static int qeth_idx_activate_channel(struct qeth_channel *channel,
		void (*idx_reply_cb)(struct qeth_channel *,
			struct qeth_cmd_buffer *))
{
	struct qeth_card *card;
	struct qeth_cmd_buffer *iob;
	unsigned long flags;
	__u16 temp;
	__u8 tmp;
	int rc;
	struct ccw_dev_id temp_devid;

	card = CARD_FROM_CDEV(channel->ccwdev);

	QETH_DBF_TEXT(SETUP, 2, "idxactch");

	iob = qeth_get_buffer(channel);
	iob->callback = idx_reply_cb;
	memcpy(&channel->ccw, WRITE_CCW, sizeof(struct ccw1));
	channel->ccw.count = IDX_ACTIVATE_SIZE;
	channel->ccw.cda = (__u32) __pa(iob->data);
	if (channel == &card->write) {
		memcpy(iob->data, IDX_ACTIVATE_WRITE, IDX_ACTIVATE_SIZE);
		memcpy(QETH_TRANSPORT_HEADER_SEQ_NO(iob->data),
		       &card->seqno.trans_hdr, QETH_SEQ_NO_LENGTH);
		card->seqno.trans_hdr++;
	} else {
		memcpy(iob->data, IDX_ACTIVATE_READ, IDX_ACTIVATE_SIZE);
		memcpy(QETH_TRANSPORT_HEADER_SEQ_NO(iob->data),
		       &card->seqno.trans_hdr, QETH_SEQ_NO_LENGTH);
	}
	tmp = ((__u8)card->info.portno) | 0x80;
	memcpy(QETH_IDX_ACT_PNO(iob->data), &tmp, 1);
	memcpy(QETH_IDX_ACT_ISSUER_RM_TOKEN(iob->data),
	       &card->token.issuer_rm_w, QETH_MPC_TOKEN_LENGTH);
	memcpy(QETH_IDX_ACT_FUNC_LEVEL(iob->data),
	       &card->info.func_level, sizeof(__u16));
	ccw_device_get_id(CARD_DDEV(card), &temp_devid);
	memcpy(QETH_IDX_ACT_QDIO_DEV_CUA(iob->data), &temp_devid.devno, 2);
	temp = (card->info.cula << 8) + card->info.unit_addr2;
	memcpy(QETH_IDX_ACT_QDIO_DEV_REALADDR(iob->data), &temp, 2);

	wait_event(card->wait_q,
		   atomic_cmpxchg(&channel->irq_pending, 0, 1) == 0);
	QETH_DBF_TEXT(SETUP, 6, "noirqpnd");
	spin_lock_irqsave(get_ccwdev_lock(channel->ccwdev), flags);
	rc = ccw_device_start(channel->ccwdev,
			      &channel->ccw, (addr_t) iob, 0, 0);
	spin_unlock_irqrestore(get_ccwdev_lock(channel->ccwdev), flags);

	if (rc) {
		QETH_DBF_MESSAGE(2, "Error1 in activating channel. rc=%d\n",
			rc);
		QETH_DBF_TEXT_(SETUP, 2, "1err%d", rc);
		atomic_set(&channel->irq_pending, 0);
		wake_up(&card->wait_q);
		return rc;
	}
	rc = wait_event_interruptible_timeout(card->wait_q,
			channel->state == CH_STATE_ACTIVATING, QETH_TIMEOUT);
	if (rc == -ERESTARTSYS)
		return rc;
	if (channel->state != CH_STATE_ACTIVATING) {
		dev_warn(&channel->ccwdev->dev, "The qeth device driver"
			" failed to recover an error on the device\n");
		QETH_DBF_MESSAGE(2, "%s IDX activate timed out\n",
			dev_name(&channel->ccwdev->dev));
		QETH_DBF_TEXT_(SETUP, 2, "2err%d", -ETIME);
		qeth_clear_cmd_buffers(channel);
		return -ETIME;
	}
	return qeth_idx_activate_get_answer(channel, idx_reply_cb);
}

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.