On Sun, Sep 06, 2009 at 05:17:34PM +0200, Felix Zielcke wrote:
> Am Sonntag, den 06.09.2009, 17:09 +0200 schrieb Robert Millan:
> > On Sun, Sep 06, 2009 at 04:58:40PM +0200, Felix Zielcke wrote:
> > >
> > > Ok here's now a patch.
> > > Robert do you think this can go into 1.97?
> >
> > For 1.97 I'd be more comfortable with a simple s/444/400/. An automated
> > check
> > smells like it could have corner cases. In fact I found one:
> >
> > > @@ -260,6 +260,11 @@ for i in ${grub_mkconfig_dir}/* ; do
> > > esac
> > > done
> > >
> > > +if [ "x${grub_cfg}" != "x" ] && grep -q "^password " ${grub_cfg}.new ;
> > > then
> > > + chmod 400 ${grub_cfg}.new || grub_warn "Could not make ${grub_cfg}.new
> > > readable by only root.\
> > > + This means your password is readable by everyone"
> > > +fi
> >
> > There's a short time window in which /boot/grub/grub.cfg.new exists, has
> > been
> > fully generated, and its mode is 444 rather than 400. An attacker could
> > poll
> > this file and with some luck extract a password from it.
> >
>
> Oh right. So how about this?
Ok.
--
Robert Millan
The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
how) you may access your data; but nobody's threatening your freedom: we
still allow you to remove your data and not access it at all."
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