// https://syzkaller.appspot.com/bug?id=17733c5870b663e9cb1fc2cce3789d87e0e85a88
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/futex.h>

static unsigned long long procid;

static void sleep_ms(uint64_t ms)
{
  usleep(ms * 1000);
}

static uint64_t current_time_ms(void)
{
  struct timespec ts;
  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    exit(1);
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

static void thread_start(void* (*fn)(void*), void* arg)
{
  pthread_t th;
  pthread_attr_t attr;
  pthread_attr_init(&attr);
  pthread_attr_setstacksize(&attr, 128 << 10);
  int i = 0;
  for (; i < 100; i++) {
    if (pthread_create(&th, &attr, fn, arg) == 0) {
      pthread_attr_destroy(&attr);
      return;
    }
    if (errno == EAGAIN) {
      usleep(50);
      continue;
    }
    break;
  }
  exit(1);
}

typedef struct {
  int state;
} event_t;

static void event_init(event_t* ev)
{
  ev->state = 0;
}

static void event_reset(event_t* ev)
{
  ev->state = 0;
}

static void event_set(event_t* ev)
{
  if (ev->state)
    exit(1);
  __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE);
  syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000);
}

static void event_wait(event_t* ev)
{
  while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0);
}

static int event_isset(event_t* ev)
{
  return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE);
}

static int event_timedwait(event_t* ev, uint64_t timeout)
{
  uint64_t start = current_time_ms();
  uint64_t now = start;
  for (;;) {
    uint64_t remain = timeout - (now - start);
    struct timespec ts;
    ts.tv_sec = remain / 1000;
    ts.tv_nsec = (remain % 1000) * 1000 * 1000;
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts);
    if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
      return 1;
    now = current_time_ms();
    if (now - start > timeout)
      return 0;
  }
}

static bool write_file(const char* file, const char* what, ...)
{
  char buf[1024];
  va_list args;
  va_start(args, what);
  vsnprintf(buf, sizeof(buf), what, args);
  va_end(args);
  buf[sizeof(buf) - 1] = 0;
  int len = strlen(buf);
  int fd = open(file, O_WRONLY | O_CLOEXEC);
  if (fd == -1)
    return false;
  if (write(fd, buf, len) != len) {
    int err = errno;
    close(fd);
    errno = err;
    return false;
  }
  close(fd);
  return true;
}

static long syz_open_dev(volatile long a0, volatile long a1, volatile long 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 {
    unsigned long nb = a1;
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf) - 1);
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(nb % 10);
      nb /= 10;
    }
    return open(buf, a2, 0);
  }
}

static void kill_and_wait(int pid, int* status)
{
  kill(-pid, SIGKILL);
  kill(pid, SIGKILL);
  for (int i = 0; i < 100; i++) {
    if (waitpid(-1, status, WNOHANG | __WALL) == pid)
      return;
    usleep(1000);
  }
  DIR* dir = opendir("/sys/fs/fuse/connections");
  if (dir) {
    for (;;) {
      struct dirent* ent = readdir(dir);
      if (!ent)
        break;
      if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
        continue;
      char abort[300];
      snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort",
               ent->d_name);
      int fd = open(abort, O_WRONLY);
      if (fd == -1) {
        continue;
      }
      if (write(fd, abort, 1) < 0) {
      }
      close(fd);
    }
    closedir(dir);
  } else {
  }
  while (waitpid(-1, status, __WALL) != pid) {
  }
}

static void setup_test()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  write_file("/proc/self/oom_score_adj", "1000");
}

struct thread_t {
  int created, call;
  event_t ready, done;
};

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 (;;) {
    event_wait(&th->ready);
    event_reset(&th->ready);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    event_set(&th->done);
  }
  return 0;
}

static void execute_one(void)
{
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  int i, call, thread;
  for (call = 0; call < 10; call++) {
    for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0]));
         thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        event_init(&th->ready);
        event_init(&th->done);
        event_set(&th->done);
        thread_start(thr, th);
      }
      if (!event_isset(&th->done))
        continue;
      event_reset(&th->done);
      th->call = call;
      __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
      event_set(&th->ready);
      event_timedwait(&th->done, 50);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter = 0;
  for (;; iter++) {
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      setup_test();
      execute_one();
      exit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      sleep_ms(10);
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
  }
}

uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0x0};

