// https://syzkaller.appspot.com/bug?id=ae496c7eb605ca41cd6192cc678f08ad2020f1c3 // 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); } #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; \ } struct csum_inet { uint32_t acc; }; static void csum_inet_init(struct csum_inet* csum) { csum->acc = 0; } static void csum_inet_update(struct csum_inet* csum, const uint8_t* data, size_t length) { if (length == 0) return; size_t i; for (i = 0; i < length - 1; i += 2) csum->acc += *(uint16_t*)&data[i]; if (length & 1) csum->acc += (uint16_t)data[length - 1]; while (csum->acc > 0xffff) csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16); } static uint16_t csum_inet_digest(struct csum_inet* csum) { return ~csum->acc; } 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(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 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]); } } #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); } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void loop() { long res = 0; memcpy((void*)0x20000000, "\x29\x53\xd0\x64\x2a\x3c", 6); *(uint8_t*)0x20000006 = -1; *(uint8_t*)0x20000007 = -1; *(uint8_t*)0x20000008 = -1; *(uint8_t*)0x20000009 = -1; *(uint8_t*)0x2000000a = -1; *(uint8_t*)0x2000000b = -1; *(uint16_t*)0x2000000c = htobe16(0x800); STORE_BY_BITMASK(uint8_t, 0x2000000e, 5, 0, 4); STORE_BY_BITMASK(uint8_t, 0x2000000e, 4, 4, 4); STORE_BY_BITMASK(uint8_t, 0x2000000f, 0, 0, 2); STORE_BY_BITMASK(uint8_t, 0x2000000f, 0, 2, 6); *(uint16_t*)0x20000010 = htobe16(0x30); *(uint16_t*)0x20000012 = htobe16(0); *(uint16_t*)0x20000014 = htobe16(0); *(uint8_t*)0x20000016 = 0; *(uint8_t*)0x20000017 = 0x6c; *(uint16_t*)0x20000018 = 0; *(uint8_t*)0x2000001a = 0xac; *(uint8_t*)0x2000001b = 0x23; *(uint8_t*)0x2000001c = 0x14; *(uint8_t*)0x2000001d = 0xbb; *(uint8_t*)0x2000001e = 0xac; *(uint8_t*)0x2000001f = 0x14; *(uint8_t*)0x20000020 = 0x14; *(uint8_t*)0x20000021 = 0; *(uint8_t*)0x20000022 = 3; *(uint8_t*)0x20000023 = -1; *(uint16_t*)0x20000024 = 0; *(uint8_t*)0x20000026 = 0; *(uint8_t*)0x20000027 = 0; *(uint16_t*)0x20000028 = 0; STORE_BY_BITMASK(uint8_t, 0x2000002a, 5, 0, 4); STORE_BY_BITMASK(uint8_t, 0x2000002a, 4, 4, 4); STORE_BY_BITMASK(uint8_t, 0x2000002b, 0, 0, 2); STORE_BY_BITMASK(uint8_t, 0x2000002b, 0, 2, 6); *(uint16_t*)0x2000002c = htobe16(0); *(uint16_t*)0x2000002e = htobe16(0); *(uint16_t*)0x20000030 = htobe16(0); *(uint8_t*)0x20000032 = 0; *(uint8_t*)0x20000033 = 0; *(uint16_t*)0x20000034 = htobe16(0); *(uint8_t*)0x20000036 = 0xac; *(uint8_t*)0x20000037 = 0x14; *(uint8_t*)0x20000038 = 0x14; *(uint8_t*)0x20000039 = 0xaa; *(uint8_t*)0x2000003a = 0xac; *(uint8_t*)0x2000003b = 0x14; *(uint8_t*)0x2000003c = 0x14; *(uint8_t*)0x2000003d = 0; *(uint32_t*)0x20000080 = 0; *(uint32_t*)0x20000084 = 0; *(uint32_t*)0x20000088 = 0; *(uint32_t*)0x2000008c = 0; *(uint32_t*)0x20000090 = 0; *(uint32_t*)0x20000094 = 0; struct csum_inet csum_1; csum_inet_init(&csum_1); csum_inet_update(&csum_1, (const uint8_t*)0x20000022, 28); *(uint16_t*)0x20000024 = csum_inet_digest(&csum_1); struct csum_inet csum_2; csum_inet_init(&csum_2); csum_inet_update(&csum_2, (const uint8_t*)0x2000000e, 20); *(uint16_t*)0x20000018 = csum_inet_digest(&csum_2); syz_emit_ethernet(0x3e, 0x20000000, 0x20000080); res = syscall(__NR_socket, 0xa, 1, 0); if (res != -1) r[0] = res; memcpy((void*)0x20000280, "\x66\x69\x6c\x74\x65\x72\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", 32); *(uint32_t*)0x200002a0 = 0xe; *(uint32_t*)0x200002a4 = 1; *(uint32_t*)0x200002a8 = 0x160; *(uint64_t*)0x200002b0 = 0; *(uint64_t*)0x200002b8 = 0x20000340; *(uint64_t*)0x200002c0 = 0x20000370; *(uint64_t*)0x200002c8 = 0x200003a0; *(uint64_t*)0x200002d0 = 0; *(uint64_t*)0x200002d8 = 0; *(uint32_t*)0x200002e0 = 0; *(uint64_t*)0x200002e8 = 0x20000000; *(uint64_t*)0x200002f0 = 0x20000340; memcpy((void*)0x20000340, "\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\xed\xff\xff\xff\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\xfe\xff\xff\xff\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\xc8\xde\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\xff\xff\xff\xff\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" "\xfe\xff\xff\xff\x01\x00\x00\x00\x19\x00\x00\x00\x02\x00\x00\x00\x08" "\x00\x62\x72\x59\x64\x67\x65\x30\x00\x00\x00\x00\x00\x00\x00\x00\x1c" "\xff\x66\x62\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xd3\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\x7f\x00\x00\x00" "\x00\x00\x00\x6e\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x80\xc2" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\xaa\xaa\xaa\xaa\xaa\xbb\x00\x00" "\x00\x00\x00\x00\x00\x00\x70\x00\x00\x00\x70\x00\x00\x00\xa0\x00\x00" "\x00\x4e\x46\x51\x55\x45\x55\x45\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\x08" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x00\x00\xf7\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" "\x01\x00\x00\x00\xfe\xff\xff\xff\x00\x00\x00\x00", 352); syscall(__NR_setsockopt, r[0], 0, 0x80, 0x20000280, 0x1d8); res = syscall(__NR_socket, 0xa, 0x100000002, 0); if (res != -1) r[1] = res; *(uint16_t*)0x20000080 = 0xa; *(uint16_t*)0x20000082 = htobe16(0); *(uint32_t*)0x20000084 = 0; *(uint8_t*)0x20000088 = -1; *(uint8_t*)0x20000089 = 1; *(uint8_t*)0x2000008a = 0; *(uint8_t*)0x2000008b = 0; *(uint8_t*)0x2000008c = 0; *(uint8_t*)0x2000008d = 0; *(uint8_t*)0x2000008e = 0; *(uint8_t*)0x2000008f = 0; *(uint8_t*)0x20000090 = 0; *(uint8_t*)0x20000091 = 0; *(uint8_t*)0x20000092 = 0; *(uint8_t*)0x20000093 = 0; *(uint8_t*)0x20000094 = 0; *(uint8_t*)0x20000095 = 0; *(uint8_t*)0x20000096 = 0; *(uint8_t*)0x20000097 = 1; *(uint32_t*)0x20000098 = 0xd; syscall(__NR_connect, r[1], 0x20000080, 0x1c); *(uint16_t*)0x200000c0 = 0xa; *(uint16_t*)0x200000c2 = htobe16(0x4e23); *(uint32_t*)0x200000c4 = 0; *(uint8_t*)0x200000c8 = 0; *(uint8_t*)0x200000c9 = 0; *(uint8_t*)0x200000ca = 0; *(uint8_t*)0x200000cb = 0; *(uint8_t*)0x200000cc = 0; *(uint8_t*)0x200000cd = 0; *(uint8_t*)0x200000ce = 0; *(uint8_t*)0x200000cf = 0; *(uint8_t*)0x200000d0 = 0; *(uint8_t*)0x200000d1 = 0; *(uint8_t*)0x200000d2 = -1; *(uint8_t*)0x200000d3 = -1; *(uint32_t*)0x200000d4 = htobe32(0xe0000002); *(uint32_t*)0x200000d8 = 0; syscall(__NR_sendto, r[1], 0x20000300, 0xfd90, 0x400806e, 0x200000c0, 0x1c); *(uint16_t*)0x20000180 = 0xa; *(uint16_t*)0x20000182 = htobe16(0); *(uint32_t*)0x20000184 = 0; *(uint64_t*)0x20000188 = htobe64(0); *(uint64_t*)0x20000190 = htobe64(1); *(uint32_t*)0x20000198 = 0; syscall(__NR_sendto, r[1], 0x20000140, 0, 0, 0x20000180, 0x1c); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); int pid = do_sandbox_none(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }