Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751885Ab3HZTnZ (ORCPT ); Mon, 26 Aug 2013 15:43:25 -0400 Received: from mail-pb0-f53.google.com ([209.85.160.53]:65515 "EHLO mail-pb0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751664Ab3HZTnY (ORCPT ); Mon, 26 Aug 2013 15:43:24 -0400 Message-ID: <521BAFD3.2060404@gmail.com> Date: Mon, 26 Aug 2013 13:43:15 -0600 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Dave Jones , Steven Rostedt , paulmck@linux.vnet.ibm.com, Linux Kernel Subject: Re: suspicious RCU usage (perf) References: <20130826145838.GA8377@redhat.com> <20130826162928.GQ3871@linux.vnet.ibm.com> <20130826133041.3d750b1b@gandalf.local.home> <20130826175012.GA25202@redhat.com> <20130826141814.54dcaa89@gandalf.local.home> <20130826182907.GB25202@redhat.com> In-Reply-To: <20130826182907.GB25202@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1189 Lines: 32 On 8/26/13 12:29 PM, Dave Jones wrote: > On Mon, Aug 26, 2013 at 02:18:14PM -0400, Steven Rostedt wrote: > > On Mon, 26 Aug 2013 13:50:12 -0400 > > Dave Jones wrote: > > > > > > This was triggered as a regular user fwiw. > > > I had not been running perf, or any other tracing. It was just left > > > fuzzing over the weekend with no interaction at all. > > > > So you are telling me that ftrace was enabled by a regular user? If so, > > that's a huge issue. > > quite. > > > So my question to you. If you were not running perf or any other > > tracing, and this is all just non-root user. How the hell did perf > > function tracing get started on your box???? > > What mechanisms are available that would trigger it being enabled ? > > Is there some path through sys_perf_open_event that might be > missing a capability check perhaps ? Do you have /sys/kernel/debug with access permissions? David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/