net: ax25: fix information leak to userland harder

Commit fe10ae53384e48c51996941b7720ee16995cbcb7 adds a memset() to clear
the structure being sent back to userspace, but accidentally used the
wrong size.

Reported-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index bb86d29..6da5dae 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1392,7 +1392,7 @@
 	ax25_cb *ax25;
 	int err = 0;
 
-	memset(fsa, 0, sizeof(fsa));
+	memset(fsa, 0, sizeof(*fsa));
 	lock_sock(sk);
 	ax25 = ax25_sk(sk);