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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 64DF0C4338F for ; Tue, 24 Aug 2021 17:24:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4719D613CD for ; Tue, 24 Aug 2021 17:24:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239895AbhHXRZO (ORCPT ); Tue, 24 Aug 2021 13:25:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:58968 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240512AbhHXRV7 (ORCPT ); Tue, 24 Aug 2021 13:21:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5676F61B08; Tue, 24 Aug 2021 17:03:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824613; bh=HHn2ZRlyD2k9AG5oa2+hGdrofZOM0lN31Owpkucosqc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G1hUcCJh277R7JIVjs7xoLq49+1YP5q5JzZIR8o6u9G2GbxTHQZZkqzIIsyMQXU+y 3LZPush0TSzM5RE3GnKhdSOdKMSwZhiWw3aw5lNXW69GcFIEKn2QpilxZ3klxAacH8 ZP3XjgGdOqcWD2yebJeWlM1li/asO2lplxMAx0/OjAQMVyp5hnAE37Puq+6/gtIyU+ L4IYteSuqxrjF5EI0+76UFiX5OPImR2BeckmuF6YUlrzHj/FZV6WYmX7H7kL6zfoEx ecu/UwxIzWx84suRUgTKF77p1FNqOJhaLSz2c5gda1rDuHhIc/JTNhZR6eHUO5/kop UHqlOFOksBFgA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Maxim Levitsky , Paolo Bonzini , Greg Kroah-Hartman Subject: [PATCH 4.19 43/84] KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653) Date: Tue, 24 Aug 2021 13:02:09 -0400 Message-Id: <20210824170250.710392-44-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824170250.710392-1-sashal@kernel.org> References: <20210824170250.710392-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.19.205-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.19.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.19.205-rc1 X-KernelTest-Deadline: 2021-08-26T17:02+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Maxim Levitsky [ upstream commit 0f923e07124df069ba68d8bb12324398f4b6b709 ] * Invert the mask of bits that we pick from L2 in nested_vmcb02_prepare_control * Invert and explicitly use VIRQ related bits bitmask in svm_clear_vintr This fixes a security issue that allowed a malicious L1 to run L2 with AVIC enabled, which allowed the L2 to exploit the uninitialized and enabled AVIC to read/write the host physical memory at some offsets. Fixes: 3d6368ef580a ("KVM: SVM: Add VMRUN handler") Signed-off-by: Maxim Levitsky Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/svm.h | 2 ++ arch/x86/kvm/svm.c | 15 ++++++++------- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index 93b462e48067..b6dedf6c835c 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -118,6 +118,8 @@ struct __attribute__ ((__packed__)) vmcb_control_area { #define V_IGN_TPR_SHIFT 20 #define V_IGN_TPR_MASK (1 << V_IGN_TPR_SHIFT) +#define V_IRQ_INJECTION_BITS_MASK (V_IRQ_MASK | V_INTR_PRIO_MASK | V_IGN_TPR_MASK) + #define V_INTR_MASKING_SHIFT 24 #define V_INTR_MASKING_MASK (1 << V_INTR_MASKING_SHIFT) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 9673ddb3d7a0..85181457413e 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1444,12 +1444,7 @@ static __init int svm_hardware_setup(void) } } - if (vgif) { - if (!boot_cpu_has(X86_FEATURE_VGIF)) - vgif = false; - else - pr_info("Virtual GIF supported\n"); - } + vgif = false; /* Disabled for CVE-2021-3653 */ return 0; @@ -3593,7 +3588,13 @@ static void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa, svm->nested.intercept = nested_vmcb->control.intercept; svm_flush_tlb(&svm->vcpu, true); - svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK; + + svm->vmcb->control.int_ctl &= + V_INTR_MASKING_MASK | V_GIF_ENABLE_MASK | V_GIF_MASK; + + svm->vmcb->control.int_ctl |= nested_vmcb->control.int_ctl & + (V_TPR_MASK | V_IRQ_INJECTION_BITS_MASK); + if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK) svm->vcpu.arch.hflags |= HF_VINTR_MASK; else -- 2.30.2