static bool blk_end_bidi_request(struct request *rq, blk_status_t error,
				 unsigned int nr_bytes, unsigned int bidi_bytes)
{
	struct request_queue *q = rq->q;
	unsigned long flags;

	WARN_ON_ONCE(q->mq_ops);

	if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
		return true;

	spin_lock_irqsave(q->queue_lock, flags);
	blk_finish_request(rq, error);
	spin_unlock_irqrestore(q->queue_lock, flags);

	return false;
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.