From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756201Ab2KNFu1 (ORCPT ); Wed, 14 Nov 2012 00:50:27 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55034 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753023Ab2KNFuW (ORCPT ); Wed, 14 Nov 2012 00:50:22 -0500 Message-Id: <20121114053944.174312334@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Wed, 14 Nov 2012 05:40:48 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Eric Leblond , "David S. Miller" Subject: [ 75/82] af-packet: fix oops when socket is not present In-Reply-To: <20121114053933.726869752@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Leblond [ Upstream commit a3d744e995d2b936c500585ae39d99ee251c89b4 ] Due to a NULL dereference, the following patch is causing oops in normal trafic condition: commit c0de08d04215031d68fa13af36f347a6cfa252ca Author: Eric Leblond Date:   Thu Aug 16 22:02:58 2012 +0000     af_packet: don't emit packet on orig fanout group This buggy patch was a feature fix and has reached most stable branches. When skb->sk is NULL and when packet fanout is used, there is a crash in match_fanout_group where skb->sk is accessed. This patch fixes the issue by returning false as soon as the socket is NULL: this correspond to the wanted behavior because the kernel as to resend the skb to all the listening socket in this case. Signed-off-by: Eric Leblond Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index f500a69..480be72 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1633,7 +1633,7 @@ static inline int deliver_skb(struct sk_buff *skb, static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb) { - if (ptype->af_packet_priv == NULL) + if (!ptype->af_packet_priv || !skb->sk) return false; if (ptype->id_match)