From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755290AbaELCDt (ORCPT ); Sun, 11 May 2014 22:03:49 -0400 Received: from 1wt.eu ([62.212.114.60]:34580 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753076AbaELBmf (ORCPT ); Sun, 11 May 2014 21:42:35 -0400 Message-Id: <20140512003201.217755511@1wt.eu> User-Agent: quilt/0.48-1 Date: Mon, 12 May 2014 02:32:14 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , Hannes Frederic Sowa , "David S. Miller" , Willy Tarreau Subject: [ 014/143] ipv6: ip6_sk_dst_check() must not assume ipv6 dst In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit a963a37d384d71ad43b3e9e79d68d42fbe0901f3 upstream It's possible to use AF_INET6 sockets and to connect to an IPv4 destination. After this, socket dst cache is a pointer to a rtable, not rt6_info. ip6_sk_dst_check() should check the socket dst cache is IPv6, or else various corruptions/crashes can happen. Dave Jones can reproduce immediate crash with trinity -q -l off -n -c sendmsg -c connect With help from Hannes Frederic Sowa Reported-by: Dave Jones Reported-by: Hannes Frederic Sowa Signed-off-by: Eric Dumazet Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Willy Tarreau --- net/ipv6/ip6_output.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 6ba0fe2..bba91a1 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -920,11 +920,17 @@ static struct dst_entry *ip6_sk_dst_check(struct sock *sk, struct flowi *fl) { struct ipv6_pinfo *np = inet6_sk(sk); - struct rt6_info *rt = (struct rt6_info *)dst; + struct rt6_info *rt; if (!dst) goto out; + if (dst->ops->family != AF_INET6) { + dst_release(dst); + return NULL; + } + + rt = (struct rt6_info *)dst; /* Yes, checking route validity in not connected * case is not very simple. Take into account, * that we do not support routing by source, TOS, -- 1.7.12.2.21.g234cd45.dirty