// https://syzkaller.appspot.com/bug?id=1eaa30de66a3dcf8f4ecffec1ecc90dba071b6f2 // 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 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(); loop(); doexit(1); } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void loop() { long res = 0; res = syscall(__NR_socket, 0x11, 0x800000000002, 0x300); if (res != -1) r[0] = res; *(uint16_t*)0x2095bffc = 0; *(uint8_t*)0x2095bffe = 0; *(uint8_t*)0x2095bfff = 0xfc; syscall(__NR_setsockopt, r[0], 0x107, 0x12, 0x2095bffc, 4); res = syscall(__NR_socket, 2, 2, 0); if (res != -1) r[1] = res; *(uint16_t*)0x20000040 = 2; *(uint16_t*)0x20000042 = htobe16(0); *(uint8_t*)0x20000044 = 0xac; *(uint8_t*)0x20000045 = 0x14; *(uint8_t*)0x20000046 = 0x14; *(uint8_t*)0x20000047 = 0xaa; *(uint8_t*)0x20000048 = 0; *(uint8_t*)0x20000049 = 0; *(uint8_t*)0x2000004a = 0; *(uint8_t*)0x2000004b = 0; *(uint8_t*)0x2000004c = 0; *(uint8_t*)0x2000004d = 0; *(uint8_t*)0x2000004e = 0; *(uint8_t*)0x2000004f = 0; syscall(__NR_connect, r[1], 0x20000040, 0x10); *(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[1], 0x20762fff, 0xfdc7, 0, 0x2057bff0, 0x10); *(uint8_t*)0x20000080 = 0xaa; *(uint8_t*)0x20000081 = 0xaa; *(uint8_t*)0x20000082 = 0xaa; *(uint8_t*)0x20000083 = 0xaa; *(uint8_t*)0x20000084 = 0xaa; *(uint8_t*)0x20000085 = 0xaa; *(uint8_t*)0x20000086 = 0xaa; *(uint8_t*)0x20000087 = 0xaa; *(uint8_t*)0x20000088 = 0xaa; *(uint8_t*)0x20000089 = 0xaa; *(uint8_t*)0x2000008a = 0xaa; *(uint8_t*)0x2000008b = 0xaa; *(uint16_t*)0x2000008c = htobe16(0x86dd); STORE_BY_BITMASK(uint8_t, 0x2000008e, 0, 0, 4); STORE_BY_BITMASK(uint8_t, 0x2000008e, 6, 4, 4); memcpy((void*)0x2000008f, "\xdc\xd5\x0f", 3); *(uint16_t*)0x20000092 = htobe16(0xb); *(uint8_t*)0x20000094 = 0x2c; *(uint8_t*)0x20000095 = 0; *(uint8_t*)0x20000096 = 0xfe; *(uint8_t*)0x20000097 = 0x80; *(uint8_t*)0x20000098 = 0; *(uint8_t*)0x20000099 = 0; *(uint8_t*)0x2000009a = 0; *(uint8_t*)0x2000009b = 0; *(uint8_t*)0x2000009c = 0; *(uint8_t*)0x2000009d = 0; *(uint8_t*)0x2000009e = 0xc0; *(uint8_t*)0x2000009f = 0; *(uint8_t*)0x200000a0 = 0xe; *(uint8_t*)0x200000a1 = 0; *(uint8_t*)0x200000a2 = 0; *(uint8_t*)0x200000a3 = 0; *(uint8_t*)0x200000a4 = 0; *(uint8_t*)0x200000a5 = 0xaa; *(uint8_t*)0x200000a6 = 0xfe; *(uint8_t*)0x200000a7 = 0x80; *(uint8_t*)0x200000a8 = 0; *(uint8_t*)0x200000a9 = 0; *(uint8_t*)0x200000aa = 0; *(uint8_t*)0x200000ab = 0; *(uint8_t*)0x200000ac = 0; *(uint8_t*)0x200000ad = 0; *(uint8_t*)0x200000ae = 0; *(uint8_t*)0x200000af = 0; *(uint8_t*)0x200000b0 = 0; *(uint8_t*)0x200000b1 = 0; *(uint8_t*)0x200000b2 = 0; *(uint8_t*)0x200000b3 = 0; *(uint8_t*)0x200000b4 = 0; *(uint8_t*)0x200000b5 = 0xaa; *(uint8_t*)0x200000b6 = 0x81; *(uint8_t*)0x200000b7 = 0; *(uint16_t*)0x200000b8 = 0; *(uint16_t*)0x200000ba = htobe16(0); *(uint16_t*)0x200000bc = htobe16(0); memcpy((void*)0x200000be, ":Jw", 3); *(uint32_t*)0x20000340 = 0; *(uint32_t*)0x20000344 = 0; *(uint32_t*)0x20000348 = 0; *(uint32_t*)0x2000034c = 0; *(uint32_t*)0x20000350 = 0; *(uint32_t*)0x20000354 = 0; struct csum_inet csum_1; csum_inet_init(&csum_1); csum_inet_update(&csum_1, (const uint8_t*)0x20000096, 16); csum_inet_update(&csum_1, (const uint8_t*)0x200000a6, 16); uint32_t csum_1_chunk_2 = 0xb000000; csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_2, 4); uint32_t csum_1_chunk_3 = 0x3a000000; csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_3, 4); csum_inet_update(&csum_1, (const uint8_t*)0x200000b6, 11); *(uint16_t*)0x200000b8 = csum_inet_digest(&csum_1); syz_emit_ethernet(0x41, 0x20000080, 0x20000340); } 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; }