Re: [CFT][PATCH 00/10] Making new mounts of proc and sysfs as safe as bind mounts (take 2)

[Greg Kroah-Hartman <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>]

On Wed, Jun 03, 2015 at 04:13:21PM -0500, Eric W. Biederman wrote:
> Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org> writes:
> 
> > One option would be to break the nosuid, nodev, and noexec parts into
> > their own patch and then avoid tagging that patch for -stable if at
> > all possible.  It would be nice to avoid another -stable ABI break if
> > at all possible.
> 
> So I don't think we actually have anything that could be called an ABI
> break in the whole mess, but it is definitely a behavioral change that
> is a regression for lxc and libvirt-lxc that prevents them from starting.
> 
> nodev does not actually matter because of the implicit silliness that
> is being added right now.
> 
> We do want those programs fixed and after those programs are fixed we
> can safely begin failing mount when those attributes are being cleared
> in a fresh mount.
> 
> So it looks to me like the best thing to do is to print a warning
> whenever lxc or libvirt-lxc gets it wrong, which should ensure the
> authors are sufficiently pestered that in a kernel release or 3 we can
> begin enforcing those attributes.  Especially as the discussion on the
> fix for those applications has already begun.

"pestering" never works, look at some of the SCSI drivers for examples
of how a distro will just patch out the "warning this driver is using an
old api and needs to be fixed" messages.

You can't break stuff like this, people will get upset :(

greg k-h