xfrm: Reinject transport-mode packets through tasklet
This is an old bugbear of mine:
https://www.mail-archive.com/netdev@vger.kernel.org/msg03894.html
By crafting special packets, it is possible to cause recursion
in our kernel when processing transport-mode packets at levels
that are only limited by packet size.
The easiest one is with DNAT, but an even worse one is where
UDP encapsulation is used in which case you just have to insert
an UDP encapsulation header in between each level of recursion.
This patch avoids this problem by reinjecting tranport-mode packets
through a tasklet.
Fixes: b05e106698d9 ("[IPV4/6]: Netfilter IPsec input hooks")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index dc28a98..ae35991 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1570,6 +1570,9 @@
int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb);
int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type);
int xfrm_input_resume(struct sk_buff *skb, int nexthdr);
+int xfrm_trans_queue(struct sk_buff *skb,
+ int (*finish)(struct net *, struct sock *,
+ struct sk_buff *));
int xfrm_output_resume(struct sk_buff *skb, int err);
int xfrm_output(struct sock *sk, struct sk_buff *skb);
int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb);