// https://syzkaller.appspot.com/bug?id=5bf48097e5838e25f9fe97d735ca74e67dbd442f
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.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/loop.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;
}

#define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off))
#define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len)               \
  *(type*)(addr) =                                                             \
      htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) |           \
            (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len))))

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 long syz_open_procfs(volatile long a0, volatile long a1)
{
  char buf[128];
  memset(buf, 0, sizeof(buf));
  if (a0 == 0) {
    snprintf(buf, sizeof(buf), "/proc/self/%s", (char*)a1);
  } else if (a0 == -1) {
    snprintf(buf, sizeof(buf), "/proc/thread-self/%s", (char*)a1);
  } else {
    snprintf(buf, sizeof(buf), "/proc/self/task/%d/%s", (int)a0, (char*)a1);
  }
  int fd = open(buf, O_RDWR);
  if (fd == -1)
    fd = open(buf, O_RDONLY);
  return fd;
}

struct fs_image_segment {
  void* data;
  uintptr_t size;
  uintptr_t offset;
};

#define IMAGE_MAX_SEGMENTS 4096
#define IMAGE_MAX_SIZE (129 << 20)

#define sys_memfd_create 319

static unsigned long fs_image_segment_check(unsigned long size,
                                            unsigned long nsegs,
                                            struct fs_image_segment* segs)
{
  if (nsegs > IMAGE_MAX_SEGMENTS)
    nsegs = IMAGE_MAX_SEGMENTS;
  for (size_t i = 0; i < nsegs; i++) {
    if (segs[i].size > IMAGE_MAX_SIZE)
      segs[i].size = IMAGE_MAX_SIZE;
    segs[i].offset %= IMAGE_MAX_SIZE;
    if (segs[i].offset > IMAGE_MAX_SIZE - segs[i].size)
      segs[i].offset = IMAGE_MAX_SIZE - segs[i].size;
    if (size < segs[i].offset + segs[i].offset)
      size = segs[i].offset + segs[i].offset;
  }
  if (size > IMAGE_MAX_SIZE)
    size = IMAGE_MAX_SIZE;
  return size;
}
static int setup_loop_device(long unsigned size, long unsigned nsegs,
                             struct fs_image_segment* segs,
                             const char* loopname, int* memfd_p, int* loopfd_p)
{
  int err = 0, loopfd = -1;
  size = fs_image_segment_check(size, nsegs, segs);
  int memfd = syscall(sys_memfd_create, "syzkaller", 0);
  if (memfd == -1) {
    err = errno;
    goto error;
  }
  if (ftruncate(memfd, size)) {
    err = errno;
    goto error_close_memfd;
  }
  for (size_t i = 0; i < nsegs; i++) {
    if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) {
    }
  }
  loopfd = open(loopname, O_RDWR);
  if (loopfd == -1) {
    err = errno;
    goto error_close_memfd;
  }
  if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
    if (errno != EBUSY) {
      err = errno;
      goto error_close_loop;
    }
    ioctl(loopfd, LOOP_CLR_FD, 0);
    usleep(1000);
    if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
      err = errno;
      goto error_close_loop;
    }
  }
  *memfd_p = memfd;
  *loopfd_p = loopfd;
  return 0;

error_close_loop:
  close(loopfd);
error_close_memfd:
  close(memfd);
error:
  errno = err;
  return -1;
}

