Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933791AbdDERMU (ORCPT ); Wed, 5 Apr 2017 13:12:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48982 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933529AbdDERLm (ORCPT ); Wed, 5 Apr 2017 13:11:42 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com AA0343D954 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dhowells@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com AA0343D954 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 11/24] uswsusp: Disable when the kernel is locked down From: David Howells To: linux-kernel@vger.kernel.org Cc: Matthew Garrett , linux-efi@vger.kernel.org, gnomes@lxorguk.ukuu.org.uk, gregkh@linuxfoundation.org, dhowells@redhat.com, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, matthew.garrett@nebula.com Date: Wed, 05 Apr 2017 18:11:38 +0100 Message-ID: <149141229803.31282.13067113052690581032.stgit@warthog.procyon.org.uk> In-Reply-To: <149141219387.31282.6648284836568938717.stgit@warthog.procyon.org.uk> References: <149141219387.31282.6648284836568938717.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Wed, 05 Apr 2017 17:11:41 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 809 Lines: 27 From: Matthew Garrett uswsusp allows a user process to dump and then restore kernel state, which makes it possible to modify the running kernel. Disable this if the kernel is locked down. Signed-off-by: Matthew Garrett Signed-off-by: David Howells --- kernel/power/user.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/power/user.c b/kernel/power/user.c index 22df9f7ff672..e4b926d329b7 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -52,6 +52,9 @@ static int snapshot_open(struct inode *inode, struct file *filp) if (!hibernation_available()) return -EPERM; + if (kernel_is_locked_down()) + return -EPERM; + lock_system_sleep(); if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {