From: Jarkko Sakkinen <jarkko@kernel.org>
To: Stefan Berger <stefanb@linux.ibm.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>,
keyrings@vger.kernel.org, dhowells@redhat.com,
nayna@linux.ibm.com, linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] Add support for ECDSA-signed kernel modules
Date: Wed, 7 Apr 2021 23:15:38 +0300 [thread overview]
Message-ID: <YG4S6qQ+vzXK6na9@kernel.org> (raw)
In-Reply-To: <70f7b2a4-ec3c-3da0-bcb6-7c96f391c1c1@linux.ibm.com>
On Wed, Apr 07, 2021 at 01:53:24PM -0400, Stefan Berger wrote:
>
> On 4/7/21 12:10 PM, Mimi Zohar wrote:
> > On Wed, 2021-04-07 at 18:53 +0300, Jarkko Sakkinen wrote:
> > > On Tue, Apr 06, 2021 at 02:53:38PM -0400, Stefan Berger wrote:
> > > > This series adds support for ECDSA-signed kernel modules.
> > > >
> > > > The first patch in this series attempts to address the issue where a
> > > > developer created an ECDSA key for signing modules and then falls back
> > > > to compiling an older version of the kernel that does not support
> > > > ECDSA keys. In this case this patch would delete that ECDSA key if it is
> > > > in certs/signing_key.pem and trigger the creation of an RSA key. However,
> > > > for this to work this patch would have to be applied to previous versions
> > > > of the kernel but would also only work for the developer if he/she used a
> > > > stable version of the kernel to which this patch was applied. So whether
> > > > this patch actually achieves the wanted effect is not always guaranteed.
> > > Just wondering why the key needs to be removed in the fallback.
> Because if you signed an older kernel's modules with the ECDSA key it won't
> be able to load the modules...
> > The main concern is with bisecting the kernel. Either elliptic curve
> > support or the first patch needs to be backported. This patch will
> > cause the kernel module signing key to be regenerated.
>
>
> This assumes of course that one will bisect via the stable kernels where
> this 1st patch has been applied. Not sure whether that's what people will
> do.
In any case, sounds non-trivial issue enough ought to be documented in the
commit message.
/Jarkko
prev parent reply other threads:[~2021-04-07 20:15 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-06 18:53 [PATCH 0/2] Add support for ECDSA-signed kernel modules Stefan Berger
2021-04-06 18:53 ` [PATCH 1/2] certs: Trigger recreation of module signing key if it's not an RSA key Stefan Berger
2021-04-06 18:53 ` [PATCH 2/2] certs: Add support for using elliptic curve keys for signing modules Stefan Berger
2021-04-07 15:53 ` [PATCH 0/2] Add support for ECDSA-signed kernel modules Jarkko Sakkinen
2021-04-07 16:10 ` Mimi Zohar
2021-04-07 17:53 ` Stefan Berger
2021-04-07 20:15 ` Jarkko Sakkinen [this message]
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