// https://syzkaller.appspot.com/bug?id=c14decede92c22649f469b249123199e99e09ab0
// 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*)0x20000040, "ext4\000", 5);
  memcpy((void*)0x20000100, "./file0\000", 8);
  *(uint64_t*)0x20000200 = 0x20000140;
  memcpy((void*)0x20000140,
         "\x20\x00\x00\x00\x00\x02\x00\x00\x19\x00\x00\x00\x50\x01\x00\x00\x0f"
         "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00"
         "\x02\x00\x00\x20\x00\x00\x20\x00\x00\x00\xd8\xf4\x65\x5f\xd8\xf4\x65"
         "\x5f\x01\x00\xff\xff\x53\xef\x01\x00\x11\x00\x00\x00\xd7\xf4\x65\x5f"
         "\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x0b"
         "\x00\x00\x00\x80\x00\x00\x00\x18\x00\x00\x00\xc2\x05\x00\x00\x2b\x02",
         102);
  *(uint64_t*)0x20000208 = 0x66;
  *(uint64_t*)0x20000210 = 0x400;
  *(uint64_t*)0x20000218 = 0x20010100;
  memcpy((void*)0x20010100, "\x00\x00\x00\x00\x00\x00\x00\x00\x11\x00\x00\x00"
                            "\xb1\x38\xd8\x44\x74\x95\xb2\x5a\x38\x51\x7e\x14"
                            "\x11\xf6\x4d\x55\x01\x00\x40",
         31);
  *(uint64_t*)0x20000220 = 0x1f;
  *(uint64_t*)0x20000228 = 0x4e0;
  *(uint64_t*)0x20000230 = 0x20010200;
  memcpy((void*)0x20010200, "\x01\x00\x00\x00\x00\x00\x05\x00\x40", 9);
  *(uint64_t*)0x20000238 = 9;
  *(uint64_t*)0x20000240 = 0x560;
  *(uint64_t*)0x20000248 = 0x20010300;
  memcpy((void*)0x20010300, "\x03\x00\x00\x00\x04\x00\x00\x00\x05", 9);
  *(uint64_t*)0x20000250 = 9;
  *(uint64_t*)0x20000258 = 0x800;
  *(uint64_t*)0x20000260 = 0x20010d00;
  memcpy((void*)0x20010d00, "\xed\x41\x00\x00\x6f\x77\x6e\x21\x35\xe7\x7a\xf7"
                            "\xd8\xf4\x65\x5f\xd8\xf4\x65\x5f\x00\x00\x00\x00"
                            "\x00\x00\x04\x00\x20",
         29);
  *(uint64_t*)0x20000268 = 0x1d;
  *(uint64_t*)0x20000270 = 0x1480;
  *(uint64_t*)0x20000278 = 0x20012000;
  memcpy((void*)0x20012000, "\x50\x4d\x4d\x00\x50\x4d\x4d\xff", 8);
  *(uint64_t*)0x20000280 = 8;
  *(uint64_t*)0x20000288 = 0x10000;
  syz_mount_image(0x20000040, 0x20000100, 0x8000c, 6, 0x20000200, 0,
                  0x200000c0);
  memcpy((void*)0x20000980, "./file0\000", 8);
  memcpy((void*)0x200009c0, "trusted.overlay.nlink\000", 22);
  syscall(__NR_lsetxattr, 0x20000980ul, 0x200009c0ul, 0ul, 0ul, 0ul);
  return 0;
}