| 1 | /* |
| 2 | * QEMU seccomp mode 2 support with libseccomp |
| 3 | * |
| 4 | * Copyright IBM, Corp. 2012 |
| 5 | * |
| 6 | * Authors: |
| 7 | * Eduardo Otubo <eotubo@br.ibm.com> |
| 8 | * |
| 9 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 10 | * the COPYING file in the top-level directory. |
| 11 | * |
| 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. |
| 14 | */ |
| 15 | |
| 16 | #include "qemu/osdep.h" |
| 17 | #include "qapi/error.h" |
| 18 | #include "qemu/config-file.h" |
| 19 | #include "qemu/option.h" |
| 20 | #include "qemu/module.h" |
| 21 | #include <sys/prctl.h> |
| 22 | #include <seccomp.h> |
| 23 | #include "system/seccomp.h" |
| 24 | #include <linux/seccomp.h> |
| 25 | |
| 26 | /* For some architectures (notably ARM) cacheflush is not supported until |
| 27 | * libseccomp 2.2.3, but configure enforces that we are using a more recent |
| 28 | * version on those hosts, so it is OK for this check to be less strict. |
| 29 | */ |
| 30 | #if SCMP_VER_MAJOR >= 3 |
| 31 | #define HAVE_CACHEFLUSH |
| 32 | #elif SCMP_VER_MAJOR == 2 && SCMP_VER_MINOR >= 2 |
| 33 | #define HAVE_CACHEFLUSH |
| 34 | #endif |
| 35 | |
| 36 | struct QemuSeccompSyscall { |
| 37 | int32_t num; |
| 38 | uint8_t set; |
| 39 | uint8_t narg; |
| 40 | const struct scmp_arg_cmp *arg_cmp; |
| 41 | uint32_t action; |
| 42 | }; |
| 43 | |
| 44 | const struct scmp_arg_cmp sched_setscheduler_arg[] = { |
| 45 | /* was SCMP_A1(SCMP_CMP_NE, SCHED_IDLE), but expanded due to GCC 4.x bug */ |
| 46 | { .arg = 1, .op = SCMP_CMP_NE, .datum_a = SCHED_IDLE } |
| 47 | }; |
| 48 | |
| 49 | /* |
| 50 | * See 'NOTES' in 'man 2 clone' - s390 has 'flags' in |
| 51 | * different position to other architectures |
| 52 | */ |
| 53 | #if defined(HOST_S390X) || defined(HOST_S390) |
| 54 | #define CLONE_FLAGS_ARG 1 |
| 55 | #else |
| 56 | #define CLONE_FLAGS_ARG 0 |
| 57 | #endif |
| 58 | |
| 59 | #ifndef CLONE_PIDFD |
| 60 | # define CLONE_PIDFD 0x00001000 |
| 61 | #endif |
| 62 | |
| 63 | #define REQUIRE_CLONE_FLAG(flag) \ |
| 64 | const struct scmp_arg_cmp clone_arg ## flag[] = { \ |
| 65 | { .arg = CLONE_FLAGS_ARG, \ |
| 66 | .op = SCMP_CMP_MASKED_EQ, \ |
| 67 | .datum_a = flag, .datum_b = 0 } } |
| 68 | |
| 69 | #define FORBID_CLONE_FLAG(flag) \ |
| 70 | const struct scmp_arg_cmp clone_arg ## flag[] = { \ |
| 71 | { .arg = CLONE_FLAGS_ARG, \ |
| 72 | .op = SCMP_CMP_MASKED_EQ, \ |
| 73 | .datum_a = flag, .datum_b = flag } } |
| 74 | |
| 75 | #define RULE_CLONE_FLAG(flag) \ |
| 76 | { SCMP_SYS(clone), QEMU_SECCOMP_SET_SPAWN, \ |
