From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753027AbdDGDHV (ORCPT ); Thu, 6 Apr 2017 23:07:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46240 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752078AbdDGDHO (ORCPT ); Thu, 6 Apr 2017 23:07:14 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 4649580F99 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dyoung@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 4649580F99 Date: Fri, 7 Apr 2017 11:07:05 +0800 From: Dave Young To: David Howells Cc: linux-kernel@vger.kernel.org, matthew.garrett@nebula.com, linux-efi@vger.kernel.org, gnomes@lxorguk.ukuu.org.uk, gregkh@linuxfoundation.org, kexec@lists.infradead.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org Subject: Re: [PATCH 07/24] kexec: Disable at runtime if the kernel is locked down Message-ID: <20170407030705.GB4296@dhcp-128-65.nay.redhat.com> References: <149142326734.5101.4596394505987813763.stgit@warthog.procyon.org.uk> <149142333752.5101.12956279967668146884.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <149142333752.5101.12956279967668146884.stgit@warthog.procyon.org.uk> User-Agent: Mutt/1.7.1 (2016-10-04) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 07 Apr 2017 03:07:14 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/05/17 at 09:15pm, David Howells wrote: > From: Matthew Garrett > > kexec permits the loading and execution of arbitrary code in ring 0, which > is something that lock-down is meant to prevent. It makes sense to disable > kexec in this situation. > > This does not affect kexec_file_load() which can check for a signature on the > image to be booted. > > Signed-off-by: Matthew Garrett > Signed-off-by: David Howells > cc: kexec@lists.infradead.org > --- > > kernel/kexec.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/kernel/kexec.c b/kernel/kexec.c > index 980936a90ee6..46de8e6b42f4 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -194,6 +194,13 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, > return -EPERM; > > /* > + * kexec can be used to circumvent module loading restrictions, so > + * prevent loading in that case > + */ > + if (kernel_is_locked_down()) > + return -EPERM; > + > + /* > * Verify we have a legal set of flags > * This leaves us room for future extensions. > */ > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec Acked-by: Dave Young Thanks Dave From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Young Subject: Re: [PATCH 07/24] kexec: Disable at runtime if the kernel is locked down Date: Fri, 7 Apr 2017 11:07:05 +0800 Message-ID: <20170407030705.GB4296@dhcp-128-65.nay.redhat.com> References: <149142326734.5101.4596394505987813763.stgit@warthog.procyon.org.uk> <149142333752.5101.12956279967668146884.stgit@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <149142333752.5101.12956279967668146884.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: David Howells Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, matthew.garrett-05XSO3Yj/JvQT0dZR+AlfA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, gnomes-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, keyrings-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-efi@vger.kernel.org On 04/05/17 at 09:15pm, David Howells wrote: > From: Matthew Garrett > > kexec permits the loading and execution of arbitrary code in ring 0, which > is something that lock-down is meant to prevent. It makes sense to disable > kexec in this situation. > > This does not affect kexec_file_load() which can check for a signature on the > image to be booted. > > Signed-off-by: Matthew Garrett > Signed-off-by: David Howells > cc: kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org > --- > > kernel/kexec.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/kernel/kexec.c b/kernel/kexec.c > index 980936a90ee6..46de8e6b42f4 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -194,6 +194,13 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, > return -EPERM; > > /* > + * kexec can be used to circumvent module loading restrictions, so > + * prevent loading in that case > + */ > + if (kernel_is_locked_down()) > + return -EPERM; > + > + /* > * Verify we have a legal set of flags > * This leaves us room for future extensions. > */ > > > _______________________________________________ > kexec mailing list > kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org > http://lists.infradead.org/mailman/listinfo/kexec Acked-by: Dave Young Thanks Dave From mboxrd@z Thu Jan 1 00:00:00 1970 From: dyoung@redhat.com (Dave Young) Date: Fri, 7 Apr 2017 11:07:05 +0800 Subject: [PATCH 07/24] kexec: Disable at runtime if the kernel is locked down In-Reply-To: <149142333752.5101.12956279967668146884.stgit@warthog.procyon.org.uk> References: <149142326734.5101.4596394505987813763.stgit@warthog.procyon.org.uk> <149142333752.5101.12956279967668146884.stgit@warthog.procyon.org.uk> Message-ID: <20170407030705.GB4296@dhcp-128-65.nay.redhat.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org On 04/05/17 at 09:15pm, David Howells wrote: > From: Matthew Garrett > > kexec permits the loading and execution of arbitrary code in ring 0, which > is something that lock-down is meant to prevent. It makes sense to disable > kexec in this situation. > > This does not affect kexec_file_load() which can check for a signature on the > image to be booted. > > Signed-off-by: Matthew Garrett > Signed-off-by: David Howells > cc: kexec at lists.infradead.org > --- > > kernel/kexec.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/kernel/kexec.c b/kernel/kexec.c > index 980936a90ee6..46de8e6b42f4 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -194,6 +194,13 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, > return -EPERM; > > /* > + * kexec can be used to circumvent module loading restrictions, so > + * prevent loading in that case > + */ > + if (kernel_is_locked_down()) > + return -EPERM; > + > + /* > * Verify we have a legal set of flags > * This leaves us room for future extensions. > */ > > > _______________________________________________ > kexec mailing list > kexec at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec Acked-by: Dave Young Thanks Dave -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1cwKFh-0005OW-Fd for kexec@lists.infradead.org; Fri, 07 Apr 2017 03:07:58 +0000 Date: Fri, 7 Apr 2017 11:07:05 +0800 From: Dave Young Subject: Re: [PATCH 07/24] kexec: Disable at runtime if the kernel is locked down Message-ID: <20170407030705.GB4296@dhcp-128-65.nay.redhat.com> References: <149142326734.5101.4596394505987813763.stgit@warthog.procyon.org.uk> <149142333752.5101.12956279967668146884.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <149142333752.5101.12956279967668146884.stgit@warthog.procyon.org.uk> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: David Howells Cc: matthew.garrett@nebula.com, linux-efi@vger.kernel.org, gnomes@lxorguk.ukuu.org.uk, gregkh@linuxfoundation.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org On 04/05/17 at 09:15pm, David Howells wrote: > From: Matthew Garrett > > kexec permits the loading and execution of arbitrary code in ring 0, which > is something that lock-down is meant to prevent. It makes sense to disable > kexec in this situation. > > This does not affect kexec_file_load() which can check for a signature on the > image to be booted. > > Signed-off-by: Matthew Garrett > Signed-off-by: David Howells > cc: kexec@lists.infradead.org > --- > > kernel/kexec.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/kernel/kexec.c b/kernel/kexec.c > index 980936a90ee6..46de8e6b42f4 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -194,6 +194,13 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, > return -EPERM; > > /* > + * kexec can be used to circumvent module loading restrictions, so > + * prevent loading in that case > + */ > + if (kernel_is_locked_down()) > + return -EPERM; > + > + /* > * Verify we have a legal set of flags > * This leaves us room for future extensions. > */ > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec Acked-by: Dave Young Thanks Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec