From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: [PATCH net] netlink: reset network header before passing to taps Date: Thu, 7 Aug 2014 22:22:47 +0200 Message-ID: <1407442967-2109-1-git-send-email-dborkman@redhat.com> Cc: netdev@vger.kernel.org, marcel@holtmann.org To: davem@davemloft.net Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8679 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752614AbaHGUWy (ORCPT ); Thu, 7 Aug 2014 16:22:54 -0400 Sender: netdev-owner@vger.kernel.org List-ID: netlink doesn't set any network header offset thus when the skb is being passed to tap devices via dev_queue_xmit_nit(), it emits klog false positives due to it being unset like: ... [ 124.990397] protocol 0000 is buggy, dev nlmon0 [ 124.990411] protocol 0000 is buggy, dev nlmon0 ... So just reset the network header before passing to the device; for packet sockets that just means nothing will change - mac and net offset hold the same value just as before. Reported-by: Marcel Holtmann Signed-off-by: Daniel Borkmann --- net/netlink/af_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index a324b4b..2e152e5 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -213,7 +213,7 @@ static int __netlink_deliver_tap_skb(struct sk_buff *skb, nskb->protocol = htons((u16) sk->sk_protocol); nskb->pkt_type = netlink_is_kernel(sk) ? PACKET_KERNEL : PACKET_USER; - + skb_reset_network_header(nskb); ret = dev_queue_xmit(nskb); if (unlikely(ret > 0)) ret = net_xmit_errno(ret); -- 1.7.11.7