_SECCOMP_SET_OBSOLETE },
78 { SCMP_SYS(sysfs), QEMU_SECCOMP_SET_OBSOLETE },
79 { SCMP_SYS(uselib), QEMU_SECCOMP_SET_OBSOLETE },
80 { SCMP_SYS(ustat), QEMU_SECCOMP_SET_OBSOLETE },
81 /* privileged */
82 { SCMP_SYS(setuid), QEMU_SECCOMP_SET_PRIVILEGED },
83 { SCMP_SYS(setgid), QEMU_SECCOMP_SET_PRIVILEGED },
84 { SCMP_SYS(setpgid), QEMU_SECCOMP_SET_PRIVILEGED },
85 { SCMP_SYS(setsid), QEMU_SECCOMP_SET_PRIVILEGED },
86 { SCMP_SYS(setreuid), QEMU_SECCOMP_SET_PRIVILEGED },
87 { SCMP_SYS(setregid), QEMU_SECCOMP_SET_PRIVILEGED },
88 { SCMP_SYS(setresuid), QEMU_SECCOMP_SET_PRIVILEGED },
89 { SCMP_SYS(setresgid), QEMU_SECCOMP_SET_PRIVILEGED },
90 { SCMP_SYS(setfsuid), QEMU_SECCOMP_SET_PRIVILEGED },
91 { SCMP_SYS(setfsgid), QEMU_SECCOMP_SET_PRIVILEGED },
92 /* spawn */
93 { SCMP_SYS(fork), QEMU_SECCOMP_SET_SPAWN },
94 { SCMP_SYS(vfork), QEMU_SECCOMP_SET_SPAWN },
95 { SCMP_SYS(execve), QEMU_SECCOMP_SET_SPAWN },
96 /* resource control */
97 { SCMP_SYS(getpriority), QEMU_SECCOMP_SET_RESOURCECTL },
98 { SCMP_SYS(setpriority), QEMU_SECCOMP_SET_RESOURCECTL },
99 { SCMP_SYS(sched_setparam), QEMU_SECCOMP_SET_RESOURCECTL },
100 { SCMP_SYS(sched_getparam), QEMU_SECCOMP_SET_RESOURCECTL },
101 { SCMP_SYS(sched_setscheduler), QEMU_SECCOMP_SET_RESOURCECTL,
102 ARRAY_SIZE(sched_setscheduler_arg), sched_setscheduler_arg },
103 { SCMP_SYS(sched_getscheduler), QEMU_SECCOMP_SET_RESOURCECTL },
104 { SCMP_SYS(sched_setaffinity), QEMU_SECCOMP_SET_RESOURCECTL },
105 { SCMP_SYS(sched_getaffinity), QEMU_SECCOMP_SET_RESOURCECTL },
106 { SCMP_SYS(sched_get_priority_max), QEMU_SECCOMP_SET_RESOURCECTL },
107 { SCMP_SYS(sched_get_priority_min), QEMU_SECCOMP_SET_RESOURCECTL },
111 static int seccomp_start(uint32_t seccomp_opts)
113 int rc = 0;
114 unsigned int i = 0;
115 scmp_filter_ctx ctx;
117 ctx = seccomp_init(SCMP_ACT_ALLOW);
118 if (ctx == NULL) {
119 rc = -1;
120 goto seccomp_return;
123 for (i = 0; i < ARRAY_SIZE(blacklist); i++) {
124 if (!(seccomp_opts & blacklist[i].set)) {
125 continue;
128 rc = seccomp_rule_add_array(ctx, SCMP_ACT_KILL, blacklist[i].num,
129 blacklist[i].narg, blacklist[i].arg_cmp);
130 if (rc < 0) {
131 goto seccomp_return;
135 rc = seccomp_load(ctx);
137 seccomp_return:
138 seccomp_release(ctx);
139 return rc;
142 #ifdef CONFIG_SECCOMP
143 int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp)
145 if (qemu_opt_get_bool(opts, "enable", false)) {
146 uint32_t seccomp_opts = QEMU_SECCOMP_SET_DEFAULT
147 | QEMU_SECCOMP_SET_OBSOLETE;
148 const char *value = NULL;
150 value = qemu_opt_get(opts, "obsolete");
151 if (value) {
152 if (g_str_equal(value, "allow")) {
153 seccomp_opts &= ~QEMU_SECCOMP_SET_OBSOLETE;
154 } else if (g_str_equal(value, "deny")) {
155 /* this is the default option, this if is here
156 * to provide a little bit of consistency for
157 * the command line */
158 } else {
159 error_report("invalid argument for obsolete");
160 return -1;
164 value = qemu_opt_get(opts, "elevateprivileges");
165 if (value) {
166 if (g_str_equal(value, "deny")) {
167 seccomp_opts |= QEMU_SECCOMP_SET_PRIVILEGED;
168 } else if (g_str_equal(value, "children")) {
169 seccomp_opts |= QEMU_SECCOMP_SET_PRIVILEGED;
171 /* calling prctl directly because we're
172 * not sure if host has CAP_SYS_ADMIN set*/
173 if (prctl(PR_SET_NO_NEW_PRIVS, 1)) {
174 error_report("failed to set no_new_privs "
175 "aborting");
176 return -1;
178 } else if (g_str_equal(value, "allow")) {
179 /* default value */
180 } else {
181 error_report("invalid argument for elevateprivileges");
182 return -1;
186 value = qemu_opt_get(opts, "spawn");
187 if (value) {
188 if (g_str_equal(value, "deny")) {
189 seccomp_opts |= QEMU_SECCOMP_SET_SPAWN;
190 } else if (g_str_equal(value, "allow")) {
191 /* default value */
192 } else {
193 error_report("invalid argument for spawn");
194 return -1;
198 value = qemu_opt_get(opts, "resourcecontrol");
199 if (value) {
200 if (g_str_equal(value, "deny")) {
201 seccomp_opts |= QEMU_SECCOMP_SET_RESOURCECTL;
202 } else if (g_str_equal(value, "allow")) {
203 /* default value */
204 } else {
205 error_report("invalid argument for resourcecontrol");
206 return -1;
210 if (seccomp_start(seccomp_opts) < 0) {
211 error_report("failed to install seccomp syscall filter "
212 "in the kernel");
213 return -1;
217 return 0;
220 static QemuOptsList qemu_sandbox_opts = {
221 .name = "sandbox",
222 .implied_opt_name = "enable",
223 .head = QTAILQ_HEAD_INITIALIZER(qemu_sandbox_opts.head),
224 .desc = {
226 .name = "enable",
227 .type = QEMU_OPT_BOOL,
230 .name = "obsolete",
231 .type = QEMU_OPT_STRING,
234 .name = "elevateprivileges",
235 .type = QEMU_OPT_STRING,
238 .name = "spawn",
239 .type = QEMU_OPT_STRING,
242 .name = "resourcecontrol",
243 .type = QEMU_OPT_STRING,
245 { /* end of list */ }
249 static void seccomp_register(void)
251 qemu_add_opts(&qemu_sandbox_opts);
253 opts_init(seccomp_register);
254 #endif