// https://syzkaller.appspot.com/bug?id=88f235e602ddecc58834e678682aba629a847fd2
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if_arp.h>
#include <sched.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <unistd.h>

#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
#include <linux/ip.h>
#include <linux/tcp.h>

#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;                                                  \
  }

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 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 = 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);
  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();
  loop();
  exit(1);
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};

void loop(void)
{
  long res = 0;
  *(uint8_t*)0x20000000 = 0xaa;
  *(uint8_t*)0x20000001 = 0xaa;
  *(uint8_t*)0x20000002 = 0xaa;
  *(uint8_t*)0x20000003 = 0xaa;
  *(uint8_t*)0x20000004 = 0xaa;
  *(uint8_t*)0x20000005 = 0xaa;
  memcpy((void*)0x20000006, "\x39\xe2\xa0\x67\xb2\x9c", 6);
  *(uint16_t*)0x2000000c = htobe16(0x86dd);
  STORE_BY_BITMASK(uint8_t, 0x2000000e, 0, 0, 4);
  STORE_BY_BITMASK(uint8_t, 0x2000000e, 6, 4, 4);
  memcpy((void*)0x2000000f, "\x63\x83\x7c", 3);
  *(uint16_t*)0x20000012 = htobe16(0x44);
  *(uint8_t*)0x20000014 = 0x2c;
  *(uint8_t*)0x20000015 = 0;
  *(uint8_t*)0x20000016 = 0xfe;
  *(uint8_t*)0x20000017 = 0x80;
  *(uint8_t*)0x20000018 = 0;
  *(uint8_t*)0x20000019 = 0;
  *(uint8_t*)0x2000001a = 0;
  *(uint8_t*)0x2000001b = 0;
  *(uint8_t*)0x2000001c = 0;
  *(uint8_t*)0x2000001d = 0;
  *(uint8_t*)0x2000001e = 0;
  *(uint8_t*)0x2000001f = 0;
  *(uint8_t*)0x20000020 = 0;
  *(uint8_t*)0x20000021 = 0;
  *(uint8_t*)0x20000022 = 0;
  *(uint8_t*)0x20000023 = 0;
  *(uint8_t*)0x20000024 = 0;
  *(uint8_t*)0x20000025 = 0xbb;
  *(uint8_t*)0x20000026 = 0xfe;
  *(uint8_t*)0x20000027 = 0x80;
  *(uint8_t*)0x20000028 = 0;
  *(uint8_t*)0x20000029 = 0;
  *(uint8_t*)0x2000002a = 0;
  *(uint8_t*)0x2000002b = 0;
  *(uint8_t*)0x2000002c = 0;
  *(uint8_t*)0x2000002d = 0;
  *(uint8_t*)0x2000002e = 0;
  *(uint8_t*)0x2000002f = 0;
  *(uint8_t*)0x20000030 = 0;
  *(uint8_t*)0x20000031 = 0;
  *(uint8_t*)0x20000032 = 0;
  *(uint8_t*)0x20000033 = 0;
  *(uint8_t*)0x20000034 = 0;
  *(uint8_t*)0x20000035 = 0xaa;
  STORE_BY_BITMASK(uint16_t, 0x20000036, 0, 0, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000036, 0, 1, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000036, 1, 2, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000036, 0, 3, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000036, 0, 4, 4);
  STORE_BY_BITMASK(uint16_t, 0x20000036, 0, 8, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000036, 0, 9, 4);
  STORE_BY_BITMASK(uint16_t, 0x20000036, 1, 13, 3);
  *(uint16_t*)0x20000038 = htobe16(0x880b);
  *(uint16_t*)0x2000003a = htobe16(0);
  *(uint16_t*)0x2000003c = htobe16(0);
  STORE_BY_BITMASK(uint16_t, 0x2000003e, 0, 0, 1);
