From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752272AbaCXHwS (ORCPT ); Mon, 24 Mar 2014 03:52:18 -0400 Received: from m12-11.163.com ([220.181.12.11]:53588 "EHLO m12-11.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750850AbaCXHwQ (ORCPT ); Mon, 24 Mar 2014 03:52:16 -0400 X-Greylist: delayed 926 seconds by postgrey-1.27 at vger.kernel.org; Mon, 24 Mar 2014 03:52:14 EDT From: Wei Zhang To: xeb@mail.ru, davem@davemloft.net, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Wei Zhang Subject: [PATCH] ipv4: gre: Fix null pointer dereference in gre_cisco_err() Date: Mon, 24 Mar 2014 15:34:31 +0800 Message-Id: <1395646471-637-1-git-send-email-asuka.com@163.com> X-Mailer: git-send-email 1.7.1 X-CM-TRANSID: C8CowEBZN0pJ4C9Tj81aAQ--.1191S2 X-Coremail-Antispam: 1Uf129KBjvdXoW7Gr4rKry3CFy7try8Zw1rXrb_yoWfXFg_uF 95trWUuw48u3ZYy343Ars3C3yfK3yFkFWFgr10qrWUJas8Jry5A3Wvkr9xCrW7XFWakryI qw1DWrWfJr47ZjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU1IeHJUUUUU== X-Originating-IP: [221.237.158.191] X-CM-SenderInfo: 5dvxytoofrzqqrwthudrp/xtbB0QpY1lEAKnLudwAAsF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When use the gre vport, openvswitch register a gre_cisco_protocol but does not supply a err_handler with it. The gre_cisco_err() call the err_handler without existence check, cause the kernel crash. This patch base on v3.14-rc7. But the bug affect all kernel newer than 3.11! Signed-off-by: Wei Zhang --- net/ipv4/gre_demux.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c index 1863422..56b0d67 100644 --- a/net/ipv4/gre_demux.c +++ b/net/ipv4/gre_demux.c @@ -250,7 +250,7 @@ static void gre_cisco_err(struct sk_buff *skb, u32 info) struct gre_cisco_protocol *proto; proto = rcu_dereference(gre_cisco_proto_list[i]); - if (!proto) + if (!proto || !proto->err_handler) continue; if (proto->err_handler(skb, info, &tpi) == PACKET_RCVD) -- 1.7.1