[PATCH] [IPSEC] Avoid null pointer dereference in xfrm4_rcv_encap

[Dave Kleikamp]

I'm getting a panic that I've traced back to this changeset:
http://www.kernel.org/git/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e695633e21ffb6a443a8c2f8b3f095c7f1a48eb0

xfrm4_rcv_encap dereferences x->encap without testing it for null.

Signed-off-by: Dave Kleikamp <shaggy@xxxxxxxxxxxxxx>
--- linux-2.6.17-rc1-mm1/net/ipv4/xfrm4_input.c.orig	2006-04-04
07:37:23.444068000 -0500
+++ linux-2.6.17-rc1-mm1/net/ipv4/xfrm4_input.c	2006-04-05
09:01:08.798510500 -0500
@@ -90,7 +90,7 @@ int xfrm4_rcv_encap(struct sk_buff *skb,
 		if (unlikely(x->km.state != XFRM_STATE_VALID))
 			goto drop_unlock;
 
-		if (x->encap->encap_type != encap_type)
+		if (x->encap && (x->encap->encap_type != encap_type))
 			goto drop_unlock;
 
 		if (x->props.replay_window && xfrm_replay_check(x, seq))

-- 
David Kleikamp
IBM Linux Technology Center

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/