From patchwork Mon Mar 1 16:05:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 389397 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 4AAB7C4332D for ; Mon, 1 Mar 2021 19:36:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08C9564D99 for ; Mon, 1 Mar 2021 19:36:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241789AbhCATd2 (ORCPT ); Mon, 1 Mar 2021 14:33:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:48630 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241536AbhCAT0p (ORCPT ); Mon, 1 Mar 2021 14:26:45 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0A63665177; Mon, 1 Mar 2021 17:07:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614618466; bh=ZxYl6ktqcOjs+mbTKfyHdPzK2plTyuCgvD4A8+rngdA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HNXzJpR5dl5m+2MrXfss63YItihzAfa5t8MMZmPOg/zWs/I52xmdDALPzuVDoKZNd IYXyHH7MS+7U7eOOn2H1t/P25uXKaidHbwcol8igaGFGqIwz3o9xQ95EwE/lbbBMvR YL6DGj03ePdIykHj7GBqO+9G7E1WerXzt2j4Tk70= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Misono Tomohiro , Borislav Petkov , Sasha Levin Subject: [PATCH 5.10 067/663] x86/MSR: Filter MSR writes through X86_IOC_WRMSR_REGS ioctl too Date: Mon, 1 Mar 2021 17:05:15 +0100 Message-Id: <20210301161145.048760354@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161141.760350206@linuxfoundation.org> References: <20210301161141.760350206@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Misono Tomohiro [ Upstream commit 02a16aa13574c8526beadfc9ae8cc9b66315fa2d ] Commit a7e1f67ed29f ("x86/msr: Filter MSR writes") introduced a module parameter to disable writing to the MSR device file and tainted the kernel upon writing. As MSR registers can be written by the X86_IOC_WRMSR_REGS ioctl too, the same filtering and tainting should be applied to the ioctl as well. [ bp: Massage commit message and space out statements. ] Fixes: a7e1f67ed29f ("x86/msr: Filter MSR writes") Signed-off-by: Misono Tomohiro Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210127122456.13939-1-misono.tomohiro@jp.fujitsu.com Signed-off-by: Sasha Levin --- arch/x86/kernel/msr.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index c0d4098106589..79f900ffde4c5 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -184,6 +184,13 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg) err = security_locked_down(LOCKDOWN_MSR); if (err) break; + + err = filter_write(regs[1]); + if (err) + return err; + + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + err = wrmsr_safe_regs_on_cpu(cpu, regs); if (err) break;