Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752657Ab3IHOkN (ORCPT ); Sun, 8 Sep 2013 10:40:13 -0400 Received: from mail-by2lp0238.outbound.protection.outlook.com ([207.46.163.238]:58371 "EHLO na01-by2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751720Ab3IHOkK (ORCPT ); Sun, 8 Sep 2013 10:40:10 -0400 From: Matthew Garrett To: Greg KH CC: "linux-kernel@vger.kernel.org" , "linux-efi@vger.kernel.org" , "keescook@chromium.org" , "hpa@zytor.com" Subject: Re: [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions Thread-Topic: [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions Thread-Index: AQHOqQBlTgRtcELUZ0K5HxHj5bQ8FZm7apqAgAALY9KAAHqeAA== Date: Sun, 8 Sep 2013 14:40:04 +0000 Message-ID: <1378651204.2300.7.camel@x230> References: <1378252218-18798-1-git-send-email-matthew.garrett@nebula.com> <1378252218-18798-9-git-send-email-matthew.garrett@nebula.com> <20130908064027.GA3587@kroah.com> <1378622648.2300.4.camel@x230> <20130908072408.GA5092@kroah.com> In-Reply-To: <20130908072408.GA5092@kroah.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [2001:470:1f07:1371:740c:5537:5f2f:efde] x-forefront-prvs: 09634B1196 x-forefront-antispam-report: SFV:NSPM;SFS:(24454002)(51704005)(189002)(199002)(377424004)(74876001)(80976001)(53806001)(56816003)(77096001)(19580395003)(19580405001)(83322001)(76482001)(54356001)(79102001)(77982001)(59766001)(83072001)(56776001)(54316002)(80022001)(63696002)(46102001)(81342001)(81816001)(65816001)(69226001)(74366001)(47446002)(74706001)(31966008)(74662001)(74502001)(50986001)(47976001)(47736001)(49866001)(4396001)(51856001)(81686001)(81542001)(76786001)(76796001)(33646001)(33716001)(3826001);DIR:OUT;SFP:;SCL:1;SRVR:BY2PR05MB221;H:BY2PR05MB222.namprd05.prod.outlook.com;CLIP:2001:470:1f07:1371:740c:5537:5f2f:efde;RD:InfoNoRecords;MX:1;A:1;LANG:en; Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-OriginatorOrg: nebula.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r88Eeilw015160 Content-Length: 625 Lines: 15 On Sun, 2013-09-08 at 00:24 -0700, Greg KH wrote: > On Sun, Sep 08, 2013 at 06:44:08AM +0000, Matthew Garrett wrote: > > At the most trivial level, grab the address of sig_enforce from > > kallsyms, jump to a kernel that doesn't enforce STRICT_DEVMEM, modify > > sig_enforce, jump back to the old kernel. > > Which proves what? sig_enforce can be set, but once it's set can't be unset. Why do you think that is? -- Matthew Garrett ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?