From: Stefan Raspl <raspl@linux.ibm.com>
Subject: net/smc: add error handling for get_user()
Patch-mainline: v4.18-rc6
Git-commit: ac0107edba253a6e58e923f9e68825decef3e681
References: FATE#325698, LTC#167867, bsc#1113481

Description:  smc: Latest upstream fixes and extensions up to 8/17/2018

Upstream-Description:

              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>

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 net/smc/af_smc.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1458,7 +1458,8 @@ static int smc_setsockopt(struct socket
 
 	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) {