// https://syzkaller.appspot.com/bug?id=f13b0c4f01171accbbff1f8a4f85471458796d96
// 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/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>

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;
  for (i = 0; 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_RELAXED))
      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;
}

#define FS_IOC_SETFLAGS _IOW('f', 2, long)
static void remove_dir(const char* dir)
{
  DIR* dp;
  struct dirent* ep;
  int iter = 0;
retry:
  while (umount2(dir, MNT_DETACH) == 0) {
  }
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exit(1);
    }
    exit(1);
  }
  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) == 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))
        exit(1);
    }
  }
  closedir(dp);
  int i;
  for (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))
          exit(1);
        continue;
      }
      if (errno == ENOTEMPTY) {
        if (iter < 100) {
          iter++;
          goto retry;
        }
      }
    }
    exit(1);
  }
}

static int inject_fault(int nth)
{
  int fd;
  fd = open("/proc/thread-self/fail-nth", O_RDWR);
  if (fd == -1)
    exit(1);
  char buf[16];
  sprintf(buf, "%d", nth + 1);
  if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf))
    exit(1);
  return fd;
}

static void kill_and_wait(int pid, int* status)
{
  kill(-pid, SIGKILL);
  kill(pid, SIGKILL);
  int i;
  for (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");
}

static void setup_fault()
{
  static struct {
    const char* file;
    const char* val;
    bool fatal;
  } files[] = {
      {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true},
      {"/sys/kernel/debug/fail_futex/ignore-private", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false},
  };
  unsigned i;
  for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
    if (!write_file(files[i].file, files[i].val)) {
      if (files[i].fatal)
        exit(1);
    }
  }
}

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;
  int collide = 0;
again:
  for (call = 0; call < 14; 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 (collide && (call % 2) == 0)
        break;
      event_timedwait(&th->done, 45);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
  if (!collide) {
    collide = 1;
    goto again;
  }
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter;
  for (iter = 0;; iter++) {
    char cwdbuf[32];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      exit(1);
    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 < 5 * 1000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
    remove_dir(cwdbuf);
  }
}

uint64_t r[8] = {0xffffffffffffffff, 0xffffffffffffffff,
                 0xffffffffffffffff, 0xffffffffffffffff,
                 0xffffffffffffffff, 0xffffffffffffffff,
                 0xffffffffffffffff, 0x0};

