From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756935Ab3IHQZG (ORCPT ); Sun, 8 Sep 2013 12:25:06 -0400 Received: from mail-bl2lp0211.outbound.protection.outlook.com ([207.46.163.211]:16776 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753804Ab3IHQZE (ORCPT ); Sun, 8 Sep 2013 12:25:04 -0400 From: Matthew Garrett To: Greg KH CC: Kees Cook , "linux-kernel@vger.kernel.org" , "linux-efi@vger.kernel.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: AQHOqQBlTgRtcELUZ0K5HxHj5bQ8FZm7apqAgAALY9KAAI6QgIAAB7GAgAABn4A= Date: Sun, 8 Sep 2013 16:24:47 +0000 Message-ID: <1378657487.2300.10.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> <20130908161859.GA18946@kroah.com> In-Reply-To: <20130908161859.GA18946@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)(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:BY2PR05MB222;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 r88GPPdv015455 On Sun, 2013-09-08 at 09:18 -0700, Greg KH wrote: > I want both, but I don't need signed kexec support because I want to use > kexec for a program that I "know" is correct because I validated the > disk image it was on before I mounted it. We already have other ways to > "verify" things without having to add individual verification of > specific pieces. The kernel has no way to know that your kexec payload is coming from a verified image. It'll just as happily take something from an unverified image. If you've ensured that there's no way an attacker can call kexec_load() on an unverified image, then you don't need signed modules. -- Matthew Garrett {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH V3 08/11] kexec: Disable at runtime if the kernel enforces module loading restrictions Date: Sun, 8 Sep 2013 16:24:47 +0000 Message-ID: <1378657487.2300.10.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> <20130908161859.GA18946@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20130908161859.GA18946-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org> Content-Language: en-US Content-ID: Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Greg KH Cc: Kees Cook , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org" List-Id: linux-efi@vger.kernel.org T24gU3VuLCAyMDEzLTA5LTA4IGF0IDA5OjE4IC0wNzAwLCBHcmVnIEtIIHdyb3RlOg0KDQo+IEkg d2FudCBib3RoLCBidXQgSSBkb24ndCBuZWVkIHNpZ25lZCBrZXhlYyBzdXBwb3J0IGJlY2F1c2Ug SSB3YW50IHRvIHVzZQ0KPiBrZXhlYyBmb3IgYSBwcm9ncmFtIHRoYXQgSSAia25vdyIgaXMgY29y cmVjdCBiZWNhdXNlIEkgdmFsaWRhdGVkIHRoZQ0KPiBkaXNrIGltYWdlIGl0IHdhcyBvbiBiZWZv cmUgSSBtb3VudGVkIGl0LiAgV2UgYWxyZWFkeSBoYXZlIG90aGVyIHdheXMgdG8NCj4gInZlcmlm eSIgdGhpbmdzIHdpdGhvdXQgaGF2aW5nIHRvIGFkZCBpbmRpdmlkdWFsIHZlcmlmaWNhdGlvbiBv Zg0KPiBzcGVjaWZpYyBwaWVjZXMuDQoNClRoZSBrZXJuZWwgaGFzIG5vIHdheSB0byBrbm93IHRo YXQgeW91ciBrZXhlYyBwYXlsb2FkIGlzIGNvbWluZyBmcm9tIGENCnZlcmlmaWVkIGltYWdlLiBJ dCdsbCBqdXN0IGFzIGhhcHBpbHkgdGFrZSBzb21ldGhpbmcgZnJvbSBhbiB1bnZlcmlmaWVkDQpp bWFnZS4gSWYgeW91J3ZlIGVuc3VyZWQgdGhhdCB0aGVyZSdzIG5vIHdheSBhbiBhdHRhY2tlciBj YW4gY2FsbA0Ka2V4ZWNfbG9hZCgpIG9uIGFuIHVudmVyaWZpZWQgaW1hZ2UsIHRoZW4geW91IGRv bid0IG5lZWQgc2lnbmVkIG1vZHVsZXMuDQoNCi0tIA0KTWF0dGhldyBHYXJyZXR0IDxtYXR0aGV3 LmdhcnJldHRAbmVidWxhLmNvbT4NCg==