// https://syzkaller.appspot.com/bug?id=fecd3274ae6917477cfd0a33b12e1f56da6223b6
// 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/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/capability.h>

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 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 void setup_common()
{
  if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) {
  }
}

static void loop();

static void sandbox_common()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  setsid();
  struct rlimit rlim;
  rlim.rlim_cur = rlim.rlim_max = (200 << 20);
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 32 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 136 << 20;
  setrlimit(RLIMIT_FSIZE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 20;
  setrlimit(RLIMIT_STACK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 0;
  setrlimit(RLIMIT_CORE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 256;
  setrlimit(RLIMIT_NOFILE, &rlim);
  if (unshare(CLONE_NEWNS)) {
  }
  if (unshare(CLONE_NEWIPC)) {
  }
  if (unshare(0x02000000)) {
  }
  if (unshare(CLONE_NEWUTS)) {
  }
  if (unshare(CLONE_SYSVSEM)) {
  }
  typedef struct {
    const char* name;
    const char* value;
  } sysctl_t;
  static const sysctl_t sysctls[] = {
      {"/proc/sys/kernel/shmmax", "16777216"},
      {"/proc/sys/kernel/shmall", "536870912"},
      {"/proc/sys/kernel/shmmni", "1024"},
      {"/proc/sys/kernel/msgmax", "8192"},
      {"/proc/sys/kernel/msgmni", "1024"},
      {"/proc/sys/kernel/msgmnb", "1024"},
      {"/proc/sys/kernel/sem", "1024 1048576 500 1024"},
  };
  unsigned i;
  for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++)
    write_file(sysctls[i].name, sysctls[i].value);
}

int wait_for_loop(int pid)
{
  if (pid < 0)
    exit(1);
  int status = 0;
  while (waitpid(-1, &status, __WALL) != pid) {
  }
  return WEXITSTATUS(status);
}

static void drop_caps(void)
{
  struct __user_cap_header_struct cap_hdr = {};
  struct __user_cap_data_struct cap_data[2] = {};
  cap_hdr.version = _LINUX_CAPABILITY_VERSION_3;
  cap_hdr.pid = getpid();
  if (syscall(SYS_capget, &cap_hdr, &cap_data))
    exit(1);
  const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE);
  cap_data[0].effective &= ~drop;
  cap_data[0].permitted &= ~drop;
  cap_data[0].inheritable &= ~drop;
  if (syscall(SYS_capset, &cap_hdr, &cap_data))
    exit(1);
}

static int do_sandbox_none(void)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid != 0)
    return wait_for_loop(pid);
  setup_common();
  sandbox_common();
  drop_caps();
  if (unshare(CLONE_NEWNET)) {
  }
  loop();
  exit(1);
}

#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 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 close_fds()
{
  int fd;
  for (fd = 3; fd < 30; fd++)
    close(fd);
}

