Re: kexec_load(2) bypasses signature verification

From: Dave Young <dyoung@redhat.com>
To: "Theodore Ts'o" <tytso@mit.edu>,
	Josh Boyer <jwboyer@fedoraproject.org>,
	Eric Biederman <ebiederm@xmission.com>,
	David Howells <dhowells@redhat.com>,
	kexec <kexec@lists.infradead.org>,
	"Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>
Subject: Re: kexec_load(2) bypasses signature verification
Date: Thu, 18 Jun 2015 09:25:36 +0800	[thread overview]
Message-ID: <20150618012536.GC8718@dhcp-128-32.nay.redhat.com> (raw)
In-Reply-To: <20150615200115.GG5003@thunk.org>

On 06/15/15 at 04:01pm, Theodore Ts'o wrote:
> On Mon, Jun 15, 2015 at 09:37:05AM -0400, Josh Boyer wrote:
> > The bits that actually read Secure Boot state out of the UEFI
> > variables, and apply protections to the machine to avoid compromise
> > under the SB threat model.  Things like disabling the old kexec...
> 
> I don't have any real interest in using Secure Boot, but I *am*
> interested in using CONFIG_KEXEC_VERIFY_SIG[1].  So perhaps we need to
> have something similar to what we have with signed modules in terms of
> CONFIG_MODULE_SIG_FORCE and module/sig_enforce, but for
> KEXEC_VERIFY_SIG.  This would mean creating a separate flag
> independent of the one Linus suggested for Secure Boot, but since we
> have one for signed modules, we do have precedent for this sort of
> thing.

Agree and vote for this way as I replied in another email about
CONFIG_KEXEC_VERIFY_SIG_FORCE.

Thanks
Dave