// https://syzkaller.appspot.com/bug?id=4f1db8b5e7dfcca55e20931aec0ee707c5cafc99 // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #include #include #include #include #include #include #include const int kFailStatus = 67; const int kRetryStatus = 69; static void fail(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus); } static void exitf(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit(kRetryStatus); } static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* uctx) { uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) && (addr < prog_start || addr > prog_end)) { _longjmp(segv_env, 1); } doexit(sig); } static void install_segv_handler() { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ { \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ } static uint64_t current_time_ms() { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) fail("clock_gettime failed"); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir() { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); } static void vsnprintf_check(char* str, size_t size, const char* format, va_list args) { int rv; rv = vsnprintf(str, size, format, args); if (rv < 0) fail("tun: snprintf failed"); if ((size_t)rv >= size) fail("tun: string '%s...' doesn't fit into buffer", str); } static void snprintf_check(char* str, size_t size, const char* format, ...) { va_list args; va_start(args, format); vsnprintf_check(str, size, format, args); va_end(args); } #define COMMAND_MAX_LEN 128 #define PATH_PREFIX \ "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin " #define PATH_PREFIX_LEN (sizeof(PATH_PREFIX) - 1) static void execute_command(bool panic, const char* format, ...) { va_list args; char command[PATH_PREFIX_LEN + COMMAND_MAX_LEN]; int rv; va_start(args, format); memcpy(command, PATH_PREFIX, PATH_PREFIX_LEN); vsnprintf_check(command + PATH_PREFIX_LEN, COMMAND_MAX_LEN, format, args); va_end(args); rv = system(command); if (rv) { if (panic) fail("command '%s' failed: %d", &command[0], rv); } } static int tunfd = -1; static int tun_frags_enabled; #define SYZ_TUN_MAX_PACKET_SIZE 1000 #define TUN_IFACE "syz_tun" #define LOCAL_MAC "aa:aa:aa:aa:aa:aa" #define REMOTE_MAC "aa:aa:aa:aa:aa:bb" #define LOCAL_IPV4 "172.20.20.170" #define REMOTE_IPV4 "172.20.20.187" #define LOCAL_IPV6 "fe80::aa" #define REMOTE_IPV6 "fe80::bb" #define IFF_NAPI 0x0010 #define IFF_NAPI_FRAGS 0x0020 static void initialize_tun(void) { tunfd = open("/dev/net/tun", O_RDWR | O_NONBLOCK); if (tunfd == -1) { printf("tun: can't open /dev/net/tun: please enable CONFIG_TUN=y\n"); printf("otherwise fuzzing or reproducing might not work as intended\n"); return; } const int kTunFd = 252; if (dup2(tunfd, kTunFd) < 0) fail("dup2(tunfd, kTunFd) failed"); close(tunfd); tunfd = kTunFd; struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, TUN_IFACE, IFNAMSIZ); ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_NAPI | IFF_NAPI_FRAGS; if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) { ifr.ifr_flags = IFF_TAP | IFF_NO_PI; if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) fail("tun: ioctl(TUNSETIFF) failed"); } if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0) fail("tun: ioctl(TUNGETIFF) failed"); tun_frags_enabled = (ifr.ifr_flags & IFF_NAPI_FRAGS) != 0; execute_command(1, "sysctl -w net.ipv6.conf.%s.accept_dad=0", TUN_IFACE); execute_command(1, "sysctl -w net.ipv6.conf.%s.router_solicitations=0", TUN_IFACE); execute_command(1, "ip link set dev %s address %s", TUN_IFACE, LOCAL_MAC); execute_command(1, "ip addr add %s/24 dev %s", LOCAL_IPV4, TUN_IFACE); execute_command(1, "ip -6 addr add %s/120 dev %s", LOCAL_IPV6, TUN_IFACE); execute_command(1, "ip neigh add %s lladdr %s dev %s nud permanent", REMOTE_IPV4, REMOTE_MAC, TUN_IFACE); execute_command(1, "ip -6 neigh add %s lladdr %s dev %s nud permanent", REMOTE_IPV6, REMOTE_MAC, TUN_IFACE); execute_command(1, "ip link set dev %s up", TUN_IFACE); } #define DEV_IPV4 "172.20.20.%d" #define DEV_IPV6 "fe80::%02hx" #define DEV_MAC "aa:aa:aa:aa:aa:%02hx" static void initialize_netdevices(void) { unsigned i; const char* devtypes[] = {"ip6gretap", "bridge", "vcan", "bond", "veth", "team"}; const char* devnames[] = { "lo", "sit0", "bridge0", "vcan0", "tunl0", "gre0", "gretap0", "ip_vti0", "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0", "erspan0", "bond0", "veth0", "veth1", "team0"}; for (i = 0; i < sizeof(devtypes) / (sizeof(devtypes[0])); i++) execute_command(0, "ip link add dev %s0 type %s", devtypes[i], devtypes[i]); execute_command(0, "ip link add dev veth1 type veth"); for (i = 0; i < sizeof(devnames) / (sizeof(devnames[0])); i++) { char addr[32]; snprintf_check(addr, sizeof(addr), DEV_IPV4, i + 10); execute_command(0, "ip -4 addr add %s/24 dev %s", addr, devnames[i]); snprintf_check(addr, sizeof(addr), DEV_IPV6, i + 10); execute_command(0, "ip -6 addr add %s/120 dev %s", addr, devnames[i]); snprintf_check(addr, sizeof(addr), DEV_MAC, i + 10); execute_command(0, "ip link set dev %s address %s", devnames[i], addr); execute_command(0, "ip link set dev %s up", devnames[i]); } } static int read_tun(char* data, int size) { if (tunfd < 0) return -1; int rv = read(tunfd, data, size); if (rv < 0) { if (errno == EAGAIN) return -1; if (errno == EBADFD) return -1; fail("tun: read failed with %d", rv); } return rv; } static void flush_tun() { char data[SYZ_TUN_MAX_PACKET_SIZE]; while (read_tun(&data[0], sizeof(data)) != -1) ; } static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { char buf[1024]; char* hash; NONFAILING(strncpy(buf, (char*)a0, sizeof(buf))); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 0); } } const char kvm_asm16_cpl3[] = "\x0f\x20\xc0\x66\x83\xc8\x01\x0f\x22\xc0\xb8\xa0" "\x00\x0f\x00\xd8\xb8\x2b\x00\x8e\xd8\x8e\xc0\x8e" "\xe0\x8e\xe8\xbc\x00\x01\xc7\x06\x00\x01\x1d\xba" "\xc7\x06\x02\x01\x23\x00\xc7\x06\x04\x01\x00\x01" "\xc7\x06\x06\x01\x2b\x00\xcb"; const char kvm_asm32_paged[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0"; const char kvm_asm32_vm86[] = "\x66\xb8\xb8\x00\x0f\x00\xd8\xea\x00\x00\x00\x00\xd0\x00"; const char kvm_asm32_paged_vm86[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22" "\xc0\x66\xb8\xb8\x00\x0f\x00\xd8\xea\x00" "\x00\x00\x00\xd0\x00"; const char kvm_asm64_vm86[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0\x66" "\xb8\xb8\x00\x0f\x00\xd8\xea\x00\x00\x00\x00\xd0" "\x00"; const char kvm_asm64_enable_long[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22" "\xc0\xea\xde\xc0\xad\x0b\x50\x00\x48\xc7" "\xc0\xd8\x00\x00\x00\x0f\x00\xd8"; const char