grub_disk_open (const char *name)
{
  const char *p;
  grub_disk_t disk;
  grub_disk_dev_t dev;
  char *raw = (char *) name;
  grub_uint64_t current_time;

  grub_dprintf ("disk", "Opening `%s'...\n", name);

  disk = (grub_disk_t) grub_zalloc (sizeof (*disk));
  if (! disk)
    return 0;

  disk->name = grub_strdup (name);
  if (! disk->name)
    goto fail;

  p = find_part_sep (name);
  if (p)
    {
      grub_size_t len = p - name;

      raw = grub_malloc (len + 1);
      if (! raw)
	goto fail;

      grub_memcpy (raw, name, len);
      raw[len] = '\0';
    }

  for (dev = grub_disk_dev_list; dev; dev = dev->next)
    {
      if ((dev->open) (raw, disk) == GRUB_ERR_NONE)
	break;
      else if (grub_errno == GRUB_ERR_UNKNOWN_DEVICE)
	grub_errno = GRUB_ERR_NONE;
      else
	goto fail;
    }

  if (! dev)
    {
      grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no such disk");
      goto fail;
    }

  if (p && ! disk->has_partitions)
    {
      grub_error (GRUB_ERR_BAD_DEVICE, "no partition on this disk");
      goto fail;
    }

  disk->dev = dev;

  if (p)
    {
      disk->partition = grub_partition_probe (disk, p + 1);
      if (! disk->partition)
	{
	  grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no such partition");
	  goto fail;
	}
    }

  /* The cache will be invalidated about 2 seconds after a device was
     closed.  */
  current_time = grub_get_time_ms ();

  if (current_time > (grub_last_time
		      + GRUB_CACHE_TIMEOUT * 1000))
    grub_disk_cache_invalidate_all ();

  grub_last_time = current_time;

 fail:

  if (raw && raw != name)
    grub_free (raw);

  if (grub_errno != GRUB_ERR_NONE)
    {
      grub_error_push ();
      grub_dprintf ("disk", "Opening `%s' failed.\n", name);
      grub_error_pop ();

      grub_disk_close (disk);
      return 0;
    }

  return disk;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.