From: Florian Westphal Date: Thu, 24 Oct 2013 19:32:42 +0000 (+0200) Subject: bridge: netfilter: orphan skb before invoking ip netfilter hooks X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6b8dbcf2c44fd7aa716560d04e9857c870bd510c;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git bridge: netfilter: orphan skb before invoking ip netfilter hooks Pekka Pietikäinen reports xt_socket behavioural change after commit 00028aa37098o (netfilter: xt_socket: use IP early demux). Reason is xt_socket now no longer does an unconditional sk lookup - it re-uses existing skb->sk if possible, assuming ->sk was set by ip early demux. However, when netfilter is invoked via bridge, this can cause 'bogus' sockets to be examined by the match, e.g. a 'tun' device socket. bridge netfilter should orphan the skb just like the routing path before invoking ipv4/ipv6 netfilter hooks to avoid this. Reported-and-tested-by: Pekka Pietikäinen Signed-off-by: Florian Westphal Acked-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso --- diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index f87736270eaa..3d553120ff04 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -559,6 +559,8 @@ static struct net_device *setup_pre_routing(struct sk_buff *skb) else if (skb->protocol == htons(ETH_P_PPP_SES)) nf_bridge->mask |= BRNF_PPPoE; + /* Must drop socket now because of tproxy. */ + skb_orphan(skb); return skb->dev; }