// https://syzkaller.appspot.com/bug?id=e2dc9aea0465d1eea101bb24cb463e2a7efe7d17
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <arpa/inet.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 <stdint.h>
#include <string.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 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(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 (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:aa:%02hx"
#define REMOTE_MAC "bb:bb:bb:bb:bb:%02hx"

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

#define LOCAL_IPV6 "fe80::%02hxaa"
#define REMOTE_IPV6 "fe80::%02hxbb"

#define IFF_NAPI 0x0010
#define IFF_NAPI_FRAGS 0x0020

static void initialize_tun(uint64_t pid)
{
  if (pid >= MAX_PIDS)
    fail("tun: no more than %d executors", MAX_PIDS);
  int id = pid;

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

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

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

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

  unshare(CLONE_NEWNS);
  unshare(CLONE_NEWIPC);
  unshare(CLONE_NEWCGROUP);
  unshare(CLONE_NEWNET);
  unshare(CLONE_NEWUTS);
  unshare(CLONE_SYSVSEM);
}

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

  sandbox_common();
  setup_tun(executor_pid, enable_tun);

  loop();
  doexit(1);
}

static void test();

void loop()
{
  while (1) {
    test();
  }
}

long r[59];
void test()
{
  memset(r, -1, sizeof(r));
  r[0] = syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul,
                 0xfffffffffffffffful, 0x0ul);
  r[1] = syscall(__NR_socket, 0x26ul, 0x5ul, 0x0ul);
  *(uint16_t*)0x20dfffa8 = (uint16_t)0x26;
  memcpy((void*)0x20dfffaa,
         "\x73\x6b\x63\x69\x70\x68\x65\x72\x00\x00\x00\x00\x00\x00",
         14);
  *(uint32_t*)0x20dfffb8 = (uint32_t)0x1;
  *(uint32_t*)0x20dfffbc = (uint32_t)0xa00;
  memcpy((void*)0x20dfffc0,
         "\x6c\x72\x77\x28\x74\x77\x6f\x66\x69\x73\x68\x29\x00\x00\x00"
         "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
         "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
         "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
         "\x00\x00\x00\x00",
         64);
  r[7] = syscall(__NR_bind, r[1], 0x20dfffa8ul, 0x58ul);
  memcpy((void*)0x2057afe0, "\x0a\x07\x75\xb0\xd5\xe3\x83\xe5\xb3\xb6"
                            "\x0c\xed\x5c\x54\xdb\xb7\x29\x5d\xf0\xdf"
                            "\x82\x17\xad\x40\x00\x00\x00\x00\x00\x00"
                            "\x00\xe6",
         32);
  r[9] = syscall(__NR_setsockopt, r[1], 0x117ul, 0x1ul, 0x2057afe0ul,
                 0x20ul);
  r[10] = syscall(__NR_accept, r[1], 0x0ul, 0x0ul);
  *(uint64_t*)0x20f6d000 = (uint64_t)0x0;
