lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[XFRM]: Fix SNAT-related crash in xfrm4_output_finish

Browse Source 
When a packet matching an IPsec policy is SNATed so it doesn't match any
policy anymore it looses its xfrm bundle, which makes xfrm4_output_finish
crash because of a NULL pointer dereference.

This patch directs these packets to the original output path instead. Since
the packets have already passed the POST_ROUTING hook, but need to start at
the beginning of the original output path which includes another
POST_ROUTING invocation, a flag is added to the IPCB to indicate that the
packet was rerouted and doesn't need to pass the POST_ROUTING hook again.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy
2006-02-15 15:10:22 -08:00
committed by David S. Miller
parent 5ecfbae093
commit 48d5cad87c
7 changed files with 40 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
net/ipv4/xfrm4_output.c
View File

@@ -152,10 +152,16 @@ error_nolock:
goto out_exit;
}
int xfrm4_output_finish(struct sk_buff *skb)
static int xfrm4_output_finish(struct sk_buff *skb)
{
int err;
#ifdef CONFIG_NETFILTER
if (!skb->dst->xfrm) {
IPCB(skb)->flags |= IPSKB_REROUTED;
return dst_output(skb);
}
#endif
while (likely((err = xfrm4_output_one(skb)) == 0)) {
nf_reset(skb);
@@ -178,6 +184,7 @@ int xfrm4_output_finish(struct sk_buff *skb)
int xfrm4_output(struct sk_buff *skb)
{
return NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
xfrm4_output_finish);
return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
xfrm4_output_finish,
!(IPCB(skb)->flags & IPSKB_REROUTED));
}