Bluetooth: sco: fix information leak to userspace

commit c4c896e1 upstream.

struct sco_conninfo has one padding byte in the end.  Local variable
cinfo of type sco_conninfo is copied to userspace with this uninizialized
one byte, leading to old stack contents leak.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

net/bluetooth/sco.c

@@ -700,6 +700,7 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname, char __user
 			break;
 		}
 
+		memset(&cinfo, 0, sizeof(cinfo));
 		cinfo.hci_handle = sco_pi(sk)->conn->hcon->handle;
 		memcpy(cinfo.dev_class, sco_pi(sk)->conn->hcon->dev_class, 3);