> On Jun 5, 2018, at 4:28 PM, David Sterba <dste...@suse.cz> wrote: > >> BTW, sys_umount() has this check in the right place - before doing anything. >> So, why not to have the same logic for mount/umount? > > What if the check is not equivalent to the one done later? may_mount > needs namespace, it will be available at umount time but not necessarily > during mount due to the security hooks.
Might be the issue, you’re right. I can’t tell it for sure as I’m not so familiar with linux/fs code.