[PATCH] ipv6: fix useless rol32 call on hash

From: Colin King
Date: Tue Jul 17 2018 - 12:12:49 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
---
include/net/ipv6.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 50eebccbf919..190015652168 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -843,7 +843,7 @@ static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
* 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;

--
2.17.1