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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH 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 574E5C433F5 for ; Sun, 2 Sep 2018 13:15:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7368205F4 for ; Sun, 2 Sep 2018 13:15:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=microsoft.com header.i=@microsoft.com header.b="f0WmudwB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7368205F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=microsoft.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 S1729920AbeIBRar (ORCPT ); Sun, 2 Sep 2018 13:30:47 -0400 Received: from mail-co1nam03on0097.outbound.protection.outlook.com ([104.47.40.97]:50844 "EHLO NAM03-CO1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729355AbeIBRap (ORCPT ); Sun, 2 Sep 2018 13:30:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=U5zfbb2/wNo2xPTtgYa9lD3IJrnve2w/0AcqYcsK+6Y=; b=f0WmudwBfIKzRXf5wfiltHc6aiPzWr/9WuPPp/fAlJpDXgy2M0eObJeVDODPCwk62UKO6Ma8QHoOffQVhsSh+eGm1gebb2cK2x1y0GOA2dROKTweguuJY/9RwJ7yB9zJq1TRC+PnuADy/b8s0ePJ61Ud1KTjtTOe/K3oe7Z8tU0= Received: from CY4PR21MB0776.namprd21.prod.outlook.com (10.173.192.22) by CY4PR21MB0120.namprd21.prod.outlook.com (10.173.189.14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1122.2; Sun, 2 Sep 2018 13:14:40 +0000 Received: from CY4PR21MB0776.namprd21.prod.outlook.com ([fe80::7c3a:eea8:1391:1611]) by CY4PR21MB0776.namprd21.prod.outlook.com ([fe80::7c3a:eea8:1391:1611%7]) with mapi id 15.20.1143.000; Sun, 2 Sep 2018 13:14:40 +0000 From: Sasha Levin To: "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Joerg Roedel , Thomas Gleixner , "H . Peter Anvin" , "linux-mm@kvack.org" , Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , "aliguori@amazon.com" , Daniel Gruss , "hughd@google.com" , "keescook@google.com" , Andrea Arcangeli , Waiman Long , Pavel Machek , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , "joro@8bytes.org" , Sasha Levin Subject: [PATCH AUTOSEL 4.9 28/62] x86/kexec: Allocate 8k PGDs for PTI Thread-Topic: [PATCH AUTOSEL 4.9 28/62] x86/kexec: Allocate 8k PGDs for PTI Thread-Index: AQHUQr7nqJCRfp8UbESRexJG3yb+dQ== Date: Sun, 2 Sep 2018 13:14:39 +0000 Message-ID: <20180902131411.183978-18-alexander.levin@microsoft.com> References: <20180902131411.183978-1-alexander.levin@microsoft.com> In-Reply-To: <20180902131411.183978-1-alexander.levin@microsoft.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [52.168.54.252] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;CY4PR21MB0120;6:bzq61ImjHO+RxrJMLDsFy/QnijkVMB8GaG/cxY8zWRYSWMl3qrtHZOamHs3eCSq8eAGcx9D0njBDwDjOtCxP9S8uHtXWQHl5PNT7XFHkTZUwV27qmdpR/Cd5I5u0za4NoicalyUdRUFXMXIlxcVa8Zex1Sz72M1A4QiWnt4yycIJLw4am/1iI8jNCWUPhUfVQrkctOHTGn4J1yRZdaFPrBR7negyJ06jsuczOhPN5UU1hFez5fSFTbDhuS+e4gzyz2xQ8JvvUtWR2h65Kr1dys33rVgiYkgaVozmJY+fW6IMiXaR3jrrOlZm1jv2cZMT7sKTDqs7/tr6pge0Qn5rxIp4dVlqo3/SmrDsFzyNEKUZt0+dLOhnvmz8C/6VL5kJQIwDKd3iAsVWiIMtSzTxck0V64ZO0QRhCnjz9x2VvEV9fIxziVVtvO4SWlMbupUn7u6TmuCMzycxwiLC1PZEVQ==;5:yl9v7lC+vAsDEXlO5p5FrJwlFs4rXDcuzyBEHo4L5LdVFwsxuPqCh6+JfFMFNlipkRTxBoTUHtMDdu+UaFEvrxfBXLv7gDvLwoDU4IgqMcUe/Nfakysu4vvsPBoArCyIkll61Dbcr3o9tw23LkwiOW2V1YqLkB1whB/z3v7EwaY=;7:wW9S50bupYqEAhVs2msDoPFs9QvqeCkMwe7caDJ3LF8lYPev0FM3RwmHJD2vHH/d6LoAVsortJZtbNyNmGiPqNyy7EGtp+wwpljK3XFPGAYum68saGSD8NRe9cAUdW0QMoIUCO6NrcfLI2n0Ag8RgRCeyqwpY30lEiA/+jHFFHga3H/hX2fKFcGGoH0RobxpqCV9pTdn4zgCg9qsESb2eWQ/JQ9n9LyQXz/HbOpKB5C9/wCpHUHEG6js2eQH//oM