From patchwork Wed May 12 15:51:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom Lendacky X-Patchwork-Id: 438399 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 AB91AC2B9FD for ; Wed, 12 May 2021 15:57:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 904C461E08 for ; Wed, 12 May 2021 15:57:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234004AbhELP6D (ORCPT ); Wed, 12 May 2021 11:58:03 -0400 Received: from mail-dm3nam07on2078.outbound.protection.outlook.com ([40.107.95.78]:6112 "EHLO NAM02-DM3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S234835AbhELPwm (ORCPT ); Wed, 12 May 2021 11:52:42 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=fWR/Pln6ANpwCnIecN2okJSpR11CqgYZcou/PbBSpbDPx7cDkJbekmxBDIPW/yS/Q90aJjqURKi1RL5uVR2skWsHzC9t5IhqQyZu+TiZKdewl/qQq482SpFK5s+elrOeRRaiQgAI/+I+fWbJyyy7HoFmGfyB3/6Fvq1FdLzI6Rg39DIXBQxdkNpplxU0i0ZdwL7HbzC5sOnSIQqWMkSTcyJcN56ouRIqy2PxJftWTQ8T1IE845fi87iK2I83tO/1hYOcHmSbE+ZG0CoXFHplV5iYep9jZHNfenMi1+pm1bXAYAoSjaRQoHReqxZi3SHOXfL88BR4vP+z03pyuir3mA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=qG42O63txZfLjZKMzgtf8+WdtnayJK9FMB5iYylntD4=; b=ZYE4zPAy4b4OsiuI7nzjJyt+XyTtEwe/rKc9EKEU6VQhEv/VLHL/gLJsuPW/x9RTjXJfgeyq9FN6NvXXTjRkgU326ERROxokuotLZjPMQf24ktxZwSYWDV4WhDzGUqtdjvYvqjCmDDEm8IrGzfcvBGVgpZHpdtJQ7VwUKjNdUS5UTDS7c4JSFv9faxvFNf7Ou2XEE+XZ0LjNHSUKg5Dhycd4cf66FBecc6FswGkYQPpC+0YGhlsJl6dHrJKXlItrYjtO5tZlWKFZ//l/un6H4NpqA5h/fCQnJRE/0XuudJykt9eoiUhdChlRGS4Ukt5JH5shsyTwZoHW4npEtAgDUw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=qG42O63txZfLjZKMzgtf8+WdtnayJK9FMB5iYylntD4=; b=sKGJGP5ZL61/UxeJFPdf+hX0Zouaun5aMBHeOUw1WkwU6OnK4ehsk3M2flIGqO4Frm3RcykS1lOPHbLGTqzLU1M6ZSy2WtyKOMJuGu1JhOMmXHN51ysSwCfsu1TKcBNBpHJt4bbDlEDRXJ9IBBDkn7AXD/C8ody2k2b1byeD410= Authentication-Results: vger.kernel.org; dkim=none (message not signed) header.d=none; vger.kernel.org; dmarc=none action=none header.from=amd.com; Received: from DM5PR12MB1355.namprd12.prod.outlook.com (2603:10b6:3:6e::7) by DM6PR12MB4603.namprd12.prod.outlook.com (2603:10b6:5:166::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4129.25; Wed, 12 May 2021 15:51:32 +0000 Received: from DM5PR12MB1355.namprd12.prod.outlook.com ([fe80::b914:4704:ad6f:aba9]) by DM5PR12MB1355.namprd12.prod.outlook.com ([fe80::b914:4704:ad6f:aba9%12]) with mapi id 15.20.4129.025; Wed, 12 May 2021 15:51:31 +0000 From: Tom Lendacky To: stable@vger.kernel.org Subject: [PATCH] KVM: SVM: Make sure GHCB is mapped before updating Date: Wed, 12 May 2021 10:51:19 -0500 Message-Id: <34360e0da35a02fe7bb468b2eef3696baaf95723.1620834679.git.thomas.lendacky@amd.com> X-Mailer: git-send-email 2.31.0 X-Originating-IP: [165.204.77.1] X-ClientProxiedBy: SN4PR0601CA0012.namprd06.prod.outlook.com (2603:10b6:803:2f::22) To DM5PR12MB1355.namprd12.prod.outlook.com (2603:10b6:3:6e::7) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from tlendack-t1.amd.com (165.204.77.1) by SN4PR0601CA0012.namprd06.prod.outlook.com (2603:10b6:803:2f::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4108.25 via Frontend Transport; Wed, 12 May 2021 15:51:31 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 9b18be9f-f0f5-4e87-4e0e-08d9155dd00e X-MS-TrafficTypeDiagnostic: DM6PR12MB4603: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:6790; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:DM5PR12MB1355.namprd12.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(346002)(396003)(376002)(366004)(39860400002)(136003)(6486002)(6916009)(8676002)(316002)(16526019)(478600001)(956004)(2906002)(186003)(52116002)(5660300002)(8936002)(26005)(2616005)(86362001)(38100700002)(38350700002)(36756003)(66556008)(6666004)(66476007)(66946007)(83380400001)(7696005); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData: 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 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 9b18be9f-f0f5-4e87-4e0e-08d9155dd00e X-MS-Exchange-CrossTenant-AuthSource: DM5PR12MB1355.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 May 2021 15:51:31.8025 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: mz8nuUvHEPotHthUXodAnw1J/nYGO7rTl+tAe3W3+Z4dWKfiqeVEJ/AplFzUbuH6ygNXHRa0kRQFWvh6stV9QA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4603 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit a3ba26ecfb569f4aa3f867e80c02aa65f20aadad upstream. Access to the GHCB is mainly in the VMGEXIT path and it is known that the GHCB will be mapped. But there are two paths where it is possible the GHCB might not be mapped. The sev_vcpu_deliver_sipi_vector() routine will update the GHCB to inform the caller of the AP Reset Hold NAE event that a SIPI has been delivered. However, if a SIPI is performed without a corresponding AP Reset Hold, then the GHCB might not be mapped (depending on the previous VMEXIT), which will result in a NULL pointer dereference. The svm_complete_emulated_msr() routine will update the GHCB to inform the caller of a RDMSR/WRMSR operation about any errors. While it is likely that the GHCB will be mapped in this situation, add a safe guard in this path to be certain a NULL pointer dereference is not encountered. Fixes: f1c6366e3043 ("KVM: SVM: Add required changes to support intercepts under SEV-ES") Fixes: 647daca25d24 ("KVM: SVM: Add support for booting APs in an SEV-ES guest") Signed-off-by: Tom Lendacky Cc: stable@vger.kernel.org Message-Id: Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/sev.c | 3 +++ arch/x86/kvm/svm/svm.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 874ea309279f..d6cf74d3b3b2 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2104,5 +2104,8 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector) * the guest will set the CS and RIP. Set SW_EXIT_INFO_2 to a * non-zero value. */ + if (!svm->ghcb) + return; + ghcb_set_sw_exit_info_2(svm->ghcb, 1); } diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 58a45bb139f8..2b6e7874c491 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2809,7 +2809,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) static int svm_complete_emulated_msr(struct kvm_vcpu *vcpu, int err) { struct vcpu_svm *svm = to_svm(vcpu); - if (!sev_es_guest(svm->vcpu.kvm) || !err) + if (!err || !sev_es_guest(vcpu->kvm) || WARN_ON_ONCE(!svm->ghcb)) return kvm_complete_insn_gp(&svm->vcpu, err); ghcb_set_sw_exit_info_1(svm->ghcb, 1);