| 77 | ARRAY_SIZE(clone_arg ## flag), clone_arg ## flag, SCMP_ACT_ERRNO(EPERM) } |
| 78 | |
| 79 | /* If no CLONE_* flags are set, except CSIGNAL, deny */ |
| 80 | const struct scmp_arg_cmp clone_arg_none[] = { |
| 81 | { .arg = CLONE_FLAGS_ARG, |
| 82 | .op = SCMP_CMP_MASKED_EQ, |
| 83 | .datum_a = ~(CSIGNAL), .datum_b = 0 } |
| 84 | }; |
| 85 | |
| 86 | /* |
| 87 | * pthread_create should always set all of these. |
| 88 | */ |
| 89 | REQUIRE_CLONE_FLAG(CLONE_VM); |
| 90 | REQUIRE_CLONE_FLAG(CLONE_FS); |
| 91 | REQUIRE_CLONE_FLAG(CLONE_FILES); |
| 92 | REQUIRE_CLONE_FLAG(CLONE_SIGHAND); |
| 93 | REQUIRE_CLONE_FLAG(CLONE_THREAD); |
| 94 | REQUIRE_CLONE_FLAG(CLONE_SYSVSEM); |
| 95 | REQUIRE_CLONE_FLAG(CLONE_SETTLS); |
| 96 | REQUIRE_CLONE_FLAG(CLONE_PARENT_SETTID); |
| 97 | REQUIRE_CLONE_FLAG(CLONE_CHILD_CLEARTID); |
| 98 | /* |
| 99 | * Musl sets this in pthread_create too, but it is |
| 100 | * obsolete and harmless since its behaviour is |
| 101 | * subsumed under CLONE_THREAD |
| 102 | */ |
| 103 | /*REQUIRE_CLONE_FLAG(CLONE_DETACHED);*/ |
| 104 | |
| 105 | |
| 106 | /* |
| 107 | * These all indicate an attempt to spawn a process |
| 108 | * instead of a thread, or other undesirable scenarios |
| 109 | */ |
| 110 | FORBID_CLONE_FLAG(CLONE_PIDFD); |
| 111 | FORBID_CLONE_FLAG(CLONE_PTRACE); |
| 112 | FORBID_CLONE_FLAG(CLONE_VFORK); |
| 113 | FORBID_CLONE_FLAG(CLONE_PARENT); |
| 114 | FORBID_CLONE_FLAG(CLONE_NEWNS); |
| 115 | FORBID_CLONE_FLAG(CLONE_UNTRACED); |
| 116 | FORBID_CLONE_FLAG(CLONE_NEWCGROUP); |
| 117 | FORBID_CLONE_FLAG(CLONE_NEWUTS); |
| 118 | FORBID_CLONE_FLAG(CLONE_NEWIPC); |
| 119 | FORBID_CLONE_FLAG(CLONE_NEWUSER); |
| 120 | FORBID_CLONE_FLAG(CLONE_NEWPID); |
| 121 | FORBID_CLONE_FLAG(CLONE_NEWNET); |
| 122 | FORBID_CLONE_FLAG(CLONE_IO); |
| 123 | |
| 124 | |
| 125 | static const struct QemuSeccompSyscall denylist[] = { |
| 126 | /* default set of syscalls that should get blocked */ |
| 127 | { SCMP_SYS(reboot), QEMU_SECCOMP_SET_DEFAULT, |
| 128 | 0, NULL, SCMP_ACT_TRAP }, |
| 129 | { SCMP_SYS(swapon), QEMU_SECCOMP_SET_DEFAULT, |
| 130 | 0, NULL, SCMP_ACT_TRAP }, |
| 131 | { SCMP_SYS(swapoff), QEMU_SECCOMP_SET_DEFAULT, |
| 132 | 0, NULL, SCMP_ACT_TRAP }, |
| 133 | { SCMP_SYS(syslog), QEMU_SECCOMP_SET_DEFAULT, |
| 134 | 0, NULL, SCMP_ACT_TRAP }, |
| 135 | { SCMP_SYS(mount), QEMU_SECCOMP_SET_DEFAULT, |
| 136 | 0, NULL, SCMP_ACT_TRAP }, |
| 137 | { SCMP_SYS(umount), QEMU_SECCOMP_SET_DEFAULT, |
| 138 | 0, NULL, SCMP_ACT_TRAP }, |
| 139 | { SCMP_SYS(kexec_load), QEMU_SECCOMP_SET_DEFAULT, |
| 140 | 0, NULL, SCMP_ACT_TRAP }, |
