// https://syzkaller.appspot.com/bug?id=4f3a544c4a1f113216b11517018d36d2007c85d6
// 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 <setjmp.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 unsigned long long procid;

static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) &&
      (addr < prog_start || addr > prog_end)) {
    _longjmp(segv_env, 1);
  }
  exit(sig);
}

static void install_segv_handler(void)
{
  struct sigaction sa;
  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = SIG_IGN;
  syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8);
  syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8);
  memset(&sa, 0, sizeof(sa));
  sa.sa_sigaction = segv_handler;
  sa.sa_flags = SA_NODEFER | SA_SIGINFO;
  sigaction(SIGSEGV, &sa, NULL);
  sigaction(SIGBUS, &sa, NULL);
}

#define NONFAILING(...)                                                        \
  {                                                                            \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    }                                                                          \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
  }

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_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;
}

#define FS_IOC_SETFLAGS _IOW('f', 2, long)
static void remove_dir(const char* dir)
{
  DIR* dp;
  struct dirent* ep;
  int iter = 0;
retry:
  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);
    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);
    }
  }
  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) {
        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);
  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");
}

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 < 4; 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, 45);
      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;
  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[1] = {0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    syscall(__NR_unshare, 0x40000000ul);
    break;
  case 1:
    syscall(__NR_getpid);
    break;
  case 2:
    res = syscall(__NR_socket, 0x10ul, 3ul, 0x14);
    if (res != -1)
      r[0] = res;
    break;
  case 3:
    NONFAILING(*(uint64_t*)0x20000200 = 0);
    NONFAILING(*(uint32_t*)0x20000208 = 0);
    NONFAILING(*(uint64_t*)0x20000210 = 0x20000100);
    NONFAILING(*(uint64_t*)0x20000100 = 0x20001740);
    NONFAILING(memcpy(
        (void*)0x20001740,
        "\x38\x00\x00\x00\x03\x14\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x09"
        "\x00\x02\x00\x73\x79\x7a\x30\x00\x00\x00\x00\x08\x00\x41\x00\x72\x78"
        "\x65\x00\x14\x00\x33\x00\x76\x69\x72\x74\x5f\x77\x69\x66\x69\x30\x00"
        "\x00\x00\x00\x00\x00\x3b\x23\x8c\x78\x53\x09\xd2\x68\xb6\x9a\xd9\x6e"
        "\x84\x09\x00\x00\x00\x00\x00\x00\x00\x63\x45\xef\x53\xb8\x7f\xe2\x70"
        "\x94\x34\x14\xa9\x1d\x5c\xc4\xb8\x33\x0f\xc8\xcd\xd3\x5f\xc9\x51\x1d"
        "\x41\x10\x73\x97\x58\x02\xb3\x65\xd8\x08\x71\xde\xe4\x8b\x4c\xea\x93"
        "\x4e\x97\x8f\x10\x81\x8e\xa2\x01\x4a\x18\xb3\x1b\x5c\xb2\xa4\x4c\x82"
