ipv6: fix useless rol32 call on hash

BugLink: http://bugs.launchpad.net/bugs/1812229
[ Upstream commit 169dc027fb02492ea37a0575db6a658cf922b854 ]

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 3d7e06bf9f7a1b4f0b827057e1178195d9f38189..e8e0408f5df54ae5342108e91c1737b4ec92f05c 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -835,7 +835,7 @@ 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;