Re: [tip:x86/pti] module: Add retpoline tag to VERMAGIC

From: Thomas Gleixner
Date: Thu Jan 18 2018 - 12:40:03 EST


On Thu, 18 Jan 2018, Josh Poimboeuf wrote:

> On Wed, Jan 17, 2018 at 02:40:43AM -0800, tip-bot for Andi Kleen wrote:
> > Commit-ID: 6cfb521ac0d5b97470883ff9b7facae264b7ab12
> > Gitweb: https://git.kernel.org/tip/6cfb521ac0d5b97470883ff9b7facae264b7ab12
> > Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> > AuthorDate: Tue, 16 Jan 2018 12:52:28 -0800
> > Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > CommitDate: Wed, 17 Jan 2018 11:35:14 +0100
> >
> > module: Add retpoline tag to VERMAGIC
> >
> > Add a marker for retpoline to the module VERMAGIC. This catches the case
> > when a non RETPOLINE compiled module gets loaded into a retpoline kernel,
> > making it insecure.
> >
> > It doesn't handle the case when retpoline has been runtime disabled. Even
> > in this case the match of the retcompile status will be enforced. This
> > implies that even with retpoline run time disabled all modules loaded need
> > to be recompiled.
>
> If the user overrides the vermagic and loads the module, shouldn't we
> update the spectre_v2 sysfs vulnerability status and print a warning
> like in v2?

If the user does that then the sysfs output is not our problem anymore,
really.

Thanks,

tglx