[PATCH] [TPROXY] fixes a possible read from an invalid location in the socket match

[PATCH] [TPROXY] fixes a possible read from an invalid location in the socket match

[Balazs Scheidler]

I've found this while looking for an unrelated issue. I guess this should 
still go in 2.6.28, if possible.

TIME_WAIT sockets need to be handled specially, and the socket match
casted inet_timewait_sock instances to inet_sock, which are not
compatible. 

Handle this special case by checking sk->sk_state.

Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>

---
 net/netfilter/xt_socket.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index 0e03922..1d521a5 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -144,7 +144,7 @@ socket_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 	sk = nf_tproxy_get_sock_v4(dev_net(skb->dev), protocol,
 				   saddr, daddr, sport, dport, par->in, false);
 	if (sk != NULL) {
-		bool wildcard = (inet_sk(sk)->rcv_saddr == 0);
+		bool wildcard = (sk->sk_state != TCP_TIME_WAIT && inet_sk(sk)->rcv_saddr == 0);
 
 		nf_tproxy_put_sock(sk);
 		if (wildcard)
-- 
1.5.6.3

Re: [PATCH] [TPROXY] fixes a possible read from an invalid location in the socket match

[David Miller]

From: Balazs Scheidler <bazsi@balabit.hu>
Date: Sun, 07 Dec 2008 19:43:34 +0100

> I've found this while looking for an unrelated issue. I guess this should 
> still go in 2.6.28, if possible.
> 
> TIME_WAIT sockets need to be handled specially, and the socket match
> casted inet_timewait_sock instances to inet_sock, which are not
> compatible. 
> 
> Handle this special case by checking sk->sk_state.
> 
> Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>

Applied, thanks.