// https://syzkaller.appspot.com/bug?id=b0e86fe42b01703cf0c726e3c358068dc3c42618
// 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/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>

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);
}

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

uint64_t r[1] = {0xffffffffffffffff};

void loop(void)
{
  long res = 0;
  res = syscall(__NR_socket, 0xa, 2, 0);
  if (res != -1)
    r[0] = res;
  *(uint32_t*)0x20000100 = htobe32(0xe0000001);
  *(uint8_t*)0x20000110 = 0xac;
  *(uint8_t*)0x20000111 = 0x14;
  *(uint8_t*)0x20000112 = 0x14;
  *(uint8_t*)0x20000113 = 0;
  *(uint16_t*)0x20000120 = htobe16(0);
  *(uint16_t*)0x20000122 = htobe16(0);
  *(uint16_t*)0x20000124 = htobe16(0);
  *(uint16_t*)0x20000126 = htobe16(0);
  *(uint16_t*)0x20000128 = 2;
  *(uint8_t*)0x2000012a = 0;
  *(uint8_t*)0x2000012b = 0;
  *(uint8_t*)0x2000012c = 0;
  *(uint32_t*)0x20000130 = 0;
  *(uint32_t*)0x20000134 = 0;
  *(uint64_t*)0x20000138 = 0;
  *(uint64_t*)0x20000140 = 0;
  *(uint64_t*)0x20000148 = 0;
  *(uint64_t*)0x20000150 = 0;
  *(uint64_t*)0x20000158 = 0;
  *(uint64_t*)0x20000160 = 0;
  *(uint64_t*)0x20000168 = 0;
  *(uint64_t*)0x20000170 = 0;
  *(uint64_t*)0x20000178 = 0;
  *(uint64_t*)0x20000180 = 0;
  *(uint64_t*)0x20000188 = 0;
  *(uint64_t*)0x20000190 = 0;
  *(uint32_t*)0x20000198 = 0;
  *(uint32_t*)0x2000019c = 0;
  *(uint8_t*)0x200001a0 = 1;
  *(uint8_t*)0x200001a1 = 0;
  *(uint8_t*)0x200001a2 = 0;
  *(uint8_t*)0x200001a3 = 0;
  *(uint8_t*)0x200001a8 = 0xac;
  *(uint8_t*)0x200001a9 = 0x14;
  *(uint8_t*)0x200001aa = 0x14;
  *(uint8_t*)0x200001ab = 0xaa;
  *(uint32_t*)0x200001b8 = htobe32(0);
  *(uint8_t*)0x200001bc = 0x33;
  *(uint16_t*)0x200001c0 = 0xa;
  *(uint32_t*)0x200001c4 = htobe32(0);
  *(uint32_t*)0x200001d4 = 0;
  *(uint8_t*)0x200001d8 = 3;
  *(uint8_t*)0x200001d9 = 0;
  *(uint8_t*)0x200001da = 0;
  *(uint32_t*)0x200001dc = 1;
  *(uint32_t*)0x200001e0 = 0;
  *(uint32_t*)0x200001e4 = 0;
  syscall(__NR_setsockopt, r[0], 0x29, 0x23, 0x20000100, 0xe8);
  *(uint16_t*)0x200000c0 = 0xa;
  *(uint16_t*)0x200000c2 = htobe16(0);
  *(uint32_t*)0x200000c4 = 0;
  *(uint8_t*)0x200000c8 = 0xfe;
  *(uint8_t*)0x200000c9 = 0x80;
  *(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 = 0xaa;
  *(uint32_t*)0x200000d8 = 6;
  syscall(__NR_connect, r[0], 0x200000c0, 0x1c);
  *(uint64_t*)0x20000000 = 0;
  *(uint32_t*)0x20000008 = 0;
  *(uint64_t*)0x20000010 = 0;
  *(uint64_t*)0x20000018 = 0;
  *(uint64_t*)0x20000020 = 0;
  *(uint64_t*)0x20000028 = 0;
  *(uint32_t*)0x20000030 = 0;
  *(uint32_t*)0x20000038 = 0;
  *(uint64_t*)0x20000040 = 0x20000580;
  *(uint16_t*)0x20000580 = 2;
  *(uint16_t*)0x20000582 = htobe16(0x4e21);
  *(uint32_t*)0x20000584 = htobe32(0xe0000002);
  *(uint8_t*)0x20000588 = 0;
  *(uint8_t*)0x20000589 = 0;
  *(uint8_t*)0x2000058a = 0;
  *(uint8_t*)0x2000058b = 0;
  *(uint8_t*)0x2000058c = 0;
  *(uint8_t*)0x2000058d = 0;
  *(uint8_t*)0x2000058e = 0;
  *(uint8_t*)0x2000058f = 0;
  *(uint32_t*)0x20000048 = 0x80;
  *(uint64_t*)0x20000050 = 0;
  *(uint64_t*)0x20000058 = 0;
  *(uint64_t*)0x20000060 = 0;
  *(uint64_t*)0x20000068 = 0;
  *(uint32_t*)0x20000070 = 0;
  *(uint32_t*)0x20000078 = 0;
  syscall(__NR_sendmmsg, r[0], 0x20000000, 2, 0);
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  do_sandbox_none();
  return 0;
}