From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from e8.ny.us.ibm.com ([32.97.182.138]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UIQI8-00038h-Dn for kexec@lists.infradead.org; Wed, 20 Mar 2013 21:11:25 +0000 Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 20 Mar 2013 17:11:23 -0400 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id CCD6FC9001A for ; Wed, 20 Mar 2013 17:11:19 -0400 (EDT) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r2KLBJTV306568 for ; Wed, 20 Mar 2013 17:11:19 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r2KLBIDF019053 for ; Wed, 20 Mar 2013 18:11:18 -0300 Message-ID: <1363813877.2580.120.camel@falcor1.watson.ibm.com> Subject: Re: [PATCH 01/12] Security: Add CAP_COMPROMISE_KERNEL From: Mimi Zohar Date: Wed, 20 Mar 2013 17:11:17 -0400 In-Reply-To: <1363811856.2553.37.camel@x230.sbx07502.somerma.wayport.net> References: <1363642353-30749-1-git-send-email-matthew.garrett@nebula.com> <1363797717.2580.10.camel@falcor1.watson.ibm.com> <1363798166.2553.29.camel@x230.sbx07502.somerma.wayport.net> <1363802506.2580.55.camel@falcor1.watson.ibm.com> <1363803158.2553.33.camel@x230.sbx07502.somerma.wayport.net> <1363806968.2580.86.camel@falcor1.watson.ibm.com> <1363811856.2553.37.camel@x230.sbx07502.somerma.wayport.net> Mime-Version: 1.0 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: Matthew Garrett Cc: "linux-efi@vger.kernel.org" , "linux-pci@vger.kernel.org" , "kexec@lists.infradead.org" , James Morris , "linux-kernel@vger.kernel.org" , "linux-security-module@vger.kernel.org" , "Serge E. Hallyn" On Wed, 2013-03-20 at 20:37 +0000, Matthew Garrett wrote: > On Wed, 2013-03-20 at 15:16 -0400, Mimi Zohar wrote: > > On Wed, 2013-03-20 at 18:12 +0000, Matthew Garrett wrote: > > > Well, in the absence of hardcoded in-kernel policy, there needs to be > > > some mechanism for ensuring the integrity of a policy. Shipping a signed > > > policy initramfs fragment and having any Secure Boot bootloaders pass a > > > flag in bootparams indicating that the kernel should panic if that > > > fragment isn't present would seem to be the easiest way of doing that. > > > Or have I misunderstood the question? > > > > Ok, I was confused by the term "fragmented" initramfs. So once you have > > verified the "early" fragmented initramfs signature, this initramfs will > > load the "trusted" public keys and could also load the MAC policy. (I > > realize that dracut is currently loading the MAC policy, not the > > initramfs.) The MAC policy would then be trusted, right? Could we then > > use the LSM labels for defining an integrity policy for kexec? > > Right, that'd be the rough idea. Any further runtime policy updates > would presumably need to be signed with a trusted key. I'm really sorry to belabor this point, but can kexec rely on an LSM label to identify a specific file, out of all the files being executed, in a secure boot environment? The SELinux integrity rule for kexec would then look something like, appraise func=BPRM_CHECK obj_type=kdump_exec_t appraise_type=imasig We could then follow this up with Serge's idea of, "a capset akin to the bounding set, saying you can only have the caps in this set if the running binary was a signed one." kexec already requires CAP_SYS_BOOT. thanks, Mimi _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec