From 58e007884a7bf7ad34552f266e7bb51cc9a7273b Mon Sep 17 00:00:00 2001
From: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Date: Thu, 28 Nov 2019 10:10:06 +0700
Subject: [PATCH] tipc: fix wrong socket reference counter after
 tipc_sk_timeout() returns

commit 91a4a3eb433e4d786420c41f3c08d1d16c605962 upstream.

When tipc_sk_timeout() is executed but user space is grabbing
ownership, this function rearms itself and returns. However, the
socket reference counter is not reduced. This causes potential
unexpected behavior.

This commit fixes it by calling sock_put() before tipc_sk_timeout()
returns in the above-mentioned case.

Fixes: afe8792fec69 ("tipc: refactor function tipc_sk_timeout()")
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/tipc/socket.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 069c6daa54c7..2d93bbd2a8ed 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2687,6 +2687,7 @@ static void tipc_sk_timeout(struct timer_list *t)
 	if (sock_owned_by_user(sk)) {
 		sk_reset_timer(sk, &sk->sk_timer, jiffies + HZ / 20);
 		bh_unlock_sock(sk);
+		sock_put(sk);
 		return;
 	}