// https://syzkaller.appspot.com/bug?id=c6c4be75ab4ce8c2a0464eab268d393b976253d3
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <fcntl.h>
#include <linux/futex.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/syscall.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 <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.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 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 uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2)
{
  if (a0 == 0xc || a0 == 0xb) {
    char buf[128];
    sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1,
            (uint8_t)a2);
    return open(buf, O_RDWR, 0);
  } else {
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf) - 1);
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

static void execute_one();
extern unsigned long long procid;

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

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 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);
        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[2] = {0xffffffffffffffff, 0xffffffffffffffff};
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    memcpy((void*)0x20000040, "/dev/net/tun", 13);
    res = syz_open_dev(0x20000040, 0, 0x1000000000000);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    memcpy((void*)0x20000000,
           "\x69\x66\x62\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint16_t*)0x20000010 = 0x33cb;
    syscall(__NR_ioctl, r[0], 0x400454ca, 0x20000000);
    break;
  case 2:
    syscall(__NR_pread64, r[0], 0x20000080, 0x62, 0);
    break;
  case 3:
    res = syscall(__NR_socket, 0x10, 3, 0);
    if (res != -1)
      r[1] = res;
    break;
  case 4:
    *(uint64_t*)0x200001c0 = 0x20000100;
    *(uint16_t*)0x20000100 = 0x10;
    *(uint16_t*)0x20000102 = 0;
    *(uint32_t*)0x20000104 = 0;
    *(uint32_t*)0x20000108 = 0;
    *(uint32_t*)0x200001c8 = 0xc;
    *(uint64_t*)0x200001d0 = 0x20000180;
    *(uint64_t*)0x20000180 = 0x200003c0;
    *(uint32_t*)0x200003c0 = 0x34;
    *(uint16_t*)0x200003c4 = 0x11;
    *(uint16_t*)0x200003c6 = 0x405;
    *(uint32_t*)0x200003c8 = 0;
    *(uint32_t*)0x200003cc = 0;
    *(uint8_t*)0x200003d0 = 0;
    *(uint8_t*)0x200003d1 = 0;
    *(uint16_t*)0x200003d2 = 0;
    *(uint32_t*)0x200003d4 = 0;
    *(uint32_t*)0x200003d8 = 0;
    *(uint32_t*)0x200003dc = 0;
    *(uint16_t*)0x200003e0 = 0x14;
    *(uint16_t*)0x200003e2 = 3;
    memcpy((void*)0x200003e4,
           "\x69\x66\x62\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint64_t*)0x20000188 = 0x34;
    *(uint64_t*)0x200001d8 = 1;
    *(uint64_t*)0x200001e0 = 0;
    *(uint64_t*)0x200001e8 = 0;
    *(uint32_t*)0x200001f0 = 0;
    syscall(__NR_sendmsg, r[1], 0x200001c0, 0);
    break;
  case 5:
    *(uint16_t*)0x20000600 = 8;
    *(uint16_t*)0x20000602 = 0x6a;
    *(uint16_t*)0x20000604 = 0;
    syscall(__NR_ioctl, -1, 0x4b68, 0x20000600);
    break;
  }
}

void execute_one()
{
  execute(6);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  char* cwd = get_current_dir_name();
  for (;;) {
    if (chdir(cwd))
      fail("failed to chdir");
    use_temporary_dir();
    loop();
  }
}