// 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 #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); } 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; } static void test(); void loop() { while (1) { test(); } } struct thread_t { int created, running, call; pthread_t th; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static int collide; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); } return 0; } static void execute(int num_calls) { int call, thread; running = 0; for (call = 0; call < num_calls; call++) { for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); pthread_create(&th->th, &attr, thr, th); } if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) { th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); if (collide && call % 2) break; struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = 20 * 1000 * 1000; syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts); if (running) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; uint64_t procid; void execute_call(int call) { long res; switch (call) { case 0: res = syscall(__NR_pipe, 0x20000ff8); if (res != -1) { r[0] = *(uint32_t*)0x20000ff8; r[1] = *(uint32_t*)0x20000ffc; } break; case 1: syscall(__NR_setsockopt, r[1], 6, 0x1c, 0x20000040, 0); break; case 2: syscall(__NR_socketpair, 0xa, 4, 9, 0x20000040); break; case 3: *(uint64_t*)0x20c4bff8 = 0; *(uint64_t*)0x20000000 = 0; syscall(__NR_splice, r[1], 0x20c4bff8, -1, 0x20000000, 0x1000, 0); break; case 4: memcpy((void*)0x20000080, "\x73\x65\x63\x75\x72\x69\x74\x79\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*)0x200000a0 = 0; *(uint32_t*)0x200000a4 = 0; *(uint32_t*)0x200000a8 = 0; *(uint32_t*)0x200000ac = 0; *(uint32_t*)0x200000b0 = 0; *(uint32_t*)0x200000b4 = 0; *(uint32_t*)0x200000b8 = 0; *(uint32_t*)0x200000bc = 0; *(uint32_t*)0x200000c0 = 0; *(uint32_t*)0x200000c4 = 0; *(uint32_t*)0x200000c8 = 0; *(uint32_t*)0x200000cc = 0; *(uint32_t*)0x200000d0 = 0; *(uint32_t*)0x20000100 = 0x54; syscall(__NR_getsockopt, r[0], 0x29, 0x40, 0x20000080, 0x20000100); break; case 5: syz_emit_ethernet(1, 0x20000000, 0); break; case 6: res = syscall(__NR_socket, 0xa, 0x80003, 0xa); if (res != -1) r[2] = res; break; case 7: *(uint16_t*)0x20032fe4 = 0xa; *(uint16_t*)0x20032fe6 = htobe16(0); *(uint32_t*)0x20032fe8 = 0; *(uint8_t*)0x20032fec = -1; *(uint8_t*)0x20032fed = 2; *(uint8_t*)0x20032fee = 0; *(uint8_t*)0x20032fef = 0; *(uint8_t*)0x20032ff0 = 0; *(uint8_t*)0x20032ff1 = 0; *(uint8_t*)0x20032ff2 = 0; *(uint8_t*)0x20032ff3 = 0; *(uint8_t*)0x20032ff4 = 0; *(uint8_t*)0x20032ff5 = 0; *(uint8_t*)0x20032ff6 = 0; *(uint8_t*)0x20032ff7 = 0; *(uint8_t*)0x20032ff8 = 0; *(uint8_t*)0x20032ff9 = 0; *(uint8_t*)0x20032ffa = 0; *(uint8_t*)0x20032ffb = 1; *(uint32_t*)0x20032ffc = 5; syscall(__NR_connect, r[2], 0x20032fe4, 0x1c); break; case 8: *(uint64_t*)0x20001300 = 0; *(uint32_t*)0x20001308 = 0; *(uint64_t*)0x20001310 = 0x20001180; *(uint64_t*)0x20001318 = 0x240; *(uint64_t*)0x20001320 = 0x200011c0; *(uint64_t*)0x20001328 = 0; *(uint32_t*)0x20001330 = 0; *(uint32_t*)0x20001338 = 0; syscall(__NR_sendmmsg, r[2], 0x20001300, 0x249, 0); break; case 9: *(uint8_t*)0x200000c0 = 0xfe; *(uint8_t*)0x200000c1 = 0x80; *(uint8_t*)0x200000c2 = 0; *(uint8_t*)0x200000c3 = 0; *(uint8_t*)0x200000c4 = 0; *(uint8_t*)0x200000c5 = 0; *(uint8_t*)0x200000c6 = 0; *(uint8_t*)0x200000c7 = 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 = 0xaa; *(uint32_t*)0x200000d0 = 0x80; *(uint8_t*)0x200000d4 = 1; *(uint8_t*)0x200000d5 = 2; *(uint16_t*)0x200000d6 = 4; *(uint16_t*)0x200000d8 = 0; *(uint16_t*)0x200000da = 0x2a; *(uint32_t*)0x200000dc = 5; syscall(__NR_setsockopt, r[2], 0x29, 0x20, 0x200000c0, 0x20); break; } } void test() { execute(10); collide = 1; execute(10); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); char* cwd = get_current_dir_name(); for (procid = 0; procid < 8; procid++) { if (fork() == 0) { for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); int pid = do_sandbox_namespace(); int status = 0; while (waitpid(pid, &status, __WALL) != pid) { } } } } sleep(1000000); return 0; }