        "\xdb\x9f\x8e\xa9\xa6\xd1\x06\xa1\xed\x19\x1e\x1c\x99\x89\xbd\x3d\xa7"
        "\x5a\x2c\x98\xfb\x24\xee\x46\xbd\x04\xcf\xf2\x9e\xb9\x08\xa0\xd3\x0a"
        "\x66\xbf\x11\x6c\xa3\x42\x15\xbb\x36\x69\xd3\x0e\x55\xc8\xaf\xf8\xbd"
        "\x83\x4b\x8d\x65\x40\xa4\xb9\xe8\xce\x79\xd3\xd7\x0b\x83\x8b\xe0\x93"
        "\x7e\xd9\x80\x28\x95\x44\x80\xc2\x05\xfe\x2b\x35\xf0\xbd\xfb\xaf\x78"
        "\x29\xe4\xab\x09\xa4\xe4\xef\x4d\xbc\x5c\x82\xa3\xd0\x19\xd0\xac\x8d"
        "\xee\xc5\x12\x4f\x4b\x1a\x0f\xbb\x7c\xf6\x41\xe2\x87\xfd\xa1\x76\x69"
        "\xa2\x1d\x4d\x0a\x78\x26\x07\xc3\xf2\x87\xc5\xd4\x6a\xfc\xe7\x93\xdd"
        "\xd6\x55\xf4\xfa\x60\x72\xef\xa0\xfa\xde\xf3\xca\xb4\x75\xd3\xe5\x1d"
        "\x0c\xa6\xcc\x7e\x37\x37\x38\x4f\x21\x71\x93\xb2\x63\x7d\xea\xe2\x4e"
        "\x5e\x74\x17\xc0\xd0\x0b\x01\x15\x22\x02\x36\xe5\xd7\xc9\x6b\x30\x27"
        "\x1d\x19\x5a\x37\xc1\xa3\xa1\x2e\x0e\x60\x87\x61\x65\x03\xaa\xb7\xa6"
        "\x6c\x13\x1e\xa8\x68\x8d\x4b\x47\xd3\xf4\xf9\xfd\x58\xee\x06\x99\x8f"
        "\xbf\x48\x4b\x2d\xae\x0b\x38\xf2\xe5\xb8\xed\xf9\x85\xca\xf8\xef\xa8"
        "\xe0\xd4\xca\x07\x91\xd0\x83\xa4\xbc\xfa\x6f\xf8\x1d\xc0\xcb\x9a\x4d"
        "\xc9\x66\x71\x4c\xff\x75\x85\xca\x2c\xa3\x43\x36\x68\x54\x98\xf2\x30"
        "\x23\x51\x35\x8e\x2a\xf5\xd4\x73\x4c\x2e\xfd\xec\x55\x1a\x2e\xdc\x18"
        "\x51\x11\x0e\xdf\x77\xec\xc1\x70\xe5\x85\xac\xfa\xcd\xc1\x25\xd0\x76"
        "\x96\x6f\x4c\x1b\xcd\x00\x4b\x24\x54\x3f\xab\x41\x91\x7b\x07\x22\x56"
        "\x34\x6b\x36\x20\x7c\xb9\xd3\xf0\x32\x8f\x44\xe4\xdd\x86\x84\x3f\x8c"
        "\x2e\x8d\xb7\x43\xde\x70\x8c\xfd\xe9\x87\xd2\xb4\x51\x7d\x9f\x46\xcb"
        "\x6f\x56\x46\x01\x07\x66\xd1\x97\x65\xd7\x2b\xaf\x9d\x78\xf9\xb9\xde"
        "\x16\x83\x07\x9a\xd4\x0a\x61\xaa\xab\xe5\xe3\x13\x5f\x64\x0c\xc0\x25"
        "\x38\x42\x3b\x3a\x25\x05\x83\xaf\x80\xb7\xe0\xf7\xd0\x44\x53\xcc\x25"
        "\x8d\x8b\x87\x1f\x64\x5c\xc8\x1d\x66\x7f\xb3\x9e\x02\x83\xfd\xe2\xee"
        "\x88\xd9\x74\x03\x4e\x4d\xb6\x8f\x2f\xac\x5f\xe9\x70\xb5\x7a\x7f\x2d"
        "\x82\xf7\x07\x65\x66\xf5\xe6\xf4\x5c\x76\x4d\xa5\xb6\x88\x63\x55\x9a"
        "\x02\x67\x33\xbe\x81\xc4\x66\x6e\x86\x32\x72\x50\x45\xc8\xb5\x61\xcd"
        "\x16\xf9\x21\x3d\x8d\x0b\xa9\x6d\x21\x6a\x50\x24\x86\x18\xd6\x93\xb5"
        "\xa7\x08\xaf\x82\x33\x15\xa7\xe6\x29\x4f\xbe\x53\x59\x3d\x10\xbd\xd4"
        "\x81\x36\xf9\x50\xe0\x6b\x98\xb7\xfe\xc9\x07\xfc\xee\x26\xc5\x1c\x6f"
        "\x43\xb4\xb5\x10\x5e\x38\xb1\xb7\xa7\xef\xd3\x26\x3f\x07\x45\x86\x97"
        "\x24\xe2\xe3\x74\xb7\xe4\xe1\x62\x12\x95\x73\x76",
        692));
    NONFAILING(*(uint64_t*)0x20000108 = 0x38);
    NONFAILING(*(uint64_t*)0x20000218 = 1);
    NONFAILING(*(uint64_t*)0x20000220 = 0);
    NONFAILING(*(uint64_t*)0x20000228 = 0);
    NONFAILING(*(uint32_t*)0x20000230 = 0);
    syscall(__NR_sendmsg, r[0], 0x20000200ul, 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);
  install_segv_handler();
  for (procid = 0; procid < 6; procid++) {
    if (fork() == 0) {
      use_temporary_dir();
      loop();
    }
  }
  sleep(1000000);
  return 0;
}