| 141 | { SCMP_SYS(afs_syscall), QEMU_SECCOMP_SET_DEFAULT, |
| 142 | 0, NULL, SCMP_ACT_TRAP }, |
| 143 | { SCMP_SYS(break), QEMU_SECCOMP_SET_DEFAULT, |
| 144 | 0, NULL, SCMP_ACT_TRAP }, |
| 145 | { SCMP_SYS(ftime), QEMU_SECCOMP_SET_DEFAULT, |
| 146 | 0, NULL, SCMP_ACT_TRAP }, |
| 147 | { SCMP_SYS(getpmsg), QEMU_SECCOMP_SET_DEFAULT, |
| 148 | 0, NULL, SCMP_ACT_TRAP }, |
| 149 | { SCMP_SYS(gtty), QEMU_SECCOMP_SET_DEFAULT, |
| 150 | 0, NULL, SCMP_ACT_TRAP }, |
| 151 | { SCMP_SYS(lock), QEMU_SECCOMP_SET_DEFAULT, |
| 152 | 0, NULL, SCMP_ACT_TRAP }, |
| 153 | { SCMP_SYS(mpx), QEMU_SECCOMP_SET_DEFAULT, |
| 154 | 0, NULL, SCMP_ACT_TRAP }, |
| 155 | { SCMP_SYS(prof), QEMU_SECCOMP_SET_DEFAULT, |
| 156 | 0, NULL, SCMP_ACT_TRAP }, |
| 157 | { SCMP_SYS(profil), QEMU_SECCOMP_SET_DEFAULT, |
| 158 | 0, NULL, SCMP_ACT_TRAP }, |
| 159 | { SCMP_SYS(putpmsg), QEMU_SECCOMP_SET_DEFAULT, |
| 160 | 0, NULL, SCMP_ACT_TRAP }, |
| 161 | { SCMP_SYS(security), QEMU_SECCOMP_SET_DEFAULT, |
| 162 | 0, NULL, SCMP_ACT_TRAP }, |
| 163 | { SCMP_SYS(stty), QEMU_SECCOMP_SET_DEFAULT, |
| 164 | 0, NULL, SCMP_ACT_TRAP }, |
| 165 | { SCMP_SYS(tuxcall), QEMU_SECCOMP_SET_DEFAULT, |
| 166 | 0, NULL, SCMP_ACT_TRAP }, |
| 167 | { SCMP_SYS(ulimit), QEMU_SECCOMP_SET_DEFAULT, |
| 168 | 0, NULL, SCMP_ACT_TRAP }, |
| 169 | { SCMP_SYS(vserver), QEMU_SECCOMP_SET_DEFAULT, |
| 170 | 0, NULL, SCMP_ACT_TRAP }, |
| 171 | /* obsolete */ |
| 172 | { SCMP_SYS(readdir), QEMU_SECCOMP_SET_OBSOLETE, |
| 173 | 0, NULL, SCMP_ACT_TRAP }, |
| 174 | { SCMP_SYS(_sysctl), QEMU_SECCOMP_SET_OBSOLETE, |
| 175 | 0, NULL, SCMP_ACT_TRAP }, |
| 176 | { SCMP_SYS(bdflush), QEMU_SECCOMP_SET_OBSOLETE, |
| 177 | 0, NULL, SCMP_ACT_TRAP }, |
| 178 | { SCMP_SYS(create_module), QEMU_SECCOMP_SET_OBSOLETE, |
| 179 | 0, NULL, SCMP_ACT_TRAP }, |
| 180 | { SCMP_SYS(get_kernel_syms), QEMU_SECCOMP_SET_OBSOLETE, |
| 181 | 0, NULL, SCMP_ACT_TRAP }, |
| 182 | { SCMP_SYS(query_module), QEMU_SECCOMP_SET_OBSOLETE, |
| 183 | 0, NULL, SCMP_ACT_TRAP }, |
| 184 | { SCMP_SYS(sgetmask), QEMU_SECCOMP_SET_OBSOLETE, |
| 185 | 0, NULL, SCMP_ACT_TRAP }, |
| 186 | { SCMP_SYS(ssetmask), QEMU_SECCOMP_SET_OBSOLETE, |
| 187 | 0, NULL, SCMP_ACT_TRAP }, |
| 188 | { SCMP_SYS(sysfs), QEMU_SECCOMP_SET_OBSOLETE, |
| 189 | 0, NULL, SCMP_ACT_TRAP }, |
| 190 | { SCMP_SYS(uselib), QEMU_SECCOMP_SET_OBSOLETE, |
| 191 | 0, NULL, SCMP_ACT_TRAP }, |
| 192 | { SCMP_SYS(ustat), QEMU_SECCOMP_SET_OBSOLETE, |
| 193 | 0, NULL, SCMP_ACT_TRAP }, |
| 194 | /* privileged */ |
| 195 | { SCMP_SYS(setuid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 196 | 0, NULL, SCMP_ACT_TRAP }, |
