diff options
Diffstat (limited to 'qemu-seccomp.c')
| -rw-r--r-- | qemu-seccomp.c | 330 |
1 files changed, 0 insertions, 330 deletions
diff --git a/qemu-seccomp.c b/qemu-seccomp.c deleted file mode 100644 index e0a1829b3d..0000000000 --- a/qemu-seccomp.c +++ /dev/null @@ -1,330 +0,0 @@ -/* - * QEMU seccomp mode 2 support with libseccomp - * - * Copyright IBM, Corp. 2012 - * - * Authors: - * Eduardo Otubo <eotubo@br.ibm.com> - * - * This work is licensed under the terms of the GNU GPL, version 2. See - * the COPYING file in the top-level directory. - * - * Contributions after 2012-01-13 are licensed under the terms of the - * GNU GPL, version 2 or (at your option) any later version. - */ - -#include "qemu/osdep.h" -#include "qapi/error.h" -#include "qemu/config-file.h" -#include "qemu/option.h" -#include "qemu/module.h" -#include <sys/prctl.h> -#include <seccomp.h> -#include "sysemu/seccomp.h" -#include <linux/seccomp.h> - -/* For some architectures (notably ARM) cacheflush is not supported until - * libseccomp 2.2.3, but configure enforces that we are using a more recent - * version on those hosts, so it is OK for this check to be less strict. - */ -#if SCMP_VER_MAJOR >= 3 - #define HAVE_CACHEFLUSH -#elif SCMP_VER_MAJOR == 2 && SCMP_VER_MINOR >= 2 - #define HAVE_CACHEFLUSH -#endif - -struct QemuSeccompSyscall { - int32_t num; - uint8_t set; - uint8_t narg; - const struct scmp_arg_cmp *arg_cmp; -}; - -const struct scmp_arg_cmp sched_setscheduler_arg[] = { - /* was SCMP_A1(SCMP_CMP_NE, SCHED_IDLE), but expanded due to GCC 4.x bug */ - { .arg = 1, .op = SCMP_CMP_NE, .datum_a = SCHED_IDLE } -}; - -static const struct QemuSeccompSyscall blacklist[] = { - /* default set of syscalls to blacklist */ - { SCMP_SYS(reboot), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(swapon), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(swapoff), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(syslog), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(mount), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(umount), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(kexec_load), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(afs_syscall), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(break), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(ftime), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(getpmsg), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(gtty), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(lock), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(mpx), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(prof), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(profil), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(putpmsg), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(security), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(stty), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(tuxcall), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(ulimit), QEMU_SECCOMP_SET_DEFAULT }, - { SCMP_SYS(vserver), QEMU_SECCOMP_SET_DEFAULT }, - /* obsolete */ - { SCMP_SYS(readdir), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(_sysctl), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(bdflush), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(create_module), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(get_kernel_syms), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(query_module), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(sgetmask), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(ssetmask), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(sysfs), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(uselib), QEMU_SECCOMP_SET_OBSOLETE }, - { SCMP_SYS(ustat), QEMU_SECCOMP_SET_OBSOLETE }, - /* privileged */ - { SCMP_SYS(setuid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setgid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setpgid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setsid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setreuid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setregid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setresuid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setresgid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setfsuid), QEMU_SECCOMP_SET_PRIVILEGED }, - { SCMP_SYS(setfsgid), QEMU_SECCOMP_SET_PRIVILEGED }, - /* spawn */ - { SCMP_SYS(fork), QEMU_SECCOMP_SET_SPAWN }, - { SCMP_SYS(vfork), QEMU_SECCOMP_SET_SPAWN }, - { SCMP_SYS(execve), QEMU_SECCOMP_SET_SPAWN }, - /* resource control */ - { SCMP_SYS(getpriority), QEMU_SECCOMP_SET_RESOURCECTL }, - { SCMP_SYS(setpriority), QEMU_SECCOMP_SET_RESOURCECTL }, - { SCMP_SYS(sched_setparam), QEMU_SECCOMP_SET_RESOURCECTL }, - { SCMP_SYS(sched_getparam), QEMU_SECCOMP_SET_RESOURCECTL }, - { SCMP_SYS(sched_setscheduler), QEMU_SECCOMP_SET_RESOURCECTL, - ARRAY_SIZE(sched_setscheduler_arg), sched_setscheduler_arg }, - { SCMP_SYS(sched_getscheduler), QEMU_SECCOMP_SET_RESOURCECTL }, - { SCMP_SYS(sched_setaffinity), QEMU_SECCOMP_SET_RESOURCECTL }, - { SCMP_SYS(sched_getaffinity), QEMU_SECCOMP_SET_RESOURCECTL }, - { SCMP_SYS(sched_get_priority_max), QEMU_SECCOMP_SET_RESOURCECTL }, - { SCMP_SYS(sched_get_priority_min), QEMU_SECCOMP_SET_RESOURCECTL }, -}; - -static inline __attribute__((unused)) int -qemu_seccomp(unsigned int operation, unsigned int flags, void *args) -{ -#ifdef __NR_seccomp - return syscall(__NR_seccomp, operation, flags, args); -#else - errno = ENOSYS; - return -1; -#endif -} - -static uint32_t qemu_seccomp_get_action(int set) -{ - switch (set) { - case QEMU_SECCOMP_SET_DEFAULT: - case QEMU_SECCOMP_SET_OBSOLETE: - case QEMU_SECCOMP_SET_PRIVILEGED: - case QEMU_SECCOMP_SET_SPAWN: { -#if defined(SECCOMP_GET_ACTION_AVAIL) && defined(SCMP_ACT_KILL_PROCESS) && \ - defined(SECCOMP_RET_KILL_PROCESS) - static int kill_process = -1; - if (kill_process == -1) { - uint32_t action = SECCOMP_RET_KILL_PROCESS; - - if (qemu_seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &action) == 0) { - kill_process = 1; - } - kill_process = 0; - } - if (kill_process == 1) { - return SCMP_ACT_KILL_PROCESS; - } -#endif - return SCMP_ACT_TRAP; - } - - case QEMU_SECCOMP_SET_RESOURCECTL: - return SCMP_ACT_ERRNO(EPERM); - - default: - g_assert_not_reached(); - } -} - - -static int seccomp_start(uint32_t seccomp_opts, Error **errp) -{ - int rc = -1; - unsigned int i = 0; - scmp_filter_ctx ctx; - - ctx = seccomp_init(SCMP_ACT_ALLOW); - if (ctx == NULL) { - error_setg(errp, "failed to initialize seccomp context"); - goto seccomp_return; - } - - rc = seccomp_attr_set(ctx, SCMP_FLTATR_CTL_TSYNC, 1); - if (rc != 0) { - error_setg_errno(errp, -rc, - "failed to set seccomp thread synchronization"); - goto seccomp_return; - } - - for (i = 0; i < ARRAY_SIZE(blacklist); i++) { - uint32_t action; - if (!(seccomp_opts & blacklist[i].set)) { - continue; - } - - action = qemu_seccomp_get_action(blacklist[i].set); - rc = seccomp_rule_add_array(ctx, action, blacklist[i].num, - blacklist[i].narg, blacklist[i].arg_cmp); - if (rc < 0) { - error_setg_errno(errp, -rc, - "failed to add seccomp blacklist rules"); - goto seccomp_return; - } - } - - rc = seccomp_load(ctx); - if (rc < 0) { - error_setg_errno(errp, -rc, - "failed to load seccomp syscall filter in kernel"); - } - - seccomp_return: - seccomp_release(ctx); - return rc < 0 ? -1 : 0; -} - -#ifdef CONFIG_SECCOMP -int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp) -{ - if (qemu_opt_get_bool(opts, "enable", false)) { - uint32_t seccomp_opts = QEMU_SECCOMP_SET_DEFAULT - | QEMU_SECCOMP_SET_OBSOLETE; - const char *value = NULL; - - value = qemu_opt_get(opts, "obsolete"); - if (value) { - if (g_str_equal(value, "allow")) { - seccomp_opts &= ~QEMU_SECCOMP_SET_OBSOLETE; - } else if (g_str_equal(value, "deny")) { - /* this is the default option, this if is here - * to provide a little bit of consistency for - * the command line */ - } else { - error_setg(errp, "invalid argument for obsolete"); - return -1; - } - } - - value = qemu_opt_get(opts, "elevateprivileges"); - if (value) { - if (g_str_equal(value, "deny")) { - seccomp_opts |= QEMU_SECCOMP_SET_PRIVILEGED; - } else if (g_str_equal(value, "children")) { - seccomp_opts |= QEMU_SECCOMP_SET_PRIVILEGED; - - /* calling prctl directly because we're - * not sure if host has CAP_SYS_ADMIN set*/ - if (prctl(PR_SET_NO_NEW_PRIVS, 1)) { - error_setg(errp, "failed to set no_new_privs aborting"); - return -1; - } - } else if (g_str_equal(value, "allow")) { - /* default value */ - } else { - error_setg(errp, "invalid argument for elevateprivileges"); - return -1; - } - } - - value = qemu_opt_get(opts, "spawn"); - if (value) { - if (g_str_equal(value, "deny")) { - seccomp_opts |= QEMU_SECCOMP_SET_SPAWN; - } else if (g_str_equal(value, "allow")) { - /* default value */ - } else { - error_setg(errp, "invalid argument for spawn"); - return -1; - } - } - - value = qemu_opt_get(opts, "resourcecontrol"); - if (value) { - if (g_str_equal(value, "deny")) { - seccomp_opts |= QEMU_SECCOMP_SET_RESOURCECTL; - } else if (g_str_equal(value, "allow")) { - /* default value */ - } else { - error_setg(errp, "invalid argument for resourcecontrol"); - return -1; - } - } - - if (seccomp_start(seccomp_opts, errp) < 0) { - return -1; - } - } - - return 0; -} - -static QemuOptsList qemu_sandbox_opts = { - .name = "sandbox", - .implied_opt_name = "enable", - .head = QTAILQ_HEAD_INITIALIZER(qemu_sandbox_opts.head), - .desc = { - { - .name = "enable", - .type = QEMU_OPT_BOOL, - }, - { - .name = "obsolete", - .type = QEMU_OPT_STRING, - }, - { - .name = "elevateprivileges", - .type = QEMU_OPT_STRING, - }, - { - .name = "spawn", - .type = QEMU_OPT_STRING, - }, - { - .name = "resourcecontrol", - .type = QEMU_OPT_STRING, - }, - { /* end of list */ } - }, -}; - -static void seccomp_register(void) -{ - bool add = false; - - /* FIXME: use seccomp_api_get() >= 2 check when released */ - -#if defined(SECCOMP_FILTER_FLAG_TSYNC) - int check; - - /* check host TSYNC capability, it returns errno == ENOSYS if unavailable */ - check = qemu_seccomp(SECCOMP_SET_MODE_FILTER, - SECCOMP_FILTER_FLAG_TSYNC, NULL); - if (check < 0 && errno == EFAULT) { - add = true; - } -#endif - - if (add) { - qemu_add_opts(&qemu_sandbox_opts); - } -} -opts_init(seccomp_register); -#endif |