Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753647Ab3FGDDJ (ORCPT ); Thu, 6 Jun 2013 23:03:09 -0400 Received: from ozlabs.org ([203.10.76.45]:42489 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751686Ab3FGDDF (ORCPT ); Thu, 6 Jun 2013 23:03:05 -0400 From: Rusty Russell To: Alexander Holler , Alexander Holler Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, Herbert Xu , "David S. Miller" , David Howells , Josh Boyer , David Woodhouse Subject: Re: [PATCH RESEND/V2] crypto: Ignore validity dates of X.509 certificates at loading/parsing time In-Reply-To: <51B06FC3.8090405@ahsoftware.de> References: <1364409710-6458-1-git-send-email-holler@ahsoftware.de> <1367503746-6431-1-git-send-email-holler@ahsoftware.de> <51B06FC3.8090405@ahsoftware.de> User-Agent: Notmuch/0.15.2+81~gd2c8818 (http://notmuchmail.org) Emacs/23.4.1 (i686-pc-linux-gnu) Date: Fri, 07 Jun 2013 11:43:41 +0930 Message-ID: <87d2ryr7l6.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1647 Lines: 45 Alexander Holler writes: > Am 02.05.2013 16:09, schrieb Alexander Holler: >> I don't see any real use case where checking the validity dates of X.509 >> certificates at parsing time adds any security gain. In contrast, doing so >> makes MODSIGN unusable on systems without a RTC (or systems with a possible >> wrong date in a existing RTC, or systems where the RTC is read after the keys >> got loaded). >> >> If something really cares about the dates, it should check them at the time >> when the certificates are used, not when they are loaded and parsed. >> >> So just remove the validity check of the dates in the parser. >> >> Signed-off-by: Alexander Holler >> Cc: stable@vger.kernel.org > > As it just happened to me again and I've recently posted some patches > which do make it possible to experience the problem on x86 systems too, > here is a reminder. > > To replay the problem (on x86 or any other arch), apply the 3 patches in > this series: > > https://lkml.org/lkml/2013/6/5/430 > > build a kernel with CONFIG_MODULE_SIG_FORCE=y and start that kernel with > hctosys=none as kernel command line parameter. > > This will disable the "persistent" clock (and any RTC), thus the kernel > will refuse to load modules because it doesn't has a valid time when > loading the certificate. > > Regards, > > Alexander Holler David? Thanks, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/