  *(uint32_t*)0x20f6d008 = (uint32_t)0x0;
  *(uint64_t*)0x20f6d010 = (uint64_t)0x206bcf60;
  *(uint64_t*)0x20f6d018 = (uint64_t)0xa;
  *(uint64_t*)0x20f6d020 = (uint64_t)0x20953000;
  *(uint64_t*)0x20f6d028 = (uint64_t)0x0;
  *(uint32_t*)0x20f6d030 = (uint32_t)0x8090;
  *(uint64_t*)0x206bcf60 = (uint64_t)0x2043cf5a;
  *(uint64_t*)0x206bcf68 = (uint64_t)0x0;
  *(uint64_t*)0x206bcf70 = (uint64_t)0x20d53000;
  *(uint64_t*)0x206bcf78 = (uint64_t)0x0;
  *(uint64_t*)0x206bcf80 = (uint64_t)0x20504000;
  *(uint64_t*)0x206bcf88 = (uint64_t)0x0;
  *(uint64_t*)0x206bcf90 = (uint64_t)0x20dd7000;
  *(uint64_t*)0x206bcf98 = (uint64_t)0x0;
  *(uint64_t*)0x206bcfa0 = (uint64_t)0x202f2000;
  *(uint64_t*)0x206bcfa8 = (uint64_t)0x0;
  *(uint64_t*)0x206bcfb0 = (uint64_t)0x20db7f7b;
  *(uint64_t*)0x206bcfb8 = (uint64_t)0x0;
  *(uint64_t*)0x206bcfc0 = (uint64_t)0x2020a000;
  *(uint64_t*)0x206bcfc8 = (uint64_t)0x0;
  *(uint64_t*)0x206bcfd0 = (uint64_t)0x204db000;
  *(uint64_t*)0x206bcfd8 = (uint64_t)0x0;
  *(uint64_t*)0x206bcfe0 = (uint64_t)0x207a7fdf;
  *(uint64_t*)0x206bcfe8 = (uint64_t)0x0;
  *(uint64_t*)0x206bcff0 = (uint64_t)0x20f7a000;
  *(uint64_t*)0x206bcff8 = (uint64_t)0x58;
  memcpy((void*)0x20f7a000,
         "\x87\xeb\x0c\xc7\xd9\x3b\xc0\xb4\xcd\x4d\xc2\xb9\xde\x47\x23"
         "\x3c\x9b\xa5\x08\x30\x5d\xcd\x60\x1d\x22\x0c\x34\x6a\x12\x61"
         "\x4a\x52\xd2\x88\x47\x4b\x57\xf7\x9a\xf3\x53\x6f\xe1\xb4\x9e"
         "\x93\xd1\xfe\xa0\x5f\x5d\x58\xde\xd4\xa2\x40\xf6\xe4\x86\xb0"
         "\x75\xf2\x3d\x08\xf7\xf3\xa4\x6f\xc2\x11\x0d\xb8\x49\x60\x9a"
         "\x13\x6e\x9c\x4f\x6a\x86\x63\xec\xcb\x39\x9a\xe2\x8f",
         88);
  r[39] = syscall(__NR_sendmsg, r[10], 0x20f6d000ul, 0x0ul);
  *(uint64_t*)0x2022efc8 = (uint64_t)0x20f6eff0;
  *(uint32_t*)0x2022efd0 = (uint32_t)0x10;
  *(uint64_t*)0x2022efd8 = (uint64_t)0x20892fb0;
  *(uint64_t*)0x2022efe0 = (uint64_t)0x5;
  *(uint64_t*)0x2022efe8 = (uint64_t)0x20aa4fba;
  *(uint64_t*)0x2022eff0 = (uint64_t)0x0;
  *(uint32_t*)0x2022eff8 = (uint32_t)0x8;
  *(uint64_t*)0x20892fb0 = (uint64_t)0x2000bf7c;
  *(uint64_t*)0x20892fb8 = (uint64_t)0x0;
  *(uint64_t*)0x20892fc0 = (uint64_t)0x20f6ef87;
  *(uint64_t*)0x20892fc8 = (uint64_t)0x0;
  *(uint64_t*)0x20892fd0 = (uint64_t)0x20f72f2b;
  *(uint64_t*)0x20892fd8 = (uint64_t)0x0;
  *(uint64_t*)0x20892fe0 = (uint64_t)0x208a8f50;
  *(uint64_t*)0x20892fe8 = (uint64_t)0xb0;
  *(uint64_t*)0x20892ff0 = (uint64_t)0x20f6e000;
  *(uint64_t*)0x20892ff8 = (uint64_t)0x0;
  r[57] = syscall(__NR_recvmsg, r[10], 0x2022efc8ul, 0x2ul);
  r[58] = syscall(__NR_mmap, 0x20000000ul, 0x1000ul, 0x3ul, 0x32ul,
                  0xfffffffffffffffful, 0x0ul);
}

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