| 197 | { SCMP_SYS(setgid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 198 | 0, NULL, SCMP_ACT_TRAP }, |
| 199 | { SCMP_SYS(setpgid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 200 | 0, NULL, SCMP_ACT_TRAP }, |
| 201 | { SCMP_SYS(setsid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 202 | 0, NULL, SCMP_ACT_TRAP }, |
| 203 | { SCMP_SYS(setreuid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 204 | 0, NULL, SCMP_ACT_TRAP }, |
| 205 | { SCMP_SYS(setregid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 206 | 0, NULL, SCMP_ACT_TRAP }, |
| 207 | { SCMP_SYS(setresuid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 208 | 0, NULL, SCMP_ACT_TRAP }, |
| 209 | { SCMP_SYS(setresgid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 210 | 0, NULL, SCMP_ACT_TRAP }, |
| 211 | { SCMP_SYS(setfsuid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 212 | 0, NULL, SCMP_ACT_TRAP }, |
| 213 | { SCMP_SYS(setfsgid), QEMU_SECCOMP_SET_PRIVILEGED, |
| 214 | 0, NULL, SCMP_ACT_TRAP }, |
| 215 | /* spawn */ |
| 216 | { SCMP_SYS(fork), QEMU_SECCOMP_SET_SPAWN, |
| 217 | 0, NULL, SCMP_ACT_ERRNO(EPERM) }, |
| 218 | { SCMP_SYS(vfork), QEMU_SECCOMP_SET_SPAWN, |
| 219 | 0, NULL, SCMP_ACT_ERRNO(EPERM) }, |
| 220 | { SCMP_SYS(execve), QEMU_SECCOMP_SET_SPAWN, |
| 221 | 0, NULL, SCMP_ACT_ERRNO(EPERM) }, |
| 222 | { SCMP_SYS(clone), QEMU_SECCOMP_SET_SPAWN, |
| 223 | ARRAY_SIZE(clone_arg_none), clone_arg_none, SCMP_ACT_ERRNO(EPERM) }, |
| 224 | RULE_CLONE_FLAG(CLONE_VM), |
| 225 | RULE_CLONE_FLAG(CLONE_FS), |
| 226 | RULE_CLONE_FLAG(CLONE_FILES), |
| 227 | RULE_CLONE_FLAG(CLONE_SIGHAND), |
| 228 | RULE_CLONE_FLAG(CLONE_THREAD), |
| 229 | RULE_CLONE_FLAG(CLONE_SYSVSEM), |
| 230 | RULE_CLONE_FLAG(CLONE_SETTLS), |
| 231 | RULE_CLONE_FLAG(CLONE_PARENT_SETTID), |
| 232 | RULE_CLONE_FLAG(CLONE_CHILD_CLEARTID), |
| 233 | /*RULE_CLONE_FLAG(CLONE_DETACHED),*/ |
| 234 | RULE_CLONE_FLAG(CLONE_PIDFD), |
| 235 | RULE_CLONE_FLAG(CLONE_PTRACE), |
| 236 | RULE_CLONE_FLAG(CLONE_VFORK), |
| 237 | RULE_CLONE_FLAG(CLONE_PARENT), |
| 238 | RULE_CLONE_FLAG(CLONE_NEWNS), |
| 239 | RULE_CLONE_FLAG(CLONE_UNTRACED), |
| 240 | RULE_CLONE_FLAG(CLONE_NEWCGROUP), |
| 241 | RULE_CLONE_FLAG(CLONE_NEWUTS), |
| 242 | RULE_CLONE_FLAG(CLONE_NEWIPC), |
| 243 | RULE_CLONE_FLAG(CLONE_NEWUSER), |
| 244 | RULE_CLONE_FLAG(CLONE_NEWPID), |
| 245 | RULE_CLONE_FLAG(CLONE_NEWNET), |
| 246 | RULE_CLONE_FLAG(CLONE_IO), |
| 247 | #ifdef __SNR_clone3 |
| 248 | { SCMP_SYS(clone3), QEMU_SECCOMP_SET_SPAWN, |
| 249 | 0, NULL, SCMP_ACT_ERRNO(ENOSYS) }, |
| 250 | #endif |
