grub_disk_cache_unlock (unsigned long dev_id, unsigned long disk_id,
			grub_disk_addr_t sector)
{
  struct grub_disk_cache *cache;
  unsigned index;

  index = grub_disk_cache_get_index (dev_id, disk_id, sector);
  cache = grub_disk_cache_table + index;

  if (cache->dev_id == dev_id && cache->disk_id == disk_id
      && cache->sector == sector)
    cache->lock = 0;
}

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.