// https://syzkaller.appspot.com/bug?id=74bd0c8c93762007e4ef95d9d1c77819825975c2
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <fcntl.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/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#include <linux/loop.h>

static unsigned long long procid;

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;
}

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);

  memcpy((void*)0x20000000, "ext4\000", 5);
  memcpy((void*)0x20000100, "./file0\000", 8);
  *(uint64_t*)0x20000200 = 0x20000280;
  memcpy((void*)0x20000280,
         "\x20\x00\x00\x00\x40\x00\x00\x00\x03\x00\x00\x00\x27\x00\x00\x00\x0f"
         "\x00\x00\x00\x00\x00\x00\x00\x02\x80\x00\x00\x00\x00\x00\x00\x00\x80"
         "\x00\x00\x00\x80\x00\x00\x20\x00\x00\x00\x28\xc4\x64\x5f\x28\xc4\x64"
         "\x5f\x01\x00\xff\xff\x53\xef\x01\x00\x4b\xed\xff\xff\x27\xc4\x64\x5f"
         "\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x0b"
         "\x00\x00\x00\x00\x04\x17\x9b\x66\xa5\x00\x4c\x0f\x4c\xdd\xc9\x61\x19"
         "\x9b\x60\xaa\xfd\x56\xc2\x1c\xde\xf9\x94\x38\xde\xa2\x20\x37\xa1\x50"
         "\xd1\x56\xb9\xee\x9f\x1a\x83\xf3\x8e\x39\xca\x8a\xe2\x03\xca\x41\x47"
         "\x41\xc2\x5f\x46\x07\x9c\xab\xd0\x22\x8c\x36\x50\x92\xaa\xa7\x62\xbe"
         "\xd5\x51\x1d\xea\x83\x63\xe7\x42\x83\xf3\xaa\x6c\x5c\x74\x5d\xef\x50"
         "\x45\x98\x88\x8a\xc0\x4a\xcd\xd3\xa1\x53\x3c\x1d\xbc\x00\xbc\xc5\xec"
         "\xf2\x87\xe9\x1a\xf1\xe5\xb5\xb8\x9a\x72\xf8\x1f\x7e\xac\xc0\x42\x5b"
         "\x8e\x7d\x8c\x10\x92\xab\xd9\xa6\xbb\xd2\x3f\xb7\x22\x71\x1e\x63\x74"
         "\x84\x48\x7f\xc3\xc7\x87\x61\xbf\x1d\x0a\xab\xb5\xc2\xb2\xd3\x9f\xbb"
         "\xeb\x23\xfa\xe4\xf9\xac\x89\xd5\x7d\xc1\xce\x95\x3b\x0a\x3a\x1d\x80"
         "\x10\xd3\xf3\xf8\x61\x68\xb9\x03\xb3\x4f\xb7\x32\x49\x5e\x65\xa0\x36"
         "\x96\xfd\x82\xbf\x12\x5c\x51\x82\x25\x19\x8d\x0c\xb6\x20\x7b\xed\xce"
         "\xd1\x58\x23\xd9\x53\xe2\xd6\xac\x26\x9c\x85\x01\xcc\xf9\x3f\xf7\x8e"
         "\x19\xff\x37\x6e\x14\x65\xb0\x0e\xfa\xe7\xa9\x3a\xb2\xe2\x1f\xba\xc1"
         "\x54\xe9\xff\x12\x79\x53\x72\xce\xdc\x42\xdb\xb2\xa4\x54\xbb\x24\x33"
         "\x8c\x02\x7b\xf8\xe1\xf4\x52\x20\x1a\x3a",
         350);
  *(uint64_t*)0x20000208 = 0x15e;
  *(uint64_t*)0x20000210 = 0x400;
  *(uint8_t*)0x20013d00 = 0;
  syz_mount_image(0x20000000, 0x20000100, 0, 1, 0x20000200, 0, 0x20013d00);
  return 0;
}