// https://syzkaller.appspot.com/bug?id=18ef292c1eda5e80eae88b755d840bc182c26a43
// 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 <stddef.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/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/futex.h>
#include <linux/loop.h>

#ifndef __NR_memfd_create
#define __NR_memfd_create 319
#endif

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 use_temporary_dir(void)
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    exit(1);
  if (chmod(tmpdir, 0777))
    exit(1);
  if (chdir(tmpdir))
    exit(1);
}

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;
}

struct fs_image_segment {
  void* data;
  uintptr_t size;
  uintptr_t offset;
};
static int setup_loop_device(long unsigned size, long unsigned nsegs,
                             struct fs_image_segment* segs,
                             const char* loopname, int* memfd_p, int* loopfd_p)
{
  int err = 0, loopfd = -1;
  int memfd = syscall(__NR_memfd_create, "syzkaller", 0);
  if (memfd == -1) {
    err = errno;
    goto error;
  }
  if (ftruncate(memfd, size)) {
    err = errno;
    goto error_close_memfd;
  }
  for (size_t i = 0; i < nsegs; i++) {
    if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) {
    }
  }
  loopfd = open(loopname, O_RDWR);
  if (loopfd == -1) {
    err = errno;
    goto error_close_memfd;
  }
  if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
    if (errno != EBUSY) {
      err = errno;
      goto error_close_loop;
    }
    ioctl(loopfd, LOOP_CLR_FD, 0);
    usleep(1000);
    if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
      err = errno;
      goto error_close_loop;
    }
  }
  *memfd_p = memfd;
  *loopfd_p = loopfd;
  return 0;

error_close_loop:
  close(loopfd);
error_close_memfd:
  close(memfd);
error:
  errno = err;
  return -1;
}

static long syz_mount_image(volatile long fsarg, volatile long dir,
                            volatile unsigned long size,
                            volatile unsigned long nsegs,
                            volatile long segments, volatile long flags,
                            volatile long optsarg, volatile long change_dir)
{
  struct fs_image_segment* segs = (struct fs_image_segment*)segments;
  int res = -1, err = 0, loopfd = -1, memfd = -1, need_loop_device = !!segs;
  char* mount_opts = (char*)optsarg;
  char* target = (char*)dir;
  char* fs = (char*)fsarg;
  char* source = NULL;
  char loopname[64];
  if (need_loop_device) {
    memset(loopname, 0, sizeof(loopname));
    snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
    if (setup_loop_device(size, nsegs, segs, loopname, &memfd, &loopfd) == -1)
      return -1;
    source = loopname;
  }
  mkdir(target, 0777);
  char opts[256];
  memset(opts, 0, sizeof(opts));
  if (strlen(mount_opts) > (sizeof(opts) - 32)) {
  }
  strncpy(opts, mount_opts, sizeof(opts) - 32);
  if (strcmp(fs, "iso9660") == 0) {
    flags |= MS_RDONLY;
  } else if (strncmp(fs, "ext", 3) == 0) {
    if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0)
      strcat(opts, ",errors=continue");
  } else if (strcmp(fs, "xfs") == 0) {
    strcat(opts, ",nouuid");
  }
  res = mount(source, target, fs, flags, opts);
  if (res == -1) {
    err = errno;
    goto error_clear_loop;
  }
  res = open(target, O_RDONLY | O_DIRECTORY);
  if (res == -1) {
    err = errno;
    goto error_clear_loop;
  }
  if (change_dir) {
    res = chdir(target);
    if (res == -1) {
      err = errno;
    }
  }

error_clear_loop:
  if (need_loop_device) {
    ioctl(loopfd, LOOP_CLR_FD, 0);
    close(loopfd);
    close(memfd);
  }
  errno = err;
  return res;
}