  STORE_BY_BITMASK(uint16_t, 0x2000003e, 0, 1, 1);
  STORE_BY_BITMASK(uint16_t, 0x2000003e, 0, 2, 1);
  STORE_BY_BITMASK(uint16_t, 0x2000003e, 0, 3, 1);
  STORE_BY_BITMASK(uint16_t, 0x2000003e, 0, 4, 9);
  STORE_BY_BITMASK(uint16_t, 0x2000003e, 0, 13, 3);
  *(uint16_t*)0x20000040 = htobe16(0x800);
  STORE_BY_BITMASK(uint16_t, 0x20000042, 0, 0, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000042, 0, 1, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000042, 0, 2, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000042, 0, 3, 1);
  STORE_BY_BITMASK(uint16_t, 0x20000042, 0, 4, 9);
  STORE_BY_BITMASK(uint16_t, 0x20000042, 0, 13, 3);
  *(uint16_t*)0x20000044 = htobe16(0x86dd);
  *(uint16_t*)0x20000046 = 8;
  *(uint16_t*)0x20000048 = htobe16(0x88be);
  *(uint32_t*)0x2000004a = htobe32(0);
  STORE_BY_BITMASK(uint8_t, 0x2000004e, 0, 0, 4);
  STORE_BY_BITMASK(uint8_t, 0x2000004e, 1, 4, 4);
  *(uint8_t*)0x2000004f = 0;
  STORE_BY_BITMASK(uint8_t, 0x20000050, 0, 0, 2);
  STORE_BY_BITMASK(uint8_t, 0x20000050, 0, 2, 1);
  STORE_BY_BITMASK(uint8_t, 0x20000050, 0, 3, 2);
  STORE_BY_BITMASK(uint8_t, 0x20000050, 0, 5, 3);
  *(uint8_t*)0x20000051 = 0;
  *(uint32_t*)0x20000052 = 1;
  *(uint32_t*)0x20000056 = htobe32(0);
  *(uint16_t*)0x2000005a = 8;
  *(uint16_t*)0x2000005c = htobe16(0x22eb);
  *(uint32_t*)0x2000005e = htobe32(0);
  STORE_BY_BITMASK(uint8_t, 0x20000062, 0, 0, 4);
  STORE_BY_BITMASK(uint8_t, 0x20000062, 2, 4, 4);
  *(uint8_t*)0x20000063 = 0;
  STORE_BY_BITMASK(uint8_t, 0x20000064, 0, 0, 2);
  STORE_BY_BITMASK(uint8_t, 0x20000064, 0, 2, 1);
  STORE_BY_BITMASK(uint8_t, 0x20000064, 0, 3, 2);
  STORE_BY_BITMASK(uint8_t, 0x20000064, 0, 5, 3);
  *(uint8_t*)0x20000065 = 0;
  *(uint32_t*)0x20000066 = 2;
  *(uint32_t*)0x2000006a = htobe32(0);
  *(uint16_t*)0x2000006e = htobe16(0);
  STORE_BY_BITMASK(uint8_t, 0x20000070, 0, 0, 2);
  STORE_BY_BITMASK(uint8_t, 0x20000070, 0, 2, 5);
  STORE_BY_BITMASK(uint8_t, 0x20000070, 0, 7, 1);
  STORE_BY_BITMASK(uint8_t, 0x20000071, 0, 0, 1);
  STORE_BY_BITMASK(uint8_t, 0x20000071, 0, 1, 2);
  STORE_BY_BITMASK(uint8_t, 0x20000071, 0, 3, 1);
  STORE_BY_BITMASK(uint8_t, 0x20000071, 0, 4, 1);
  *(uint16_t*)0x20000072 = 8;
  *(uint16_t*)0x20000074 = htobe16(0x6558);
  *(uint32_t*)0x20000076 = htobe32(0);
  syz_emit_ethernet(0x7a, 0x20000000, 0);
  res = syscall(__NR_socket, 2, 2, 0);
  if (res != -1)
    r[0] = res;
  res = syscall(__NR_socket, 0x11, 0x800000000002, 0x300);
  if (res != -1)
    r[1] = res;
  *(uint16_t*)0x2095bffc = 0;
  *(uint8_t*)0x2095bffe = 0;
  *(uint8_t*)0x2095bfff = 0xfc;
  syscall(__NR_setsockopt, r[1], 0x107, 0x12, 0x2095bffc, 4);
  *(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[0], 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[0], 0x20762fff, 0xfdc7, 0, 0x2057bff0, 0x10);
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  do_sandbox_none();
  return 0;
}