// https://syzkaller.appspot.com/bug?id=9263e9eed9b2dafcf463cd7189fd73186e0890a3
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <sched.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/sched.h>

#ifndef __NR_clone3
#define __NR_clone3 435
#endif
#ifndef __NR_close
#define __NR_close 57
#endif
#ifndef __NR_exit
#define __NR_exit 93
#endif
#ifndef __NR_mmap
#define __NR_mmap 222
#endif
#ifndef __NR_openat
#define __NR_openat 56
#endif

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 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)
{
  int iter = 0;
  DIR* dp = 0;
  const int umount_flags = MNT_FORCE | UMOUNT_NOFOLLOW;

retry:
  while (umount2(dir, umount_flags) == 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, umount_flags) == 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, umount_flags))
        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, umount_flags))
          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 setup_test()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  write_file("/proc/self/oom_score_adj", "1000");
  if (symlink("/dev/binderfs", "./binderfs")) {
  }
}

static void setup_sysctl()
{
  int cad_pid = fork();
  if (cad_pid < 0)
    exit(1);
  if (cad_pid == 0) {
    for (;;)
      sleep(100);
  }
  char tmppid[32];
  snprintf(tmppid, sizeof(tmppid), "%d", cad_pid);
  struct {
    const char* name;
    const char* data;
  } files[] = {
      {"/proc/sys/kernel/hung_task_check_interval_secs", "20"},
      {"/proc/sys/net/core/bpf_jit_kallsyms", "1"},
      {"/proc/sys/net/core/bpf_jit_harden", "0"},
      {"/proc/sys/kernel/kptr_restrict", "0"},
      {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"},
      {"/proc/sys/fs/mount-max", "100"},
      {"/proc/sys/vm/oom_dump_tasks", "0"},
      {"/proc/sys/debug/exception-trace", "0"},
      {"/proc/sys/kernel/printk", "7 4 1 3"},
      {"/proc/sys/kernel/keys/gc_delay", "1"},
      {"/proc/sys/vm/oom_kill_allocating_task", "1"},
      {"/proc/sys/kernel/ctrl-alt-del", "0"},
      {"/proc/sys/kernel/cad_pid", tmppid},
  };
  for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
    if (!write_file(files[i].name, files[i].data)) {
    }
  }
  kill(cad_pid, SIGKILL);
  while (waitpid(cad_pid, NULL, 0) != cad_pid)
    ;
}

#define USLEEP_FORKED_CHILD (3 * 50 * 1000)

static long handle_clone_ret(long ret)
{
  if (ret != 0) {
    return ret;
  }
  usleep(USLEEP_FORKED_CHILD);
  syscall(__NR_exit, 0);
  while (1) {
  }
}

#define MAX_CLONE_ARGS_BYTES 256
static long syz_clone3(volatile long a0, volatile long a1)
{
  unsigned long copy_size = a1;
  if (copy_size < sizeof(uint64_t) || copy_size > MAX_CLONE_ARGS_BYTES)
    return -1;
  char clone_args[MAX_CLONE_ARGS_BYTES];
  memcpy(&clone_args, (void*)a0, copy_size);
  uint64_t* flags = (uint64_t*)&clone_args;
  *flags &= ~CLONE_VM;
  return handle_clone_ret((long)syscall(__NR_clone3, &clone_args, copy_size));
}

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);
    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 (;;) {
      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;
    }
    remove_dir(cwdbuf);
  }
}

uint64_t r[1] = {0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  //  openat$random arguments: [
  //    fd: const = 0xffffffffffffff9c (8 bytes)
  //    file: ptr[in, buffer] {
  //      buffer: {2f 64 65 76 2f 72 61 6e 64 6f 6d 00} (length 0xc)
  //    }
  //    flags: open_flags = 0x800 (4 bytes)
  //    mode: const = 0x0 (2 bytes)
  //  ]
  //  returns fd_random
  memcpy((void*)0x20000000, "/dev/random\000", 12);
  syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000000ul,
          /*flags=O_NONBLOCK*/ 0x800, /*mode=*/0);
  //  syz_clone3 arguments: [
  //    args: ptr[in, clone_args] {
  //      clone_args {
  //        flags: clone3_flags = 0x4080000 (8 bytes)
  //        pidfd: ptr[out, fd_pidfd] {
  //          fd_pidfd (resource)
  //        }
  //        child_tid: nil
  //        parent_tid: nil
  //        exit_signal: align64[signalno] {
  //          v: int32 = 0x2b (4 bytes)
  //          pad = 0x0 (4 bytes)
  //        }
  //        stack: nil
  //        stack_size: bytesize = 0x0 (8 bytes)
  //        tls: nil
  //        set_tid: nil
  //        set_tid_size: len = 0xfffffe21 (8 bytes)
  //        cgroup: align64[fd_cgroup] {
  //          v: fd_cgroup (resource)
  //          pad = 0x0 (4 bytes)
  //        }
  //      }
  //    }
  //    size: bytesize = 0x58 (8 bytes)
  //  ]
  //  returns pid
  *(uint64_t*)0x20000100 = 0x4080000;
  *(uint64_t*)0x20000108 = 0x20000000;
  *(uint64_t*)0x20000110 = 0;
  *(uint64_t*)0x20000118 = 0;
  *(uint32_t*)0x20000120 = 0x2b;
  *(uint64_t*)0x20000128 = 0;
  *(uint64_t*)0x20000130 = 0;
  *(uint64_t*)0x20000138 = 0;
  *(uint64_t*)0x20000140 = 0;
  *(uint64_t*)0x20000148 = 0xfffffe21;
  *(uint32_t*)0x20000150 = -1;
  res = -1;
  res = syz_clone3(/*args=*/0x20000100, /*size=*/0x58);
  if (res != -1)
    r[0] = *(uint32_t*)0x20000000;
  //  close arguments: [
  //    fd: fd (resource)
  //  ]
  syscall(__NR_close, /*fd=*/r[0]);
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000,
          /*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=*/0x21000000ul, /*len=*/0x1000, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  setup_sysctl();
  const char* reason;
  (void)reason;
  use_temporary_dir();
  loop();
  return 0;
}