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    //  syz_open_dev$ndb arguments: [
    //    dev: ptr[in, buffer] {
    //      buffer: {2f 64 65 76 2f 6e 62 64 23 00} (length 0xa)
    //    }
    //    id: proc = 0x0 (8 bytes)
    //    flags: open_flags = 0x2 (8 bytes)
    //  ]
    //  returns fd_nbd
    memcpy((void*)0x200000000000, "/dev/nbd#\000", 10);
    res = -1;
    res = syz_open_dev(/*dev=*/0x200000000000, /*id=*/0 + procid * 1,
                       /*flags=O_RDWR*/ 2);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    //  socketpair$nbd arguments: [
    //    domain: const = 0x1 (8 bytes)
    //    type: const = 0x1 (8 bytes)
    //    proto: const = 0x0 (4 bytes)
    //    fds: ptr[out, nbd_sock_pair] {
    //      nbd_sock_pair {
    //        client: sock_nbd_client (resource)
    //        server: sock_nbd_server (resource)
    //      }
    //    }
    //  ]
    res = syscall(__NR_socketpair, /*domain=*/1ul, /*type=*/1ul, /*proto=*/0,
                  /*fds=*/0x200000000040ul);
    if (res != -1)
      r[1] = *(uint32_t*)0x200000000040;
    break;
  case 2:
    //  ioctl$NBD_SET_SOCK arguments: [
    //    fd: fd_nbd (resource)
    //    cmd: const = 0xab00 (4 bytes)
    //    arg: sock_nbd_client (resource)
    //  ]
    syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xab00, /*arg=*/r[1]);
    break;
  case 3:
    //  ioctl$NBD_SET_SIZE_BLOCKS arguments: [
    //    fd: fd_nbd (resource)
    //    cmd: const = 0xab07 (4 bytes)
    //    arg: intptr = 0x4 (8 bytes)
    //  ]
    syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xab07, /*arg=*/4ul);
    break;
  case 4:
    //  gettid arguments: [
    //  ]
    //  returns pid
    res = syscall(__NR_gettid);
    if (res != -1)
      r[2] = res;
    break;
  case 5:
    //  timer_create arguments: [
    //    id: clock_id = 0x0 (8 bytes)
    //    ev: ptr[in, sigevent] {
    //      sigevent {
    //        val: const = 0x0 (8 bytes)
    //        signo: int32 = 0x21 (4 bytes)
    //        notify: sigev_notify = 0x800000000004 (4 bytes)
    //        u: union sigevent_u {
    //          tid: pid (resource)
    //        }
    //        pad = 0x0 (32 bytes)
    //      }
    //    }
    //    timerid: ptr[out, timerid] {
    //      timerid (resource)
    //    }
    //  ]
    *(uint64_t*)0x200000533fa0 = 0;
    *(uint32_t*)0x200000533fa8 = 0x21;
    *(uint32_t*)0x200000533fac = 4;
    *(uint32_t*)0x200000533fb0 = r[2];
    syscall(__NR_timer_create, /*id=*/0ul, /*ev=*/0x200000533fa0ul,
            /*timerid=*/0x200000bbdffcul);
    break;
  case 6:
    //  timer_settime arguments: [
    //    timerid: timerid (resource)
    //    flags: timer_flags = 0x0 (8 bytes)
    //    new: ptr[in, itimerspec] {
    //      itimerspec {
    //        interv: timespec {
    //          sec: time_sec (resource)
    //          nsec: time_nsec (resource)
    //        }
    //        value: timespec {
    //          sec: time_sec (resource)
    //          nsec: time_nsec (resource)
    //        }
    //      }
    //    }
    //    old: nil
    //  ]
    *(uint64_t*)0x2000000002c0 = 0;
    *(uint64_t*)0x2000000002c8 = 0x989680;
    *(uint64_t*)0x2000000002d0 = 0;
    *(uint64_t*)0x2000000002d8 = 0x989680;
    syscall(__NR_timer_settime, /*timerid=*/0, /*flags=*/0ul,
            /*new=*/0x2000000002c0ul, /*old=*/0ul);
    break;
  case 7:
    //  openat$dsp arguments: [
    //    fd: const = 0xffffffffffffff9c (8 bytes)
    //    file: nil
    //    flags: open_flags = 0x42 (4 bytes)
    //    mode: const = 0x0 (2 bytes)
    //  ]
    //  returns fd_dsp
    syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0ul,
            /*flags=O_CREAT|O_RDWR*/ 0x42, /*mode=*/0);
    break;
  case 8:
    //  ioctl$NBD_DO_IT arguments: [
    //    fd: fd_nbd (resource)
    //    cmd: const = 0xab03 (4 bytes)
    //  ]
    syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xab03, 0);
    break;
  case 9:
    //  ioctl$NBD_CLEAR_SOCK arguments: [
    //    fd: fd_nbd (resource)
    //    cmd: const = 0xab04 (4 bytes)
    //  ]
    syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xab04, 0);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  const char* reason;
  (void)reason;
  for (procid = 0; procid < 5; procid++) {
    if (fork() == 0) {
      loop();
    }
  }
  sleep(1000000);
  return 0;
}