static void qeth_send_control_data_cb(struct qeth_channel *channel,
		  struct qeth_cmd_buffer *iob)
{
	struct qeth_card *card;
	struct qeth_reply *reply, *r;
	struct qeth_ipa_cmd *cmd;
	unsigned long flags;
	int keep_reply;
	int rc = 0;

	card = CARD_FROM_CDEV(channel->ccwdev);
	QETH_CARD_TEXT(card, 4, "sndctlcb");
	rc = qeth_check_idx_response(card, iob->data);
	switch (rc) {
	case 0:
		break;
	case -EIO:
		qeth_clear_ipacmd_list(card);
		qeth_schedule_recovery(card);
		/* fall through */
	default:
		goto out;
	}

	cmd = qeth_check_ipa_data(card, iob);
	if ((cmd == NULL) && (card->state != CARD_STATE_DOWN))
		goto out;
	/*in case of OSN : check if cmd is set */
	if (card->info.type == QETH_CARD_TYPE_OSN &&
	    cmd &&
	    cmd->hdr.command != IPA_CMD_STARTLAN &&
	    card->osn_info.assist_cb != NULL) {
		card->osn_info.assist_cb(card->dev, cmd);
		goto out;
	}

	spin_lock_irqsave(&card->lock, flags);
	list_for_each_entry_safe(reply, r, &card->cmd_waiter_list, list) {
		if ((reply->seqno == QETH_IDX_COMMAND_SEQNO) ||
		    ((cmd) && (reply->seqno == cmd->hdr.seqno))) {
			qeth_get_reply(reply);
			list_del_init(&reply->list);
			spin_unlock_irqrestore(&card->lock, flags);
			keep_reply = 0;
			if (reply->callback != NULL) {
				if (cmd) {
					reply->offset = (__u16)((char *)cmd -
							(char *)iob->data);
					keep_reply = reply->callback(card,
							reply,
							(unsigned long)cmd);
				} else
					keep_reply = reply->callback(card,
							reply,
							(unsigned long)iob);
			}
			if (cmd)
				reply->rc = (u16) cmd->hdr.return_code;
			else if (iob->rc)
				reply->rc = iob->rc;
			if (keep_reply) {
				spin_lock_irqsave(&card->lock, flags);
				list_add_tail(&reply->list,
					      &card->cmd_waiter_list);
				spin_unlock_irqrestore(&card->lock, flags);
			} else {
				atomic_inc(&reply->received);
				wake_up(&reply->wait_q);
			}
			qeth_put_reply(reply);
			goto out;
		}
	}
	spin_unlock_irqrestore(&card->lock, flags);
out:
	memcpy(&card->seqno.pdu_hdr_ack,
		QETH_PDU_HEADER_SEQ_NO(iob->data),
		QETH_SEQ_NO_LENGTH);
	qeth_release_buffer(channel, iob);
}

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.