From mboxrd@z Thu Jan 1 00:00:00 1970 From: 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> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Wei Zhang To: xeb@mail.ru, davem@davemloft.net, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.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