From: Peter Moody Subject: Re: Oops with ext(3|4) and audit and Xen Date: Mon, 8 Oct 2012 14:19:05 -0700 Message-ID: References: <20121008211500.GD22980@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-ext4@vger.kernel.org To: "Theodore Ts'o" Return-path: Received: from mail-wi0-f172.google.com ([209.85.212.172]:53434 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755015Ab2JHVTh (ORCPT ); Mon, 8 Oct 2012 17:19:37 -0400 Received: by mail-wi0-f172.google.com with SMTP id hq12so4500734wib.1 for ; Mon, 08 Oct 2012 14:19:36 -0700 (PDT) In-Reply-To: <20121008211500.GD22980@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Oct 8, 2012 at 2:15 PM, Theodore Ts'o wrote: > On Mon, Oct 08, 2012 at 11:19:53AM -0700, Peter Moody wrote: >> >> I'm trying to track down a BUG() that seems to strike a particular >> system configuration (unfortunately, an increasingly common >> configuration), but does so with 100% reliability. > > Peter, this looks like exactly the same issue that you asked me about > back in July, isn't it? Check your corp e-mail archives for the > subject line: "advice/pointers on debugging a potential kernel race". > > As I recall, the problem was a missing path_put() in audit_putname() > in kernel/auditsc.c? > > - Ted Yep, this is that issue and I thought that was the fix but it turns out it wasn't. The dentry was already being pinned in: if (!context->pwd.dentry) get_fs_pwd(current->fs, &context->pwd); so my path_get/path_put patch just needlessly grabbed a second reference. -- Peter Moody Google 1.650.253.7306 Security Engineer pgp:0xC3410038