From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261165AbVHATBW (ORCPT ); Mon, 1 Aug 2005 15:01:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261169AbVHATBW (ORCPT ); Mon, 1 Aug 2005 15:01:22 -0400 Received: from smtp.osdl.org ([65.172.181.4]:36749 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S261165AbVHATBW (ORCPT ); Mon, 1 Aug 2005 15:01:22 -0400 Date: Mon, 1 Aug 2005 12:03:21 -0700 From: Andrew Morton To: Keith Owens Cc: linux-kernel@vger.kernel.org Subject: Re: 2.6.13-rc4 use after free in class_device_attr_show Message-Id: <20050801120321.230349c5.akpm@osdl.org> In-Reply-To: <8551.1122898445@ocs3.ocs.com.au> References: <20050730022955.6c7dd2e8.akpm@osdl.org> <8551.1122898445@ocs3.ocs.com.au> X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i386-vine-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Keith Owens wrote: > > On Sat, 30 Jul 2005 02:29:55 -0700, > Andrew Morton wrote: > >Keith Owens wrote: > >> > >> 2.6.13-rc4 + kdb, with lots of CONFIG_DEBUG options. There is an > >> intermittent use after free in class_device_attr_show. Reboot with no > >> changes and the problem does not always recur. > >> ... > >> ip is at class_device_attr_show+0x50/0xa0 > >> ... > > > >It might help to know which file is being read from here. > > > >The below patch will record the name of the most-recently-opened sysfs > >file. You can print last_sysfs_file[] in the debugger or add the > >appropriate printk to the ia64 code? > > No need for a patch. It is /dev/vcsa2. You mean /sys/class/vc/vcsa2? That appears to be using generic code... Can you please summarise what you curently know about this bug? What is being accessed after free in class_device_attr_show()? class_dev_attr? cd?