On Tue, Aug 06, 2024 at 12:38:04AM +0100, Al Viro wrote:
> On Mon, Aug 05, 2024 at 05:35:35PM +0200, Christian Brauner wrote:
> > > To my reading that path_noexec is still there only for debug, not
> > > because of any security need.
> >
> > I don't think it's there for debug. I think that WARN_ON_ONCE() is based
> > on the assumption that the mount properties can't change. IOW, someone
> > must've thought that somehow stable mount properties are guaranteed
> > after may_open() irrespective of how the file was opened. And in that
> > sense they thought they might actually catch a bug.
>
> That would be a neat trick, seeing that there'd never been anything to
> prevent mount -o remount,exec while something is executed on the
noexec, obviously...
