// https://syzkaller.appspot.com/bug?id=c92aa0a33fd6b7bd312ad063d4d13d525417cb36
// 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>

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 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 MAX_FDS 30

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);
}

static 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:
  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");
}

static void close_fds()
{
  int fd;
  for (fd = 3; fd < MAX_FDS; 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, 0x20000000ul, 0ul);
  memcpy((void*)0x200000c0, "./file0\000", 8);
  syscall(__NR_mount, 0x20000000ul, 0x200000c0ul, 0ul, 0x2001001ul, 0ul);
  memcpy((void*)0x20000380, "./file0\000", 8);
  memcpy((void*)0x20000340, "./file0\000", 8);
  syscall(__NR_pivot_root, 0x20000380ul, 0x20000340ul);
  *(uint64_t*)0x20005c00 = 0;
  *(uint32_t*)0x20005c08 = 0xfffffd95;
  *(uint64_t*)0x20005c10 = 0;
  *(uint64_t*)0x20005c18 = 0;
  *(uint64_t*)0x20005c20 = 0x20000340;
  memcpy(
      (void*)0x20000340,
      "\x18\x00\x00\x00\x00\x00\x00\x00\x10\x01\x00\x00\x01\x00\x00\x00\x05\xe8"
      "\x00\x00\x00\x00\x00\x00\xe5\x58\xc5\x98\x6f\x00\x00\x00\x00\x00\x00\x00"
      "\x87\x69\x59\x31\x51\x57\x81\xae\x36\xa4\xd1\x48\xf2\x69\x39\x90\x22\xf5"
      "\xce\x7e\xc3\xb6\xd9\x46\xbe\x4f\xac\x95\x08\xcc\xe4\xdf\x4d\x70\x15\xf5"
      "\x59\x0b\xbf\xb4\x5e\x25\x84\xf4\x46\x72\x20\x53\xf1\x50\x25\x98\x80\x8b"
      "\x35\x5f\x7b\x81\x5b\xdb\x22\xba\x86\xdd\xdc\x01\x87\xf8\x94\xde\x7e\x81"
      "\x14\x5d\xd6\x88\x75\x99\x44\xbd\x09\xb0\xf5\x5e\x7c\xa5\x4b\x07\xbd\x91"
      "\x89\xde\x8d\xef\xce\xa2\x27\xe5\x6f\x94\xdd\xc8\xd5\xe0\x2f\x38\xfd\xcd"
      "\xad\x2e\x5c\xc2\x2b\x1f\x09\x0e\xcf\x60\x60\x5f\xa2\x6c\x0e\x48\xa8\x0a"
      "\x6b\xd5\x44\xfa\x30\x0d\x06\x6a\x4d\x16\x2d\x7e\xf8\x50\x02\x02\x5f\xaf"
      "\x08\x31\xff\xfb\xb5\xf1\xa1\x2a\x6f\x5f\x15\x8a\x75\x2e\xaf\x25\xa8\x59"
      "\xb4\x0a\x57\x38\x11\x47\xcd\xd7\xc9\xfd\x7c\xea\xe3\x03\x04\x78\x3f\xd7"
      "\xf2\xee\xc7\x9c\x49\xb6\x9a\x61\x28\x7b\x59\x13\x71\xf3\xf6\x0b\x34\x47"
      "\x06\x92\x21\x7a\x89\x30\xa1\x1f\x0e\x0c\x79\x6c\x58\x7d\xa2\x35\xe5\xed"
      "\x34\xce\x84\x48\x27\x03\x3a\x3b\xac\x99\xab\x94\x98\xf9\x44\xfe\xc7\x30"
      "\x01\xfd\x8b\xe2\xb4\xb3\x6b\x0b\x3c\x96\x72\xaf\x72\x78\x31\x27\x50\x17"
      "\xa6\xd5\xaf\xf5\x0c\x09\xbf\xc2\x2e\xbf\x54\x89\x06\x13\x8e\x7d\xae\x98"
      "\xda\x1b\x8a\x39\xbf\x88\x00\x00\x00\x00\x33\x9b\x56\x7e\x58\x68\x9a\x4d"
      "\xa6\x4c\xf3\x1b\x4e\xa5\x06\x61\x03\xba\x67\x0c\x27\x72\xb5\x48\xc8\xf1"
      "\x38\xaf\x70\x29\xf1\x22\x69\x01\xc8\x6f\x51\x0b\x46\xe3\xa0\x27\xd6\x13"
      "\x5f\x99\xb5\x85\xd0\xaa\x73\xb7\x1c\xd8\xe7\x44\x8f\x10\x73\x36\xed\x8a"
      "\x46\xa3\x59\x36\xd5\xa2\x4a\x92\xa4\xe2\xbe\x4b\x78\xca\x3d\x30\x4e\x40"
      "\xf3\x93\x13\x19\xf8\xb3\xe3\xf6\xfe\xeb\xfd\xce\xfa\x89\x4f\x5b\x25\x37"
      "\xfa\x42\x34\x9e\x69\x57\xc1\xb0\x96\x52\x42\x19\x4e\x87\xe3\xca\x02",
      431);
  *(uint64_t*)0x20005c28 = 0x18;
  *(uint32_t*)0x20005c30 = 0;
  *(uint32_t*)0x20005c38 = 0;
  syscall(__NR_sendmmsg, -1, 0x20005c00ul, 1ul, 0ul);
  res = syscall(__NR_socket, 0x2000000000000021ul, 2ul, 2);
  if (res != -1)
    r[0] = res;
  *(uint16_t*)0x20000180 = 0x21;
  *(uint16_t*)0x20000182 = 0;
  *(uint16_t*)0x20000184 = 2;
  *(uint16_t*)0x20000186 = 0x10;
  *(uint16_t*)0x20000188 = 2;
  *(uint16_t*)0x2000018a = htobe16(0);
  *(uint32_t*)0x2000018c = htobe32(0);
  syscall(__NR_connect, r[0], 0x20000180ul, 0x24ul);
  syscall(__NR_sendmmsg, r[0], 0x20005c00ul, 0x40000000000037bul, 0ul);
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0ul);
  for (procid = 0; procid < 6; procid++) {
    if (fork() == 0) {
      use_temporary_dir();
      do_sandbox_none();
    }
  }
  sleep(1000000);
  return 0;
}