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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8186BC433F5 for ; Sun, 23 Jan 2022 05:50:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235649AbiAWFuh (ORCPT ); Sun, 23 Jan 2022 00:50:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229776AbiAWFug (ORCPT ); Sun, 23 Jan 2022 00:50:36 -0500 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E55AC06173B; Sat, 22 Jan 2022 21:50:36 -0800 (PST) Received: by mail-pf1-x435.google.com with SMTP id u10so8232482pfg.10; Sat, 22 Jan 2022 21:50:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=VC+au0p/0264rLSy2tjWxRamXhLbDclhx0GW2hJ1SB8=; b=JgSQcWrPgPhAWoJbHVwKdXb19alZdAg1LDjFSFiLyN+M0UnvCjDRoRfL3f4Ohbw0Z/ N1bzhQcxkMhPE0OgXgbeHC+Tujt8E3D57IwL0p5wIizdvRqFpo6lSltn2gJf5M3p5vRv cgNYQh1Nfvg3j9KJJiEuz8UqTE6AVVaUEJdFTNiCUDmyw7AB5fFvH2Ov0wpPubzB1ED0 lrRa6snl3pyWmsm1D3jYhYfgZHUXN/ul42/VQGQlaVTLrq28PalECa4kMA54kT6MRsRH qTxiR6lU39rPpOJUWqWQF3eBy0MW2zztBeRe9F1GlHYwQ6YfojtcgPuK6Rjg/fV/9j9R xvpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=VC+au0p/0264rLSy2tjWxRamXhLbDclhx0GW2hJ1SB8=; b=eVgiivBvcJ2048I7vsvZtTzl/OfX1EgvaIbkKEK1KJVlOy2dVlqFiD6XlBM/xmanES 5wwz3dWTEZfg6l9grADjYGDzp5+mL60hmFt2bwKnue1DDVonBC2PaDipqajqz67UBp4g Jzn4XDodrjUSTh3w/AFKAT4cG+Qt9jx4BUrfcNUGWiTXiASBZ6HFI+dxcGDxY5vRKIAR DvROY6WWVX48tMG5mHiQ2M3Snx0Q7taafRpfOdpyJlegkA4HouY3/CTKxQb9J3rUyYWz 2GxQ9TYRS3LKZjQ7w3MXMrui/5+asHm20ihx0rGfQX0fuuWBizuypVYmJk4tjXPcRXd8 j1+g== X-Gm-Message-State: AOAM530b0jX/FVMx6gjwubhblsjysdogYIUp36r84kyXBJzbJh5PA4d7 EMHSIrkBwaQHgnGaBuYnbPVESdF2vggxjA== X-Google-Smtp-Source: ABdhPJxMjHfL9c5UtJumDzxk7MrUHTaz2wUMkfRerIdqotNbqHQ2mRydvVOFX/gZ4hWrL7K57pRC/g== X-Received: by 2002:a63:c009:: with SMTP id h9mr7897491pgg.36.1642917035537; Sat, 22 Jan 2022 21:50:35 -0800 (PST) Received: from localhost.localdomain ([103.7.29.32]) by smtp.gmail.com with ESMTPSA id g8sm11492760pfc.57.2022.01.22.21.50.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 22 Jan 2022 21:50:35 -0800 (PST) From: Like Xu X-Google-Original-From: Like Xu To: Paolo Bonzini Cc: Jing Liu , Wanpeng Li , Sean Christopherson , Jim Mattson , Vitaly Kuznetsov , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] KVM: x86/cpuid: Exclude unpermitted xfeatures for vcpu->arch.guest_supported_xcr0 Date: Sun, 23 Jan 2022 13:50:25 +0800 Message-Id: <20220123055025.81342-1-likexu@tencent.com> X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Like Xu A malicious user space can bypass xstate_get_guest_group_perm() in the KVM_GET_SUPPORTED_CPUID mechanism and obtain unpermitted xfeatures, since the validity check of xcr0 depends only on guest_supported_xcr0. Fixes: 445ecdf79be0 ("kvm: x86: Exclude unpermitted xfeatures at KVM_GET_SUPPORTED_CPUID") Signed-off-by: Like Xu --- arch/x86/kvm/cpuid.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 3902c28fb6cb..1bd4d560cbdd 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -266,7 +266,8 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) vcpu->arch.guest_supported_xcr0 = 0; else vcpu->arch.guest_supported_xcr0 = - (best->eax | ((u64)best->edx << 32)) & supported_xcr0; + (best->eax | ((u64)best->edx << 32)) & + (supported_xcr0 & xstate_get_guest_group_perm()); /* * Bits 127:0 of the allowed SECS.ATTRIBUTES (CPUID.0x12.0x1) enumerate -- 2.33.1