TLS: Fix length check in do_tls_getsockopt_tx()

copy_to_user() copies the struct the pointer is pointing to, but the
length check compares against sizeof(pointer) and not sizeof(struct).
On 32-bit the size is probably the same, so it might have worked
accidentally.
Signed-off-by: Matthias Rosenfelder <mrosenfelder.lkml@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tls/tls_main.c

@@ -272,7 +272,7 @@ static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
 		goto out;
 	}
 
-	if (len == sizeof(crypto_info)) {
+	if (len == sizeof(*crypto_info)) {
 		if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
 			rc = -EFAULT;
 		goto out;