// https://syzkaller.appspot.com/bug?id=cfba89a589babce43df1bc4093465318ee3599f3 // 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 __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #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 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", "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]); } } #define MAX_FRAGS 4 struct vnet_fragmentation { uint32_t full; uint32_t count; uint32_t frags[MAX_FRAGS]; }; static uintptr_t syz_emit_ethernet(uintptr_t a0, uintptr_t a1, uintptr_t a2) { if (tunfd < 0) return (uintptr_t)-1; uint32_t length = a0; char* data = (char*)a1; struct vnet_fragmentation* frags = (struct vnet_fragmentation*)a2; struct iovec vecs[MAX_FRAGS + 1]; uint32_t nfrags = 0; if (!tun_frags_enabled || frags == NULL) { vecs[nfrags].iov_base = data; vecs[nfrags].iov_len = length; nfrags++; } else { bool full = true; uint32_t i, count = 0; full = frags->full; count = frags->count; if (count > MAX_FRAGS) count = MAX_FRAGS; for (i = 0; i < count && length != 0; i++) { uint32_t size = 0; size = frags->frags[i]; if (size > length) size = length; vecs[nfrags].iov_base = data; vecs[nfrags].iov_len = size; nfrags++; data += size; length -= size; } if (length != 0 && (full || nfrags == 0)) { vecs[nfrags].iov_base = data; vecs[nfrags].iov_len = length; nfrags++; } } return writev(tunfd, vecs, nfrags); } 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)) { } } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid < 0) fail("sandbox fork failed"); if (pid) return pid; sandbox_common(); if (unshare(CLONE_NEWNET)) { } initialize_tun(); initialize_netdevices(); loop(); doexit(1); } static void execute_one(); extern unsigned long long procid; void loop() { while (1) { execute_one(); } } uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0x0, 0xffffffffffffffff}; void execute_one() { long res = 0; res = syscall(__NR_socket, 2, 2, 0); if (res != -1) r[0] = res; res = syscall(__NR_socket, 0x11, 0x800000000002, 0x300); if (res != -1) r[1] = res; memcpy((void*)0x20000100, "\x69\x70\x36\x74\x6e\x6c\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16); *(uint32_t*)0x20000110 = 0; res = syscall(__NR_ioctl, r[1], 0x8933, 0x20000100); if (res != -1) r[2] = *(uint32_t*)0x20000110; *(uint32_t*)0x20000140 = htobe32(0x7f000001); *(uint32_t*)0x20000144 = htobe32(0); *(uint32_t*)0x20000148 = r[2]; syscall(__NR_setsockopt, r[0], 0, 0x20, 0x20000140, 0x3c5); *(uint16_t*)0x2057bff0 = 2; *(uint16_t*)0x2057bff2 = htobe16(0x4e20); *(uint32_t*)0x2057bff4 = htobe32(0xe0000001); *(uint8_t*)0x2057bff8 = 0; *(uint8_t*)0x2057bff9 = 0; *(uint8_t*)0x2057bffa = 0; *(uint8_t*)0x2057bffb = 0; *(uint8_t*)0x2057bffc = 0; *(uint8_t*)0x2057bffd = 0; *(uint8_t*)0x2057bffe = 0; *(uint8_t*)0x2057bfff = 0; syscall(__NR_sendto, r[0], 0x20762fff, 0xfdc7, 0, 0x2057bff0, 0x10); res = syscall(__NR_socket, 0x10, 3, 0); if (res != -1) r[3] = res; memcpy((void*)0x20000140, "\x69\x70\x36\x74\x6e\x6c\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16); *(uint64_t*)0x20000150 = 0x20000240; memcpy((void*)0x20000240, "\x9a\x6e\x25\x50\x6c\x7d\x44\x11\x96\xb9\xa5\xed" "\xba\xb1\xa7\xb6\xab\xca\x1f\xa4\x00\x87\x9c\x30" "\x2d\xff\x8a\x38\x8c\xfd\x28\x5a", 32); syscall(__NR_ioctl, r[3], 0x89f3, 0x20000140); *(uint8_t*)0x20000280 = 0xaa; *(uint8_t*)0x20000281 = 0xaa; *(uint8_t*)0x20000282 = 0xaa; *(uint8_t*)0x20000283 = 0xaa; *(uint8_t*)0x20000284 = 0xaa; *(uint8_t*)0x20000285 = 0xaa; *(uint8_t*)0x20000286 = 1; *(uint8_t*)0x20000287 = 0x80; *(uint8_t*)0x20000288 = 0xc2; *(uint8_t*)0x20000289 = 0; *(uint8_t*)0x2000028a = 0; *(uint8_t*)0x2000028b = 0xf; *(uint16_t*)0x2000028c = htobe16(4); *(uint8_t*)0x2000028e = 0x7e; *(uint8_t*)0x2000028f = -1; memcpy((void*)0x20000290, "S", 1); syz_emit_ethernet(0x11, 0x20000280, 0); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); for (;;) { int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } }