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authorSteffen Klassert <steffen.klassert@secunet.com>2014-04-07 08:08:52 +0200
committerSteffen Klassert <steffen.klassert@secunet.com>2014-04-07 10:52:38 +0200
commit5596732fa8c14139018ecda8356eabbfb599d830 (patch)
treed4d4a5178f22ee795e2e7a44b1ca49fb0dc209fc /net
parentd80e773f16f66a610e04f6875d4da84e74a8fb6c (diff)
xfrm: Fix crash with ipv6 IPsec tunnel and NAT.
The ipv6 xfrm output path is not aware that packets can be rerouted by NAT to not use IPsec. We crash in this case because we expect to have a xfrm state at the dst_entry. This crash happens if the ipv6 layer does IPsec and NAT or if we have an interfamily IPsec tunnel with ipv4 NAT. We fix this by checking for a NAT rerouted packet in each address family and dst_output() to the new destination in this case. Reported-by: Martin Pelikan <martin.pelikan@gmail.com> Tested-by: Martin Pelikan <martin.pelikan@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/xfrm4_output.c32
-rw-r--r--net/ipv6/xfrm6_output.c22
2 files changed, 31 insertions, 23 deletions
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index baa0f63731fd..f3800bf79d86 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -62,10 +62,7 @@ int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
if (err)
return err;
- memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
- IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED;
-
- skb->protocol = htons(ETH_P_IP);
+ IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
return x->outer_mode->output2(x, skb);
}
@@ -73,27 +70,34 @@ EXPORT_SYMBOL(xfrm4_prepare_output);
int xfrm4_output_finish(struct sk_buff *skb)
{
+ memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+ skb->protocol = htons(ETH_P_IP);
+
+#ifdef CONFIG_NETFILTER
+ IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
+#endif
+
+ return xfrm_output(skb);
+}
+
+static int __xfrm4_output(struct sk_buff *skb)
+{
+ struct xfrm_state *x = skb_dst(skb)->xfrm;
+
#ifdef CONFIG_NETFILTER
- if (!skb_dst(skb)->xfrm) {
+ if (!x) {
IPCB(skb)->flags |= IPSKB_REROUTED;
return dst_output(skb);
}
-
- IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
#endif
- skb->protocol = htons(ETH_P_IP);
- return xfrm_output(skb);
+ return x->outer_mode->afinfo->output_finish(skb);
}
int xfrm4_output(struct sk_buff *skb)
{
- struct dst_entry *dst = skb_dst(skb);
- struct xfrm_state *x = dst->xfrm;
-
return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb,
- NULL, dst->dev,
- x->outer_mode->afinfo->output_finish,
+ NULL, skb_dst(skb)->dev, __xfrm4_output,
!(IPCB(skb)->flags & IPSKB_REROUTED));
}
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 6cd625e37706..ba624331451c 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -114,12 +114,6 @@ int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
if (err)
return err;
- memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
-#ifdef CONFIG_NETFILTER
- IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
-#endif
-
- skb->protocol = htons(ETH_P_IPV6);
skb->local_df = 1;
return x->outer_mode->output2(x, skb);
@@ -128,11 +122,13 @@ EXPORT_SYMBOL(xfrm6_prepare_output);
int xfrm6_output_finish(struct sk_buff *skb)
{
+ memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+ skb->protocol = htons(ETH_P_IPV6);
+
#ifdef CONFIG_NETFILTER
IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
#endif
- skb->protocol = htons(ETH_P_IPV6);
return xfrm_output(skb);
}
@@ -142,6 +138,13 @@ static int __xfrm6_output(struct sk_buff *skb)
struct xfrm_state *x = dst->xfrm;
int mtu;
+#ifdef CONFIG_NETFILTER
+ if (!x) {
+ IP6CB(skb)->flags |= IP6SKB_REROUTED;
+ return dst_output(skb);
+ }
+#endif
+
if (skb->protocol == htons(ETH_P_IPV6))
mtu = ip6_skb_dst_mtu(skb);
else
@@ -165,6 +168,7 @@ static int __xfrm6_output(struct sk_buff *skb)
int xfrm6_output(struct sk_buff *skb)
{
- return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL,
- skb_dst(skb)->dev, __xfrm6_output);
+ return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb,
+ NULL, skb_dst(skb)->dev, __xfrm6_output,
+ !(IP6CB(skb)->flags & IP6SKB_REROUTED));
}