From: Stefan Raspl <raspl@linux.ibm.com>
Subject: net/smc: fix shutdown in state SMC_LISTEN
Patch-mainline: v4.17-rc2
Git-commit: 1255fcb2a655f05e02f3a74675a6d6525f187afd
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: fix shutdown in state SMC_LISTEN

             Calling shutdown with SHUT_RD and SHUT_RDWR for a listening SMC socket
             crashes, because
                commit 127f49705823 ("net/smc: release clcsock from tcp_listen_worker")
             releases the internal clcsock in smc_close_active() and sets smc->clcsock
             to NULL.
             For SHUT_RD the smc_close_active() call is removed.
             For SHUT_RDWR the kernel_sock_shutdown() call is omitted, since the
             clcsock is already released.

             Fixes: 127f49705823 ("net/smc: release clcsock from tcp_listen_worker")
             Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
             Reported-by: Stephen Hemminger <stephen@networkplumber.org>
             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 |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1259,14 +1259,12 @@ static int smc_shutdown(struct socket *s
 		rc = smc_close_shutdown_write(smc);
 		break;
 	case SHUT_RD:
-		if (sk->sk_state == SMC_LISTEN)
-			rc = smc_close_active(smc);
-		else
-			rc = 0;
-			/* nothing more to do because peer is not involved */
+		rc = 0;
+		/* nothing more to do because peer is not involved */
 		break;
 	}
-	rc1 = kernel_sock_shutdown(smc->clcsock, how);
+	if (smc->clcsock)
+		rc1 = kernel_sock_shutdown(smc->clcsock, how);
 	/* map sock_shutdown_cmd constants to sk_shutdown value range */
 	sk->sk_shutdown |= how + 1;