commit 67c5c6cb upstream.

struct aunhdr has 4 padding bytes between 'pad' and 'handle' fields on
x86_64.  These bytes are not initialized in the variable 'ah' before
sending 'ah' to the network.  This leads to 4 bytes kernel stack
infoleak.

This bug was introduced before the git epoch.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Phil Blundell <philb@gnu.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>