From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761114AbXIJTfi (ORCPT ); Mon, 10 Sep 2007 15:35:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759153AbXIJTfb (ORCPT ); Mon, 10 Sep 2007 15:35:31 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:33936 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756861AbXIJTfa (ORCPT ); Mon, 10 Sep 2007 15:35:30 -0400 Date: Mon, 10 Sep 2007 21:34:53 +0200 From: Ingo Molnar To: arnd@arndb.de Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Andrew Morton , David Miller Subject: Re: [patch 1/3] futex_compat: fix list traversal bugs Message-ID: <20070910193453.GA4964@elte.hu> References: <20070910191324.847651727@arndb.de> <20070910191648.561256021@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070910191648.561256021@arndb.de> User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -1.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * arnd@arndb.de wrote: > The futex list traversal on the compat side appears to have a bug. > > It's loop termination condition compares: > > while (compat_ptr(uentry) != &head->list) > > But that can't be right because "uentry" has the special "pi" > indicator bit still potentially set at bit 0. This is cleared by > fetch_robust_entry() into the "entry" return value. hm. I remember having tested this - not well enough i guess :-/ Acked-by: Ingo Molnar Ingo