qeth: avoid skb_under_panic for malformatted inbound data

To make the qeth driver more robust in case of malformatted inbound
packets due to hardware problems, an additional check for
OSN-card-type is added for OSN-type packets.
Signed-off-by: NUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: NFrank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

drivers/s390/net/qeth_l2_main.c

@@ -449,12 +449,15 @@ static void qeth_l2_process_inbound_buffer(struct qeth_card *card,
 			netif_rx(skb);
 			break;
 		case QETH_HEADER_TYPE_OSN:
-			skb_push(skb, sizeof(struct qeth_hdr));
-			skb_copy_to_linear_data(skb, hdr,
+			if (card->info.type == QETH_CARD_TYPE_OSN) {
+				skb_push(skb, sizeof(struct qeth_hdr));
+				skb_copy_to_linear_data(skb, hdr,
 						sizeof(struct qeth_hdr));
-			len = skb->len;
-			card->osn_info.data_cb(skb);
-			break;
+				len = skb->len;
+				card->osn_info.data_cb(skb);
+				break;
+			}
+			/* else unknown */
 		default:
 			dev_kfree_skb_any(skb);
 			QETH_DBF_TEXT(TRACE, 3, "inbunkno");