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From:   Matthew Garrett <mjg59@google.com>
Date:   Fri, 8 Mar 2019 15:30:48 -0800
Message-ID: <CACdnJuvhPd2dD7cWkxP78YMMFKU3FsigLHgkDntwhnbamNZr-w@mail.gmail.com>
Subject: Re: [PATCH 03/27] Enforce module signatures if the kernel is locked down
To:     James Morris <jmorris@namei.org>
Cc:     LSM List <linux-security-module@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        David Howells <dhowells@redhat.com>
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On Fri, Mar 8, 2019 at 3:00 PM James Morris <jmorris@namei.org> wrote:
>
> On Wed, 6 Mar 2019, Matthew Garrett wrote:
>
> > From: David Howells <dhowells@redhat.com>
> >
> > If the kernel is locked down, require that all modules have valid
> > signatures that we can verify.
>
> Perhaps note that this won't cover the case where folk are using DM-Verity
> with a signed root hash for verifying kernel modules.

Mm. I can't see a terribly good way of doing this generically -
loadpin gives no indication to the module loading code that it comes
from a trusted source. Would making the lockdown/module signature
enforcement a separate config option be reasonable?