Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755818AbZJFBQQ (ORCPT ); Mon, 5 Oct 2009 21:16:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754895AbZJFBQP (ORCPT ); Mon, 5 Oct 2009 21:16:15 -0400 Received: from hera.kernel.org ([140.211.167.34]:50240 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754446AbZJFBQP (ORCPT ); Mon, 5 Oct 2009 21:16:15 -0400 Message-ID: <4ACA9A20.4050809@kernel.org> Date: Tue, 06 Oct 2009 10:15:12 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Greg KH CC: Colin Guthrie , Kay Sievers , Linux Kernel Subject: Re: get_device_parent() race bug References: <4ABC7DB5.9010402@kernel.org> <4AC7EDD7.3080906@kernel.org> <20091005142201.GA21891@kroah.com> In-Reply-To: <20091005142201.GA21891@kroah.com> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Tue, 06 Oct 2009 01:15:15 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1066 Lines: 31 Greg KH wrote: >>> BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 >> Ping. This one needs to be fixed in -stable. It can be triggered by >> other char devices too. > > Sorry, been slowly catching up... > > This can be triggered by char devices? Huh? How? I don't see the > failure path that is happening here. Oooh, s/char/virtual/. The bug is in the path which creates a directory under the phony parent. > And char devices shouldn't really be using the kobject at all, except > for a very basic reference count. > > I keep threatening to rip kobject out of a char device and just use a > kref, as that is all that is really needed. Well, that and the kmap > stuff, but again, it's not a "real" kobject being used there... > > Perhaps now is the time to do this. Yay! -- tejun -- 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/