// https://syzkaller.appspot.com/bug?id=f1834e1735946170a8a3a4c85edb978e94bada81 // 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 __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #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 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 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(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); rv = system(command); if (rv != 0) fail("tun: command \"%s\" failed with code %d", &command[0], rv); va_end(args); } static int tunfd = -1; static int tun_frags_enabled; #define SYZ_TUN_MAX_PACKET_SIZE 1000 #define MAX_PIDS 32 #define ADDR_MAX_LEN 32 #define LOCAL_MAC "aa:aa:aa:aa:aa:%02hx" #define REMOTE_MAC "bb:bb:bb:bb:bb:%02hx" #define LOCAL_IPV4 "172.20.%d.170" #define REMOTE_IPV4 "172.20.%d.187" #define LOCAL_IPV6 "fe80::%02hxaa" #define REMOTE_IPV6 "fe80::%02hxbb" #define IFF_NAPI 0x0010 #define IFF_NAPI_FRAGS 0x0020 static void initialize_tun(uint64_t pid) { if (pid >= MAX_PIDS) fail("tun: no more than %d executors", MAX_PIDS); int id = pid; 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; } char iface[IFNAMSIZ]; snprintf_check(iface, sizeof(iface), "syz%d", id); struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, 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; char local_mac[ADDR_MAX_LEN]; snprintf_check(local_mac, sizeof(local_mac), LOCAL_MAC, id); char remote_mac[ADDR_MAX_LEN]; snprintf_check(remote_mac, sizeof(remote_mac), REMOTE_MAC, id); char local_ipv4[ADDR_MAX_LEN]; snprintf_check(local_ipv4, sizeof(local_ipv4), LOCAL_IPV4, id); char remote_ipv4[ADDR_MAX_LEN]; snprintf_check(remote_ipv4, sizeof(remote_ipv4), REMOTE_IPV4, id); char local_ipv6[ADDR_MAX_LEN]; snprintf_check(local_ipv6, sizeof(local_ipv6), LOCAL_IPV6, id); char remote_ipv6[ADDR_MAX_LEN]; snprintf_check(remote_ipv6, sizeof(remote_ipv6), REMOTE_IPV6, id); execute_command("sysctl -w net.ipv6.conf.%s.accept_dad=0", iface); execute_command("sysctl -w net.ipv6.conf.%s.router_solicitations=0", iface); execute_command("ip link set dev %s address %s", iface, local_mac); execute_command("ip addr add %s/24 dev %s", local_ipv4, iface); execute_command("ip -6 addr add %s/120 dev %s", local_ipv6, iface); execute_command("ip neigh add %s lladdr %s dev %s nud permanent", remote_ipv4, remote_mac, iface); execute_command("ip -6 neigh add %s lladdr %s dev %s nud permanent", remote_ipv6, remote_mac, iface); execute_command("ip link set dev %s up", iface); } static void setup_tun(uint64_t pid, bool enable_tun) { if (enable_tun) initialize_tun(pid); } 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 void test(); void loop() { int iter; for (iter = 0;; iter++) { int pid = fork(); if (pid < 0) fail("loop fork failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); flush_tun(); test(); 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 > 5 * 1000) { kill(-pid, SIGKILL); kill(pid, SIGKILL); while (waitpid(-1, &status, __WALL) != pid) { } break; } } } } long r[27]; void* thr(void* arg) { switch ((long)arg) { case 0: r[0] = syscall(__NR_mmap, 0x20000000ul, 0xf42000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); break; case 1: r[1] = syscall(__NR_socket, 0x26ul, 0x5ul, 0x0ul); break; case 2: *(uint16_t*)0x20f37000 = (uint16_t)0x26; memcpy((void*)0x20f37002, "\x61\x65\x61\x64\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 14); *(uint32_t*)0x20f37010 = (uint32_t)0x0; *(uint32_t*)0x20f37014 = (uint32_t)0x0; memcpy((void*)0x20f37018, "\x67\x63\x6d\x28\x61\x65\x73\x29\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00", 64); r[7] = syscall(__NR_bind, r[1], 0x20f37000ul, 0x58ul); break; case 3: memcpy((void*)0x204f7000, "\x64\x9c\x47\xad\x46\x39\x0d\xc8\x6d\xae" "\x79\xfa\x40\x9d\x4d\x54", 16); r[9] = syscall(__NR_setsockopt, r[1], 0x117ul, 0x1ul, 0x204f7000ul, 0x10ul); break; case 4: r[10] = syscall(__NR_accept, r[1], 0x0ul, 0x0ul); break; case 5: r[11] = syscall(__NR_accept, r[1], 0x0ul, 0x0ul); break; case 6: memcpy((void*)0x20519f73, "\x35\x95\xc9\x17\xd6\x71\xb6\xb5\x38\x5f\x00\x42\xbd\x83" "\xa6\xd2\x6b\x71\xaa\x9a\x6d\xea\xf4\xce\xde\xed\x63\xf6" "\xad\x0a\x14\xcf\xab\x6e\x65\xf4\xbc\xd7\x40\x82\x9a\x3a" "\x6e\xfa\xc8\xec\x4c\x77\xb3\x74\x9b\x24\x4a\xbc\xf0\xb5" "\x99\x8c\x60\xf6\xd0\x43\x0a\xce\x54\xba\xa4\x15\x6e\xbb" "\xfa\xa2\xff\xdf\xf4\xbb\xa9\x89\xf4\xae\xb3\xcd\x1f\x87" "\x87\x87\xd9\xfc\x26\xac\x60\x20\x14\x40\x00\x00\x00\x00" "\x00\x59\xfc\x8d\xd6\x23\xe5\xcb\xbe\xc8\x5d\x30\xdb\x1a" "\xb1\x64\x17\x4f\xe4\x0b\x99\x98\x89\xf0\x29\x88\x36\x9b" "\xe7\x57\x01\x71\x78\xac\x1e\x74\x7f\x49\x2f\xc2\x65\x65" "\x4d", 141); r[13] = syscall(__NR_write, r[10], 0x20519f73ul, 0x8dul); break; case 7: *(uint64_t*)0x206b0fc8 = (uint64_t)0x20f38ff7; *(uint32_t*)0x206b0fd0 = (uint32_t)0x9; *(uint64_t*)0x206b0fd8 = (uint64_t)0x20f38fe0; *(uint64_t*)0x206b0fe0 = (uint64_t)0x2; *(uint64_t*)0x206b0fe8 = (uint64_t)0x204d3f31; *(uint64_t*)0x206b0ff0 = (uint64_t)0x0; *(uint32_t*)0x206b0ff8 = (uint32_t)0x3; *(uint64_t*)0x20f38fe0 = (uint64_t)0x20f41000; *(uint64_t*)0x20f38fe8 = (uint64_t)0x0; *(uint64_t*)0x20f38ff0 = (uint64_t)0x207c0000; *(uint64_t*)0x20f38ff8 = (uint64_t)0x26; r[25] = syscall(__NR_recvmsg, r[10], 0x206b0fc8ul, 0x40ul); break; case 8: r[26] = syscall(__NR_accept, r[1], 0x0ul, 0x0ul); break; } return 0; } void test() { long i; pthread_t th[18]; memset(r, -1, sizeof(r)); for (i = 0; i < 9; i++) { pthread_create(&th[i], 0, thr, (void*)i); usleep(rand() % 10000); } usleep(rand() % 100000); } int main() { int i; for (i = 0; i < 8; i++) { if (fork() == 0) { setup_tun(i, true); loop(); return 0; } } sleep(1000000); return 0; }