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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 6A3E8C3B18B for ; Thu, 13 Feb 2020 15:23:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 428DD246D1 for ; Thu, 13 Feb 2020 15:23:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581607420; bh=AZy+x0Fk55noPNLyjgWXk9oE7vO+9pjKvSk7zRzEL5o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jucCSVzkyBp7YJP9kUCP8AUzbHGegYuFC91Xl30aLqUUjJsyvDwaFjksAtr/jNKiM Z39g9jOshdf5wr0VH5eezZse1LQJHU4R6i9479qrjueEJJ/nFYJnOKtTqFxVV0JKJc bTdIP0H1lGiSGZu2Yv8If2HGvMhQ7q7dsXHbijDQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728440AbgBMPXi (ORCPT ); Thu, 13 Feb 2020 10:23:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:33102 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728066AbgBMPW5 (ORCPT ); Thu, 13 Feb 2020 10:22:57 -0500 Received: from localhost (unknown [104.132.1.104]) (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 455AE246A3; Thu, 13 Feb 2020 15:22:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581607375; bh=AZy+x0Fk55noPNLyjgWXk9oE7vO+9pjKvSk7zRzEL5o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I1TfMKgz34+sB+TnL4jpEg7tyoAFjx5oqDyiiUJHcUM0d8E53U66N2RA5w0zw3ilr G+Iaa1sT5To/UHAs5/rPVryKF3yT6TSxl48PSDBDRXWdYYNAP8Li0MnXkmAFLzaHFc ra9rie5KRDzTPnV6kRsEehG6wHV9EsJ77rtPp9EM= 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 , Sasha Levin Subject: [PATCH 4.4 69/91] KVM: x86: Refactor picdev_write() to prevent Spectre-v1/L1TF attacks Date: Thu, 13 Feb 2020 07:20:26 -0800 Message-Id: <20200213151848.896341565@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200213151821.384445454@linuxfoundation.org> References: <20200213151821.384445454@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 [ Upstream commit 14e32321f3606e4b0970200b6e5e47ee6f1e6410 ] This fixes a Spectre-v1/L1TF vulnerability in picdev_write(). It replaces index computations based on the (attacked-controlled) port number with constants through a minor refactoring. Fixes: 85f455f7ddbe ("KVM: Add support for in-kernel PIC emulation") 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: Sasha Levin --- arch/x86/kvm/i8259.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index ce0f29e5d7c43..791850bfc9817 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -468,10 +468,14 @@ static int picdev_write(struct kvm_pic *s, switch (addr) { case 0x20: case 0x21: + pic_lock(s); + pic_ioport_write(&s->pics[0], addr, data); + pic_unlock(s); + break; case 0xa0: case 0xa1: pic_lock(s); - pic_ioport_write(&s->pics[addr >> 7], addr, data); + pic_ioport_write(&s->pics[1], addr, data); pic_unlock(s); break; case 0x4d0: -- 2.20.1