Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752905AbcDZTrt (ORCPT ); Tue, 26 Apr 2016 15:47:49 -0400 Received: from smtprelay0042.hostedemail.com ([216.40.44.42]:39726 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752435AbcDZTrr (ORCPT ); Tue, 26 Apr 2016 15:47:47 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1538:1593:1594:1711:1714:1730:1747:1777:1792:2393:2553:2559:2562:2693:3138:3139:3140:3141:3142:3351:3622:3865:3867:3870:3871:3872:3874:5007:6261:7875:7903:10004:10400:10450:10455:10848:10967:11232:11658:11914:12517:12519:12663:12740:13069:13311:13357:13439:14181:14659:19904:19999:21080:21212,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:2,LUA_SUMMARY:none X-HE-Tag: bread15_951ea2e8672b X-Filterd-Recvd-Size: 1616 Date: Tue, 26 Apr 2016 15:47:42 -0400 From: Steven Rostedt To: Pavel Machek Cc: Linus Torvalds , LKML , Andrew Morton , Ingo Molnar , Peter Zijlstra , Borislav Petkov , Greg Kroah-Hartman Subject: Re: printk: Add kernel parameter to disable writes to /dev/kmsg Message-ID: <20160426154742.0da764a9@gandalf.local.home> In-Reply-To: <20160426184458.GB8162@amd> References: <20160425130629.188a901c@gandalf.local.home> <20160426184458.GB8162@amd> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 544 Lines: 14 On Tue, 26 Apr 2016 20:44:58 +0200 Pavel Machek wrote: > > I simply propose a way to let us kernel developers keep user space from > > interfering, by adding a new kernel command line parameter that will > > disable writing to /dev/kmsg. Any attempt to open the file in write > > mode will return a -EPERM error. > > chmod 400 /dev/kmsg? With udev, it should be possible to make it persistent... But this opened while initramdisk is used. I'm thinking this wont work, or does udev run before main root is mounted? -- Steve