linux-kernel - Re: [PATCH 1/3] module: Invalidate signatures on force-loaded modules

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Message-ID: <87pota4ngf.fsf@rustcorp.com.au>
Date:	Thu, 28 Apr 2016 09:24:40 +0930
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	Ben Hutchings <ben@...adent.org.uk>
Cc:	David Howells <dhowells@...hat.com>,
	David Woodhouse <dwmw2@...radead.org>,
	keyrings@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] module: Invalidate signatures on force-loaded modules

Ben Hutchings <ben@...adent.org.uk> writes:
> On Tue, 2016-04-26 at 20:07 +0930, Rusty Russell wrote:
>> Ben Hutchings <ben@...adent.org.uk> writes:
>> > -	if (info->len > markerlen &&
>> > +	/*
>> > +	 * Require flags == 0, as a module with version information
>> > +	 * removed is no longer the module that was signed
>> > +	 */
>> > +	if (flags == 0 &&
>> This check is a bit lazy.  We could have other flags in future,
>> so this should really be !(flags &
>> (MODULE_INIT_IGNORE_MODVERSIONS|MODULE_INIT_IGNORE_VERMAGIC) right?
>
> Yes we could, but I'd prefer this to fail-safe in case no-one thinks
> about whether it should be updated then.

Yeah, line ball.  We could screw up either way, and I can't think of
an reasonable new flag off the top of my head to give a concrete
example.

I've applied all three, thanks!
Rusty.