Re: [patch 2/8] allow unprivileged umount

Andrew Morton
2007-04-21T08:37:45Z

On Sat, 21 Apr 2007 10:09:42 +0200 Miklos Szeredi <miklos@szeredi.hu> wrote:

> > > +static bool permit_umount(struct vfsmount *mnt, int flags)
> > > +{
> > >
> > > ...
> > >
> > > + return mnt->mnt_uid == current->uid;
> > > +}
> >
> > Yes, this seems very wrong. I'd have thought that comparing user_struct*'s
> > would get us a heck of a lot closer to being able to support aliasing of
> > UIDs between different namespaces.
> >
>
> OK, I'll fix this up.
>
> Actually an earlier version of this patch did use user_struct's but
> I'd changed it to uids, because it's simpler.

OK..

> I didn't think about
> this being contrary to the id namespaces thing.

Well I was madly assuming that when serarate UID namespaces are in use, UID
42 in container A will have a different user_struct from UID 42 in
container B. I'd suggest that we provoke an opinion from Eric & co before
you do work on this.