From: Stefan Raspl <raspl@linux.ibm.com>
Subject: net/smc: keep clcsock reference in smc_tcp_listen_work()
Patch-mainline: v4.17-rc4
Git-commit: 070204a34884110ac5e19c1e2e036fcfd033f8e3
References: FATE#325694, LTC#167874, bsc#1113480

Summary:     net/smc: SMC-R MVP
Description: Add latest upstream patches to push SMC-R to the MVP level

Upstream-Description:

             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 3d502067599f ("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: 127f49705823 ("net/smc: release clcsock from tcp_listen_worker")
             Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
             Reported-by: syzbot+9045fc589fcd196ef522@syzkaller.appspotmail.com
             Reported-by: syzbot+28a2c86cf19c81d871fa@syzkaller.appspotmail.com
             Reported-by: syzbot+9605e6cace1b5efd4a0a@syzkaller.appspotmail.com
             Reported-by: syzbot+cf9012c597c8379d535c@syzkaller.appspotmail.com
             Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 net/smc/af_smc.c |    4 ----
 1 file changed, 4 deletions(-)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -978,10 +978,6 @@ static void smc_tcp_listen_work(struct w
 	}
 
 out:
-	if (lsmc->clcsock) {
-		sock_release(lsmc->clcsock);
-		lsmc->clcsock = NULL;
-	}
 	release_sock(lsk);
 	sock_put(&lsmc->sk); /* sock_hold in smc_listen */
 }