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=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 98C17C43381 for ; Thu, 28 Feb 2019 23:13:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61A752133D for ; Thu, 28 Feb 2019 23:13:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="IpVUN+Ln" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387615AbfB1XNv (ORCPT ); Thu, 28 Feb 2019 18:13:51 -0500 Received: from mail-pf1-f201.google.com ([209.85.210.201]:48089 "EHLO mail-pf1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388051AbfB1XM7 (ORCPT ); Thu, 28 Feb 2019 18:12:59 -0500 Received: by mail-pf1-f201.google.com with SMTP id e4so17306390pfh.14 for ; Thu, 28 Feb 2019 15:12:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=pGMKAmmDh5CXWuiQ7W09QK/FwS2bHkIIbTbOhTQuPUY=; b=IpVUN+LnDhNCnYgH87Yti/gH8YcHfd3eB0nigEUV7nIBR7yUCtn8GYobBEJYY1+3Jx D9t+k05834I29T2Sf2A6lVcrFiWh46QBO1J+cKI7uCvU+ydhut+eHS5Cb1YsqAWa9PWQ NYkfFRn5xgKOIfEsrVIeLj0A42O3PtwH/A5BZlTGMBfZD6jfRKafOCLNwSTK7nLrDQ3u JhnooqXvCTwySTQBTHWZv0usxXx7UZeGT+4fKRkEUMQT8hZwSiW5HzoqQLFGdytfBpFV S1y8NrZqwCjD1xrR+mT1C5LbDhSJL0i5O7UDf0QHQylgwFBKVxjlHqQCV13OPaCKcShT lzCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=pGMKAmmDh5CXWuiQ7W09QK/FwS2bHkIIbTbOhTQuPUY=; b=kg/hGQMfH8+4T8Wg0KzyYVnklWCIru3Y6JhTX9z2CaOTqn49Wu4OC2brWfn3WcmqAr 5rR4+qD8s/TzTKCgh53C36ZYGMwAqXLI9v7dVqeqJwOGUswENfnej6PO5Z4aFjkH5O7O PtlfVEwcHG428SCS7tg8ZFRbddPt84VxD9H2yWnhdOTRNxHx4opXblJnytuX9G+0v5YC SO+v3FQnuP2uqlllpOlnPMeGg9RlZHugSBuwMKBvq9g3mv1KuId9fHyITtv/7n/WXBTJ EAvD2KQfE5hHeC/xFWnHWQgu5EaBmZ65kQwkv5FLtHkAgfUiLLjxaG9aiZARyiNynTQr CRDQ== X-Gm-Message-State: APjAAAWGFMQE6ir0h5pfK7TuvTDkI33ajW7vhzqjBz/U+Kf+WXNonWvd zgV1EBFrTssGHCEddGV5WKnGjLofjoxnHtSq5S4+lA== X-Google-Smtp-Source: AHgI3IbdRsmVD4cLGmyor1MNc5tkjRGqx/qg/fddoUfCqLYQ0pZsImsOab5wV8/apSee3hsgNQESH3ULN0YMTwdETvbmSA== X-Received: by 2002:a62:2e05:: with SMTP id u5mr960236pfu.137.1551395578986; Thu, 28 Feb 2019 15:12:58 -0800 (PST) Date: Thu, 28 Feb 2019 15:11:57 -0800 In-Reply-To: <20190228231203.212359-1-matthewgarrett@google.com> Message-Id: <20190228231203.212359-21-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190228231203.212359-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.352.gf09ad66450-goog Subject: [PATCH 21/27] x86/mmiotrace: Lock down the testmmiotrace module From: Matthew Garrett To: jmorris@namei.org Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Howells The testmmiotrace module shouldn't be permitted when the kernel is locked down as it can be used to arbitrarily read and write MMIO space. Suggested-by: Thomas Gleixner Signed-off-by: David Howells cc: Steven Rostedt cc: Ingo Molnar cc: "H. Peter Anvin" cc: x86@kernel.org --- arch/x86/mm/testmmiotrace.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c index f6ae6830b341..bbaad357f5d7 100644 --- a/arch/x86/mm/testmmiotrace.c +++ b/arch/x86/mm/testmmiotrace.c @@ -115,6 +115,9 @@ static int __init init(void) { unsigned long size = (read_far) ? (8 << 20) : (16 << 10); + if (kernel_is_locked_down("MMIO trace testing")) + return -EPERM; + if (mmio_address == 0) { pr_err("you have to use the module argument mmio_address.\n"); pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n"); -- 2.21.0.352.gf09ad66450-goog