From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933293Ab3GZVHW (ORCPT ); Fri, 26 Jul 2013 17:07:22 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51351 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760105Ab3GZU6T (ORCPT ); Fri, 26 Jul 2013 16:58:19 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Jones , Hannes Frederic Sowa , Eric Dumazet , "David S. Miller" Subject: [ 15/45] ipv6: ip6_sk_dst_check() must not assume ipv6 dst Date: Fri, 26 Jul 2013 13:57:35 -0700 Message-Id: <20130726205656.578098370@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130726205654.896050165@linuxfoundation.org> References: <20130726205654.896050165@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit a963a37d384d71ad43b3e9e79d68d42fbe0901f3 ] 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: Greg Kroah-Hartman --- net/ipv6/ip6_output.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -925,11 +925,17 @@ static struct dst_entry *ip6_sk_dst_chec const struct flowi6 *fl6) { 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,