This is a permission issue. Are you sure WordPress isn’t running with the www user? I would try to make sure all your files have 77* or 66* access, instead of 74* and 65*. Also, make sure that you are running WordPress under the correct user. Now days, unless changed by web host, it is usually run under www by default.
After you are done updating/upgrading, be sure to return your permissions to normal. 😉