From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA662C433F5 for ; Wed, 29 Aug 2018 16:06:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82AE620685 for ; Wed, 29 Aug 2018 16:06:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82AE620685 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729178AbeH2UEd (ORCPT ); Wed, 29 Aug 2018 16:04:33 -0400 Received: from shelob.surriel.com ([96.67.55.147]:37510 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728976AbeH2UEd (ORCPT ); Wed, 29 Aug 2018 16:04:33 -0400 Received: from imladris.surriel.com ([96.67.55.152]) by shelob.surriel.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1fv2zf-0000NW-6V; Wed, 29 Aug 2018 12:06:55 -0400 Message-ID: <9ff9dd41ff99560dcb3eb78f5835da67293f860c.camel@surriel.com> Subject: Re: [PATCH v2] x86/nmi: Fix some races in NMI uaccess From: Rik van Riel To: Andy Lutomirski , x86@kernel.org, Nadav Amit Cc: Borislav Petkov , Jann Horn , LKML , stable@vger.kernel.org, Peter Zijlstra Date: Wed, 29 Aug 2018 12:06:54 -0400 In-Reply-To: References: Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-nStG//HEP214a3gQ/inZ" X-Mailer: Evolution 3.28.5 (3.28.5-1.fc28) Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-nStG//HEP214a3gQ/inZ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2018-08-29 at 08:47 -0700, Andy Lutomirski wrote: > In NMI context, we might be in the middle of context switching or in > the middle of switch_mm_irqs_off(). In either case, CR3 might not > match current->mm, which could cause copy_from_user_nmi() and > friends to read the wrong memory. >=20 > Fix it by adding a new nmi_uaccess_okay() helper and checking it in > copy_from_user_nmi() and in __copy_from_user_nmi()'s callers. >=20 > Cc: stable@vger.kernel.org > Cc: Peter Zijlstra > Cc: Nadav Amit > Signed-off-by: Andy Lutomirski Reviewed-by: Rik van Riel --=20 All Rights Reversed. --=-nStG//HEP214a3gQ/inZ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAluGxJ4ACgkQznnekoTE 3oPRawf9FDAGQGrXHrkWkB7dhuU6VpIDXvowhfrrWtLk2Yt69cm2XZuDetCVCbAE plSadIuGuaRm4E0IJXlBQNNRpY+kFNYtOzdklt5yEKe0eB4g5+pcQmYuGgBJu+Xh /si8oPUD52Yp8+J2pmEDdQUlCa3jR7an7LRO4rE7gsg007HZ6YbA4l3FJE31gkWm XRkDaHZZ15oKxxscycUWiwnWC8zFTYDViHZgjnDlsXuOd3ZpNd61dP+5DscqkPh/ coTdliPzSSq8/N1+mZJbFPLny0ksMiw0YHpunNGdHWNwdSxqpXhW8UKMFLK1QBGB gSdXff0o3K6tfXO2BPOGIRCO0P2lGg== =ZCwn -----END PGP SIGNATURE----- --=-nStG//HEP214a3gQ/inZ--