| 251 | #ifdef __SNR_execveat |
| 252 | { SCMP_SYS(execveat), QEMU_SECCOMP_SET_SPAWN }, |
| 253 | #endif |
| 254 | { SCMP_SYS(setns), QEMU_SECCOMP_SET_SPAWN }, |
| 255 | { SCMP_SYS(unshare), QEMU_SECCOMP_SET_SPAWN }, |
| 256 | /* resource control */ |
| 257 | { SCMP_SYS(setpriority), QEMU_SECCOMP_SET_RESOURCECTL, |
| 258 | 0, NULL, SCMP_ACT_ERRNO(EPERM) }, |
| 259 | { SCMP_SYS(sched_setparam), QEMU_SECCOMP_SET_RESOURCECTL, |
| 260 | 0, NULL, SCMP_ACT_ERRNO(EPERM) }, |
| 261 | { SCMP_SYS(sched_setscheduler), QEMU_SECCOMP_SET_RESOURCECTL, |
| 262 | ARRAY_SIZE(sched_setscheduler_arg), sched_setscheduler_arg, |
| 263 | SCMP_ACT_ERRNO(EPERM) }, |
| 264 | { SCMP_SYS(sched_setaffinity), QEMU_SECCOMP_SET_RESOURCECTL, |
| 265 | 0, NULL, SCMP_ACT_ERRNO(EPERM) }, |
| 266 | }; |
| 267 | |
| 268 | static inline __attribute__((unused)) int |
| 269 | qemu_seccomp(unsigned int operation, unsigned int flags, void *args) |
| 270 | { |
| 271 | #ifdef __NR_seccomp |
| 272 | return syscall(__NR_seccomp, operation, flags, args); |
| 273 | #else |
| 274 | errno = ENOSYS; |
| 275 | return -1; |
| 276 | #endif |
| 277 | } |
| 278 | |
| 279 | static uint32_t qemu_seccomp_update_action(uint32_t action) |
| 280 | { |
| 281 | #if defined(SECCOMP_GET_ACTION_AVAIL) && defined(SCMP_ACT_KILL_PROCESS) && \ |
| 282 | defined(SECCOMP_RET_KILL_PROCESS) |
| 283 | if (action == SCMP_ACT_TRAP) { |
| 284 | static int kill_process = -1; |
| 285 | if (kill_process == -1) { |
| 286 | uint32_t testaction = SECCOMP_RET_KILL_PROCESS; |
| 287 | |
| 288 | if (qemu_seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &testaction) == 0) { |
| 289 | kill_process = 1; |
| 290 | } else { |
| 291 | kill_process = 0; |
| 292 | } |
| 293 | } |
| 294 | if (kill_process == 1) { |
| 295 | return SCMP_ACT_KILL_PROCESS; |
| 296 | } |
| 297 | } |
| 298 | #endif |
| 299 | return action; |
| 300 | } |
| 301 | |
| 302 | |
| 303 | static int seccomp_start(uint32_t seccomp_opts, Error **errp) |
| 304 | { |
| 305 | int rc = -1; |
| 306 | unsigned int i = 0; |
| 307 | scmp_filter_ctx ctx; |
| 308 | |
| 309 | ctx = seccomp_init(SCMP_ACT_ALLOW); |
| 310 | if (ctx == NULL) { |
| 311 | error_setg(errp, "failed to initialize seccomp context"); |
| 312 | goto seccomp_return; |
| 313 | } |
| 314 | |
| 315 | #if defined(CONFIG_SECCOMP_SYSRAWRC) |
| 316 | /* |
| 317 | * This must be the first seccomp_attr_set() call to have full |
| 318 | * error propagation from subsequent seccomp APIs. |
| 319 | */ |
| 320 | rc = seccomp_attr_set(ctx, SCMP_FLTATR_API_SYSRAWRC, 1); |
| 321 | if (rc != 0) { |