x-ms-office365-filtering-correlation-id: 502c3bc9-4219-4d95-7622-08d610d60a3e x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: BCL:0;PCL:0;RULEID:(7020095)(4652040)(4534165)(4627221)(201703031133081)(201702281549075)(5600074)(711020)(4618075)(2017052603328)(7193020);SRVR:CY4PR21MB0120; 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received-spf: None (protection.outlook.com: microsoft.com does not designate permitted sender hosts) x-microsoft-antispam-message-info: wo8SuRiYLQ3XWBMGq49mVRzSZ1nukkGCDmP/Eo8rbpfQhoA/tVpypWEDnsEy2RhM/NfvbIC2K2nexJshWfD1BLXxceJJQnx9/tE1v4M3/xxj+1OJ3VrgfIyMO/2gIdIQvnxltv0sRgkE1o8YQMx6NBsZP+nMWCC7E7MNY7jF5LYKJSN7Z59TVMYoHn7rQEGwLc86qtkIykirnGoXZ9SFd4KtsJd1WPNaOZbOg9FWlt58Aswyfj0rX9/xg8pGso/oADPu3ktsNYfrYXiciVHc6ZfpxCp3OdVCUrQGu0361fd12PS7yZz3gzYLid0QRPIbH3ZgiwrzwdJQPOXdZmn3+IiuqVAuLaXP1lgvU/4SGMw= spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: 502c3bc9-4219-4d95-7622-08d610d60a3e X-MS-Exchange-CrossTenant-originalarrivaltime: 02 Sep 2018 13:14:39.7472 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR21MB0120 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel [ Upstream commit ca38dc8f2724d101038b1205122c93a1c7f38f11 ] Fuzzing the PTI-x86-32 code with trinity showed unhandled kernel paging request oops-messages that looked a lot like silent data corruption. Lot's of debugging and testing lead to the kexec-32bit code, which is still allocating 4k PGDs when PTI is enabled. But since it uses native_set_pud() to build the page-table, it will unevitably call into __pti_set_user_pgtbl(), which writes beyond the allocated 4k page. Use PGD_ALLOCATION_ORDER to allocate PGDs in the kexec code to fix the issue. Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Tested-by: David H. Gutteridge Cc: "H . Peter Anvin" Cc: linux-mm@kvack.org Cc: Linus Torvalds Cc: Andy Lutomirski Cc: Dave Hansen Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Jiri Kosina Cc: Boris Ostrovsky Cc: Brian Gerst Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli Cc: Waiman Long Cc: Pavel Machek Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1532533683-5988-4-git-send-email-joro@8byte= s.org Signed-off-by: Sasha Levin --- arch/x86/kernel/machine_kexec_32.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_k= exec_32.c index fd7e9937ddd6..e9359272c5cb 100644 --- a/arch/x86/kernel/machine_kexec_32.c +++ b/arch/x86/kernel/machine_kexec_32.c @@ -70,7 +70,7 @@ static void load_segments(void) =20 static void machine_kexec_free_page_tables(struct kimage *image) { - free_page((unsigned long)image->arch.pgd); + free_pages((unsigned long)image->arch.pgd, PGD_ALLOCATION_ORDER); image->arch.pgd =3D NULL; #ifdef CONFIG_X86_PAE free_page((unsigned long)image->arch.pmd0); @@ -86,7 +86,8 @@ static void machine_kexec_free_page_tables(struct kimage = *image) =20 static int machine_kexec_alloc_page_tables(struct kimage *image) { - image->arch.pgd =3D (pgd_t *)get_zeroed_page(GFP_KERNEL); + image->arch.pgd =3D (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, + PGD_ALLOCATION_ORDER); #ifdef CONFIG_X86_PAE image->arch.pmd0 =3D (pmd_t *)get_zeroed_page(GFP_KERNEL); image->arch.pmd1 =3D (pmd_t *)get_zeroed_page(GFP_KERNEL); --=20 2.17.1