[PATCH 5.4 026/102] tipc: fix wrong socket reference counter after tipc_sk_timeout() returns

[Greg Kroah-Hartman]

From: Tung Nguyen <tung.q.nguyen@xxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxx>
Acked-by: Ying Xue <ying.xue@xxxxxxxxxxxxx>
Acked-by: Jon Maloy <jon.maloy@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/tipc/socket.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2687,6 +2687,7 @@ static void tipc_sk_timeout(struct timer
 	if (sock_owned_by_user(sk)) {
 		sk_reset_timer(sk, &sk->sk_timer, jiffies + HZ / 20);
 		bh_unlock_sock(sk);
+		sock_put(sk);
 		return;
 	}