linux-kernel - Re: [PATCH 04/30] Enforce module signatures if the kernel is locked down

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Date:   Thu, 22 Feb 2018 19:44:28 +0100
From:   Jiri Bohac <jbohac@...e.cz>
To:     David Howells <dhowells@...hat.com>
Cc:     linux-security-module@...r.kernel.org, jforbes@...hat.com,
        linux-efi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 04/30] Enforce module signatures if the kernel is locked
 down

On Thu, Feb 22, 2018 at 01:07:57PM +0000, David Howells wrote:
> I'm considering folding the attached changes into this patch.
> 
> It adjusts the errors generated:
> 
>  (1) If there's no signature (ENODATA) or we can't check it (ENOPKG, ENOKEY),
>      then:
> 
>      (a) If signatures are enforced then EKEYREJECTED is returned.
> 
>      (b) If IMA will have validated the image, return 0 (okay).
> 
>      (c) If there's no signature or we can't check it, but the kernel is
> 	 locked down then EPERM is returned (this is then consistent with
> 	 other lockdown cases).
> 
>  (2) If the signature is unparseable (EBADMSG, EINVAL), the signature fails
>      the check (EKEYREJECTED) or a system error occurs (eg. ENOMEM), we return
>      the error we got.
> 
> Note that the X.509 code doesn't check for key expiry as the RTC might not be
> valid or might not have been transferred to the kernel's clock yet.

Looks good. 

Reviewed-by: Jiri Bohac <jbohac@...e.cz>

-- 
Jiri Bohac <jbohac@...e.cz>
SUSE Labs, Prague, Czechia