Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935133Ab3E2Hox (ORCPT ); Wed, 29 May 2013 03:44:53 -0400 Received: from merlin.infradead.org ([205.233.59.134]:47581 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935093Ab3E2How (ORCPT ); Wed, 29 May 2013 03:44:52 -0400 Date: Wed, 29 May 2013 09:44:33 +0200 From: Peter Zijlstra To: Vince Weaver Cc: Al Viro , linux-kernel@vger.kernel.org, Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , trinity@vger.kernel.org Subject: Re: OOPS in perf_mmap_close() Message-ID: <20130529074433.GB12193@twins.programming.kicks-ass.net> References: <20130523044803.GA25399@ZenIV.linux.org.uk> <20130523125218.GB23650@twins.programming.kicks-ass.net> <20130523152611.GE23650@twins.programming.kicks-ass.net> <20130528085548.GA12193@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1102 Lines: 27 On Tue, May 28, 2013 at 02:22:11PM -0400, Vince Weaver wrote: > On Tue, 28 May 2013, Vince Weaver wrote: > > > It looks like this is already in tip, but I can confirm that this > > patch seems to fix things on my machine and holds up against longer > > fuzzing runs. > > OK, I take it back. Even with the new patch applied, my fuzzer can still > make the kernel leak user->locked_vm > > I assume that the locked_vm value should go back to 0 once a process that > has a bunch of mmap'd perf_events opened exits? Yep. > I admit this is sort of an obscure corner case, but it does mean that a > user can leak user->locked_vm to the point that "perf record" no longer > works. Hurm.. I don't suppose you have an easy reproducer handy eh? I'll go stare at it. At least the current state is better than before, but clearly we're not quite there yet. -- 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/