Bluetooth: SMP: Fail if remote and local public keys are identical

stable inclusion
from linux-4.19.192
commit 30126d4ba73119565f1748b116b9869ac6bbda6b
CVE: CVE-2021-0129

--------------------------------

commit 6d19628f539fccf899298ff02ee4c73e4bf6df3f upstream.

This fails the pairing procedure when both remote and local non-debug
public keys are identical.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>