kvm_asm64_init_vm[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0\xea\xde\xc0\xad\x0b\x50\x00" "\x48\xc7\xc0\xd8\x00\x00\x00\x0f\x00\xd8\x48\xc7\xc1\x3a\x00\x00\x00\x0f" "\x32\x48\x83\xc8\x05\x0f\x30\x0f\x20\xe0\x48\x0d\x00\x20\x00\x00\x0f\x22" "\xe0\x48\xc7\xc1\x80\x04\x00\x00\x0f\x32\x48\xc7\xc2\x00\x60\x00\x00\x89" "\x02\x48\xc7\xc2\x00\x70\x00\x00\x89\x02\x48\xc7\xc0\x00\x5f\x00\x00\xf3" "\x0f\xc7\x30\x48\xc7\xc0\x08\x5f\x00\x00\x66\x0f\xc7\x30\x0f\xc7\x30\x48" "\xc7\xc1\x81\x04\x00\x00\x0f\x32\x48\x83\xc8\x3f\x48\x21\xd0\x48\xc7\xc2" "\x00\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x02\x40\x00\x00\x48\xb8\x84\x9e" "\x99\xf3\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x1e\x40\x00\x00\x48\xc7" "\xc0\x81\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc1\x83\x04\x00\x00\x0f\x32\x48" "\x0d\xff\x6f\x03\x00\x48\x21\xd0\x48\xc7\xc2\x0c\x40\x00\x00\x0f\x79\xd0" "\x48\xc7\xc1\x84\x04\x00\x00\x0f\x32\x48\x0d\xff\x17\x00\x00\x48\x21\xd0" "\x48\xc7\xc2\x12\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x04\x2c\x00\x00\x48" "\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x00\x28\x00\x00\x48\xc7" "\xc0\xff\xff\xff\xff\x0f\x79\xd0\x48\xc7\xc2\x02\x0c\x00\x00\x48\xc7\xc0" "\x50\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc0\x58\x00\x00\x00\x48\xc7\xc2\x00" "\x0c\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x04\x0c\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x06\x0c\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x08\x0c\x00\x00\x0f\x79\xd0" "\x48\xc7\xc2\x0a\x0c\x00\x00\x0f\x79\xd0\x48\xc7\xc0\xd8\x00\x00\x00\x48" "\xc7\xc2\x0c\x0c\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x02\x2c\x00\x00\x48\xc7" "\xc0\x00\x05\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x00\x4c\x00\x00\x48\xc7\xc0" "\x50\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x10\x6c\x00\x00\x48\xc7\xc0\x00" "\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x12\x6c\x00\x00\x48\xc7\xc0\x00\x00" "\x00\x00\x0f\x79\xd0\x0f\x20\xc0\x48\xc7\xc2\x00\x6c\x00\x00\x48\x89\xc0" "\x0f\x79\xd0\x0f\x20\xd8\x48\xc7\xc2\x02\x6c\x00\x00\x48\x89\xc0\x0f\x79" "\xd0\x0f\x20\xe0\x48\xc7\xc2\x04\x6c\x00\x00\x48\x89\xc0\x0f\x79\xd0\x48" "\xc7\xc2\x06\x6c\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x08\x6c\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x0a\x6c\x00\x00\x48\xc7\xc0\x00\x3a\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0c" "\x6c\x00\x00\x48\xc7\xc0\x00\x10\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0e\x6c" "\x00\x00\x48\xc7\xc0\x00\x38\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x14\x6c\x00" "\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x16\x6c\x00\x00" "\x48\x8b\x04\x25\x10\x5f\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x00\x00\x00\x00" "\x48\xc7\xc0\x01\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x02\x00\x00\x00\x48" "\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x00\x20\x00\x00\x48\xc7" "\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x02\x20\x00\x00\x48\xc7\xc0" "\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x04\x20\x00\x00\x48\xc7\xc0\x00" "\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x06\x20\x00\x00\x48\xc7\xc0\x00\x00" "\x00\x00\x0f\x79\xd0\x48\xc7\xc1\x77\x02\x00\x00\x0f\x32\x48\xc1\xe2\x20" "\x48\x09\xd0\x48\xc7\xc2\x00\x2c\x00\x00\x48\x89\xc0\x0f\x79\xd0\x48\xc7" "\xc2\x04\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x0a\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0e" "\x40\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x10\x40" "\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x16\x40\x00" "\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x14\x40\x00\x00" "\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x00\x60\x00\x00\x48" "\xc7\xc0\xff\xff\xff\xff\x0f\x79\xd0\x48\xc7\xc2\x02\x60\x00\x00\x48\xc7" "\xc0\xff\xff\xff\xff\x0f\x79\xd0\x48\xc7\xc2\x1c\x20\x00\x00\x48\xc7\xc0" "\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x1e\x20\x00\x00\x48\xc7\xc0\x00" "\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x20\x20\x00\x00\x48\xc7\xc0\x00\x00" "\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x22\x20\x00\x00\x48\xc7\xc0\x00\x00\x00" "\x00\x0f\x79\xd0\x48\xc7\xc2\x00\x08\x00\x00\x48\xc7\xc0\x58\x00\x00\x00" "\x0f\x79\xd0\x48\xc7\xc2\x02\x08\x00\x00\x48\xc7\xc0\x50\x00\x00\x00\x0f" "\x79\xd0\x48\xc7\xc2\x04\x08\x00\x00\x48\xc7\xc0\x58\x00\x00\x00\x0f\x79" "\xd0\x48\xc7\xc2\x06\x08\x00\x00\x48\xc7\xc0\x58\x00\x00\x00\x0f\x79\xd0" "\x48\xc7\xc2\x08\x08\x00\x00\x48\xc7\xc0\x58\x00\x00\x00\x0f\x79\xd0\x48" "\xc7\xc2\x0a\x08\x00\x00\x48\xc7\xc0\x58\x00\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x0c\x08\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x0e\x08\x00\x00\x48\xc7\xc0\xd8\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x12" "\x68\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x14\x68" "\x00\x00\x48\xc7\xc0\x00\x3a\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x16\x68\x00" "\x00\x48\xc7\xc0\x00\x10\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x18\x68\x00\x00" "\x48\xc7\xc0\x00\x38\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x00\x48\x00\x00\x48" "\xc7\xc0\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x02\x48\x00\x00\x48\xc7" "\xc0\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x04\x48\x00\x00\x48\xc7\xc0" "\xff\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x06\x48\x00\x00\x48\xc7\xc0\xff" "\xff\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x08\x48\x00\x00\x48\xc7\xc0\xff\xff" "\x0f\x00\x0f\x79\xd0\x48\xc7\xc2\x0a\x48\x00\x00\x48\xc7\xc0\xff\xff\x0f" "\x00\x0f\x79\xd0\x48\xc7\xc2\x0c\x48\x00\x00\x48\xc7\xc0\x00\x00\x00\x00" "\x0f\x79\xd0\x48\xc7\xc2\x0e\x48\x00\x00\x48\xc7\xc0\xff\x1f\x00\x00\x0f" "\x79\xd0\x48\xc7\xc2\x10\x48\x00\x00\x48\xc7\xc0\xff\x1f\x00\x00\x0f\x79" "\xd0\x48\xc7\xc2\x12\x48\x00\x00\x48\xc7\xc0\xff\x1f\x00\x00\x0f\x79\xd0" "\x48\xc7\xc2\x14\x48\x00\x00\x48\xc7\xc0\x93\x40\x00\x00\x0f\x79\xd0\x48" "\xc7\xc2\x16\x48\x00\x00\x48\xc7\xc0\x9b\x20\x00\x00\x0f\x79\xd0\x48\xc7" "\xc2\x18\x48\x00\x00\x48\xc7\xc0\x93\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc2" "\x1a\x48\x00\x00\x48\xc7\xc0\x93\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x1c" "\x48\x00\x00\x48\xc7\xc0\x93\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x1e\x48" "\x00\x00\x48\xc7\xc0\x93\x40\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x20\x48\x00" "\x00\x48\xc7\xc0\x82\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x22\x48\x00\x00" "\x48\xc7\xc0\x8b\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x1c\x68\x00\x00\x48" "\xc7\xc0\x00\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x1e\x68\x00\x00\x48\xc7" "\xc0\x00\x91\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x20\x68\x00\x00\x48\xc7\xc0" "\x02\x00\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x06\x28\x00\x00\x48\xc7\xc0\x00" "\x05\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0a\x28\x00\x00\x48\xc7\xc0\x00\x00" "\x00\x00\x0f\x79\xd0\x48\xc7\xc2\x0c\x28\x00\x00\x48\xc7\xc0\x00\x00\x00" "\x00\x0f\x79\xd0\x48\xc7\xc2\x0e\x28\x00\x00\x48\xc7\xc0\x00\x00\x00\x00" "\x0f\x79\xd0\x48\xc7\xc2\x10\x28\x00\x00\x48\xc7\xc0\x00\x00\x00\x00\x0f" "\x79\xd0\x0f\x20\xc0\x48\xc7\xc2\x00\x68\x00\x00\x48\x89\xc0\x0f\x79\xd0" "\x0f\x20\xd8\x48\xc7\xc2\x02\x68\x00\x00\x48\x89\xc0\x0f\x79\xd0\x0f\x20" "\xe0\x48\xc7\xc2\x04\x68\x00\x00\x48\x89\xc0\x0f\x79\xd0\x48\xc7\xc0\x18" "\x5f\x00\x00\x48\x8b\x10\x48\xc7\xc0\x20\x5f\x00\x00\x48\x8b\x08\x48\x31" "\xc0\x0f\x78\xd0\x48\x31\xc8\x0f\x79\xd0\x0f\x01\xc2\x48\xc7\xc2\x00\x44" "\x00\x00\x0f\x78\xd0\xf4"; const char