From 47e0e1ca13d64eeeb687995fbe4e239e743d7544 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 12 Jan 2009 00:06:03 +0000 Subject: [PATCH] netfilter 03/09: bridge: Disable PPPOE/VLAN processing by default The PPPOE/VLAN processing code in the bridge netfilter is broken by design. The VLAN tag and the PPPOE session ID are an integral part of the packet flow information, yet they're completely ignored by the bridge netfilter. This is potentially a security hole as it treats all VLANs and PPPOE sessions as the same. What's more, it's actually broken for PPPOE as the bridge netfilter tries to trim the packets to the IP length without adjusting the PPPOE header (and adjusting the PPPOE header isn't much better since the PPPOE peer may require the padding to be present). Therefore we should disable this by default. It does mean that people relying on this feature may lose networking depending on how their bridge netfilter rules are configured. However, IMHO the problems this code causes are serious enough to warrant this. Signed-off-by: Herbert Xu Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/bridge/br_netfilter.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 9a1cd757ec4e..cf754ace0b75 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -58,11 +58,11 @@ static struct ctl_table_header *brnf_sysctl_header; static int brnf_call_iptables __read_mostly = 1; static int brnf_call_ip6tables __read_mostly = 1; static int brnf_call_arptables __read_mostly = 1; -static int brnf_filter_vlan_tagged __read_mostly = 1; -static int brnf_filter_pppoe_tagged __read_mostly = 1; +static int brnf_filter_vlan_tagged __read_mostly = 0; +static int brnf_filter_pppoe_tagged __read_mostly = 0; #else -#define brnf_filter_vlan_tagged 1 -#define brnf_filter_pppoe_tagged 1 +#define brnf_filter_vlan_tagged 0 +#define brnf_filter_pppoe_tagged 0 #endif static inline __be16 vlan_proto(const struct sk_buff *skb) -- 2.20.1