From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Peter Huang (Peng)" Subject: [PATCH] set fake_rtable's dst to NULL to avoid kernel Oops. Date: Tue, 17 Apr 2012 14:22:26 +0800 Message-ID: <000001cd1c62$75d10de0$617329a0$%huangpeng@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7BIT Cc: eric.dumazet@gmail.com, linux-kernel@vger.kernel.org, ctrix+debianbugs@navynet.it, peter.huangpeng@huawei.com, peter.huangpeng@gmail.com, harry.majun@huawei.com To: shemminger@vyatta.com, "'David S. Miller'" , netdev@vger.kernel.org Return-path: Content-language: zh-cn Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org When bridge is deleted before tap/vif device's delete, kernel may encounter an oops because of NULL reference to fake_rtable's dst. Set fake_rtable's dst to NULL before sending packets out can solve this problem. Acked-by: Eric Dumazet Signed-off-by: Peter Huang --- include/linux/netfilter_bridge.h | 8 ++++++++ net/bridge/br_forward.c | 1 + net/bridge/br_netfilter.c | 6 +----- 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/linux/netfilter_bridge.h b/include/linux/netfilter_bridge.h index 0ddd161..70744fe 100644 --- a/include/linux/netfilter_bridge.h +++ b/include/linux/netfilter_bridge.h @@ -104,9 +104,17 @@ struct bridge_skb_cb { } daddr; }; +static inline void br_drop_fake_rtable(struct sk_buff *skb) { + struct dst_entry *dst = skb_dst(skb); + /* abuse fact that only fake_rtable has DST_NOPEER set */ + if (dst && (dst->flags & DST_NOPEER)) + skb_dst_drop(skb); +} + #else #define nf_bridge_maybe_copy_header(skb) (0) #define nf_bridge_pad(skb) (0) +#define br_drop_fake_rtable(skb) (0) #endif /* CONFIG_BRIDGE_NETFILTER */ #endif /* __KERNEL__ */ diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c index 61f6534..a2098e3 100644 --- a/net/bridge/br_forward.c +++ b/net/bridge/br_forward.c @@ -47,6 +47,7 @@ int br_dev_queue_push_xmit(struct sk_buff *skb) kfree_skb(skb); } else { skb_push(skb, ETH_HLEN); + br_drop_fake_rtable(skb); dev_queue_xmit(skb); } diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index dec4f38..946dcb0 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -694,11 +694,7 @@ static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff *skb, const struct net_device *out, int (*okfn)(struct sk_buff *)) { - struct rtable *rt = skb_rtable(skb); - - if (rt && rt == bridge_parent_rtable(in)) - skb_dst_drop(skb); - + br_drop_fake_rtable(skb); return NF_ACCEPT; } -------------------------------- Peter Huang(peng)