static long syz_mount_image(volatile long fsarg, volatile long dir,
                            volatile unsigned long size,
                            volatile unsigned long nsegs,
                            volatile long segments, volatile long flags,
                            volatile long optsarg)
{
  struct fs_image_segment* segs = (struct fs_image_segment*)segments;
  int res = -1, err = 0, loopfd = -1, memfd = -1, need_loop_device = !!segs;
  char* mount_opts = (char*)optsarg;
  char* target = (char*)dir;
  char* fs = (char*)fsarg;
  char* source = NULL;
  char loopname[64];
  if (need_loop_device) {
    memset(loopname, 0, sizeof(loopname));
    snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
    if (setup_loop_device(size, nsegs, segs, loopname, &memfd, &loopfd) == -1)
      return -1;
    source = loopname;
  }
  mkdir(target, 0777);
  char opts[256];
  memset(opts, 0, sizeof(opts));
  if (strlen(mount_opts) > (sizeof(opts) - 32)) {
  }
  strncpy(opts, mount_opts, sizeof(opts) - 32);
  if (strcmp(fs, "iso9660") == 0) {
    flags |= MS_RDONLY;
  } else if (strncmp(fs, "ext", 3) == 0) {
    if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0)
      strcat(opts, ",errors=continue");
  } else if (strcmp(fs, "xfs") == 0) {
    strcat(opts, ",nouuid");
  }
  res = mount(source, target, fs, flags, opts);
  if (res == -1) {
    err = errno;
    goto error_clear_loop;
  }
  res = open(target, O_RDONLY | O_DIRECTORY);
  if (res == -1) {
    err = errno;
  }

error_clear_loop:
  if (need_loop_device) {
    ioctl(loopfd, LOOP_CLR_FD, 0);
    close(loopfd);
    close(memfd);
  }
  errno = err;
  return res;
}

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 reset_loop()
{
  char buf[64];
  snprintf(buf, sizeof(buf), "/dev/loop%llu", procid);
  int loopfd = open(buf, O_RDWR);
  if (loopfd != -1) {
    ioctl(loopfd, LOOP_CLR_FD, 0);
    close(loopfd);
  }
}

static void setup_test()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  write_file("/proc/self/oom_score_adj", "1000");
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter = 0;
  for (;; iter++) {
    reset_loop();
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      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;
    }
  }
}

void execute_one(void)
{
  syscall(__NR_accept, -1, 0ul, 0ul);
  syz_open_procfs(0, 0);
  *(uint32_t*)0x20000000 = 2;
  *(uint32_t*)0x20000004 = 0x70;
  *(uint8_t*)0x20000008 = 0xd5;
  *(uint8_t*)0x20000009 = 0;
  *(uint8_t*)0x2000000a = 0;
  *(uint8_t*)0x2000000b = 0;
  *(uint32_t*)0x2000000c = 0;
  *(uint64_t*)0x20000010 = 7;
  *(uint64_t*)0x20000018 = 0x2120;
  *(uint64_t*)0x20000020 = 0;
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 0, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 1, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 2, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 3, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 4, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 5, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 6, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 7, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 8, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 9, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 10, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 11, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 12, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 13, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 14, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 15, 2);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 17, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 18, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 19, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 20, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 21, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 22, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 23, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 24, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 25, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 26, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 27, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 28, 1);
  STORE_BY_BITMASK(uint64_t, , 0x20000028, 0, 29, 35);
  *(uint32_t*)0x20000030 = 0;
  *(uint32_t*)0x20000034 = 0;
  *(uint64_t*)0x20000038 = 0;
  *(uint64_t*)0x20000040 = 0;
  *(uint64_t*)0x20000048 = 0;
  *(uint64_t*)0x20000050 = 0;
  *(uint32_t*)0x20000058 = 0;
  *(uint32_t*)0x2000005c = 0;
  *(uint64_t*)0x20000060 = 0;
  *(uint32_t*)0x20000068 = 0;
  *(uint16_t*)0x2000006c = 0;
  *(uint16_t*)0x2000006e = 0;
  syscall(__NR_perf_event_open, 0x20000000ul, 0, 0ul, -1, 0ul);
  memcpy((void*)0x20000180, "./file0\000", 8);
  syz_mount_image(0, 0x20000180, 3, 0, 0, 0x1000, 0);
  syscall(__NR_socket, 2ul, 5ul, 0x84);
}
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);
  for (procid = 0; procid < 6; procid++) {
    if (fork() == 0) {
      loop();
    }
  }
  sleep(1000000);
  return 0;
}