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 filesystem in question. > But having it in there isn't wrong. In procfs permission/eligibility > checks often are checked as close to the open as possible. Worst case > it's something similar here. But it's certainly wrong to splat about it. Bury it.
