// https://syzkaller.appspot.com/bug?id=dda626cdbd87eafe9a755acbbe102e2b6096b256 // autogenerated by syzkaller (https://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 #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) 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) exit(1); if ((size_t)rv >= size) exit(1); } #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) exit(1); } } 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 = 240; if (dup2(tunfd, kTunFd) < 0) exit(1); 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) exit(1); } if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0) exit(1); 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]); } } #define MAX_FRAGS 4 struct vnet_fragmentation { uint32_t full; uint32_t count; uint32_t frags[MAX_FRAGS]; }; static long syz_emit_ethernet(long a0, long a1, long 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 setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) { } } 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 = 200 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 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); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &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) exit(1); 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); setup_common(); sandbox_common(); if (unshare(CLONE_NEWNET)) { } initialize_tun(); initialize_netdevices(); loop(); exit(1); } void loop(void) { *(uint8_t*)0x200000c0 = 0xaa; *(uint8_t*)0x200000c1 = 0xaa; *(uint8_t*)0x200000c2 = 0xaa; *(uint8_t*)0x200000c3 = 0xaa; *(uint8_t*)0x200000c4 = 0xaa; *(uint8_t*)0x200000c5 = 0xaa; *(uint8_t*)0x200000c6 = -1; *(uint8_t*)0x200000c7 = -1; *(uint8_t*)0x200000c8 = -1; *(uint8_t*)0x200000c9 = -1; *(uint8_t*)0x200000ca = -1; *(uint8_t*)0x200000cb = -1; *(uint16_t*)0x200000cc = htobe16(0x800); STORE_BY_BITMASK(uint8_t, , 0x200000ce, 5, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x200000ce, 4, 4, 4); STORE_BY_BITMASK(uint8_t, , 0x200000cf, 0, 0, 2); STORE_BY_BITMASK(uint8_t, , 0x200000cf, 0, 2, 6); *(uint16_t*)0x200000d0 = htobe16(0x5c); *(uint16_t*)0x200000d2 = htobe16(0); *(uint16_t*)0x200000d4 = htobe16(0); *(uint8_t*)0x200000d6 = 0; *(uint8_t*)0x200000d7 = 1; *(uint16_t*)0x200000d8 = htobe16(0); *(uint8_t*)0x200000da = 0xac; *(uint8_t*)0x200000db = 0x23; *(uint8_t*)0x200000dc = 0x14; *(uint8_t*)0x200000dd = 0xbb; *(uint8_t*)0x200000de = 0xac; *(uint8_t*)0x200000df = 0x14; *(uint8_t*)0x200000e0 = 0x14; *(uint8_t*)0x200000e1 = 0x11; *(uint8_t*)0x200000e2 = 5; *(uint8_t*)0x200000e3 = 4; *(uint16_t*)0x200000e4 = htobe16(0); *(uint8_t*)0x200000e6 = 0; *(uint8_t*)0x200000e7 = 0; *(uint16_t*)0x200000e8 = 0; STORE_BY_BITMASK(uint8_t, , 0x200000ea, 0x10, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x200000ea, 4, 4, 4); STORE_BY_BITMASK(uint8_t, , 0x200000eb, 0, 0, 2); STORE_BY_BITMASK(uint8_t, , 0x200000eb, 0, 2, 6); *(uint16_t*)0x200000ec = htobe16(0); *(uint16_t*)0x200000ee = htobe16(0); *(uint16_t*)0x200000f0 = htobe16(0); *(uint8_t*)0x200000f2 = 0; *(uint8_t*)0x200000f3 = 0x11; *(uint16_t*)0x200000f4 = htobe16(0); *(uint8_t*)0x200000f6 = 0xac; *(uint8_t*)0x200000f7 = 0x23; *(uint8_t*)0x200000f8 = 0x14; *(uint8_t*)0x200000f9 = 0xaa; *(uint8_t*)0x200000fa = 0xac; *(uint8_t*)0x200000fb = 0x14; *(uint8_t*)0x200000fc = 0x14; *(uint8_t*)0x200000fd = 0; *(uint8_t*)0x200000fe = 8; *(uint8_t*)0x200000ff = 0x2c; *(uint8_t*)0x20000100 = 0; STORE_BY_BITMASK(uint8_t, , 0x20000101, 0, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000101, 0, 4, 4); *(uint32_t*)0x20000102 = htobe32(0); *(uint32_t*)0x20000106 = htobe32(0); *(uint32_t*)0x2000010a = htobe32(0xe0000002); *(uint32_t*)0x2000010e = htobe32(0); *(uint32_t*)0x20000112 = htobe32(0xe0000001); *(uint32_t*)0x20000116 = htobe32(0); *(uint32_t*)0x2000011a = htobe32(0); *(uint32_t*)0x2000011e = htobe32(0x7f000001); *(uint32_t*)0x20000122 = htobe32(0); *(uint32_t*)0x20000126 = htobe32(0); struct csum_inet csum_1; csum_inet_init(&csum_1); csum_inet_update(&csum_1, (const uint8_t*)0x200000e2, 72); *(uint16_t*)0x200000e4 = csum_inet_digest(&csum_1); struct csum_inet csum_2; csum_inet_init(&csum_2); csum_inet_update(&csum_2, (const uint8_t*)0x200000ce, 20); *(uint16_t*)0x200000d8 = csum_inet_digest(&csum_2); syz_emit_ethernet(0x6a, 0x200000c0, 0); syscall(__NR_setsockopt, -1, 0x117, 5, 0, 0); syscall(__NR_accept, -1, 0, 0); } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); do_sandbox_none(); return 0; }