From: Colin Ian King <colin.king@canonical.com>
Date: Tue, 17 Jul 2018 17:12:39 +0100
Subject: ipv6: fix useless rol32 call on hash
Git-commit: 169dc027fb02492ea37a0575db6a658cf922b854
Patch-mainline: v4.18-rc6
References: netfilter-stable-18_07_23

The rol32 call is currently rotating hash but the rol'd value is
being discarded. I believe the current code is incorrect and hash
should be assigned the rotated value returned from rol32.

Thanks to David Lebrun for spotting this.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 include/net/ipv6.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -794,7 +794,7 @@ static inline __be32 ip6_make_flowlabel(
 	 * to minimize possbility that any useful information to an
 	 * attacker is leaked. Only lower 20 bits are relevant.
 	 */
-	rol32(hash, 16);
+	hash = rol32(hash, 16);
 
 	flowlabel = (__force __be32)hash & IPV6_FLOWLABEL_MASK;