void execute_call(int call)
{
  intptr_t res;
  switch (call) {
  case 0:
    res = syscall(__NR_socket, 0x10ul, 3ul, 0ul);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    res = syscall(__NR_socket, 0x10ul, 3ul, 0ul);
    if (res != -1)
      r[1] = res;
    break;
  case 2:
    res = syscall(__NR_socket, 0x10ul, 3ul, 0ul);
    if (res != -1)
      r[2] = res;
    break;
  case 3:
    res = syscall(__NR_socket, 0x10ul, 0x803ul, 0);
    if (res != -1)
      r[3] = res;
    break;
  case 4:
    *(uint64_t*)0x200001c0 = 0;
    *(uint32_t*)0x200001c8 = 0;
    *(uint64_t*)0x200001d0 = 0x20000180;
    *(uint64_t*)0x20000180 = 0;
    *(uint64_t*)0x20000188 = 0;
    *(uint64_t*)0x200001d8 = 1;
    *(uint64_t*)0x200001e0 = 0;
    *(uint64_t*)0x200001e8 = 0;
    *(uint32_t*)0x200001f0 = 0;
    syscall(__NR_sendmsg, r[3], 0x200001c0ul, 0ul);
    break;
  case 5:
    *(uint32_t*)0x20000200 = 0x14;
    res = syscall(__NR_getsockname, r[3], 0x20000100ul, 0x20000200ul);
    if (res != -1)
      r[4] = *(uint32_t*)0x20000104;
    break;
  case 6:
    *(uint64_t*)0x20000040 = 0;
    *(uint32_t*)0x20000048 = 0;
    *(uint64_t*)0x20000050 = 0x20000000;
    *(uint64_t*)0x20000000 = 0x200003c0;
    memcpy((void*)0x200003c0, "\x48\x00\x00\x00\x10\x00\x05\x07\x00\x00\x00\x00"
                              "\x10\x00\x00\x00\x00\x00\x00\x40",
           20);
    *(uint32_t*)0x200003d4 = r[4];
    memcpy((void*)0x200003d8, "\x00\x00\x00\x00\x00\x00\x00\x00\x28\x00\x12\x00"
                              "\x0c\x00\x01\x00\x76\x65\x74\x68\x00\x4c\x23\xf2"
                              "\x29\x00\x02\x00\x14\x00\x01\x00\x00\x00\x00"
                              "\x00",
           36);
    *(uint32_t*)0x200003fc = 0;
    memcpy((void*)0x20000400,
           "\x00\x20\x00\x00\x00\x00\x00\x00\x75\x1d\xc2\x3d\x8e\x00\x86\x72"
           "\x39\x1e\x51\x82\x37\x99\xa0\x83\x7e\xb9\x04\xc9\xce\xdb\x38\x3d"
           "\xb4\xef\xf9\xd3\xf9\x61\xea\x48\xaf\x33\xfb\x08\x6d\xd8\x09\xe7"
           "\x4b\x05\x00\x8b\x92\x5b\x75\x9f\xb9\x7b\x84\x43\x4f\x35\x7b\xf5"
           "\x52\x90\xae\x22\x54\xdb\x82\x2b\x9f\x4b\x0a\x02\x56\xfa\xcb\x44"
           "\x52\x1f\xa8\x75\x66\x9d\xd6\x5b\x11\xc4\x70\x25\x2c\x5c\x3d\x9f"
           "\x46\x36\xbd\x89\x7f\xf9\x50\xe7\x96\xe6\x8a\x63\xff\x88\xba\x46"
           "\x00\xf2\x41\xc9\x13\xde\x35\x20\x49\x3f\x7a\xa2\x63\x98\x9a\xc3"
           "\xf7\xd2\x50\xdb\xa5\xe5\xbc\x91\x88\x09\xc9\xee\x4a\x16\xe2\x70"
           "\x37\x08\xf0\xdd\x2e\xdb\x37\x83\x00\x00\x00\x00",
           156);
    *(uint64_t*)0x20000008 = 0x48;
    *(uint64_t*)0x20000058 = 1;
    *(uint64_t*)0x20000060 = 0;
    *(uint64_t*)0x20000068 = 0;
    *(uint32_t*)0x20000070 = 0;
    syscall(__NR_sendmsg, r[2], 0x20000040ul, 0ul);
    break;
  case 7:
    *(uint64_t*)0x20000240 = 0;
    *(uint32_t*)0x20000248 = 0;
    *(uint64_t*)0x20000250 = 0x20000280;
    *(uint64_t*)0x20000280 = 0x20000340;
    memcpy((void*)0x20000340, "\x74\x00\x00\x00\x24\x00\x07\x05\x00\x00\x00\x00"
                              "\x00\x00\x00\x00\x00\x00\x00\x00",
           20);
    *(uint32_t*)0x20000354 = r[4];
    memcpy((void*)0x20000358,
           "\x00\x00\x00\x00\xff\xff\xff\xff\x00\x00\x00\x00\x08\x00\x01\x00"
           "\x71\x66\x71\x00\x48\x00\x02\x29\xc6\x09\x00\x32\xd0\xed\x64\xf3"
           "\xc3\x54\x5a\xaf\x6e\x00\x00\x85\xa4\xe4\xeb\xb5\xef\x67\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"
           "\xa0\x10\xc3",
           99);
    *(uint64_t*)0x20000288 = 0x74;
    *(uint64_t*)0x20000258 = 1;
    *(uint64_t*)0x20000260 = 0;
    *(uint64_t*)0x20000268 = 0;
    *(uint32_t*)0x20000270 = 0;
    syscall(__NR_sendmsg, r[1], 0x20000240ul, 0ul);
    break;
  case 8:
    *(uint64_t*)0x200001c0 = 0;
    *(uint32_t*)0x200001c8 = 0;
    *(uint64_t*)0x200001d0 = 0;
    *(uint64_t*)0x200001d8 = 1;
    *(uint64_t*)0x200001e0 = 0;
    *(uint64_t*)0x200001e8 = 0;
    *(uint32_t*)0x200001f0 = 0;
    syscall(__NR_sendmsg, r[0], 0x200001c0ul, 0ul);
    break;
  case 9:
    res = syscall(__NR_socket, 0x10ul, 3ul, 0ul);
    if (res != -1)
      r[5] = res;
    break;
  case 10:
    syscall(__NR_ioctl, r[5], 0x1000008912ul, 0ul);
    break;
  case 11:
    res = syscall(__NR_socket, 0x10ul, 3ul, 0ul);
    if (res != -1)
      r[6] = res;
    break;
  case 12:
    *(uint32_t*)0x20000200 = 0xb;
    res = syscall(__NR_getsockname, r[3], 0x20000100ul, 0x20000200ul);
    if (res != -1)
      r[7] = *(uint32_t*)0x20000104;
    break;
  case 13:
    *(uint64_t*)0x200001c0 = 0;
    *(uint32_t*)0x200001c8 = 0;
    *(uint64_t*)0x200001d0 = 0x20000180;
    *(uint64_t*)0x20000180 = 0x200004c0;
    *(uint32_t*)0x200004c0 = 0x34;
    *(uint16_t*)0x200004c4 = 0x28;
    *(uint16_t*)0x200004c6 = 0xd27;
    *(uint32_t*)0x200004c8 = 0;
    *(uint32_t*)0x200004cc = 0;
    *(uint8_t*)0x200004d0 = 0;
    *(uint8_t*)0x200004d1 = 0;
    *(uint16_t*)0x200004d2 = 0;
    *(uint32_t*)0x200004d4 = r[7];
    *(uint16_t*)0x200004d8 = 4;
    *(uint16_t*)0x200004da = 0;
    *(uint16_t*)0x200004dc = 0;
    *(uint16_t*)0x200004de = 0;
    *(uint16_t*)0x200004e0 = 0;
    *(uint16_t*)0x200004e2 = 0;
    *(uint16_t*)0x200004e4 = 0xa;
    *(uint16_t*)0x200004e6 = 1;
    memcpy((void*)0x200004e8, "rsvp6\000", 6);
    *(uint16_t*)0x200004f0 = 4;
    *(uint16_t*)0x200004f2 = 2;
    *(uint64_t*)0x20000188 = 0x34;
    *(uint64_t*)0x200001d8 = 1;
    *(uint64_t*)0x200001e0 = 0;
    *(uint64_t*)0x200001e8 = 0;
    *(uint32_t*)0x200001f0 = 0;
    inject_fault(5);
    syscall(__NR_sendmsg, r[6], 0x200001c0ul, 0ul);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0);
  setup_fault();
  use_temporary_dir();
  loop();
  return 0;
}