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();
      close_fds();
      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_one(void)
{
  intptr_t res = 0;
  memcpy((void*)0x20000000, "./file0\000", 8);
  syscall(__NR_mkdir, 0x20000000, 0);
  memcpy((void*)0x200001c0, "./file0\000", 8);
  syscall(__NR_mount, 0x20000000, 0x200001c0, 0, 0x2001001, 0);
  memcpy((void*)0x200000c0, "./file0\000", 8);
  memcpy((void*)0x20000100, "./file0\000", 8);
  syscall(__NR_pivot_root, 0x200000c0, 0x20000100);
  *(uint64_t*)0x20000180 = 0;
  *(uint32_t*)0x20000188 = 0;
  *(uint64_t*)0x20000190 = 0x20000040;
  *(uint64_t*)0x20000040 = 0;
  *(uint64_t*)0x20000048 = 0;
  *(uint64_t*)0x20000198 = 1;
  *(uint64_t*)0x200001a0 = 0;
  *(uint64_t*)0x200001a8 = 0;
  *(uint32_t*)0x200001b0 = 0;
  syscall(__NR_sendmsg, -1, 0x20000180, 0);
  res = syscall(__NR_socket, 0xf, 3, 2);
  if (res != -1)
    r[0] = res;
  *(uint64_t*)0x200001c0 = 0x40000000;
  *(uint32_t*)0x200001c8 = 0;
  *(uint64_t*)0x200001d0 = 0x20000040;
  *(uint64_t*)0x20000040 = 0x20000400;
  memcpy((void*)0x20000400,
         "\x02\x03\x06\x09\x10\x00\x00\x00\x00\x00\x00\x4c\x9e\x00\x00\x00\x02"
         "\x00\x13\x00\x02\x00\x51\x66\x93\xe3\x46\x68\xdf\xf9\x00\x01\x05\x00"
         "\x06\x00\x20\x00\x00\x00\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x05\x00"
         "\xe5\x00\x00\x07\x00\x00\x00\x1f\x00\x00\x00\x00\x00\x00\x03\x00\x00"
         "\x00\x00\x00\x00\x02\x00\x01\x00\xf5\x00\x00\x00\x00\x00\x00\x02\x00"
         "\x00\x00\x00\x05\x00\x05\x00\x00\x00\x00\x00\x0a\x00\x00\x00\x00\xf4"
         "\x8d\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x17\x00\x00\x00\x00\xa3"
         "\x9f\xd3\xd0\x74\xe0\x7a\xdc\x57\xb3\x68\x07\xf3\x14\x4f\xf9\xe9\xe6"
         "\x00\xc6\xcd\x7f\x6f\xc1\xda\x05\xfb\xdf\xab\x5e\x32\xfb\xe1\xfe\xce"
         "\xe9\x9f\xac\xcb\x3f\x3e\x32\xd8\x16\x28\x0b\x92\xa4\xfb\x8b\xc8\x9a"
         "\x39\x03\x7a\x2b\x1a\xca\x15\x33\x04\xd3\xb5\xa4\xfc\xb6\x69\x3f\x7d"
         "\x7b\x24\xf7\x51\xb1\x3b\x04\x4e\xc0\xb7\xe3\xa5\x4f\x17\xb0\x43\x8c"
         "\x14\x42\xc5\xd8\xba\x54\x8e\xcd\x19\x44\x40\xe8\xc9\x08\x2c\x86\xd5"
         "\x2b\xb8\x42\xbc\x91\x9e\x6c\xdb\x97\x5f\x82\xfe\x23\x5c\x63\xff\x5d"
         "\x84\xc2\x2a\xdd\xdd\xb5\x16\x5a\xe1\x2e\xe7\x49\xec\x8b\x03\xd1\xf0"
         "\xbe\x5d\x09\xe1\x02\xda\x34\x50\x8e\x72\x7a\x01\x62\x7e\x9b\x33\x9b"
         "\xb9\x86\x1b\xee\xc0\xc7\x80\x65\x25\x13\x99\x07\x24\xde\x78\xff\xbb"
         "\x14\xf2\xf5\x18\xe9\x63\xb4\x27\xea\x3a\x08\x8e\xaa\x67\x1a\xc7\xe4"
         "\x1f\xd4\xe7\x12\x99\x2e\xc3\x5f\xad\xdc\x55\xbc\x63\x1a\x07\x45\xe8"
         "\x19\x51\x0e\x62\x81\x15\x00\x00\x00\xdc\x9d\x3c\x86\x42\x28\xc7\x68"
         "\x15\x9d\xcd\x5d\x19\x32\x36\xf0\x49\x8d\x47\x69\x3d\x9c\xed\xd0\x32"
         "\x47\x0e\xd9\x36\xfb\xa4\x00\x98\x47\xdf\x95\x9c\xbb\x8e\x97\x38\xf7"
         "\x32\xce\xa1\xf3\x4a\x9d\xd7\x3f\xdd\x24\x1d\x0d\xcd\xb5\x22\x20\x45"
         "\xc3\xc8\xfa\x80\x37\x15\x0b\xfe\xaf\x3b\x6a\x4c\xef\xc1\xb4\x5e\xd1"
         "\xdb\x31\xec\x8a\x0c\x42\x41\xbb\x09\xed\x2d\x17\xbb\x75\x72\xa1\xe6"
         "\xfc\x7c\xde\xc4\xab\xa9\x47\x1f\xad\x74\x28\x09\x9f\xbe\x5f\x8e\xc0"
         "\x7c\xbe\x94\xdf\xb9\x94\x8c\x41\x19\x64\x6b\x68\x5d\x25\xd2\xa1\x3f"
         "\xb4\x83\x1d\x84\xc2\x1e\x00\x07\x53\xcd\xa5\xfe\xb7\x3a\xf8",
         474);
  *(uint64_t*)0x20000048 = 0x80;
  *(uint64_t*)0x200001d8 = 1;
  *(uint64_t*)0x200001e0 = 0;
  *(uint64_t*)0x200001e8 = 0;
  *(uint32_t*)0x200001f0 = 0;
  syscall(__NR_sendmsg, -1, 0x200001c0, 0);
  syscall(__NR_sendmmsg, r[0], 0x20000180, 0x400000000000002, 0);
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  for (procid = 0; procid < 6; procid++) {
    if (fork() == 0) {
      use_temporary_dir();
      do_sandbox_none();
    }
  }
  sleep(1000000);
  return 0;
}