From: Julian Wiedmann <jwi@linux.ibm.com>
Date: Fri, 20 Nov 2020 10:09:37 +0100
Subject: s390/qeth: make af_iucv TX notification call more robust
Git-commit: 34c7f50f7d0d36fa663c74aee39e25e912505320
Patch-mainline: v5.10-rc6
References: git-fixes

Calling into socket code is ugly already, at least check whether we are
dealing with the expected sk_family. Only looking at skb->protocol is
bound to cause troubles (consider eg. af_packet).

Fixes: b333293058aa ("qeth: add support for af_iucv HiperSockets transport")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/s390/net/qeth_core_main.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -28,6 +28,7 @@
 
 #include <net/iucv/af_iucv.h>
 #include <net/dsfield.h>
+#include <net/sock.h>
 
 #include <asm/ebcdic.h>
 #include <asm/chpid.h>
@@ -1196,7 +1197,7 @@ static void qeth_notify_skbs(struct qeth
 	skb_queue_walk(&buf->skb_list, skb) {
 		QETH_CARD_TEXT_(q->card, 5, "skbn%d", notification);
 		QETH_CARD_TEXT_(q->card, 5, "%lx", (long) skb);
-		if (skb->protocol == htons(ETH_P_AF_IUCV) && skb->sk)
+		if (skb->sk && skb->sk->sk_family == PF_IUCV)
 			iucv_sk(skb->sk)->sk_txnotify(skb, notification);
 	}
 }