From patchwork Mon Mar 1 16:03:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 389338 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 E1448C433E0 for ; Mon, 1 Mar 2021 19:48:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9301B64D8F for ; Mon, 1 Mar 2021 19:48:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242020AbhCATr7 (ORCPT ); Mon, 1 Mar 2021 14:47:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:50728 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236373AbhCATgF (ORCPT ); Mon, 1 Mar 2021 14:36:05 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C9B21652C5; Mon, 1 Mar 2021 17:37:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614620254; bh=59z9DCx7gWyWXZ01EJHXNaYY1N8ZH3NhkKAdIVFQC9s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NiZ1Dp9n0cvP7mpyZKuYcyzpONgld4BKYKd4yIRHtvFDnotXzlm5XAJl2dtVq9HbX POk4Ibsa20Ru8ixWmX9XYmkPpQiVV9wYSZ4JXYBgTZtsHah3NYLhBdKNd9UOIGYy84 ixOqrWRNnklw6hxxo3VyYRHONPTUb1Rwks8BF6KA= 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 5.11 069/775] x86/MSR: Filter MSR writes through X86_IOC_WRMSR_REGS ioctl too Date: Mon, 1 Mar 2021 17:03:57 +0100 Message-Id: <20210301161205.091222005@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161201.679371205@linuxfoundation.org> References: <20210301161201.679371205@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 8a67d1fa8dc58..ed8ac6bcbafb2 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -182,6 +182,13 @@ 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;