#define FS_IOC_SETFLAGS _IOW('f', 2, long)
static void remove_dir(const char* dir)
{
  int iter = 0;
  DIR* dp = 0;
retry:
  while (umount2(dir, MNT_DETACH | UMOUNT_NOFOLLOW) == 0) {
  }
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exit(1);
    }
    exit(1);
  }
  struct dirent* ep = 0;
  while ((ep = readdir(dp))) {
    if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
      continue;
    char filename[FILENAME_MAX];
    snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
    while (umount2(filename, MNT_DETACH | UMOUNT_NOFOLLOW) == 0) {
    }
    struct stat st;
    if (lstat(filename, &st))
      exit(1);
    if (S_ISDIR(st.st_mode)) {
      remove_dir(filename);
      continue;
    }
    int i;
    for (i = 0;; i++) {
      if (unlink(filename) == 0)
        break;
      if (errno == EPERM) {
        int fd = open(filename, O_RDONLY);
        if (fd != -1) {
          long flags = 0;
          if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) {
          }
          close(fd);
          continue;
        }
      }
      if (errno == EROFS) {
        break;
      }
      if (errno != EBUSY || i > 100)
        exit(1);
      if (umount2(filename, MNT_DETACH | UMOUNT_NOFOLLOW))
        exit(1);
    }
  }
  closedir(dp);
  for (int i = 0;; i++) {
    if (rmdir(dir) == 0)
      break;
    if (i < 100) {
      if (errno == EPERM) {
        int fd = open(dir, O_RDONLY);
        if (fd != -1) {
          long flags = 0;
          if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) {
          }
          close(fd);
          continue;
        }
      }
      if (errno == EROFS) {
        break;
      }
      if (errno == EBUSY) {
        if (umount2(dir, MNT_DETACH | UMOUNT_NOFOLLOW))
          exit(1);
        continue;
      }
      if (errno == ENOTEMPTY) {
        if (iter < 100) {
          iter++;
          goto retry;
        }
      }
    }
    exit(1);
  }
}

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 reset_loop()
{
  char buf[64];
  snprintf(buf, sizeof(buf), "/dev/loop%llu", procid);
  int loopfd = open(buf, O_RDWR);
  if (loopfd != -1) {
    ioctl(loopfd, LOOP_CLR_FD, 0);
    close(loopfd);
  }
}

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

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)
{
  int i, call, thread;
  for (call = 0; call < 7; 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);
      if (call == 5)
        break;
      event_timedwait(&th->done, 50 + (call == 1 ? 50 : 0));
      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++) {
    char cwdbuf[32];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      exit(1);
    reset_loop();
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      if (chdir(cwdbuf))
        exit(1);
      setup_test();
      execute_one();
      exit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      sleep_ms(1);
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
    remove_dir(cwdbuf);
  }
}

