linux-kernel - Re: MODSIGN: Modules fail signature verification with -ENOKEY

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Date:	Sat, 12 Jan 2013 08:08:15 -0500
From:	Josh Boyer <jwboyer@...il.com>
To:	Chris Samuel <chris@...muel.org>
Cc:	linux-kernel@...r.kernel.org,
	Rusty Russell <rusty@...tcorp.com.au>, dhowells@...hat.com
Subject: Re: MODSIGN: Modules fail signature verification with -ENOKEY

On Sat, Jan 12, 2013 at 1:28 AM, Chris Samuel <chris@...muel.org> wrote:
> /* Please CC, not on LKML */
>
> Hi Josh,
>
>
> On 12/01/13 00:44, Josh Boyer wrote:
>
>> Check the installed modules.  A simple:
>>
>>      hexdump -C <path to module> | tail -n 20
>>
>> should be enough to tell you if the installed modules at least look like
>> they're signed.  You should see the expected "~Module signature appended~"
>> string.  You could also check the modules in the kernel build tree for
>> the same thing. [...]
>
>
> Good call - neither the modules in the build tree, nor the installed ones
> are signed.   I did a "make mrproper", changed scripts/sign-file to be
> verbose by default and rebuilt.  That confirmed that the modules are getting
> signed, which left the possibility of make-kpkg stripping the modules after
> compiling as an option.

Having worked through 3 different versions of the module signing code, I
forgot that they aren't signed until you do modules_install now.  So the
modules in the build tree won't be signed.  I misspoke on that.  The
installed modules still should be.

> Google pointed me at the likely culprit, a patch from a certain Mr Ted Ts'o
> in 2009 to make-kpkg so that it would strip kernel modules by default.
>
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=517290
>
> I'll file a bug against it asking for the it to not strip if
> CONFIG_MODULE_SIG is set.
>
> Thanks for the pointer!

Great.  Glad you figured it out.

josh
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