From ac0107edba253a6e58e923f9e68825decef3e681 Mon Sep 17 00:00:00 2001
From: Ursula Braun <ursula.braun@linux.ibm.com>
Date: Wed, 18 Jul 2018 15:22:50 +0200
Subject: [PATCH] net/smc: add error handling for get_user()

For security reasons the return code of get_user() should always be
checked.

Fixes: 01d2f7e2cdd31 ("net/smc: sockopts TCP_NODELAY and TCP_CORK")
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/smc/af_smc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index c12a7fc..6e54790 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1456,7 +1456,8 @@ static int smc_setsockopt(struct socket *sock, int level, int optname,
 
 	if (optlen < sizeof(int))
 		return -EINVAL;
-	get_user(val, (int __user *)optval);
+	if (get_user(val, (int __user *)optval))
+		return -EFAULT;
 
 	lock_sock(sk);
 	switch (optname) {
-- 
2.7.4