From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH V3 03/11] x86: Lock down IO port access when module security is enabled Date: Thu, 5 Sep 2013 03:58:45 +0000 Message-ID: <1378353524.13193.26.camel@x230> References: <1378252218-18798-1-git-send-email-matthew.garrett@nebula.com> <1378252218-18798-4-git-send-email-matthew.garrett@nebula.com> <5227FFE8.5050102@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <5227FFE8.5050102-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org> Content-Language: en-US Content-ID: <20382F52C93E8C47A347896EBF08F954-HX+pjaQZbrqcE4WynfumptQqCkab/8FMAL8bYrjMMd8@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "H. Peter Anvin" Cc: "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org" List-Id: linux-efi@vger.kernel.org T24gV2VkLCAyMDEzLTA5LTA0IGF0IDIwOjUyIC0wNzAwLCBILiBQZXRlciBBbnZpbiB3cm90ZToN Cj4gT24gMDkvMDMvMjAxMyAwNDo1MCBQTSwgTWF0dGhldyBHYXJyZXR0IHdyb3RlOg0KPiA+IElP IHBvcnQgYWNjZXNzIHdvdWxkIHBlcm1pdCB1c2VycyB0byBnYWluIGFjY2VzcyB0byBQQ0kgY29u ZmlndXJhdGlvbg0KPiA+IHJlZ2lzdGVycywgd2hpY2ggaW4gdHVybiAob24gYSBsb3Qgb2YgaGFy ZHdhcmUpIGdpdmUgYWNjZXNzIHRvIE1NSU8gcmVnaXN0ZXINCj4gPiBzcGFjZS4gVGhpcyB3b3Vs ZCBwb3RlbnRpYWxseSBwZXJtaXQgcm9vdCB0byB0cmlnZ2VyIGFyYml0cmFyeSBETUEsIHNvIGxv Y2sNCj4gPiBpdCBkb3duIGJ5IGRlZmF1bHQuDQo+ID4gDQo+ID4gU2lnbmVkLW9mZi1ieTogTWF0 dGhldyBHYXJyZXR0IDxtYXR0aGV3LmdhcnJldHRAbmVidWxhLmNvbT4NCj4gDQo+IFNlcmlvdXNs eS4uLiBqdXN0IGRlbnkgQ0FQX1NZU19SQVdJTyB0byBhbnkgc3lzdGVtIGluIHNlY3VyZSBtb2Rl Lg0KDQpOby4gQ0FQX1NZU19SQVdJTyBibG9ja3MgdGhpbmdzIHRoYXQgd2UgZG9uJ3Qgd2FudCBi bG9ja2VkICh4ODYNCm1pY3JvY29kZSB1cGRhdGVzLCB2YXJpb3VzIGRpc2sgaW9jdGxzLCAqZGV2 aWNlIGZpcm13YXJlIHVwbG9hZHMqIGFuZCBhDQpmZXcgb3RoZXJzKSAtIHRoZSBzZW1hbnRpY3Mg anVzdCBkb24ndCBtYXRjaC4gV2UgY291bGQgcmVsYXggdGhvc2UNCnBlcm1pc3Npb25zLCBidXQg dGhlbiB3ZSdkIHBvdGVudGlhbGx5IGJyZWFrIHNvbWVvbmUgZWxzZSdzIHNlY3VyaXR5DQpjb25z aWRlcmF0aW9ucy4NCg0KLS0gDQpNYXR0aGV3IEdhcnJldHQgPG1hdHRoZXcuZ2FycmV0dEBuZWJ1 bGEuY29tPg0K From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754146Ab3IED6w (ORCPT ); Wed, 4 Sep 2013 23:58:52 -0400 Received: from mail-bl2lp0205.outbound.protection.outlook.com ([207.46.163.205]:13424 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753829Ab3IED6u (ORCPT ); Wed, 4 Sep 2013 23:58:50 -0400 From: Matthew Garrett To: "H. Peter Anvin" CC: "linux-kernel@vger.kernel.org" , "linux-efi@vger.kernel.org" , "keescook@chromium.org" Subject: Re: [PATCH V3 03/11] x86: Lock down IO port access when module security is enabled Thread-Topic: [PATCH V3 03/11] x86: Lock down IO port access when module security is enabled Thread-Index: AQHOqQBh9VrXJc6zbUqVxxtEmQPfAJm2hJUAgAAB2AA= Date: Thu, 5 Sep 2013 03:58:45 +0000 Message-ID: <1378353524.13193.26.camel@x230> References: <1378252218-18798-1-git-send-email-matthew.garrett@nebula.com> <1378252218-18798-4-git-send-email-matthew.garrett@nebula.com> <5227FFE8.5050102@zytor.com> In-Reply-To: <5227FFE8.5050102@zytor.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [209.6.207.143] x-forefront-prvs: 096029FF66 x-forefront-antispam-report: SFV:NSPM;SFS:(479174003)(377454003)(24454002)(189002)(199002)(377424004)(51704005)(51856001)(4396001)(66066001)(33716001)(80022001)(83072001)(59766001)(46102001)(77982001)(65816001)(81816001)(33646001)(81686001)(79102001)(81342001)(50986001)(47976001)(47736001)(49866001)(74876001)(54356001)(76482001)(81542001)(54316002)(56776001)(63696002)(74502001)(31966008)(74662001)(47446002)(19580405001)(74706001)(83322001)(56816003)(77096001)(76786001)(76796001)(69226001)(74366001)(19580395003)(80976001)(53806001);DIR:OUT;SFP:;SCL:1;SRVR:BY2PR05MB224;H:BY2PR05MB222.namprd05.prod.outlook.com;CLIP:209.6.207.143;RD:InfoNoRecords;MX:1;A:1;LANG:en; Content-Type: text/plain; charset="utf-8" Content-ID: <20382F52C93E8C47A347896EBF08F954@namprd05.prod.outlook.com> 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 r853wu4n027492 On Wed, 2013-09-04 at 20:52 -0700, H. Peter Anvin wrote: > On 09/03/2013 04:50 PM, Matthew Garrett wrote: > > IO port access would permit users to gain access to PCI configuration > > registers, which in turn (on a lot of hardware) give access to MMIO register > > space. This would potentially permit root to trigger arbitrary DMA, so lock > > it down by default. > > > > Signed-off-by: Matthew Garrett > > Seriously... just deny CAP_SYS_RAWIO to any system in secure mode. No. CAP_SYS_RAWIO blocks things that we don't want blocked (x86 microcode updates, various disk ioctls, *device firmware uploads* and a few others) - the semantics just don't match. We could relax those permissions, but then we'd potentially break someone else's security considerations. -- Matthew Garrett {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I