From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE19EC43219 for ; Wed, 9 Feb 2022 19:12:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231243AbiBITMb (ORCPT ); Wed, 9 Feb 2022 14:12:31 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:58776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbiBITMa (ORCPT ); Wed, 9 Feb 2022 14:12:30 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED768C014F39; Wed, 9 Feb 2022 11:12:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=9gl0k3PijnwzBappKxAOI37Vix6kLRRS+YqO+Vq3rvI=; b=qFAtiO6z0mbXRm+tzfImRHlYJg OTEmLv3RZ5U4u0wpUQrFULpv3aIekvg8pPgOqufzZ44EoTEJRYqPSLm3JGr+Hkhb9v5cTOHPaGHt+ L1ed4WJpmRlqB70lLATDhIrdvbCy9V7Zxz6O7Gd7OaK2wVVeC2qgUjnErZk0WUeFZepkiwT6rvQdE 8NZyyRdqBDI9s8fqf8jM+8S4NTygZ0SXY80sjtpWI0jW4xrr9WN/nD5/uUjoGEti0DiY0nRVgM/R5 qpAN95PzKrlZ2wQOoHCBtwZMyAIQpzFoKC8ls0PsakKTGsXuShImt2K9EfxTNU36x3onbKSwsTwsG cmiykScg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHsNu-008U5F-Dw; Wed, 09 Feb 2022 19:12:10 +0000 Date: Wed, 9 Feb 2022 19:12:10 +0000 From: Matthew Wilcox To: Lee Jones Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, Stable , Dave Chinner , Goldwyn Rodrigues , "Darrick J . Wong" , Bob Peterson , Damien Le Moal , Theodore Ts'o , Andreas Gruenbacher , Ritesh Harjani , Johannes Thumshirn , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, cluster-devel@redhat.com, syzbot+0ed9f769264276638893@syzkaller.appspotmail.com Subject: Re: [PATCH 1/1] Revert "iomap: fall back to buffered writes for invalidation failures" Message-ID: References: <20220209085243.3136536-1-lee.jones@linaro.org> <20220209150904.GA22025@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Feb 09, 2022 at 03:59:48PM +0000, Lee Jones wrote: > On Wed, 09 Feb 2022, Christoph Hellwig wrote: > > > On Wed, Feb 09, 2022 at 08:52:43AM +0000, Lee Jones wrote: > > > This reverts commit 60263d5889e6dc5987dc51b801be4955ff2e4aa7. > > > > > > Reverting since this commit opens a potential avenue for abuse. > > > > > > The C-reproducer and more information can be found at the link below. > > > > > > With this patch applied, I can no longer get the repro to trigger. > > > > Well, maybe you should actually debug and try to understand what is > > going on before blindly reverting random commits. > > That is not a reasonable suggestion. > > Requesting that someone becomes an area expert on a huge and complex > subject such as file systems (various) in order to fix your broken > code is not rational. Sending a patch to revert a change you don't understand is also not rational. If you've bisected it to a single change -- great! If reverting the patch still fixes the bug -- also great! But don't send a patch when you clearly don't understand what the patch did. > If you'd like to use the PoC provided as a basis to test your own > solution, then go right ahead. However, as it stands this API should > be considered to contain security risk and should be patched as > quickly as can be mustered. Reversion of the offending commit seems > to be the fastest method to achieve that currently. This is incoherent. There is no security risk.