From: JP Abgrall <jpa@google.com>
Date: Thu, 21 Feb 2013 00:38:34 +0000 (-0800)
Subject: netfilter: xt_qtaguid: fix bad tcp_time_wait sock handling
X-Git-Tag: firefly_0821_release~4090^2~528
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=24d852635bf4fe9b98e4e8f6b5e2b0a43dd63b8c;p=firefly-linux-kernel-4.4.55.git

netfilter: xt_qtaguid: fix bad tcp_time_wait sock handling

Since (41063e9 ipv4: Early TCP socket demux), skb's can have an sk which
is not a struct sock but the smaller struct inet_timewait_sock without an
sk->sk_socket. Now we bypass sk_state == TCP_TIME_WAIT

Signed-off-by: JP Abgrall <jpa@google.com>
---

diff --git a/net/netfilter/xt_qtaguid.c b/net/netfilter/xt_qtaguid.c
index 4ec6d23876c5..5e07c3375b56 100644
--- a/net/netfilter/xt_qtaguid.c
+++ b/net/netfilter/xt_qtaguid.c
@@ -1694,14 +1694,13 @@ static struct sock *qtaguid_find_sk(const struct sk_buff *skb,
 		return NULL;
 	}
 
-	/*
-	 * Seems to be issues on the file ptr for TCP_TIME_WAIT SKs.
-	 * http://kerneltrap.org/mailarchive/linux-netdev/2010/10/21/6287959
-	 * Not fixed in 3.0-r3 :(
-	 */
 	if (sk) {
 		MT_DEBUG("qtaguid: %p->sk_proto=%u "
 			 "->sk_state=%d\n", sk, sk->sk_protocol, sk->sk_state);
+		/*
+		 * When in TCP_TIME_WAIT the sk is not a "struct sock" but
+		 * "struct inet_timewait_sock" which is missing fields.
+		 */
 		if (sk->sk_state  == TCP_TIME_WAIT) {
 			xt_socket_put_sk(sk);
 			sk = NULL;
@@ -1785,6 +1784,13 @@ static bool qtaguid_mt(const struct sk_buff *skb, struct xt_action_param *par)
 	}
 
 	sk = skb->sk;
+	/*
+	 * When in TCP_TIME_WAIT the sk is not a "struct sock" but
+	 * "struct inet_timewait_sock" which is missing fields.
+	 * So we ignore it.
+	 */
+	if (sk && sk->sk_state == TCP_TIME_WAIT)
+		sk = NULL;
 	if (sk == NULL) {
 		/*
 		 * A missing sk->sk_socket happens when packets are in-flight