s390/qeth: don't dump past end of unknown HW header

BugLink: https://bugs.launchpad.net/bugs/1798770

[ Upstream commit 0ac1487c ]

For inbound data with an unsupported HW header format, only dump the
actual HW header. We have no idea how much payload follows it, and what
it contains. Worst case, we dump past the end of the Inbound Buffer and
access whatever is located next in memory.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/s390/net/qeth_l2_main.c

@@ -523,7 +523,7 @@ static int qeth_l2_process_inbound_buffer(struct qeth_card *card,
 		default:
 			dev_kfree_skb_any(skb);
 			QETH_CARD_TEXT(card, 3, "inbunkno");
-			QETH_DBF_HEX(CTRL, 3, hdr, QETH_DBF_CTRL_LEN);
+			QETH_DBF_HEX(CTRL, 3, hdr, sizeof(*hdr));
 			continue;
 		}
 		work_done++;

drivers/s390/net/qeth_l3_main.c

@@ -1902,7 +1902,7 @@ static int qeth_l3_process_inbound_buffer(struct qeth_card *card,
 		default:
 			dev_kfree_skb_any(skb);
 			QETH_CARD_TEXT(card, 3, "inbunkno");
-			QETH_DBF_HEX(CTRL, 3, hdr, QETH_DBF_CTRL_LEN);
+			QETH_DBF_HEX(CTRL, 3, hdr, sizeof(*hdr));
 			continue;
 		}
 		work_done++;