kvm_asm64_vm_exit[] = "\x48\xc7\xc3\x00\x44\x00\x00\x0f\x78\xda\x48" "\xc7\xc3\x02\x44\x00\x00\x0f\x78\xd9\x48\xc7" "\xc0\x00\x64\x00\x00\x0f\x78\xc0\x48\xc7\xc3" "\x1e\x68\x00\x00\x0f\x78\xdb\xf4"; const char kvm_asm64_cpl3[] = "\x0f\x20\xc0\x0d\x00\x00\x00\x80\x0f\x22\xc0\xea\xde\xc0\xad\x0b\x50\x00" "\x48\xc7\xc0\xd8\x00\x00\x00\x0f\x00\xd8\x48\xc7\xc0\x6b\x00\x00\x00\x8e" "\xd8\x8e\xc0\x8e\xe0\x8e\xe8\x48\xc7\xc4\x80\x0f\x00\x00\x48\xc7\x04\x24" "\x1d\xba\x00\x00\x48\xc7\x44\x24\x04\x63\x00\x00\x00\x48\xc7\x44\x24\x08" "\x80\x0f\x00\x00\x48\xc7\x44\x24\x0c\x6b\x00\x00\x00\xcb"; #define ADDR_TEXT 0x0000 #define ADDR_GDT 0x1000 #define ADDR_LDT 0x1800 #define ADDR_PML4 0x2000 #define ADDR_PDP 0x3000 #define ADDR_PD 0x4000 #define ADDR_STACK0 0x0f80 #define ADDR_VAR_HLT 0x2800 #define ADDR_VAR_SYSRET 0x2808 #define ADDR_VAR_SYSEXIT 0x2810 #define ADDR_VAR_IDT 0x3800 #define ADDR_VAR_TSS64 0x3a00 #define ADDR_VAR_TSS64_CPL3 0x3c00 #define ADDR_VAR_TSS16 0x3d00 #define ADDR_VAR_TSS16_2 0x3e00 #define ADDR_VAR_TSS16_CPL3 0x3f00 #define ADDR_VAR_TSS32 0x4800 #define ADDR_VAR_TSS32_2 0x4a00 #define ADDR_VAR_TSS32_CPL3 0x4c00 #define ADDR_VAR_TSS32_VM86 0x4e00 #define ADDR_VAR_VMXON_PTR 0x5f00 #define ADDR_VAR_VMCS_PTR 0x5f08 #define ADDR_VAR_VMEXIT_PTR 0x5f10 #define ADDR_VAR_VMWRITE_FLD 0x5f18 #define ADDR_VAR_VMWRITE_VAL 0x5f20 #define ADDR_VAR_VMXON 0x6000 #define ADDR_VAR_VMCS 0x7000 #define ADDR_VAR_VMEXIT_CODE 0x9000 #define ADDR_VAR_USER_CODE 0x9100 #define ADDR_VAR_USER_CODE2 0x9120 #define SEL_LDT (1 << 3) #define SEL_CS16 (2 << 3) #define SEL_DS16 (3 << 3) #define SEL_CS16_CPL3 ((4 << 3) + 3) #define SEL_DS16_CPL3 ((5 << 3) + 3) #define SEL_CS32 (6 << 3) #define SEL_DS32 (7 << 3) #define SEL_CS32_CPL3 ((8 << 3) + 3) #define SEL_DS32_CPL3 ((9 << 3) + 3) #define SEL_CS64 (10 << 3) #define SEL_DS64 (11 << 3) #define SEL_CS64_CPL3 ((12 << 3) + 3) #define SEL_DS64_CPL3 ((13 << 3) + 3) #define SEL_CGATE16 (14 << 3) #define SEL_TGATE16 (15 << 3) #define SEL_CGATE32 (16 << 3) #define SEL_TGATE32 (17 << 3) #define SEL_CGATE64 (18 << 3) #define SEL_CGATE64_HI (19 << 3) #define SEL_TSS16 (20 << 3) #define SEL_TSS16_2 (21 << 3) #define SEL_TSS16_CPL3 ((22 << 3) + 3) #define SEL_TSS32 (23 << 3) #define SEL_TSS32_2 (24 << 3) #define SEL_TSS32_CPL3 ((25 << 3) + 3) #define SEL_TSS32_VM86 (26 << 3) #define SEL_TSS64 (27 << 3) #define SEL_TSS64_HI (28 << 3) #define SEL_TSS64_CPL3 ((29 << 3) + 3) #define SEL_TSS64_CPL3_HI (30 << 3) #define MSR_IA32_FEATURE_CONTROL 0x3a #define MSR_IA32_VMX_BASIC 0x480 #define MSR_IA32_SMBASE 0x9e #define MSR_IA32_SYSENTER_CS 0x174 #define MSR_IA32_SYSENTER_ESP 0x175 #define MSR_IA32_SYSENTER_EIP 0x176 #define MSR_IA32_STAR 0xC0000081 #define MSR_IA32_LSTAR 0xC0000082 #define MSR_IA32_VMX_PROCBASED_CTLS2 0x48B #define NEXT_INSN $0xbadc0de #define PREFIX_SIZE 0xba1d #define KVM_SMI _IO(KVMIO, 0xb7) #define CR0_PE 1 #define CR0_MP (1 << 1) #define CR0_EM (1 << 2) #define CR0_TS (1 << 3) #define CR0_ET (1 << 4) #define CR0_NE (1 << 5) #define CR0_WP (1 << 16) #define CR0_AM (1 << 18) #define CR0_NW (1 << 29) #define CR0_CD (1 << 30) #define CR0_PG (1 << 31) #define CR4_VME 1 #define CR4_PVI (1 << 1) #define CR4_TSD (1 << 2) #define CR4_DE (1 << 3) #define CR4_PSE (1 << 4) #define CR4_PAE (1 << 5) #define CR4_MCE (1 << 6) #define CR4_PGE (1 << 7) #define CR4_PCE (1 << 8) #define CR4_OSFXSR (1 << 8) #define CR4_OSXMMEXCPT (1 << 10) #define CR4_UMIP (1 << 11) #define CR4_VMXE (1 << 13) #define CR4_SMXE (1 << 14) #define CR4_FSGSBASE (1 << 16) #define CR4_PCIDE (1 << 17) #define CR4_OSXSAVE (1 << 18) #define CR4_SMEP (1 << 20) #define CR4_SMAP (1 << 21) #define CR4_PKE (1 << 22) #define EFER_SCE 1 #define EFER_LME (1 << 8) #define EFER_LMA (1 << 10) #define EFER_NXE (1 << 11) #define EFER_SVME (1 << 12) #define EFER_LMSLE (1 << 13) #define EFER_FFXSR (1 << 14) #define EFER_TCE (1 << 15) #define PDE32_PRESENT 1 #define PDE32_RW (1 << 1) #define PDE32_USER (1 << 2) #define PDE32_PS (1 << 7) #define PDE64_PRESENT 1 #define PDE64_RW (1 << 1) #define PDE64_USER (1 << 2) #define PDE64_ACCESSED (1 << 5) #define PDE64_DIRTY (1 << 6) #define PDE64_PS (1 << 7) #define PDE64_G (1 << 8) struct tss16 { uint16_t prev; uint16_t sp0; uint16_t ss0; uint16_t sp1; uint16_t ss1; uint16_t sp2; uint16_t ss2; uint16_t ip; uint16_t flags; uint16_t ax; uint16_t cx; uint16_t dx; uint16_t bx; uint16_t sp; uint16_t bp; uint16_t si; uint16_t di; uint16_t es; uint16_t cs; uint16_t ss; uint16_t ds; uint16_t ldt; } __attribute__((packed)); struct tss32 { uint16_t prev, prevh; uint32_t sp0; uint16_t ss0, ss0h; uint32_t sp1; uint16_t ss1, ss1h; uint32_t sp2; uint16_t ss2, ss2h; uint32_t cr3; uint32_t ip; uint32_t flags; uint32_t ax; uint32_t cx; uint32_t dx; uint32_t bx; uint32_t sp; uint32_t bp; uint32_t si; uint32_t di; uint16_t es, esh; uint16_t cs, csh; uint16_t ss, ssh; uint16_t ds, dsh; uint16_t fs, fsh; uint16_t gs, gsh; uint16_t ldt, ldth; uint16_t trace; uint16_t io_bitmap; } __attribute__((packed)); struct tss64 { uint32_t reserved0; uint64_t rsp[3]; uint64_t reserved1; uint64_t ist[7]; uint64_t reserved2; uint32_t reserved3; uint32_t io_bitmap; } __attribute__((packed)); static void fill_segment_descriptor(uint64_t* dt, uint64_t* lt, struct kvm_segment* seg) { uint16_t index = seg->selector >> 3; uint64_t limit = seg->g ? seg->limit >> 12 : seg->limit; uint64_t sd = (limit & 0xffff) | (seg->base & 0xffffff) << 16 | (uint64_t)seg->type << 40 | (uint64_t)seg->s << 44 | (uint64_t)seg->dpl << 45 | (uint64_t)seg->present << 47 | (limit & 0xf0000ULL) << 48 | (uint64_t)seg->avl << 52 | (uint64_t)seg->l << 53 | (uint64_t)seg->db << 54 | (uint64_t)seg->g << 55 | (seg->base & 0xff000000ULL) << 56; NONFAILING(dt[index] = sd); NONFAILING(lt[index] = sd); } static void fill_segment_descriptor_dword(uint64_t* dt, uint64_t* lt, struct kvm_segment* seg) { fill_segment_descriptor(dt, lt, seg); uint16_t index = seg->selector >> 3; NONFAILING(dt[index + 1] = 0); NONFAILING(lt[index + 1] = 0); } static void setup_syscall_msrs(int cpufd, uint16_t sel_cs, uint16_t sel_cs_cpl3) { char buf[sizeof(struct kvm_msrs) + 5 * sizeof(struct kvm_msr_entry)]; memset(buf, 0, sizeof(buf)); struct kvm_msrs* msrs = (struct kvm_msrs*)buf; struct kvm_msr_entry* entries = msrs->entries; msrs->nmsrs = 5; entries[0].index = MSR_IA32_SYSENTER_CS; entries[0].data = sel_cs; entries[1].index = MSR_IA32_SYSENTER_ESP; entries[1].data = ADDR_STACK0; entries[2].index = MSR_IA32_SYSENTER_EIP; entries[2].data = ADDR_VAR_SYSEXIT; entries[3].index = MSR_IA32_STAR; entries[3].data = ((uint64_t)sel_cs << 32) | ((uint64_t)sel_cs_cpl3 << 48); entries[4].index = MSR_IA32_LSTAR; entries[4].data = ADDR_VAR_SYSRET; ioctl(cpufd, KVM_SET_MSRS, msrs); } static void setup_32bit_idt(struct kvm_sregs* sregs, char* host_mem, uintptr_t guest_mem) { sregs->idt.base = guest_mem + ADDR_VAR_IDT; sregs->idt.limit = 0x1ff; uint64_t* idt = (uint64_t*)(host_mem + sregs->idt.base); int i; for (i = 0; i < 32; i++) { struct kvm_segment gate; gate.selector = i << 3; switch (i % 6) { case 0: gate.type = 6; gate.base = SEL_CS16; break; case 1: gate.type = 7; gate.base = SEL_CS16; break; case 2: gate.type = 3; gate.base = SEL_TGATE16; break; case 3: gate.type = 14; gate.base = SEL_CS32; break; case 4: gate.type = 15; gate.base = SEL_CS32; break; case 6: gate.type = 11; gate.base = SEL_TGATE32; break; } gate.limit = guest_mem + ADDR_VAR_USER_CODE2; gate.present = 1; gate.dpl = 0; gate.s = 0; gate.g = 0; gate.db = 0; gate.l = 0; gate.avl = 0; fill_segment_descriptor(idt, idt, &gate); } } static void setup_64bit_idt(struct kvm_sregs* sregs, char* host_mem, uintptr_t guest_mem) { sregs->idt.base = guest_mem + ADDR_VAR_IDT; sregs->idt.limit = 0x1ff; uint64_t* idt = (uint64_t*)(host_mem + sregs->idt.base); int i; for (i = 0; i < 32; i++) { struct kvm_segment gate; gate.selector = (i * 2) << 3; gate.type = (i & 1) ? 