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,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 D502AC433F5 for ; Sun, 2 Sep 2018 13:18:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D15820652 for ; Sun, 2 Sep 2018 13:18:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=microsoft.com header.i=@microsoft.com header.b="GIZ8oEfK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D15820652 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 S1729937AbeIBRd4 (ORCPT ); Sun, 2 Sep 2018 13:33:56 -0400 Received: from mail-cys01nam02on0107.outbound.protection.outlook.com ([104.47.37.107]:15264 "EHLO NAM02-CY1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730263AbeIBRc1 (ORCPT ); Sun, 2 Sep 2018 13:32:27 -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=GIZ8oEfKw/v92+2ls6coCzcs56LT4Fu60ICtXSakvUSirDOc0OveMAZZZ1FF+FiCGE8yhogFYXDNksWsFab464O23eO+8dSNDbZzHAkaCk0sevLP6SK1Bgh09J4cVa0KXT67z8Ue9En99+h9/U1TEnc0BOkIKqfx23J0jhBWFU4= Received: from CY4PR21MB0776.namprd21.prod.outlook.com (10.173.192.22) by CY4PR21MB0629.namprd21.prod.outlook.com (10.175.115.19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1122.7; Sun, 2 Sep 2018 13:16:24 +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 13:16:24 +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 4.4 23/47] x86/kexec: Allocate 8k PGDs for PTI Thread-Topic: [PATCH AUTOSEL 4.4 23/47] x86/kexec: Allocate 8k PGDs for PTI Thread-Index: AQHUQr8cQlafy3ciR0q/ULSflFCkLA== Date: Sun, 2 Sep 2018 13:16:08 +0000 Message-ID: <20180902131533.184092-23-alexander.levin@microsoft.com> References: <20180902131533.184092-1-alexander.levin@microsoft.com> In-Reply-To: <20180902131533.184092-1-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;CY4PR21MB0629;6:n+lRPJ0T4F3wGXbMIvq8HwGgMFehaf/GI8FXV92tS+eOP7mUHipaLq3XUuiSoJgmLjgo7kkxHzGRkUQd89Y3vIn6bfAG3aJWNLUZ/0D6NWT0CICbv1OcqzHFvisnsAYxaILhCDjDCCGMd4hnyYa1WMm9crwZZckzJC5zzhB9TXb351S0Qkqcmtcyo/O2RcGwGuNVNM+fokP5w2pnTrt1afrdJBf/YiyiyCyB5FUkdFUAq4RKyYPZLcELI/5vqt7kEBCGWhcpg7qIg5/bTyNxAbDysfyKiiWDXgf30qhk2ogomRRvzu5nRkNGZoVM5mAfcFS4cbvZrHnSiBp8uaqCUys328JwK097L90Z/+yLZkn3h6sYzp6n8SWTuEf7bGRMQVtY7s4RF9XduBGwN0xSP0fjV5d/8PSpa29yL3izbKZqtNIkOjHSVezJNEFuUf9IKM7HkCnNYCgKACHB7wHiaQ==;5:qsR6fth6eLvLf5FvvBNXhmvEngXc48fwYEol5RgEAiLXmceQWXhqLblxNxBQn3DV2RmOkGc/cM7QXfAMxbTKRsfY/ezG1x/72mAtDQpALEpfxfy4wLjPU+4Qu2ak4hkxbUXKyu3VD4APb1D+spIjhaCI9X3BaZo/kLn2teqfYLw=;7:BGn1SMAA3LT3lRylG+fEfLihrK4j5IOlDMu4T72UDZt1Dz9jlranqfc52gblXVZur982fm89hC4+cdc8j8Fr9bfcWSsA/QlK+5/rLlojvjIZOb2eQGwY+bpgecoRu4RaQzykv8ARVajB5klCN37WJf7kiEr+Uvpjhbqo9h+vcV3XwekfdFmpcFMPcES2H6qC2JHQ5zMXN6wmBXdOnxQ42X8RFOq/xSOJoRqn3uVzsRUG2iyIGGJddhOXJYn7UV3W x-ms-office365-filtering-correlation-id: dbae3e62-4741-441b-1674-08d610d6488f 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:CY4PR21MB0629; 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received-spf: None (protection.outlook.com: microsoft.com does not designate permitted sender hosts) authentication-results: spf=none (sender IP is ) smtp.mailfrom=Alexander.Levin@microsoft.com; x-microsoft-antispam-message-info: 0Q/9ZjT6c6xKUxgKOBCNoVQuH9S3paoT1EczMPEkNFe4bHY9FzaToLvbvUUPbiL4jtk84xea2Pj+h/n//oFHQYkkney4OJ9GV9tg4CWLEqBDsOqAu0rIeDZ/EPP7b+10NrBuCOG1uhbFaG+OwMnBQLgL+7IC31anPO5eoGPXf+u7RmeiyHbl7hSj+m4FlpHHsIiFWP83Pbx1tjn30Gvu9AsC3ilke8Xy09sL4NYXkY8OxrTNuBFdxT/EIheUtBbYQMfckROfccaElwOwzfq95/GKyKqDc7NzE2Ob8BKA1d2c7+ORDKoeu/0KHV1EbdiXwSA799gd2F2zczuvZmGssgzUVi8axRPL/dplhUTuXq8= 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: dbae3e62-4741-441b-1674-08d610d6488f X-MS-Exchange-CrossTenant-originalarrivaltime: 02 Sep 2018 13:16:08.0310 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR21MB0629 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