// https://syzkaller.appspot.com/bug?id=9ff117082222e5ec493fca16a22c0f0611b715cf
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <net/if_arp.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <unistd.h>

__attribute__((noreturn)) static void doexit(int status)
{
  volatile unsigned i;
  syscall(__NR_exit_group, status);
  for (i = 0;; i++) {
  }
}
#include <errno.h>
#include <setjmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string.h>
#include <sys/stat.h>

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 __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* uctx)
{
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) &&
      (addr < prog_start || addr > prog_end)) {
    _longjmp(segv_env, 1);
  }
  doexit(sig);
}

static void install_segv_handler()
{
  struct sigaction sa;

  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = SIG_IGN;
  syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8);
  syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8);

  memset(&sa, 0, sizeof(sa));
  sa.sa_sigaction = segv_handler;
  sa.sa_flags = SA_NODEFER | SA_SIGINFO;
  sigaction(SIGSEGV, &sa, NULL);
  sigaction(SIGBUS, &sa, NULL);
}

#define NONFAILING(...)                                                        \
  {                                                                            \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    }                                                                          \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
  }

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 MAX_PIDS 32
#define ADDR_MAX_LEN 32

#define LOCAL_MAC "aa:aa:aa:aa:%02hx:aa"
#define REMOTE_MAC "aa:aa:aa:aa:%02hx:bb"

#define LOCAL_IPV4 "172.20.%d.170"
#define REMOTE_IPV4 "172.20.%d.187"

#define LOCAL_IPV6 "fe80::%02hx:aa"
#define REMOTE_IPV6 "fe80::%02hx:bb"

#define IFF_NAPI 0x0010
#define IFF_NAPI_FRAGS 0x0020

static void initialize_tun(int id)
{
  if (id >= MAX_PIDS)
    fail("tun: no more than %d executors", MAX_PIDS);

  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;
  }

  char iface[IFNAMSIZ];
  snprintf_check(iface, sizeof(iface), "syz%d", id);

  struct ifreq ifr;
  memset(&ifr, 0, sizeof(ifr));
  strncpy(ifr.ifr_name, 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;

  char local_mac[ADDR_MAX_LEN];
  snprintf_check(local_mac, sizeof(local_mac), LOCAL_MAC, id);
  char remote_mac[ADDR_MAX_LEN];
  snprintf_check(remote_mac, sizeof(remote_mac), REMOTE_MAC, id);

  char local_ipv4[ADDR_MAX_LEN];
  snprintf_check(local_ipv4, sizeof(local_ipv4), LOCAL_IPV4, id);
  char remote_ipv4[ADDR_MAX_LEN];
  snprintf_check(remote_ipv4, sizeof(remote_ipv4), REMOTE_IPV4, id);

  char local_ipv6[ADDR_MAX_LEN];
  snprintf_check(local_ipv6, sizeof(local_ipv6), LOCAL_IPV6, id);
  char remote_ipv6[ADDR_MAX_LEN];
  snprintf_check(remote_ipv6, sizeof(remote_ipv6), REMOTE_IPV6, id);

  execute_command(1, "sysctl -w net.ipv6.conf.%s.accept_dad=0", iface);

  execute_command(1, "sysctl -w net.ipv6.conf.%s.router_solicitations=0",
                  iface);

  execute_command(1, "ip link set dev %s address %s", iface, local_mac);
  execute_command(1, "ip addr add %s/24 dev %s", local_ipv4, iface);
  execute_command(1, "ip -6 addr add %s/120 dev %s", local_ipv6, iface);
  execute_command(1, "ip neigh add %s lladdr %s dev %s nud permanent",
                  remote_ipv4, remote_mac, iface);
  execute_command(1, "ip -6 neigh add %s lladdr %s dev %s nud permanent",
                  remote_ipv6, remote_mac, iface);
  execute_command(1, "ip link set dev %s up", iface);
}

#define DEV_IPV4 "172.20.%d.%d"
#define DEV_IPV6 "fe80::%02hx:%02hx"
#define DEV_MAC "aa:aa:aa:aa:%02hx:%02hx"

static void initialize_netdevices(int id)
{
  unsigned i;
  const char* devtypes[] = {"ip6gretap", "bridge", "vcan"};
  const char* devnames[] = {"lo",       "sit0",    "bridge0", "vcan0",
                            "tunl0",    "gre0",    "gretap0", "ip_vti0",
                            "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0",
                            "erspan0"};

  for (i = 0; i < sizeof(devtypes) / (sizeof(devtypes[0])); i++)
    execute_command(0, "ip link add dev %s0 type %s", devtypes[i], devtypes[i]);
  for (i = 0; i < sizeof(devnames) / (sizeof(devnames[0])); i++) {
    char addr[ADDR_MAX_LEN];
    snprintf_check(addr, sizeof(addr), DEV_IPV4, id, id + 10);
    execute_command(0, "ip -4 addr add %s/24 dev %s", addr, devnames[i]);
    snprintf_check(addr, sizeof(addr), DEV_IPV6, id, id + 10);
    execute_command(0, "ip -6 addr add %s/120 dev %s", addr, devnames[i]);
    snprintf_check(addr, sizeof(addr), DEV_MAC, id, id + 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]);
  }
}

static void setup_tun(uint64_t pid, bool enable_tun)
{
  if (enable_tun) {
    initialize_tun(pid);
    initialize_netdevices(pid);
  }
}

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 int do_sandbox_none(int executor_pid, bool enable_tun)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid < 0)
    fail("sandbox fork failed");
  if (pid)
    return pid;

  sandbox_common();
  if (unshare(CLONE_NEWNET)) {
  }
  setup_tun(executor_pid, enable_tun);

