Re: [patch V2 1/2] sysfs/cpu: Add vulnerability folder

[Greg Kroah-Hartman]

On Fri, Jan 26, 2018 at 05:23:31PM +0100, Andrea Arcangeli wrote:
> Hello,
> 
> On Sun, Jan 07, 2018 at 10:48:00PM +0100, Thomas Gleixner wrote:
> > +static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
> > +static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
> > +static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
> 
> This sysfs feature implemented as above is weakening kernel security,
> it should be 0400 above.

See the patch from Jason A. Donenfeld <Jason@xxxxxxxxx> to do just that:
	Subject: [PATCH] cpu: do not leak vulnerabilities to unprivileged users
	Message-Id: <20180125120401.30596-1-Jason@xxxxxxxxx>

I'll be queueing it up for 4.16-rc1 and backport it everywhere.

thanks,

greg k-h