14 : 15; gate.base = SEL_CS64; gate.limit = guest_mem + ADDR_VAR_USER_CODE2; gate.present = 1; gate.dpl = 0; gate.s = 0; gate.g = 0; gate.db = 0; gate.l = 0; gate.avl = 0; fill_segment_descriptor_dword(idt, idt, &gate); } } struct kvm_text { uintptr_t typ; const void* text; uintptr_t size; }; struct kvm_opt { uint64_t typ; uint64_t val; }; #define KVM_SETUP_PAGING (1 << 0) #define KVM_SETUP_PAE (1 << 1) #define KVM_SETUP_PROTECTED (1 << 2) #define KVM_SETUP_CPL3 (1 << 3) #define KVM_SETUP_VIRT86 (1 << 4) #define KVM_SETUP_SMM (1 << 5) #define KVM_SETUP_VM (1 << 6) static uintptr_t syz_kvm_setup_cpu(uintptr_t a0, uintptr_t a1, uintptr_t a2, uintptr_t a3, uintptr_t a4, uintptr_t a5, uintptr_t a6, uintptr_t a7) { const int vmfd = a0; const int cpufd = a1; char* const host_mem = (char*)a2; const struct kvm_text* const text_array_ptr = (struct kvm_text*)a3; const uintptr_t text_count = a4; const uintptr_t flags = a5; const struct kvm_opt* const opt_array_ptr = (struct kvm_opt*)a6; uintptr_t opt_count = a7; const uintptr_t page_size = 4 << 10; const uintptr_t ioapic_page = 10; const uintptr_t guest_mem_size = 24 * page_size; const uintptr_t guest_mem = 0; (void)text_count; int text_type = 0; const void* text = 0; uintptr_t text_size = 0; NONFAILING(text_type = text_array_ptr[0].typ); NONFAILING(text = text_array_ptr[0].text); NONFAILING(text_size = text_array_ptr[0].size); uintptr_t i; for (i = 0; i < guest_mem_size / page_size; i++) { struct kvm_userspace_memory_region memreg; memreg.slot = i; memreg.flags = 0; memreg.guest_phys_addr = guest_mem + i * page_size; if (i == ioapic_page) memreg.guest_phys_addr = 0xfec00000; memreg.memory_size = page_size; memreg.userspace_addr = (uintptr_t)host_mem + i * page_size; ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &memreg); } struct kvm_userspace_memory_region memreg; memreg.slot = 1 + (1 << 16); memreg.flags = 0; memreg.guest_phys_addr = 0x30000; memreg.memory_size = 64 << 10; memreg.userspace_addr = (uintptr_t)host_mem; ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &memreg); struct kvm_sregs sregs; if (ioctl(cpufd, KVM_GET_SREGS, &sregs)) return -1; struct kvm_regs regs; memset(®s, 0, sizeof(regs)); regs.rip = guest_mem + ADDR_TEXT; regs.rsp = ADDR_STACK0; sregs.gdt.base = guest_mem + ADDR_GDT; sregs.gdt.limit = 256 * sizeof(uint64_t) - 1; uint64_t* gdt = (uint64_t*)(host_mem + sregs.gdt.base); struct kvm_segment seg_ldt; seg_ldt.selector = SEL_LDT; seg_ldt.type = 2; seg_ldt.base = guest_mem + ADDR_LDT; seg_ldt.limit = 256 * sizeof(uint64_t) - 1; seg_ldt.present = 1; seg_ldt.dpl = 0; seg_ldt.s = 0; seg_ldt.g = 0; seg_ldt.db = 1; seg_ldt.l = 0; sregs.ldt = seg_ldt; uint64_t* ldt = (uint64_t*)(host_mem + sregs.ldt.base); struct kvm_segment seg_cs16; seg_cs16.selector = SEL_CS16; seg_cs16.type = 11; seg_cs16.base = 0; seg_cs16.limit = 0xfffff; seg_cs16.present = 1; seg_cs16.dpl = 0; seg_cs16.s = 1; seg_cs16.g = 0; seg_cs16.db = 0; seg_cs16.l = 0; struct kvm_segment seg_ds16 = seg_cs16; seg_ds16.selector = SEL_DS16; seg_ds16.type = 3; struct kvm_segment seg_cs16_cpl3 = seg_cs16; seg_cs16_cpl3.selector = SEL_CS16_CPL3; seg_cs16_cpl3.dpl = 3; struct kvm_segment seg_ds16_cpl3 = seg_ds16; seg_ds16_cpl3.selector = SEL_DS16_CPL3; seg_ds16_cpl3.dpl = 3; struct kvm_segment seg_cs32 = seg_cs16; seg_cs32.selector = SEL_CS32; seg_cs32.db = 1; struct kvm_segment seg_ds32 = seg_ds16; seg_ds32.selector = SEL_DS32; seg_ds32.db = 1; struct kvm_segment seg_cs32_cpl3 = seg_cs32; seg_cs32_cpl3.selector = SEL_CS32_CPL3; seg_cs32_cpl3.dpl = 3; struct kvm_segment seg_ds32_cpl3 = seg_ds32; seg_ds32_cpl3.selector = SEL_DS32_CPL3; seg_ds32_cpl3.dpl = 3; struct kvm_segment seg_cs64 = seg_cs16; seg_cs64.selector = SEL_CS64; seg_cs64.l = 1; struct kvm_segment seg_ds64 = seg_ds32; seg_ds64.selector = SEL_DS64; struct kvm_segment seg_cs64_cpl3 = seg_cs64; seg_cs64_cpl3.selector = SEL_CS64_CPL3; seg_cs64_cpl3.dpl = 3; struct kvm_segment seg_ds64_cpl3 = seg_ds64; seg_ds64_cpl3.selector = SEL_DS64_CPL3; seg_ds64_cpl3.dpl = 3; struct kvm_segment seg_tss32; seg_tss32.selector = SEL_TSS32; seg_tss32.type = 9; seg_tss32.base = ADDR_VAR_TSS32; seg_tss32.limit = 0x1ff; seg_tss32.present = 1; seg_tss32.dpl = 0; seg_tss32.s = 0; seg_tss32.g = 0; seg_tss32.db = 0; seg_tss32.l = 0; struct kvm_segment seg_tss32_2 = seg_tss32; seg_tss32_2.selector = SEL_TSS32_2; seg_tss32_2.base = ADDR_VAR_TSS32_2; struct kvm_segment seg_tss32_cpl3 = seg_tss32; seg_tss32_cpl3.selector = SEL_TSS32_CPL3; seg_tss32_cpl3.base = ADDR_VAR_TSS32_CPL3; struct kvm_segment seg_tss32_vm86 = seg_tss32; seg_tss32_vm86.selector = SEL_TSS32_VM86; seg_tss32_vm86.base = ADDR_VAR_TSS32_VM86; struct kvm_segment seg_tss16 = seg_tss32; seg_tss16.selector = SEL_TSS16; seg_tss16.base = ADDR_VAR_TSS16; seg_tss16.limit = 0xff; seg_tss16.type = 1; struct kvm_segment seg_tss16_2 = seg_tss16; seg_tss16_2.selector = SEL_TSS16_2; seg_tss16_2.base = ADDR_VAR_TSS16_2; seg_tss16_2.dpl = 0; struct kvm_segment seg_tss16_cpl3 = seg_tss16; seg_tss16_cpl3.selector = SEL_TSS16_CPL3; seg_tss16_cpl3.base = ADDR_VAR_TSS16_CPL3; seg_tss16_cpl3.dpl = 3; struct kvm_segment seg_tss64 = seg_tss32; seg_tss64.selector = SEL_TSS64; seg_tss64.base = ADDR_VAR_TSS64; seg_tss64.limit = 0x1ff; struct kvm_segment seg_tss64_cpl3 = seg_tss64; seg_tss64_cpl3.selector = SEL_TSS64_CPL3; seg_tss64_cpl3.base = ADDR_VAR_TSS64_CPL3; seg_tss64_cpl3.dpl = 3; struct kvm_segment seg_cgate16; seg_cgate16.selector = SEL_CGATE16; seg_cgate16.type = 4; seg_cgate16.base = SEL_CS16 | (2 << 16); seg_cgate16.limit = ADDR_VAR_USER_CODE2; seg_cgate16.present = 1; seg_cgate16.dpl = 0; seg_cgate16.s = 0; seg_cgate16.g = 0; seg_cgate16.db = 0; seg_cgate16.l = 0; seg_cgate16.avl = 0; struct kvm_segment seg_tgate16 = seg_cgate16; seg_tgate16.selector = SEL_TGATE16; seg_tgate16.type = 3; seg_cgate16.base = SEL_TSS16_2; seg_tgate16.limit = 0; struct kvm_segment seg_cgate32 = seg_cgate16; seg_cgate32.selector = SEL_CGATE32; seg_cgate32.type = 12; seg_cgate32.base = SEL_CS32 | (2 << 16); struct kvm_segment seg_tgate32 = seg_cgate32; seg_tgate32.selector = SEL_TGATE32; seg_tgate32.type = 11; seg_tgate32.base = SEL_TSS32_2; seg_tgate32.limit = 0; struct kvm_segment seg_cgate64 = seg_cgate16; seg_cgate64.selector = SEL_CGATE64; seg_cgate64.type = 12; seg_cgate64.base = SEL_CS64; int kvmfd = open("/dev/kvm", O_RDWR); char buf[sizeof(struct