net/smc: keep clcsock reference in smc_tcp_listen_work()

The internal CLC socket should exist till the SMC-socket is released.
Function tcp_listen_worker() releases the internal CLC socket of a
listen socket, if an smc_close_active() is called. This function
is called for the final release(), but it is called for shutdown
SHUT_RDWR as well. This opens a door for protection faults, if
socket calls using the internal CLC socket are called for a
shutdown listen socket.

With the changes of
commit 3d50206 ("net/smc: simplify wait when closing listen socket")
there is no need anymore to release the internal CLC socket in
function tcp_listen_worker((). It is sufficient to release it in
smc_release().

Fixes: 127f497 ("net/smc: release clcsock from tcp_listen_worker")
Signed-off-by: Ursula Braun <[email protected]>
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Reported-by: [email protected]
Signed-off-by: David S. Miller <[email protected]>

net/smc/af_smc.c

@@ -978,10 +978,6 @@ static void smc_tcp_listen_work(struct work_struct *work)
 	}
 
 out:
-	if (lsmc->clcsock) {
-		sock_release(lsmc->clcsock);
-		lsmc->clcsock = NULL;
-	}
 	release_sock(lsk);
 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
 }