bridge: netfilter: fix update_pmtu crash with GRE (631339f1) · Commits · 戴 / test

As GRE tries to call the update_pmtu function on skb->dst and bridge supplies an skb->dst that has a NULL ops field, all is not well. This patch fixes this by giving the bridge device an ops field with an update_pmtu function. For the moment I've left all other fields blank but we can fill them in later should the need arise. Based on report and patch by Philip Craig. Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:

Patrick McHardy <kaber@trash.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/bridge/br_netfilter.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -101,6 +101,18 @@ static inline __be16 pppoe_proto(const struct sk_buff *skb)
		pppoe_proto(skb) == htons(PPP_IPV6) && \
		brnf_filter_pppoe_tagged)

		static void fake_update_pmtu(struct dst_entry *dst, u32 mtu)
		{
		}

		static struct dst_ops fake_dst_ops = {
		.family = AF_INET,
		.protocol = __constant_htons(ETH_P_IP),
		.update_pmtu = fake_update_pmtu,
		.entry_size = sizeof(struct rtable),
		.entries = ATOMIC_INIT(0),
		};

		/*
		* Initialize bogus route table used to keep netfilter happy.
		* Currently, we fill in the PMTU entry because netfilter
		@@ -117,6 +129,7 @@ void br_netfilter_rtable_init(struct net_bridge *br)
		rt->u.dst.path = &rt->u.dst;
		rt->u.dst.metrics[RTAX_MTU - 1] = 1500;
		rt->u.dst.flags = DST_NOXFRM;
		rt->u.dst.ops = &fake_dst_ops;
		}

		static inline struct rtable bridge_parent_rtable(const struct net_device dev)

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