kvm_cpuid2) + 128 * sizeof(struct kvm_cpuid_entry2)]; memset(buf, 0, sizeof(buf)); struct kvm_cpuid2* cpuid = (struct kvm_cpuid2*)buf; cpuid->nent = 128; ioctl(kvmfd, KVM_GET_SUPPORTED_CPUID, cpuid); ioctl(cpufd, KVM_SET_CPUID2, cpuid); close(kvmfd); const char* text_prefix = 0; int text_prefix_size = 0; char* host_text = host_mem + ADDR_TEXT; if (text_type == 8) { if (flags & KVM_SETUP_SMM) { if (flags & KVM_SETUP_PROTECTED) { sregs.cs = seg_cs16; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds16; sregs.cr0 |= CR0_PE; } else { sregs.cs.selector = 0; sregs.cs.base = 0; } NONFAILING(*(host_mem + ADDR_TEXT) = 0xf4); host_text = host_mem + 0x8000; ioctl(cpufd, KVM_SMI, 0); } else if (flags & KVM_SETUP_VIRT86) { sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; sregs.cr0 |= CR0_PE; sregs.efer |= EFER_SCE; setup_syscall_msrs(cpufd, SEL_CS32, SEL_CS32_CPL3); setup_32bit_idt(&sregs, host_mem, guest_mem); if (flags & KVM_SETUP_PAGING) { uint64_t pd_addr = guest_mem + ADDR_PD; uint64_t* pd = (uint64_t*)(host_mem + ADDR_PD); NONFAILING(pd[0] = PDE32_PRESENT | PDE32_RW | PDE32_USER | PDE32_PS); sregs.cr3 = pd_addr; sregs.cr4 |= CR4_PSE; text_prefix = kvm_asm32_paged_vm86; text_prefix_size = sizeof(kvm_asm32_paged_vm86) - 1; } else { text_prefix = kvm_asm32_vm86; text_prefix_size = sizeof(kvm_asm32_vm86) - 1; } } else { sregs.cs.selector = 0; sregs.cs.base = 0; } } else if (text_type == 16) { if (flags & KVM_SETUP_CPL3) { sregs.cs = seg_cs16; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds16; text_prefix = kvm_asm16_cpl3; text_prefix_size = sizeof(kvm_asm16_cpl3) - 1; } else { sregs.cr0 |= CR0_PE; sregs.cs = seg_cs16; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds16; } } else if (text_type == 32) { sregs.cr0 |= CR0_PE; sregs.efer |= EFER_SCE; setup_syscall_msrs(cpufd, SEL_CS32, SEL_CS32_CPL3); setup_32bit_idt(&sregs, host_mem, guest_mem); if (flags & KVM_SETUP_SMM) { sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; NONFAILING(*(host_mem + ADDR_TEXT) = 0xf4); host_text = host_mem + 0x8000; ioctl(cpufd, KVM_SMI, 0); } else if (flags & KVM_SETUP_PAGING) { sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; uint64_t pd_addr = guest_mem + ADDR_PD; uint64_t* pd = (uint64_t*)(host_mem + ADDR_PD); NONFAILING(pd[0] = PDE32_PRESENT | PDE32_RW | PDE32_USER | PDE32_PS); sregs.cr3 = pd_addr; sregs.cr4 |= CR4_PSE; text_prefix = kvm_asm32_paged; text_prefix_size = sizeof(kvm_asm32_paged) - 1; } else if (flags & KVM_SETUP_CPL3) { sregs.cs = seg_cs32_cpl3; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32_cpl3; } else { sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; } } else { sregs.efer |= EFER_LME | EFER_SCE; sregs.cr0 |= CR0_PE; setup_syscall_msrs(cpufd, SEL_CS64, SEL_CS64_CPL3); setup_64bit_idt(&sregs, host_mem, guest_mem); sregs.cs = seg_cs32; sregs.ds = sregs.es = sregs.fs = sregs.gs = sregs.ss = seg_ds32; uint64_t pml4_addr = guest_mem + ADDR_PML4; uint64_t* pml4 = (uint64_t*)(host_mem + ADDR_PML4); uint64_t pdpt_addr = guest_mem + ADDR_PDP; uint64_t* pdpt = (uint64_t*)(host_mem + ADDR_PDP); uint64_t pd_addr = guest_mem + ADDR_PD; uint64_t* pd = (uint64_t*)(host_mem + ADDR_PD); NONFAILING(pml4[0] = PDE64_PRESENT | PDE64_RW | PDE64_USER | pdpt_addr); NONFAILING(pdpt[0] = PDE64_PRESENT | PDE64_RW | PDE64_USER | pd_addr); NONFAILING(pd[0] = PDE64_PRESENT | PDE64_RW | PDE64_USER | PDE64_PS); sregs.cr3 = pml4_addr; sregs.cr4 |= CR4_PAE; if (flags & KVM_SETUP_VM) { sregs.cr0 |= CR0_NE; NONFAILING(*((uint64_t*)(host_mem + ADDR_VAR_VMXON_PTR)) = ADDR_VAR_VMXON); NONFAILING(*((uint64_t*)(host_mem + ADDR_VAR_VMCS_PTR)) = ADDR_VAR_VMCS); NONFAILING(memcpy(host_mem + ADDR_VAR_VMEXIT_CODE, kvm_asm64_vm_exit, sizeof(kvm_asm64_vm_exit) - 1)); NONFAILING(*((uint64_t*)(host_mem + ADDR_VAR_VMEXIT_PTR)) = ADDR_VAR_VMEXIT_CODE); text_prefix = kvm_asm64_init_vm; text_prefix_size = sizeof(kvm_asm64_init_vm) - 1; } else if (flags & KVM_SETUP_CPL3) { text_prefix = kvm_asm64_cpl3; text_prefix_size = sizeof(kvm_asm64_cpl3) - 1; } else { text_prefix = kvm_asm64_enable_long; text_prefix_size = sizeof(kvm_asm64_enable_long) - 1; } } struct tss16 tss16; memset(&tss16, 0, sizeof(tss16)); tss16.ss0 = tss16.ss1 = tss16.ss2 = SEL_DS16; tss16.sp0 = tss16.sp1 = tss16.sp2 = ADDR_STACK0; tss16.ip = ADDR_VAR_USER_CODE2; tss16.flags = (1 << 1); tss16.cs = SEL_CS16; tss16.es = tss16.ds = tss16.ss = SEL_DS16; tss16.ldt = SEL_LDT; struct tss16* tss16_addr = (struct tss16*)(host_mem + seg_tss16_2.base); NONFAILING(memcpy(tss16_addr, &tss16, sizeof(tss16))); memset(&tss16, 0, sizeof(tss16)); tss16.ss0 = tss16.ss1 = tss16.ss2 = SEL_DS16; tss16.sp0 = tss16.sp1 = tss16.sp2 = ADDR_STACK0; tss16.ip = ADDR_VAR_USER_CODE2; tss16.flags = (1 << 1); tss16.cs = SEL_CS16_CPL3; tss16.es = tss16.ds = tss16.ss = SEL_DS16_CPL3; tss16.ldt = SEL_LDT; struct tss16* tss16_cpl3_addr = (struct tss16*)(host_mem + seg_tss16_cpl3.base); NONFAILING(memcpy(tss16_cpl3_addr, &tss16, sizeof(tss16))); struct tss32 tss32; memset(&tss32, 0, sizeof(tss32)); tss32.ss0 = tss32.ss1 = tss32.ss2 = SEL_DS32; tss32.sp0 = tss32.sp1 = tss32.sp2 = ADDR_STACK0; tss32.ip = ADDR_VAR_USER_CODE; tss32.flags = (1 << 1) | (1 << 17); tss32.ldt = SEL_LDT; tss32.cr3 = sregs.cr3; tss32.io_bitmap = offsetof(struct tss32, io_bitmap); struct tss32* tss32_addr = (struct tss32*)(host_mem + seg_tss32_vm86.base); NONFAILING(memcpy(tss32_addr, &tss32, sizeof(tss32))); memset(&tss32, 0, sizeof(tss32)); tss32.ss0 = tss32.ss1 = tss32.ss2 = SEL_DS32; tss32.sp0 = tss32.sp1 = tss32.sp2 = ADDR_STACK0; tss32.ip = ADDR_VAR_USER_CODE; tss32.flags = (1 << 1); tss32.cr3 = sregs.cr3; tss32.es = tss32.ds = tss32.ss = tss32.gs = tss32.fs = SEL_DS32; tss32.cs = SEL_CS32; tss32.ldt = SEL_LDT; tss32.cr3 = sregs.cr3; tss32.io_bitmap = offsetof(struct tss32, io_bitmap); struct tss32* tss32_cpl3_addr = (struct tss32*)(host_mem + seg_tss32_2.base); NONFAILING(memcpy(tss32_cpl3_addr, &tss32, sizeof(tss32))); struct tss64 tss64; memset(&tss64, 0, sizeof(tss64)); tss64.rsp[0] = ADDR_STACK0; tss64.rsp[1] = ADDR_STACK0; tss64.rsp[2] = ADDR_STACK0; tss64.io_bitmap = offsetof(struct tss64, io_bitmap); struct tss64* tss64_addr = (struct tss64*)(host_mem + seg_tss64.base); NONFAILING(memcpy(tss64_addr, &tss64, sizeof(tss64))); memset(&tss64, 0, sizeof(tss64)); tss64.rsp[0] = ADDR_STACK0; tss64.rsp[1] = ADDR_STACK0; tss64.rsp[2] = ADDR_STACK0; tss64.io_bitmap = offsetof(struct tss64, io_bitmap); struct tss64* tss64_cpl3_addr = (struct tss64*)(host_mem + seg_tss64_cpl3.base); NONFAILING(memcpy(tss64_cpl3_addr, &tss64, sizeof(tss64))); if (text_size > 1000) text_size = 1000; if (text_prefix) { NONFAILING(memcpy(host_text, text_prefix, text_prefix_size)); void* patch = 0; NONFAILING(patch = memmem(host_text, text_prefix_size, "\xde\xc0\xad\x0b", 4)); if (patch) NONFAILING(*((uint32_t*)patch) = guest_mem + ADDR_TEXT + ((char*)patch - host_text) + 6); uint16_t magic = PREFIX_SIZE; patch = 0; NONFAILING(patch = memmem(host_text, text_prefix_size, &magic, sizeof(magic))); if (patch) NONFAILING(*((uint16_t*)patch) = guest_mem + ADDR_TEXT + text_prefix_size); } NONFAILING(memcpy((void*)(host_text + text_prefix_size), text, text_size)); NONFAILING(*(host_text + text_prefix_size + text_size) = 0xf4); NONFAILING(memcpy(host_mem + ADDR_VAR_USER_CODE, text, text_size)); NONFAILING(*(host_mem + ADDR_VAR_USER_CODE + text_size) = 0xf4); NONFAILING(*(host_mem + ADDR_VAR_HLT) = 0xf4); NONFAILING(memcpy(host_mem + ADDR_VAR_SYSRET, "\x0f\x07\xf4", 3)); NONFAILING(memcpy(host_mem + ADDR_VAR_SYSEXIT, "\x0f\x35\xf4", 3)); NONFAILING(*(uint64_t*)(host_mem + ADDR_VAR_VMWRITE_FLD) = 0); NONFAILING(*(uint64_t*)(host_mem + ADDR_VAR_VMWRITE_VAL) = 0); if (opt_count > 2) opt_count = 2; for (i = 0; i < opt_count; i++) { uint64_t typ = 0; uint64_t val = 0; NONFAILING(typ = opt_array_ptr[i].typ); NONFAILING(val = opt_array_ptr[i].val); switch (typ % 9) { case 0: sregs.cr0 ^= val & (CR0_MP | CR0_EM | CR0_ET | CR0_NE | CR0_WP | CR0_AM | CR0_NW | CR0_CD); break; case 1: sregs.cr4 ^= val & (CR4_VME | CR4_PVI | CR4_TSD | CR4_DE | CR4_MCE | CR4_PGE | CR4_PCE | CR4_OSFXSR | CR4_OSXMMEXCPT | CR4_UMIP | CR4_VMXE | CR4_SMXE | CR4_FSGSBASE | CR4_PCIDE | CR4_OSXSAVE | CR4_SMEP | CR4_SMAP | CR4_PKE); break; case 2: sregs.efer ^= val & (EFER_SCE | EFER_NXE | EFER_SVME | EFER_LMSLE | EFER_FFXSR | EFER_TCE); break; case 3: val &= ((1 << 8) | (1 << 9) | (1 << 10) | (1 << 12) | (1 << 13) | (1 << 14) | (1 << 15) | (1 << 18) | (1 << 19) | (1 << 20) | (1 << 21)); regs.rflags ^= val; NONFAILING(tss16_addr->flags ^= val); NONFAILING(tss16_cpl3_addr->flags ^= val); NONFAILING(tss32_addr->flags ^= val); NONFAILING(tss32_cpl3_addr->flags ^= val); break; case 4: seg_cs16.type = val & 0xf; seg_cs32.type = val & 0xf; seg_cs64.type = val & 0xf; break; case 5: seg_cs16_cpl3.type = val & 0xf; seg_cs32_cpl3.type = val & 0xf; seg_cs64_cpl3.type = val & 0xf; break; case 6: seg_ds16.type = val & 0xf; seg_ds32.type = val & 0xf; seg_ds64.type = val & 0xf; break; case 7: seg_ds16_cpl3.type = val & 0xf; seg_ds32_cpl3.type = val & 0xf; seg_ds64_cpl3.type = val & 0xf; break; case 8: NONFAILING(*(uint64_t*)(host_mem + ADDR_VAR_VMWRITE_FLD) = (val & 0xffff)); NONFAILING(*(uint64_t*)(host_mem + ADDR_VAR_VMWRITE_VAL) = (val >> 16)); break; default: fail("bad kvm setup opt"); } } regs.rflags |= 2; fill_segment_descriptor(gdt, ldt, &seg_ldt); fill_segment_descriptor(gdt, ldt, &seg_cs16); fill_segment_descriptor(gdt, ldt, &seg_ds16); fill_segment_descriptor(gdt, ldt, &seg_cs16_cpl3); fill_segment_descriptor(gdt, ldt, &seg_ds16_cpl3); fill_segment_descriptor(gdt, ldt, &seg_cs32); fill_segment_descriptor(gdt, ldt, &seg_ds32); fill_segment_descriptor(gdt, ldt, &seg_cs32_cpl3); fill_segment_descriptor(gdt, ldt, &seg_ds32_cpl3); fill_segment_descriptor(gdt, ldt, &seg_cs64); fill_segment_descriptor(gdt, ldt, &seg_ds64); fill_segment_descriptor(gdt, ldt, &seg_cs64_cpl3); fill_segment_descriptor(gdt, ldt, &seg_ds64_cpl3); fill_segment_descriptor(gdt, ldt, &seg_tss32); fill_segment_descriptor(gdt, ldt, &seg_tss32_2); fill_segment_descriptor(gdt, ldt, &seg_tss32_cpl3); fill_segment_descriptor(gdt, ldt, &seg_tss32_vm86); fill_segment_descriptor(gdt, ldt, &seg_tss16); fill_segment_descriptor(gdt, ldt, &seg_tss16_2); fill_segment_descriptor(gdt, ldt, &seg_tss16_cpl3); fill_segment_descriptor_dword(gdt, ldt, &seg_tss64); fill_segment_descriptor_dword(gdt, ldt, &seg_tss64_cpl3); fill_segment_descriptor(gdt, ldt, &seg_cgate16); fill_segment_descriptor(gdt, ldt, &seg_tgate16); fill_segment_descriptor(gdt, ldt, &seg_cgate32); fill_segment_descriptor(gdt, ldt, &seg_tgate32); fill_segment_descriptor_dword(gdt, ldt, &seg_cgate64); if (ioctl(cpufd, KVM_SET_SREGS, &sregs)) return -1; if (ioctl(cpufd, KVM_SET_REGS, ®s)) return -1; return 0; } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static void setup_cgroups() { if (mkdir("/syzcgroup", 0777)) { } if (mkdir("/syzcgroup/unified", 0777)) { } if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) { } if (chmod("/syzcgroup/unified", 0777)) { } if (!write_file("/syzcgroup/unified/cgroup.subtree_control", "+cpu +memory +io +pids +rdma")) { } if (mkdir("/syzcgroup/cpu", 0777)) { } if (mount("none", "/syzcgroup/cpu", "cgroup", 0, "cpuset,cpuacct,perf_event,hugetlb")) { } if (!write_file("/syzcgroup/cpu/cgroup.clone_children", "1")) { } if (chmod("/syzcgroup/cpu", 0777)) { } if (mkdir("/syzcgroup/net", 0777)) { } if (mount("none", "/syzcgroup/net", "cgroup", 0, "net_cls,net_prio,devices,freezer")) { } if (chmod("/syzcgroup/net", 0777)) { } } static void setup_binfmt_misc() { if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz0:M:0:syz0::./file0:")) { } if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz1:M:1:yz1::./file0:POC")) { } } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; setup_cgroups(); setup_binfmt_misc(); sandbox_common(); if (unshare(CLONE_NEWNET)) { } initialize_tun(); initialize_netdevices(); loop(); doexit(1); } #define XT_TABLE_SIZE 1536 #define XT_MAX_ENTRIES 10 struct xt_counters { uint64_t pcnt, bcnt; }; struct ipt_getinfo { char name[32]; unsigned int valid_hooks; unsigned int hook_entry[5]; unsigned int underflow[5]; unsigned int num_entries; unsigned int size; }; struct ipt_get_entries { char name[32]; unsigned int size; void* entrytable[XT_TABLE_SIZE / sizeof(void*)]; }; struct ipt_replace { char name[32]; unsigned int valid_hooks; unsigned int num_entries; unsigned int size; unsigned int hook_entry[5]; unsigned int underflow[5]; unsigned int num_counters; struct xt_counters* counters; char entrytable[XT_TABLE_SIZE]; }; struct ipt_table_desc { const char* name; struct ipt_getinfo info; struct ipt_replace replace; }; static struct ipt_table_desc ipv4_tables[] = { {.name = "filter"}, {.name = "nat"}, {.name = "mangle"}, {.name = "raw"}, {.name = "security"}, }; static struct ipt_table_desc ipv6_tables[] = { {.name = "filter"}, {.name = "nat"}, {.name = "mangle"}, {.name = "raw"}, {.name = "security"}, }; #define IPT_BASE_CTL 64 #define IPT_SO_SET_REPLACE (IPT_BASE_CTL) #define IPT_SO_GET_INFO (IPT_BASE_CTL) #define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1) struct arpt_getinfo { char name[32]; unsigned int valid_hooks; unsigned int hook_entry[3]; unsigned int underflow[3]; unsigned int num_entries; unsigned int size; }; struct arpt_get_entries { char name[32]; unsigned int size; void* entrytable[XT_TABLE_SIZE / sizeof(void*)]; }; struct arpt_replace { char name[32]; unsigned int valid_hooks; unsigned int num_entries; unsigned int size; unsigned int hook_entry[3]; unsigned int underflow[3]; unsigned int num_counters; struct xt_counters* counters; char entrytable[XT_TABLE_SIZE]; }; struct arpt_table_desc { const char* name; struct arpt_getinfo info; struct arpt_replace replace; }; static struct arpt_table_desc arpt_tables[] = { {.name = "filter"}, }; #define ARPT_BASE_CTL 96 #define ARPT_SO_SET_REPLACE (ARPT_BASE_CTL) #define ARPT_SO_GET_INFO (ARPT_BASE_CTL) #define ARPT_SO_GET_ENTRIES (ARPT_BASE_CTL + 1) static void checkpoint_iptables(struct ipt_table_desc* tables, int num_tables, int family, int level) { struct ipt_get_entries entries; socklen_t optlen; int fd, i; fd = socket(family, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(%d, SOCK_STREAM, IPPROTO_TCP)", family); for (i = 0; i < num_tables; i++) { struct ipt_table_desc* table = &tables[i]; strcpy(table->info.name, table->name); strcpy(table->replace.name, table->name); optlen = sizeof(table->info); if (getsockopt(fd, level, IPT_SO_GET_INFO, &table->info, &optlen)) { switch (errno) { case EPERM: case ENOENT: case ENOPROTOOPT: continue; } fail("getsockopt(IPT_SO_GET_INFO)"); } if (table->info.size > sizeof(table->replace.entrytable)) fail("table size is too large: %u", table->info.size); if (table->info.num_entries > XT_MAX_ENTRIES) fail("too many counters: %u", table->info.num_entries); memset(&entries, 0, sizeof(entries)); strcpy(entries.name, table->name); entries.size = table->info.size; optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size; if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen)) fail("getsockopt(IPT_SO_GET_ENTRIES)"); table->replace.valid_hooks = table->info.valid_hooks; table->replace.num_entries = table->info.num_entries; table->replace.size = table->info.size; memcpy(table->replace.hook_entry, table->info.hook_entry, sizeof(table->replace.hook_entry)); memcpy(table->replace.underflow, table->info.underflow, sizeof(table->replace.underflow)); memcpy(table->replace.entrytable, entries.entrytable, table->info.size); } close(fd); } static void reset_iptables(struct ipt_table_desc* tables, int num_tables, int family, int level) { struct xt_counters counters[XT_MAX_ENTRIES]; struct ipt_get_entries entries; struct ipt_getinfo info; socklen_t optlen; int fd, i; fd = socket(family, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(%d, SOCK_STREAM, IPPROTO_TCP)", family); for (i = 0; i < num_tables; i++) { struct ipt_table_desc* table = &tables[i]; if (table->info.valid_hooks == 0) continue; memset(&info, 0, sizeof(info)); strcpy(info.name, table->name); optlen = sizeof(info); if (getsockopt(fd, level, IPT_SO_GET_INFO, &info, &optlen)) fail("getsockopt(IPT_SO_GET_INFO)"); if (memcmp(&table->info, &info, sizeof(table->info)) == 0) { memset(&entries, 0, sizeof(entries)); strcpy(entries.name, table->name); entries.size = table->info.size; optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size; if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen)) fail("getsockopt(IPT_SO_GET_ENTRIES)"); if (memcmp(table->replace.entrytable, entries.entrytable, table->info.size) == 0) continue; } table->replace.num_counters = info.num_entries; table->replace.counters = counters; optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) + table->replace.size; if (setsockopt(fd, level, IPT_SO_SET_REPLACE, &table->replace, optlen)) fail("setsockopt(IPT_SO_SET_REPLACE)"); } close(fd); } static void checkpoint_arptables(void) { struct arpt_get_entries entries; socklen_t optlen; unsigned i; int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)"); for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) { struct arpt_table_desc* table = &arpt_tables[i]; strcpy(table->info.name, table->name); strcpy(table->replace.name, table->name); optlen = sizeof(table->info); if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &table->info, &optlen)) { switch (errno) { case EPERM: case ENOENT: case ENOPROTOOPT: continue; } fail("getsockopt(ARPT_SO_GET_INFO)"); } if (table->info.size > sizeof(table->replace.entrytable)) fail("table size is too large: %u", table->info.size); if (table->info.num_entries > XT_MAX_ENTRIES) fail("too many counters: %u", table->info.num_entries); memset(&entries, 0, sizeof(entries)); strcpy(entries.name, table->name); entries.size = table->info.size; optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size; if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen)) fail("getsockopt(ARPT_SO_GET_ENTRIES)"); table->replace.valid_hooks = table->info.valid_hooks; table->replace.num_entries = table->info.num_entries; table->replace.size = table->info.size; memcpy(table->replace.hook_entry, table->info.hook_entry, sizeof(table->replace.hook_entry)); memcpy(table->replace.underflow, table->info.underflow, sizeof(table->replace.underflow)); memcpy(table->replace.entrytable, entries.entrytable, table->info.size); } close(fd); } static void reset_arptables() { struct xt_counters counters[XT_MAX_ENTRIES]; struct arpt_get_entries entries; struct arpt_getinfo info; socklen_t optlen; unsigned i; int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)"); for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) { struct arpt_table_desc* table = &arpt_tables[i]; if (table->info.valid_hooks == 0) continue; memset(&info, 0, sizeof(info)); strcpy(info.name, table->name); optlen = sizeof(info); if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &info, &optlen)) fail("getsockopt(ARPT_SO_GET_INFO)"); if (memcmp(&table->info, &info, sizeof(table->info)) == 0) { memset(&entries, 0, sizeof(entries)); strcpy(entries.name, table->name); entries.size = table->info.size; optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size; if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen)) fail("getsockopt(ARPT_SO_GET_ENTRIES)"); if (memcmp(table->replace.entrytable, entries.entrytable, table->info.size) == 0) continue; } table->replace.num_counters = info.num_entries; table->replace.counters = counters; optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) + table->replace.size; if (setsockopt(fd, SOL_IP, ARPT_SO_SET_REPLACE, &table->replace, optlen)) fail("setsockopt(ARPT_SO_SET_REPLACE)"); } close(fd); } #include #include struct ebt_table_desc { const char* name; struct ebt_replace replace; char entrytable[XT_TABLE_SIZE]; }; static struct ebt_table_desc ebt_tables[] = { {.name = "filter"}, {.name = "nat"}, {.name = "broute"}, }; static void checkpoint_ebtables(void) { socklen_t optlen; unsigned i; int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)"); for (i = 0; i < sizeof(ebt_tables) / sizeof(ebt_tables[0]); i++) { struct ebt_table_desc* table = &ebt_tables[i]; strcpy(table->replace.name, table->name); optlen = sizeof(table->replace); if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_INFO, &table->replace, &optlen)) { switch (errno) { case EPERM: case ENOENT: case ENOPROTOOPT: continue; } fail("getsockopt(EBT_SO_GET_INIT_INFO)"); } if (table->replace.entries_size > sizeof(table->entrytable)) fail("table size is too large: %u", table->replace.entries_size); table->replace.num_counters = 0; table->replace.entries = table->entrytable; optlen = sizeof(table->replace) + table->replace.entries_size; if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_ENTRIES, &table->replace, &optlen)) fail("getsockopt(EBT_SO_GET_INIT_ENTRIES)"); } close(fd); } static void reset_ebtables() { struct ebt_replace replace; char entrytable[XT_TABLE_SIZE]; socklen_t optlen; unsigned i, j, h; int fd; fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)"); for (i = 0; i < sizeof(ebt_tables) / sizeof(ebt_tables[0]); i++) { struct ebt_table_desc* table = &ebt_tables[i]; if (table->replace.valid_hooks == 0) continue; memset(&replace, 0, sizeof(replace)); strcpy(replace.name, table->name); optlen = sizeof(replace); if (getsockopt(fd, SOL_IP, EBT_SO_GET_INFO, &replace, &optlen)) fail("getsockopt(EBT_SO_GET_INFO)"); replace.num_counters = 0; table->replace.entries = 0; for (h = 0; h < NF_BR_NUMHOOKS; h++) table->replace.hook_entry[h] = 0; if (memcmp(&table->replace, &replace, sizeof(table->replace)) == 0) { memset(&entrytable, 0, sizeof(entrytable)); replace.entries = entrytable; optlen = sizeof(replace) + replace.entries_size; if (getsockopt(fd, SOL_IP, EBT_SO_GET_ENTRIES, &replace, &optlen)) fail("getsockopt(EBT_SO_GET_ENTRIES)"); if (memcmp(table->entrytable, entrytable, replace.entries_size) == 0) continue; } for (j = 0, h = 0; h < NF_BR_NUMHOOKS; h++) { if (table->replace.valid_hooks & (1 << h)) { table->replace.hook_entry[h] = (struct ebt_entries*)table->entrytable + j; j++; } } table->replace.entries = table->entrytable; optlen = sizeof(table->replace) + table->replace.entries_size; if (setsockopt(fd, SOL_IP, EBT_SO_SET_ENTRIES, &table->replace, optlen)) fail("setsockopt(EBT_SO_SET_ENTRIES)"); } close(fd); } static void checkpoint_net_namespace(void) { checkpoint_ebtables(); checkpoint_arptables(); checkpoint_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]), AF_INET, SOL_IP); checkpoint_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]), AF_INET6, SOL_IPV6); } static void reset_net_namespace(void) { reset_ebtables(); reset_arptables(); reset_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]), AF_INET, SOL_IP); reset_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]), AF_INET6, SOL_IPV6); } static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: while (umount2(dir, MNT_DETACH) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exitf("opendir(%s) failed due to NOFILE, exiting", dir); } exitf("opendir(%s) failed", dir); } while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); struct stat st; if (lstat(filename, &st)) exitf("lstat(%s) failed", filename); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename); if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exitf("umount(%s) failed", dir); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exitf("rmdir(%s) failed", dir); } } static void execute_one(); extern unsigned long long procid; static void loop() { checkpoint_net_namespace(); char cgroupdir[64]; snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid); char cgroupdir_cpu[64]; snprintf(cgroupdir_cpu, sizeof(cgroupdir_cpu), "/syzcgroup/cpu/syz%llu", procid); char cgroupdir_net[64]; snprintf(cgroupdir_net, sizeof(cgroupdir_net), "/syzcgroup/net/syz%llu", procid); if (mkdir(cgroupdir, 0777)) { } if (mkdir(cgroupdir_cpu, 0777)) { } if (mkdir(cgroupdir_net, 0777)) { } int pid = getpid(); char procs_file[128]; snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir); if (!write_file(procs_file, "%d", pid)) { } snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir_cpu); if (!write_file(procs_file, "%d", pid)) { } snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir_net); if (!write_file(procs_file, "%d", pid)) { } int iter; for (iter = 0;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) fail("failed to mkdir"); int pid = fork(); if (pid < 0) fail("clone failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); if (chdir(cwdbuf)) fail("failed to chdir"); if (symlink(cgroupdir, "./cgroup")) { } if (symlink(cgroupdir_cpu, "./cgroup.cpu")) { } if (symlink(cgroupdir_net, "./cgroup.net")) { } flush_tun(); execute_one(); doexit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { int res = waitpid(-1, &status, __WALL | WNOHANG); if (res == pid) { break; } usleep(1000); if (current_time_ms() - start < 3 * 1000) continue; kill(-pid, SIGKILL); kill(pid, SIGKILL); while (waitpid(-1, &status, __WALL) != pid) { } break; } remove_dir(cwdbuf); reset_net_namespace(); } } struct thread_t { int created, running, call; pthread_t th; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static int collide; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); } return 0; } static void execute(int num_calls) { int call, thread; running = 0; for (call = 0; call < num_calls; call++) { for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); pthread_create(&th->th, &attr, thr, th); } if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) { th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); if (collide && call % 2) break; struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = 20 * 1000 * 1000; syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts); if (running) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } uint64_t r[5] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0x0}; unsigned long long procid; void execute_call(int call) { long res; switch (call) { case 0: NONFAILING(memcpy((void*)0x20000280, "/dev/kvm", 9)); res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000280, 0, 0); if (res != -1) r[0] = res; break; case 1: res = syscall(__NR_ioctl, r[0], 0xae01, 0); if (res != -1) r[1] = res; break; case 2: res = syscall(__NR_ioctl, r[1], 0xae41, 0); if (res != -1) r[2] = res; break; case 3: NONFAILING(*(uint32_t*)0x20bf7000 = 0); NONFAILING(*(uint32_t*)0x20bf7004 = 0); NONFAILING(*(uint64_t*)0x20bf7008 = 0); NONFAILING(*(uint64_t*)0x20bf7010 = 0x2000); NONFAILING(*(uint64_t*)0x20bf7018 = 0x20000000); syscall(__NR_ioctl, r[1], 0x4020ae46, 0x20bf7000); break; case 4: NONFAILING(*(uint64_t*)0x20000040 = 0x20); NONFAILING(*(uint64_t*)0x20000048 = 0x20000000); NONFAILING(memcpy((void*)0x20000000, "\x44\x0f\x20\xc0\x35\x0f\x00\x00\x00\x44\x0f\x22\xc0\x0f" "\x30\x66\xba\xf8\x0c\xb8\x20\x8c\x72\x83\xef\x66\xba\xfc" "\x0c\xed\xf4\xf2\x36\x0f\x01\xdf\x64\x0f\x01\xd1\x0f\x85" "\x02\x00\x00\x00\x66\xba\x40\x00\x66\xb8\x00\x20\x66\xef" "\x66\x0f\x75\xfd\x65\x0f\x09", 63)); NONFAILING(*(uint64_t*)0x20000050 = 0x3f); syz_kvm_setup_cpu(-1, r[2], 0x20001000, 0x20000040, 1, 0, 0x20000080, 0); break; case 5: NONFAILING(memcpy((void*)0x20000080, "/dev/snd/pcmC#D#c", 18)); res = syz_open_dev(0x20000080, 6, 0x800); if (res != -1) r[3] = res; break; case 6: NONFAILING(*(uint32_t*)0x200000c0 = 3); NONFAILING(*(uint32_t*)0x20000100 = 4); syscall(__NR_getsockopt, r[3], 0x103, 2, 0x200000c0, 0x20000100); break; case 7: res = syscall(__NR_fcntl, r[0], 9); if (res != -1) r[4] = res; break; case 8: syscall(__NR_sched_rr_get_interval, r[4], 0x20000140); break; case 9: NONFAILING(*(uint32_t*)0x200001c0 = 0xc); syscall(__NR_getsockopt, r[3], 0, 0x20, 0x20000180, 0x200001c0); break; case 10: syscall(__NR_ioctl, r[2], 0xae80, 0); break; case 11: NONFAILING(*(uint32_t*)0x20000400 = 0); NONFAILING(*(uint32_t*)0x20000404 = 1); NONFAILING(*(uint64_t*)0x20000408 = 0); NONFAILING(*(uint64_t*)0x20000410 = 0x2000); NONFAILING(*(uint64_t*)0x20000418 = 0x20000000); syscall(__NR_ioctl, r[1], 0x4020ae46, 0x20000400); break; case 12: syscall(__NR_ioctl, r[3], 0xae80, 0); break; } } void execute_one() { execute(13); collide = 1; execute(13); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); char* cwd = get_current_dir_name(); for (procid = 0; procid < 8; procid++) { if (fork() == 0) { install_segv_handler(); for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } } } sleep(1000000); return 0; }