void execute_call(int call)
{
  switch (call) {
  case 0:
    memcpy((void*)0x20000300, "./bus\000", 6);
    syscall(__NR_mkdir, 0x20000300ul, 0ul);
    break;
  case 1:
    memcpy((void*)0x200002c0, "squashfs\000", 9);
    memcpy((void*)0x20000100, "./file0\000", 8);
    *(uint64_t*)0x20000200 = 0x20001b80;
    memcpy(
        (void*)0x20001b80,
        "\x68\x73\x71\x73\x07\x00\x00\x00\x91\x1d\x67\x5f\x00\x10\x00\x00\x00"
        "\x00\x00\x00\x01\x00\x0c\x00\xd0\x00\x02\x00\x04\x00\x00\x00\x26\x01"
        "\x00\x00\x00\x00\x00\x00\x06\x02\x00\x00\x00\x00\x00\x00\xb5\x01\x00"
        "\x00\x00\x00\x00\x00\xee\x01\x00\x00\x00\x00\x00\x00\x99\x00\x00\x00"
        "\x00\x00\x00\x00\x3e\x01\x00\x00\x00\x00\x00\x00\x85\x01\x00\x00\x00"
        "\x00\x00\x00\xa3\x01\x00\x00\x00\x00\x00\x00\x78\xda\x2b\xae\xac\xca"
        "\x4e\xcc\xc9\x49\x2d\x2a\xa6\x1d\x03\x00\x85\x49\x2b\x1f\x78\xda\x2b"
        "\xae\xac\xca\x4e\xcc\xc9\x49\x2d\x2a\x1e\x65\x8c\x32\x46\x19\xa3\x0c"
        "\x18\x03\x00\x55\x65\xc4\xa2\x73\x79\x7a\x6b\x61\x6c\x6c\x65\x72\x73"
        "\xa3\x00\x78\xda\x63\x62\x78\xcb\xc8\xc0\xc0\xc8\x30\x51\x36\x3d\x1e"
        "\xc8\x60\x48\x00\xe2\xff\x40\x00\xa4\x18\x52\x80\x58\x04\x88\x99\x90"
        "\xd4\x30\x03\xf9\x25\x48\x6a\xa4\x58\x18\x18\xa4\x81\x34\x33\xc3\x7f"
        "\xb8\x1a\xa0\x10\x03\xc8\x2c\x35\x20\xd6\x2f\xc9\x2d\xd0\x2f\xae\xac"
        "\xd2\xcd\xcc\x4d\x4c\x4f\x4d\x4f\xcd\x33\x31\xb4\x34\x37\x37\x33\xb6"
        "\x34\xd2\x4f\xcb\xcc\x49\x35\x80\x90\x8c\x48\x36\x30\x31\x40\x00\x88"
        "\xd6\x04\x62\x76\x20\xe6\x44\x92\x67\x05\xf2\xfb\xa1\x6a\xb8\x18\x50"
        "\x01\x23\x92\xcb\xa0\xf2\x8c\xc8\x7a\xd9\x80\x62\x33\xa1\x72\x1a\xca"
        "\xa8\x7a\x99\x90\xf4\x22\x9b\x01\x31\xf7\x00\xdc\x0c\x76\xa8\x18\x28"
        "\x24\x42\x80\x7e\xe4\x00\xd2\x00\x8b\x6a\x35\x09\x45\x00\x78\xda\x63"
        "\x64\x80\x00\x66\x20\x56\x01\x62\x26\x06\x16\x86\xb4\xcc\x9c\x54\x03"
        "\x0f\x06\x46\xa0\x20\x84\x63\xc8\x02\x55\xc5\x08\xa5\x99\x18\x38\xc0"
        "\x12\x7a\xc9\xf9\x39\x29\x6d\x40\x61\x46\x98\xb6\x65\x40\x06\xcc\x0c"
        "\xc3\x47\x0c\xac\x70\x8e\x11\x32\xc7\x18\x00\x42\x1f\x11\xfb\x1c\x00"
        "\x78\xda\x63\x60\x80\x80\x36\x28\xad\x02\xa5\x3d\xa0\xf4\x32\x28\xfd"
        "\x08\x4a\xab\x31\x42\x68\x00\x46\xdf\x02\xa2\x85\x01\x00\x00\x00\x00"
        "\x00\x00\x08\x80\x5c\xf9\x01\x00\x53\x5f\x01\x00\xab\x01\x00\x00\x00"
        "\x00\x00\x00\x1d\x00\x78\xda\x63\x60\x60\x63\xa8\x48\x2c\x29\x29\x32"
        "\x64\x63\x60\x80\xb2\x18\x60\x62\x46\x70\x31\x23\x00\xb5\xbc\x09\xab"
        "\x10\x80\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x24\x00\x00"
        "\x00\xbd\x01\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00"
        "\xdc\x01",
        512);
    *(uint64_t*)0x20000208 = 0x200;
    *(uint64_t*)0x20000210 = 0;
    syz_mount_image(0x200002c0, 0x20000100, 0x8100000, 1, 0x20000200, 0,
                    0x200000c0, 0);
    break;
  case 2:
    memcpy((void*)0x20000240, "./file1\000", 8);
    syscall(__NR_mkdir, 0x20000240ul, 0ul);
    break;
  case 3:
    memcpy((void*)0x200000c0, "./bus\000", 6);
    memcpy((void*)0x20000080, "overlay\000", 8);
    memcpy((void*)0x20000340,
           "workdir=./bus,lowerdir=./file0,upperdir=./file1,metacopy=on", 59);
    syscall(__NR_mount, 0ul, 0x200000c0ul, 0x20000080ul, 0ul, 0x20000340ul);
    break;
  case 4:
    memcpy((void*)0x200001c0, "./bus\000", 6);
    syscall(__NR_chdir, 0x200001c0ul);
    break;
  case 5:
    memcpy((void*)0x20000000, "./file1\000", 8);
    memcpy((void*)0x20000080, "./bus\000", 6);
    syscall(__NR_link, 0x20000000ul, 0x20000080ul);
    break;
  case 6:
    memcpy((void*)0x20000140, "./bus\000", 6);
    syscall(__NR_open, 0x20000140ul, 0x300ul, 0ul);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
  syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul);
  syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
  use_temporary_dir();
  loop();
  return 0;
}