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[NETFILTER]: Fix skb->nf_bridge lifetime issues

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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>
This commit is contained in:
Patrick McHardy 2006-03-20 19:23:05 -08:00 committed by David S. Miller
parent 6ffd30fbbb
commit a193a4abdd
2 changed files with 14 additions and 14 deletions
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24
include/linux/skbuff.h
View file

@ -1351,16 +1351,6 @@ static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
kfree_skb(skb);
}
#endif
static inline void nf_reset(struct sk_buff *skb)
{
nf_conntrack_put(skb->nfct);
skb->nfct = NULL;
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
nf_conntrack_put_reasm(skb->nfct_reasm);
skb->nfct_reasm = NULL;
#endif
}
#ifdef CONFIG_BRIDGE_NETFILTER
static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
{
@ -1373,6 +1363,20 @@ static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
atomic_inc(&nf_bridge->use);
}
#endif /* CONFIG_BRIDGE_NETFILTER */
static inline void nf_reset(struct sk_buff *skb)
{
nf_conntrack_put(skb->nfct);
skb->nfct = NULL;
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
nf_conntrack_put_reasm(skb->nfct_reasm);
skb->nfct_reasm = NULL;
#endif
#ifdef CONFIG_BRIDGE_NETFILTER
nf_bridge_put(skb->nf_bridge);
skb->nf_bridge = NULL;
#endif
}
#else /* CONFIG_NETFILTER */
static inline void nf_reset(struct sk_buff *skb) {}
#endif /* CONFIG_NETFILTER */

4
net/ipv4/netfilter/ipt_REJECT.c
View file

@ -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);