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.
--
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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