[PATCH 4.4 033/342] tcp: md5: release request socket instead of listener

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ Upstream commit 729235554d805c63e5e274fcc6a98e71015dd847 ]

If tcp_v4_inbound_md5_hash() returns an error, we must release
the refcount on the request socket, not on the listener.

The bug was added for IPv4 only.

Fixes: 079096f103fac ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/ipv4/tcp_ipv4.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1597,8 +1597,10 @@ process:
 		struct sock *nsk = NULL;
 
 		sk = req->rsk_listener;
-		if (tcp_v4_inbound_md5_hash(sk, skb))
-			goto discard_and_relse;
+		if (unlikely(tcp_v4_inbound_md5_hash(sk, skb))) {
+			reqsk_put(req);
+			goto discard_it;
+		}
 		if (likely(sk->sk_state == TCP_LISTEN)) {
 			nsk = tcp_check_req(sk, skb, req, false);
 		} else {