Re: [patch 0/8] unprivileged mount syscall

Serge E. Hallyn
2007-04-11T14:26:08Z

Quoting Ian Kent (raven-PKsaG3nR2I+sTnJN9+BGXg@public.gmane.org):
> On Wed, 2007-04-11 at 12:48 +0200, Miklos Szeredi wrote:
> > > > >>
> > > > >> - users can use bind mounts without having to pre-configure them in
> > > > >> /etc/fstab
> > > > >>
> > > >
> > > > This is by far the biggest concern I see. I think the security
> > > > implication of allowing anyone to do bind mounts are poorly understood.
> > >
> > > And especially so since there is no way for a filesystem module to veto
> > > such requests.
> >
> > The filesystem can't veto initial mounts based on destination either.
> > I don't think it's up to the filesystem to police bind/move mounts in
> > any way.
>
> But if a filesystem can't or the developer thinks that it shouldn't for
> some reason, support bind/move mounts then there should be a way for the

Can you list some valid reasons why an fs could care where it is
mounted? The only thing I could think of is a stackable fs, but it
shouldn't care whether it is overlay-mounted or not.

thanks,
-serge

> filesystem to tell the kernel that.
>
> Surely a filesystem is in a good position to be able to decide if a
> mount request "for it" should be allowed to continue based on it's "own
> situation and capabilities".
>
> Ian
>
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html