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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 8D398C352A4 for ; Mon, 10 Feb 2020 12:59:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BDAB20708 for ; Mon, 10 Feb 2020 12:59:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581339553; bh=L1GsdPk/THW9c/zYiE5ibwAz+d1guyHIhB3MHKaRyHY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yB9xXFSIxrUTLsRJ7DG8XSA4UqM5Znn5SdZHmWKoew9NWBnkESVPom9hKyjvWiiFA rVttbinTzleQA6mwovwdGf6oPg5yEbSBaUUSvL+YQ6CgcfnVdoTSJ71qRLvYVN5kA2 zc/ypOyjXGH3uyyNzSSVAnWls51A+kiLzqtBCHVA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729993AbgBJM7M (ORCPT ); Mon, 10 Feb 2020 07:59:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:42972 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729926AbgBJMlM (ORCPT ); Mon, 10 Feb 2020 07:41:12 -0500 Received: from localhost (unknown [209.37.97.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5CBBF208C3; Mon, 10 Feb 2020 12:41:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338472; bh=L1GsdPk/THW9c/zYiE5ibwAz+d1guyHIhB3MHKaRyHY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0fp/SvRLAOigCuo0DFQ/JNQEvZ/C3d7nozZ56uGMrfViEZWNfF/LcPIOq60963/D3 R9UFAWzsOeNzNQbt0RWwLnFFOKM6lTQO0NIViunv+xI0+wDqjzVbz7u9PksUSmWHm3 vqDDYOlxlvd6K7eXYULmu8sQkizODGoXSlukk+h4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nick Finco , Marios Pomonis , Andrew Honig , Jim Mattson , Paolo Bonzini Subject: [PATCH 5.5 238/367] KVM: x86: Protect MSR-based index computations in fixed_msr_to_seg_unit() from Spectre-v1/L1TF attacks Date: Mon, 10 Feb 2020 04:32:31 -0800 Message-Id: <20200210122446.151419024@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122423.695146547@linuxfoundation.org> References: <20200210122423.695146547@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marios Pomonis commit 25a5edea71b7c154b6a0b8cec14c711cafa31d26 upstream. This fixes a Spectre-v1/L1TF vulnerability in fixed_msr_to_seg_unit(). This function contains index computations based on the (attacker-controlled) MSR number. Fixes: de9aef5e1ad6 ("KVM: MTRR: introduce fixed_mtrr_segment table") Signed-off-by: Nick Finco Signed-off-by: Marios Pomonis Reviewed-by: Andrew Honig Cc: stable@vger.kernel.org Reviewed-by: Jim Mattson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/mtrr.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/mtrr.c +++ b/arch/x86/kvm/mtrr.c @@ -192,11 +192,15 @@ static bool fixed_msr_to_seg_unit(u32 ms break; case MSR_MTRRfix16K_80000 ... MSR_MTRRfix16K_A0000: *seg = 1; - *unit = msr - MSR_MTRRfix16K_80000; + *unit = array_index_nospec( + msr - MSR_MTRRfix16K_80000, + MSR_MTRRfix16K_A0000 - MSR_MTRRfix16K_80000 + 1); break; case MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000: *seg = 2; - *unit = msr - MSR_MTRRfix4K_C0000; + *unit = array_index_nospec( + msr - MSR_MTRRfix4K_C0000, + MSR_MTRRfix4K_F8000 - MSR_MTRRfix4K_C0000 + 1); break; default: return false;