// 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 #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 #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 use_temporary_dir() { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); } 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); rv = system(command); if (panic && 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 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", "veth"}; const char* devnames[] = {"lo", "sit0", "bridge0", "vcan0", "tunl0", "gre0", "gretap0", "ip_vti0", "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0", "erspan0", "bond0", "veth0", "veth1"}; 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 dev veth1 type veth"); 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 = 128 << 20; setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 8 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 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); #define CLONE_NEWCGROUP 0x02000000 if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(CLONE_NEWCGROUP)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { close(fd); return false; } close(fd); return true; } static int real_uid; static int real_gid; __attribute__((aligned(64 << 10))) static char sandbox_stack[1 << 20]; static int namespace_sandbox_proc(void* arg) { sandbox_common(); write_file("/proc/self/setgroups", "deny"); if (!write_file("/proc/self/uid_map", "0 %d 1\n", real_uid)) fail("write of /proc/self/uid_map failed"); if (!write_file("/proc/self/gid_map", "0 %d 1\n", real_gid)) fail("write of /proc/self/gid_map failed"); if (unshare(CLONE_NEWNET)) fail("unshare(CLONE_NEWNET)"); initialize_tun(); initialize_netdevices(); if (mkdir("./syz-tmp", 0777)) fail("mkdir(syz-tmp) failed"); if (mount("", "./syz-tmp", "tmpfs", 0, NULL)) fail("mount(tmpfs) failed"); if (mkdir("./syz-tmp/newroot", 0777)) fail("mkdir failed"); if (mkdir("./syz-tmp/newroot/dev", 0700)) fail("mkdir failed"); unsigned mount_flags = MS_BIND | MS_REC | MS_PRIVATE; if (mount("/dev", "./syz-tmp/newroot/dev", NULL, mount_flags, NULL)) fail("mount(dev) failed"); if (mkdir("./syz-tmp/newroot/proc", 0700)) fail("mkdir failed"); if (mount(NULL, "./syz-tmp/newroot/proc", "proc", 0, NULL)) fail("mount(proc) failed"); if (mkdir("./syz-tmp/newroot/selinux", 0700)) fail("mkdir failed"); const char* selinux_path = "./syz-tmp/newroot/selinux"; if (mount("/selinux", selinux_path, NULL, mount_flags, NULL)) { if (errno != ENOENT) fail("mount(/selinux) failed"); if (mount("/sys/fs/selinux", selinux_path, NULL, mount_flags, NULL) && errno != ENOENT) fail("mount(/sys/fs/selinux) failed"); } if (mkdir("./syz-tmp/pivot", 0777)) fail("mkdir failed"); if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) { if (chdir("./syz-tmp")) fail("chdir failed"); } else { if (chdir("/")) fail("chdir failed"); if (umount2("./pivot", MNT_DETACH)) fail("umount failed"); } if (chroot("./newroot")) fail("chroot failed"); if (chdir("/")) fail("chdir failed"); struct __user_cap_header_struct cap_hdr = {}; struct __user_cap_data_struct cap_data[2] = {}; cap_hdr.version = _LINUX_CAPABILITY_VERSION_3; cap_hdr.pid = getpid(); if (syscall(SYS_capget, &cap_hdr, &cap_data)) fail("capget failed"); cap_data[0].effective &= ~(1 << CAP_SYS_PTRACE); cap_data[0].permitted &= ~(1 << CAP_SYS_PTRACE); cap_data[0].inheritable &= ~(1 << CAP_SYS_PTRACE); if (syscall(SYS_capset, &cap_hdr, &cap_data)) fail("capset failed"); loop(); doexit(1); } static int do_sandbox_namespace(void) { int pid; real_uid = getuid(); real_gid = getgid(); mprotect(sandbox_stack, 4096, PROT_NONE); pid = clone(namespace_sandbox_proc, &sandbox_stack[sizeof(sandbox_stack) - 64], CLONE_NEWUSER | CLONE_NEWPID, 0); if (pid < 0) fail("sandbox clone failed"); return pid; } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void loop() { long res; res = syscall(__NR_socket, 0xa, 2, 0); if (res != -1) r[0] = res; *(uint16_t*)0x20000000 = 0xa; *(uint16_t*)0x20000002 = htobe16(0x4e20); *(uint32_t*)0x20000004 = 0; *(uint8_t*)0x20000008 = 0; *(uint8_t*)0x20000009 = 0; *(uint8_t*)0x2000000a = 0; *(uint8_t*)0x2000000b = 0; *(uint8_t*)0x2000000c = 0; *(uint8_t*)0x2000000d = 0; *(uint8_t*)0x2000000e = 0; *(uint8_t*)0x2000000f = 0; *(uint8_t*)0x20000010 = 0; *(uint8_t*)0x20000011 = 0; *(uint8_t*)0x20000012 = -1; *(uint8_t*)0x20000013 = -1; *(uint32_t*)0x20000014 = htobe32(0x7f000001); *(uint32_t*)0x20000018 = 5; syscall(__NR_connect, r[0], 0x20000000, 0x1c); *(uint16_t*)0x200000c0 = 0xa; *(uint16_t*)0x200000c2 = htobe16(0x4e22); *(uint32_t*)0x200000c4 = 0xdba; *(uint8_t*)0x200000c8 = -1; *(uint8_t*)0x200000c9 = 1; *(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 = 0; *(uint8_t*)0x200000d3 = 0; *(uint8_t*)0x200000d4 = 0; *(uint8_t*)0x200000d5 = 0; *(uint8_t*)0x200000d6 = 0; *(uint8_t*)0x200000d7 = 1; *(uint32_t*)0x200000d8 = 9; syscall(__NR_connect, r[0], 0x200000c0, 0x1c); res = syscall(__NR_socket, 0x18, 1, 1); if (res != -1) r[1] = res; *(uint16_t*)0x205fafd2 = 0x18; *(uint32_t*)0x205fafd4 = 1; *(uint32_t*)0x205fafd8 = 0; *(uint32_t*)0x205fafdc = r[0]; *(uint16_t*)0x205fafe0 = 2; *(uint16_t*)0x205fafe2 = htobe16(0x4e21); *(uint32_t*)0x205fafe4 = htobe32(0xe0000002); *(uint8_t*)0x205fafe8 = 0; *(uint8_t*)0x205fafe9 = 0; *(uint8_t*)0x205fafea = 0; *(uint8_t*)0x205fafeb = 0; *(uint8_t*)0x205fafec = 0; *(uint8_t*)0x205fafed = 0; *(uint8_t*)0x205fafee = 0; *(uint8_t*)0x205fafef = 0; *(uint32_t*)0x205faff0 = 4; *(uint32_t*)0x205faff4 = 0; *(uint32_t*)0x205faff8 = 2; *(uint32_t*)0x205faffc = 0; syscall(__NR_connect, r[1], 0x205fafd2, 0x2e); *(uint64_t*)0x2037ffc8 = 0x20041000; *(uint16_t*)0x20041000 = 0x10; *(uint16_t*)0x20041002 = 0; *(uint32_t*)0x20041004 = 0; *(uint32_t*)0x20041008 = 2; *(uint32_t*)0x2037ffd0 = 0xc; *(uint64_t*)0x2037ffd8 = 0x20000140; *(uint64_t*)0x20000140 = 0x20000100; *(uint32_t*)0x20000100 = 0x10; *(uint16_t*)0x20000104 = 0x14; *(uint16_t*)0x20000106 = 0x200; *(uint32_t*)0x20000108 = 0; *(uint32_t*)0x2000010c = 3; *(uint64_t*)0x20000148 = 0x10; *(uint64_t*)0x2037ffe0 = 1; *(uint64_t*)0x2037ffe8 = 0; *(uint64_t*)0x2037fff0 = 0; *(uint32_t*)0x2037fff8 = 0x20000000; syscall(__NR_sendmsg, r[1], 0x2037ffc8, 0x81); *(uint8_t*)0x20000080 = 1; *(uint8_t*)0x20000081 = 0x80; *(uint8_t*)0x20000082 = 0xc2; *(uint8_t*)0x20000083 = 0; *(uint8_t*)0x20000084 = 0; *(uint8_t*)0x20000085 = 0; *(uint8_t*)0x20000086 = -1; *(uint8_t*)0x20000087 = -1; *(uint8_t*)0x20000088 = -1; *(uint8_t*)0x20000089 = -1; *(uint8_t*)0x2000008a = -1; *(uint8_t*)0x2000008b = -1; *(uint16_t*)0x2000008c = htobe16(0x8100); STORE_BY_BITMASK(uint16_t, 0x2000008e, 0, 0, 3); STORE_BY_BITMASK(uint16_t, 0x2000008e, 0, 3, 1); STORE_BY_BITMASK(uint16_t, 0x2000008e, 0, 4, 12); *(uint16_t*)0x20000090 = htobe16(0x800); STORE_BY_BITMASK(uint8_t, 0x20000092, 5, 0, 4); STORE_BY_BITMASK(uint8_t, 0x20000092, 4, 4, 4); STORE_BY_BITMASK(uint8_t, 0x20000093, 0, 0, 2); STORE_BY_BITMASK(uint8_t, 0x20000093, 0, 2, 6); *(uint16_t*)0x20000094 = htobe16(0x1c); *(uint16_t*)0x20000096 = htobe16(-1); *(uint16_t*)0x20000098 = htobe16(0); *(uint8_t*)0x2000009a = 0; *(uint8_t*)0x2000009b = 0; *(uint16_t*)0x2000009c = 0; *(uint8_t*)0x2000009e = 0xac; *(uint8_t*)0x2000009f = 0x14; *(uint8_t*)0x200000a0 = 0; *(uint8_t*)0x200000a1 = 0; *(uint32_t*)0x200000a2 = htobe32(0xe0000001); *(uint8_t*)0x200000a6 = 0; *(uint8_t*)0x200000a7 = 0; *(uint16_t*)0x200000a8 = 0; *(uint32_t*)0x200000aa = htobe32(0xe0000001); *(uint32_t*)0x20003fec = 0; *(uint32_t*)0x20003ff0 = 1; *(uint32_t*)0x20003ff4 = 0; *(uint32_t*)0x20003ff8 = 0; *(uint32_t*)0x20003ffc = 0; *(uint32_t*)0x20004000 = 0; struct csum_inet csum_1; csum_inet_init(&csum_1); csum_inet_update(&csum_1, (const uint8_t*)0x200000a6, 8); *(uint16_t*)0x200000a8 = csum_inet_digest(&csum_1); struct csum_inet csum_2; csum_inet_init(&csum_2); csum_inet_update(&csum_2, (const uint8_t*)0x20000092, 20); *(uint16_t*)0x2000009c = csum_inet_digest(&csum_2); syz_emit_ethernet(0x2e, 0x20000080, 0x20003fec); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); use_temporary_dir(); int pid = do_sandbox_namespace(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } return 0; }