  loop();
  doexit(1);
}

long r[2];
void loop()
{
  memset(r, -1, sizeof(r));
  syscall(__NR_mmap, 0x20000000, 0xe75000, 3, 0x32, -1, 0);
  r[0] = syscall(__NR_socket, 0xa, 2, 0);
  NONFAILING(*(uint16_t*)0x20d4c000 = 0xa);
  NONFAILING(*(uint16_t*)0x20d4c002 = htobe16(0x4e21));
  NONFAILING(*(uint32_t*)0x20d4c004 = 7);
  NONFAILING(*(uint64_t*)0x20d4c008 = htobe64(0));
  NONFAILING(*(uint64_t*)0x20d4c010 = htobe64(1));
  NONFAILING(*(uint32_t*)0x20d4c018 = 0x1c28);
  syscall(__NR_connect, r[0], 0x20d4c000, 0x1c);
  NONFAILING(*(uint16_t*)0x20e6f000 = 0xa);
  NONFAILING(*(uint16_t*)0x20e6f002 = htobe16(0x4e22));
  NONFAILING(*(uint32_t*)0x20e6f004 = 0);
  NONFAILING(*(uint8_t*)0x20e6f008 = 0);
  NONFAILING(*(uint8_t*)0x20e6f009 = 0);
  NONFAILING(*(uint8_t*)0x20e6f00a = 0);
  NONFAILING(*(uint8_t*)0x20e6f00b = 0);
  NONFAILING(*(uint8_t*)0x20e6f00c = 0);
  NONFAILING(*(uint8_t*)0x20e6f00d = 0);
  NONFAILING(*(uint8_t*)0x20e6f00e = 0);
  NONFAILING(*(uint8_t*)0x20e6f00f = 0);
  NONFAILING(*(uint8_t*)0x20e6f010 = 0);
  NONFAILING(*(uint8_t*)0x20e6f011 = 0);
  NONFAILING(*(uint8_t*)0x20e6f012 = -1);
  NONFAILING(*(uint8_t*)0x20e6f013 = -1);
  NONFAILING(*(uint8_t*)0x20e6f014 = 0xac);
  NONFAILING(*(uint8_t*)0x20e6f015 = 0x14);
  NONFAILING(*(uint8_t*)0x20e6f016 = 0);
  NONFAILING(*(uint8_t*)0x20e6f017 = 0xaa);
  NONFAILING(*(uint32_t*)0x20e6f018 = 1);
  syscall(__NR_connect, r[0], 0x20e6f000, 0x1c);
  r[1] = syscall(__NR_socket, 0x18, 1, 1);
  NONFAILING(*(uint16_t*)0x205fafd2 = 0x18);
  NONFAILING(*(uint32_t*)0x205fafd4 = 1);
  NONFAILING(*(uint32_t*)0x205fafd8 = 0);
  NONFAILING(*(uint32_t*)0x205fafdc = r[0]);
  NONFAILING(*(uint16_t*)0x205fafe0 = 2);
  NONFAILING(*(uint16_t*)0x205fafe2 = htobe16(0x4e21));
  NONFAILING(*(uint32_t*)0x205fafe4 = htobe32(0xe0000002));
  NONFAILING(*(uint8_t*)0x205fafe8 = 0);
  NONFAILING(*(uint8_t*)0x205fafe9 = 0);
  NONFAILING(*(uint8_t*)0x205fafea = 0);
  NONFAILING(*(uint8_t*)0x205fafeb = 0);
  NONFAILING(*(uint8_t*)0x205fafec = 0);
  NONFAILING(*(uint8_t*)0x205fafed = 0);
  NONFAILING(*(uint8_t*)0x205fafee = 0);
  NONFAILING(*(uint8_t*)0x205fafef = 0);
  NONFAILING(*(uint32_t*)0x205faff0 = 4);
  NONFAILING(*(uint32_t*)0x205faff4 = 0);
  NONFAILING(*(uint32_t*)0x205faff8 = 2);
  NONFAILING(*(uint32_t*)0x205faffc = 0);
  syscall(__NR_connect, r[1], 0x205fafd2, 0x2e);
  NONFAILING(*(uint64_t*)0x2037ffc8 = 0x209dd000);
  NONFAILING(*(uint32_t*)0x2037ffd0 = 0xc);
  NONFAILING(*(uint64_t*)0x2037ffd8 = 0x202ceff0);
  NONFAILING(*(uint64_t*)0x2037ffe0 = 1);
  NONFAILING(*(uint64_t*)0x2037ffe8 = 0);
  NONFAILING(*(uint64_t*)0x2037fff0 = 0);
  NONFAILING(*(uint32_t*)0x2037fff8 = 0x8820);
  NONFAILING(*(uint16_t*)0x209dd000 = 0x10);
  NONFAILING(*(uint16_t*)0x209dd002 = 0);
  NONFAILING(*(uint32_t*)0x209dd004 = 0);
  NONFAILING(*(uint32_t*)0x209dd008 = 2);
  NONFAILING(*(uint64_t*)0x202ceff0 = 0x2097b000);
  NONFAILING(*(uint64_t*)0x202ceff8 = 0xfff1);
  NONFAILING(*(uint32_t*)0x2097b000 = 0x10);
  NONFAILING(*(uint16_t*)0x2097b004 = 0x14);
  NONFAILING(*(uint16_t*)0x2097b006 = 0x200);
  NONFAILING(*(uint32_t*)0x2097b008 = 0x70bd26);
  NONFAILING(*(uint32_t*)0x2097b00c = 0x25dfdbfe);
  syscall(__NR_sendmsg, r[1], 0x2037ffc8, 0x81);
}

int main()
{
  install_segv_handler();
  use_temporary_dir();
  int pid = do_sandbox_none(0, true);
  int status = 0;
  while (waitpid(pid, &status, __WALL) != pid) {
  }
  return 0;
}