| 322 | error_setg_errno(errp, -rc, |
| 323 | "failed to set seccomp rawrc attribute"); |
| 324 | goto seccomp_return; |
| 325 | } |
| 326 | #endif |
| 327 | |
| 328 | rc = seccomp_attr_set(ctx, SCMP_FLTATR_CTL_TSYNC, 1); |
| 329 | if (rc != 0) { |
| 330 | error_setg_errno(errp, -rc, |
| 331 | "failed to set seccomp thread synchronization"); |
| 332 | goto seccomp_return; |
| 333 | } |
| 334 | |
| 335 | for (i = 0; i < ARRAY_SIZE(denylist); i++) { |
| 336 | uint32_t action; |
| 337 | if (!(seccomp_opts & denylist[i].set)) { |
| 338 | continue; |
| 339 | } |
| 340 | |
| 341 | action = qemu_seccomp_update_action(denylist[i].action); |
| 342 | rc = seccomp_rule_add_array(ctx, action, denylist[i].num, |
| 343 | denylist[i].narg, denylist[i].arg_cmp); |
| 344 | if (rc < 0) { |
| 345 | error_setg_errno(errp, -rc, |
| 346 | "failed to add seccomp denylist rules"); |
| 347 | goto seccomp_return; |
| 348 | } |
| 349 | } |
| 350 | |
| 351 | rc = seccomp_load(ctx); |
| 352 | if (rc < 0) { |
| 353 | error_setg_errno(errp, -rc, |
| 354 | "failed to load seccomp syscall filter in kernel"); |
| 355 | } |
| 356 | |
| 357 | seccomp_return: |
| 358 | seccomp_release(ctx); |
| 359 | return rc < 0 ? -1 : 0; |
| 360 | } |
| 361 | |
| 362 | int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp) |
| 363 | { |
| 364 | if (qemu_opt_get_bool(opts, "enable", false)) { |
| 365 | uint32_t seccomp_opts = QEMU_SECCOMP_SET_DEFAULT |
| 366 | | QEMU_SECCOMP_SET_OBSOLETE; |
| 367 | const char *value = NULL; |
| 368 | |
| 369 | value = qemu_opt_get(opts, "obsolete"); |
| 370 | if (value) { |
| 371 | if (g_str_equal(value, "allow")) { |
| 372 | seccomp_opts &= ~QEMU_SECCOMP_SET_OBSOLETE; |
| 373 | } else if (g_str_equal(value, "deny")) { |
| 374 | /* this is the default option, this if is here |
| 375 | * to provide a little bit of consistency for |
| 376 | * the command line */ |
| 377 | } else { |
| 378 | error_setg(errp, "invalid argument for obsolete"); |
| 379 | return -1; |
| 380 | } |
| 381 | } |
| 382 | |
| 383 | value = qemu_opt_get(opts, "elevateprivileges"); |
| 384 | if (value) { |
| 385 | if (g_str_equal(value, "deny")) { |
| 386 | seccomp_opts |= QEMU_SECCOMP_SET_PRIVILEGED; |
| 387 | } else if (g_str_equal(value, "children")) { |
| 388 | seccomp_opts |= QEMU_SECCOMP_SET_PRIVILEGED; |
| 389 | |
| 390 | /* calling prctl directly because we're |
| 391 | * not sure if host has CAP_SYS_ADMIN set*/ |
| 392 | if (prctl(PR_SET_NO_NEW_PRIVS, 1)) { |
| 393 | error_setg(errp, "failed to set no_new_privs aborting"); |
| 394 | return -1; |
| 395 | } |
| 396 | } else if (g_str_equal(value, "allow")) { |
| 397 | /* default value */ |
| 398 | } else { |
| 399 | error_setg(errp, "invalid argument for elevateprivileges"); |
| 400 | return -1; |
| 401 | } |
| 402 | } |
| 403 | |
| 404 | value = qemu_opt_get(opts, "spawn"); |
| 405 | if (value) { |
| 406 | if (g_str_equal(value, "deny")) { |
| 407 | seccomp_opts |= QEMU_SECCOMP_SET_SPAWN; |
| 408 | } else if (g_str_equal(value, "allow")) { |
| 409 | /* default value */ |
| 410 | } else { |
| 411 | error_setg(errp, "invalid argument for spawn"); |
| 412 | return -1; |
| 413 | } |
| 414 | } |
| 415 | |
| 416 | value = qemu_opt_get(opts, "resourcecontrol"); |
| 417 | if (value) { |
| 418 | if (g_str_equal(value, "deny")) { |
| 419 | seccomp_opts |= QEMU_SECCOMP_SET_RESOURCECTL; |
| 420 | } else if (g_str_equal(value, "allow")) { |
| 421 | /* default value */ |
| 422 | } else { |
| 423 | error_setg(errp, "invalid argument for resourcecontrol"); |
| 424 | return -1; |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | if (seccomp_start(seccomp_opts, errp) < 0) { |
| 429 | return -1; |
| 430 | } |
| 431 | } |
| 432 | |
| 433 | return 0; |
| 434 | } |
| 435 | |
| 436 | static QemuOptsList qemu_sandbox_opts = { |
| 437 | .name = "sandbox", |
| 438 | .implied_opt_name = "enable", |
| 439 | .head = QTAILQ_HEAD_INITIALIZER(qemu_sandbox_opts.head), |
| 440 | .desc = { |
| 441 | { |
| 442 | .name = "enable", |
| 443 | .type = QEMU_OPT_BOOL, |
| 444 | }, |
| 445 | { |
| 446 | .name = "obsolete", |
| 447 | .type = QEMU_OPT_STRING, |
| 448 | }, |
| 449 | { |
| 450 | .name = "elevateprivileges", |
| 451 | .type = QEMU_OPT_STRING, |
| 452 | }, |
| 453 | { |
| 454 | .name = "spawn", |
| 455 | .type = QEMU_OPT_STRING, |
| 456 | }, |
| 457 | { |
| 458 | .name = "resourcecontrol", |
| 459 | .type = QEMU_OPT_STRING, |
| 460 | }, |
| 461 | { /* end of list */ } |
| 462 | }, |
| 463 | }; |
| 464 | |
| 465 | static void seccomp_register(void) |
| 466 | { |
| 467 | bool add = false; |
| 468 | |
| 469 | /* FIXME: use seccomp_api_get() >= 2 check when released */ |
| 470 | |
| 471 | #if defined(SECCOMP_FILTER_FLAG_TSYNC) |
| 472 | int check; |
| 473 | |
| 474 | /* check host TSYNC capability, it returns errno == ENOSYS if unavailable */ |
| 475 | check = qemu_seccomp(SECCOMP_SET_MODE_FILTER, |
| 476 | SECCOMP_FILTER_FLAG_TSYNC, NULL); |
| 477 | if (check < 0 && errno == EFAULT) { |
| 478 | add = true; |
| 479 | } |
| 480 | #endif |
| 481 | |
| 482 | if (add) { |
| 483 | qemu_add_opts(&qemu_sandbox_opts); |
| 484 | } |
| 485 | } |
| 486 | opts_init(seccomp_register); |