From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:41260 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751941AbcAEP3J (ORCPT ); Tue, 5 Jan 2016 10:29:09 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: Daniel Borkmann , "David S . Miller" , Jiri Slaby Subject: [patch added to the 3.12 stable tree] packet: do skb_probe_transport_header when we actually have data Date: Tue, 5 Jan 2016 16:28:07 +0100 Message-Id: <1452007726-3747-6-git-send-email-jslaby@suse.cz> In-Reply-To: <1452007726-3747-1-git-send-email-jslaby@suse.cz> References: <1452007726-3747-1-git-send-email-jslaby@suse.cz> Sender: stable-owner@vger.kernel.org List-ID: From: Daniel Borkmann This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== [ Upstream commit efdfa2f7848f64517008136fb41f53c4a1faf93a ] In tpacket_fill_skb() commit c1aad275b029 ("packet: set transport header before doing xmit") and later on 40893fd0fd4e ("net: switch to use skb_probe_transport_header()") was probing for a transport header on the skb from a ring buffer slot, but at a time, where the skb has _not even_ been filled with data yet. So that call into the flow dissector is pretty useless. Lets do it after we've set up the skb frags. Fixes: c1aad275b029 ("packet: set transport header before doing xmit") Reported-by: Eric Dumazet Signed-off-by: Daniel Borkmann Acked-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/packet/af_packet.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 7f63613148b9..645010b9abc0 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1991,7 +1991,6 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, skb_reserve(skb, hlen); skb_reset_network_header(skb); - skb_probe_transport_header(skb, 0); if (po->tp_tx_has_off) { int off_min, off_max, off; @@ -2076,6 +2075,8 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, len = ((to_write > len_max) ? len_max : to_write); } + skb_probe_transport_header(skb, 0); + return tp_len; } -- 2.6.4