bridge: Do not compile options in br_parse_ip_options (7677e868) · Commits · 戴 / test

Commit bridge : Sanitize skb before it enters the IP stack broke when IP options are actually used because it mangles the skb as if it entered the IP stack which is wrong because the bridge is supposed to operate below the IP stack. Since nobody has actually requested for parsing of IP options this patch fixes it by simply reverting to the previous approach of ignoring all IP options, i.e., zeroing the IPCB. If and when somebody who uses IP options and actually needs them to be parsed by the bridge complains then we can revisit this. Reported-by:

David Newall <davidn@davidnewall.com> Signed-off-by:

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

Florian Westphal <fw@strlen.de> Signed-off-by:

Pablo Neira Ayuso <pablo@netfilter.org>

net/bridge/br_netfilter.c

+5 −19

Original line number	Diff line number	Diff line
		@@ -192,7 +192,6 @@ static inline void nf_bridge_save_header(struct sk_buff *skb)

		static int br_parse_ip_options(struct sk_buff *skb)
		{
		struct ip_options *opt;
		const struct iphdr *iph;
		struct net_device *dev = skb->dev;
		u32 len;
		@@ -201,7 +200,6 @@ static int br_parse_ip_options(struct sk_buff *skb)
		goto inhdr_error;

		iph = ip_hdr(skb);
		opt = &(IPCB(skb)->opt);

		/* Basic sanity checks */
		if (iph->ihl < 5 \|\| iph->version != 4)
		@@ -227,23 +225,11 @@ static int br_parse_ip_options(struct sk_buff *skb)
		}

		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
		if (iph->ihl == 5)
		return 0;

		opt->optlen = iph->ihl*4 - sizeof(struct iphdr);
		if (ip_options_compile(dev_net(dev), opt, skb))
		goto inhdr_error;

		/* Check correct handling of SRR option */
		if (unlikely(opt->srr)) {
		struct in_device *in_dev = __in_dev_get_rcu(dev);
		if (in_dev && !IN_DEV_SOURCE_ROUTE(in_dev))
		goto drop;

		if (ip_options_rcv_srr(skb))
		goto drop;
		}

		/* We should really parse IP options here but until
		* somebody who actually uses IP options complains to
		* us we'll just silently ignore the options because
		* we're lazy!
		*/
		return 0;

		inhdr_error:

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