Return-Path: Received: from scorn.kernelslacker.org ([45.56.101.199]:58562 "EHLO scorn.kernelslacker.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751496AbdHARud (ORCPT ); Tue, 1 Aug 2017 13:50:33 -0400 Date: Tue, 1 Aug 2017 13:50:31 -0400 From: "davej@codemonkey.org.uk" To: Linus Torvalds Cc: Trond Myklebust , "linux-kernel@vger.kernel.org" , "bfields@fieldses.org" , "linux-nfs@vger.kernel.org" , "schumaker.anna@gmail.com" , "linux-fsdevel@vger.kernel.org" Subject: Re: [GIT PULL] Please pull NFS client changes for Linux 4.13 Message-ID: <20170801175031.74llpntgz3qirv3s@codemonkey.org.uk> References: <20170714142543.k5xcbnb4mww3sxpy@codemonkey.org.uk> <20170716211530.sx7mn35f2mhmykug@codemonkey.org.uk> <1500245845.13893.3.camel@primarydata.com> <20170717030504.qca74wsswct26ytn@codemonkey.org.uk> <20170731154322.tfzkukscda4fe7wm@codemonkey.org.uk> <20170801155131.xy7nbw5ih7ml5fmf@codemonkey.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Aug 01, 2017 at 10:20:31AM -0700, Linus Torvalds wrote: > So I think the 'pathname' part may actually be entirely a red herring, > and it's the underlying access itself that just picks up a random > pointer from a stack that now contains something different. And KASAN > didn't notice the stale stack access itself, because the stack slot is > still valid - it's just no longer the original 'verifier' allocation. > > Or *something* like that. > > None of this looks even remotely new, though - the code seems to go > back to 2009. Have you just changed what you're testing to trigger > these things? No idea why it only just showed up, but it isn't 100% reproducable either. A month or so ago I did disable the V4 code on the server completely (as I was using v3 everywhere else), so maybe I started hitting a fallback path somewhere. *shrug* Dave