// https://syzkaller.appspot.com/bug?id=5a017f4bf840b4bd755b0e45c43ce4f376154728 // 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 __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); } #define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1) #define BITMASK_LEN_OFF(type, bf_off, bf_len) \ (type)(BITMASK_LEN(type, (bf_len)) << (bf_off)) #define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len) \ if ((bf_off) == 0 && (bf_len) == 0) { \ *(type*)(addr) = (type)(val); \ } else { \ type new_val = *(type*)(addr); \ new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len)); \ new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off); \ *(type*)(addr) = new_val; \ } 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 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); } #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(0, "sysctl -w net.ipv6.conf.%s.accept_dad=0", TUN_IFACE); execute_command(0, "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 neigh add %s lladdr %s dev %s nud permanent", REMOTE_IPV4, REMOTE_MAC, TUN_IFACE); execute_command(0, "ip -6 addr add %s/120 dev %s", LOCAL_IPV6, TUN_IFACE); execute_command(0, "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 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); } static void initialize_netdevices(void) { unsigned i; const char* devtypes[] = {"ip6gretap", "bridge", "vcan", "bond", "team"}; const char* devnames[] = {"lo", "sit0", "bridge0", "vcan0", "tunl0", "gre0", "gretap0", "ip_vti0", "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0", "erspan0", "bond0", "veth0", "veth1", "team0", "veth0_to_bridge", "veth1_to_bridge", "veth0_to_bond", "veth1_to_bond", "veth0_to_team", "veth1_to_team"}; const char* devmasters[] = {"bridge", "bond", "team"}; 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 type veth"); for (i = 0; i < sizeof(devmasters) / (sizeof(devmasters[0])); i++) { execute_command( 0, "ip link add name %s_slave_0 type veth peer name veth0_to_%s", devmasters[i], devmasters[i]); execute_command( 0, "ip link add name %s_slave_1 type veth peer name veth1_to_%s", devmasters[i], devmasters[i]); execute_command(0, "ip link set %s_slave_0 master %s0", devmasters[i], devmasters[i]); execute_command(0, "ip link set %s_slave_1 master %s0", devmasters[i], devmasters[i]); execute_command(0, "ip link set veth0_to_%s up", devmasters[i]); execute_command(0, "ip link set veth1_to_%s up", devmasters[i]); } execute_command(0, "ip link set bridge_slave_0 up"); execute_command(0, "ip link set bridge_slave_1 up"); 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 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 = 160 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 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)) { } } int wait_for_loop(int pid) { if (pid < 0) fail("sandbox fork failed"); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); sandbox_common(); if (unshare(CLONE_NEWNET)) { } initialize_tun(); initialize_netdevices(); loop(); doexit(1); } 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 (__atomic_load_n(&running, __ATOMIC_RELAXED)) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } #ifndef __NR_bpf #define __NR_bpf 321 #endif uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_call(int call) { long res; switch (call) { case 0: NONFAILING(*(uint32_t*)0x20000200 = 2); NONFAILING(*(uint32_t*)0x20000204 = 0x70); NONFAILING(*(uint8_t*)0x20000208 = 0xe6); NONFAILING(*(uint8_t*)0x20000209 = 0); NONFAILING(*(uint8_t*)0x2000020a = 0); NONFAILING(*(uint8_t*)0x2000020b = 0); NONFAILING(*(uint32_t*)0x2000020c = 0); NONFAILING(*(uint64_t*)0x20000210 = 0); NONFAILING(*(uint64_t*)0x20000218 = 0); NONFAILING(*(uint64_t*)0x20000220 = 0); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 0, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 1, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 2, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 3, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 4, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 5, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 6, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 7, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 8, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 9, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 10, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 11, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 12, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 13, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 14, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 15, 2)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 17, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 18, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 19, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 20, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 21, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 22, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 23, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 24, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 25, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 26, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 27, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 28, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, 0x20000228, 0, 29, 35)); NONFAILING(*(uint32_t*)0x20000230 = 0); NONFAILING(*(uint32_t*)0x20000234 = 0); NONFAILING(*(uint64_t*)0x20000238 = 0); NONFAILING(*(uint64_t*)0x20000240 = 0); NONFAILING(*(uint64_t*)0x20000248 = 0); NONFAILING(*(uint64_t*)0x20000250 = 0); NONFAILING(*(uint32_t*)0x20000258 = 0); NONFAILING(*(uint32_t*)0x2000025c = 0); NONFAILING(*(uint64_t*)0x20000260 = 0); NONFAILING(*(uint32_t*)0x20000268 = 0); NONFAILING(*(uint16_t*)0x2000026c = 0); NONFAILING(*(uint16_t*)0x2000026e = 0); syscall(__NR_perf_event_open, 0x20000200, 0, 0, -1, 0); break; case 1: NONFAILING(*(uint32_t*)0x20000a40 = -1); syscall(__NR_setsockopt, -1, 0x29, 0x24, 0x20000a40, 0x173); break; case 2: res = syscall(__NR_socketpair, 0, 0, 0, 0x20000140); if (res != -1) NONFAILING(r[0] = *(uint32_t*)0x20000140); break; case 3: syscall(__NR_socket, 0xa, 1, 0); break; case 4: NONFAILING(*(uint32_t*)0x200001c0 = r[0]); NONFAILING(*(uint64_t*)0x200001c8 = 0x20000040); NONFAILING(*(uint64_t*)0x200001d0 = 0x20000080); NONFAILING(*(uint64_t*)0x200001d8 = 3); syscall(__NR_bpf, 2, 0x200001c0, 0x20); break; case 5: NONFAILING(*(uint32_t*)0x20000280 = 0x12); NONFAILING(*(uint32_t*)0x20000284 = 9); NONFAILING(*(uint32_t*)0x20000288 = 4); NONFAILING(*(uint32_t*)0x2000028c = 1); NONFAILING(*(uint32_t*)0x20000290 = 0); NONFAILING(*(uint32_t*)0x20000294 = -1); NONFAILING(*(uint32_t*)0x20000298 = 0); NONFAILING(*(uint8_t*)0x2000029c = 0); NONFAILING(*(uint8_t*)0x2000029d = 0); NONFAILING(*(uint8_t*)0x2000029e = 0); NONFAILING(*(uint8_t*)0x2000029f = 0); NONFAILING(*(uint8_t*)0x200002a0 = 0); NONFAILING(*(uint8_t*)0x200002a1 = 0); NONFAILING(*(uint8_t*)0x200002a2 = 0); NONFAILING(*(uint8_t*)0x200002a3 = 0); NONFAILING(*(uint8_t*)0x200002a4 = 0); NONFAILING(*(uint8_t*)0x200002a5 = 0); NONFAILING(*(uint8_t*)0x200002a6 = 0); NONFAILING(*(uint8_t*)0x200002a7 = 0); NONFAILING(*(uint8_t*)0x200002a8 = 0); NONFAILING(*(uint8_t*)0x200002a9 = 0); NONFAILING(*(uint8_t*)0x200002aa = 0); NONFAILING(*(uint8_t*)0x200002ab = 0); res = syscall(__NR_bpf, 0, 0x20000280, 0x34d); if (res != -1) r[1] = res; break; case 6: NONFAILING(*(uint32_t*)0x20000000 = 0); NONFAILING(*(uint32_t*)0x20000004 = 0); NONFAILING(*(uint32_t*)0x20000008 = 4); NONFAILING(*(uint32_t*)0x2000000c = 0); NONFAILING(*(uint32_t*)0x20000010 = 0); NONFAILING(*(uint32_t*)0x20000014 = -1); NONFAILING(*(uint32_t*)0x20000018 = 0); NONFAILING(*(uint8_t*)0x2000001c = 0); NONFAILING(*(uint8_t*)0x2000001d = 0); NONFAILING(*(uint8_t*)0x2000001e = 0); NONFAILING(*(uint8_t*)0x2000001f = 0); NONFAILING(*(uint8_t*)0x20000020 = 0); NONFAILING(*(uint8_t*)0x20000021 = 0); NONFAILING(*(uint8_t*)0x20000022 = 0); NONFAILING(*(uint8_t*)0x20000023 = 0); NONFAILING(*(uint8_t*)0x20000024 = 0); NONFAILING(*(uint8_t*)0x20000025 = 0); NONFAILING(*(uint8_t*)0x20000026 = 0); NONFAILING(*(uint8_t*)0x20000027 = 0); NONFAILING(*(uint8_t*)0x20000028 = 0); NONFAILING(*(uint8_t*)0x20000029 = 0); NONFAILING(*(uint8_t*)0x2000002a = 0); NONFAILING(*(uint8_t*)0x2000002b = 0); syscall(__NR_bpf, 0, 0x20000000, 0xce); break; case 7: NONFAILING(*(uint32_t*)0x20000180 = r[1]); NONFAILING(*(uint64_t*)0x20000188 = 0x20000000); NONFAILING(*(uint64_t*)0x20000190 = 0x20000140); NONFAILING(*(uint64_t*)0x20000198 = 0); syscall(__NR_bpf, 2, 0x20000180, 0x20); break; case 8: NONFAILING(*(uint32_t*)0x20000180 = r[1]); NONFAILING(*(uint64_t*)0x20000188 = 0x20000080); NONFAILING(*(uint64_t*)0x20000190 = 0x20000140); NONFAILING(*(uint64_t*)0x20000198 = 0); syscall(__NR_bpf, 2, 0x20000180, 0x20); break; } } void loop() { execute(9); collide = 1; execute(9); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); install_segv_handler(); use_temporary_dir(); do_sandbox_none(); return 0; }