[NETFILTER]: Fix skb->nf_bridge lifetime issues

The bridge netfilter code simulates the NF_IP_PRE_ROUTING hook and skips
the real hook by registering with high priority and returning NF_STOP if
skb->nf_bridge is present and the BRNF_NF_BRIDGE_PREROUTING flag is not
set. The flag is only set during the simulated hook.

Because skb->nf_bridge is only freed when the packet is destroyed, the
packet will not only skip the first invocation of NF_IP_PRE_ROUTING, but
in the case of tunnel devices on top of the bridge also all further ones.
Forwarded packets from a bridge encapsulated by a tunnel device and sent
as locally outgoing packet will also still have the incorrect bridge
information from the input path attached.

We already have nf_reset calls on all RX/TX paths of tunnel devices,
so simply reset the nf_bridge field there too. As an added bonus,
the bridge information for locally delivered packets is now also freed
when the packet is queued to a socket.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 4 deletions

diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c
index 26ea6c19f5bd..9d3b3579f27c 100644
--- a/net/ipv4/netfilter/ipt_REJECT.c
+++ b/net/ipv4/netfilter/ipt_REJECT.c
@@ -154,10 +154,6 @@ static void send_reset(struct sk_buff *oldskb, int hook)
         /* This packet will not be the same as the other: clear nf fields */
         nf_reset(nskb);
         nskb->nfmark = 0;
-#ifdef CONFIG_BRIDGE_NETFILTER
-        nf_bridge_put(nskb->nf_bridge);
-        nskb->nf_bridge = NULL;
-#endif
 
         tcph = (struct tcphdr *)((u_int32_t*)nskb->nh.iph + nskb->nh.iph->ihl);