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

From: Josh Poimboeuf
Date: Thu Jan 18 2018 - 12:03:04 EST


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?

--
Josh