linux-kernel - Re: Allow automatic kernel taint on unsigned module load to be disabled

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Message-ID: <CACdnJutWdHi5YOG1Mn0vZwTmZyQHyyABeZ0caNn2rJCYehCGhg@mail.gmail.com>
Date:   Tue, 29 Aug 2017 13:22:59 -0700
From:   Matthew Garrett <mjg59@...gle.com>
To:     Jessica Yu <jeyu@...nel.org>
Cc:     linux-kernel@...r.kernel.org,
        Rusty Russell <rusty@...tcorp.com.au>, ben@...adent.org.uk
Subject: Re: Allow automatic kernel taint on unsigned module load to be disabled

On Tue, Aug 29, 2017 at 10:56 AM, Jessica Yu <jeyu@...nel.org> wrote:
> I understand what the patch is doing, what I don't yet understand is
> _why_ you would want to remove the unsigned module taint when
> CONFIG_MODULE_SIG is enabled. Which distributions are asking for this
> exactly, and for what use cases? I find it a bit contradictory to have
> CONFIG_MODULE_SIG enabled and at the same time expect the kernel to
> behave as if the option wasn't enabled.

Debian disable CONFIG_MODULE_SIG because of this additional taint
(I've Cc:ed Ben who made this change).

> I would really prefer not to add extra code to remove what is cosmetic
> and still has informational/debug value. If the unsigned module taint
> is for whatever reason that bothersome, why can't distro(s) carry a
> 2-line patch removing the message and taint for those particular
> setups where signatures are considered "irrelevant" even with
> CONFIG_MODULE_SIG=y?

If it's functionality that distributions want to patch out, it makes
sense to provide them with a config option rather than forcing them to
maintain a patch separately.