From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755582AbcGFSdC (ORCPT ); Wed, 6 Jul 2016 14:33:02 -0400 Received: from mail.skyhub.de ([78.46.96.112]:45175 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754490AbcGFSdA (ORCPT ); Wed, 6 Jul 2016 14:33:00 -0400 Date: Wed, 6 Jul 2016 20:32:45 +0200 From: Borislav Petkov To: Steven Rostedt Cc: LKML , Andrew Morton , Franck Bui , Greg Kroah-Hartman , Ingo Molnar , Linus Torvalds , Peter Zijlstra , Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= Subject: Re: [PATCH -v3.1 2/2] printk: Add kernel parameter to control writes to /dev/kmsg Message-ID: <20160706183245.GJ7300@pd.tnic> References: <1467642292-15671-1-git-send-email-bp@alien8.de> <1467642292-15671-3-git-send-email-bp@alien8.de> <20160706132924.GE7300@pd.tnic> <20160706135211.3e4f968e@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160706135211.3e4f968e@gandalf.local.home> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 06, 2016 at 01:52:11PM -0400, Steven Rostedt wrote: > Hmm, this does nothing to stop user space from doing the following: > > while :; do echo '5,0,0,-;hello' > /dev/kmsg; done I wouldn't worry too much if /dev/kmsg has root:root perms elsewhere too, like it is the case in my guest here: crw-r--r-- 1 root root 1, 11 Jul 6 22:28 /dev/kmsg root can shoot herself in the foot in countless ways anyway. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.