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 CC519C433F5 for ; Wed, 9 Feb 2022 15:59:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236415AbiBIP7x (ORCPT ); Wed, 9 Feb 2022 10:59:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236404AbiBIP7t (ORCPT ); Wed, 9 Feb 2022 10:59:49 -0500 Received: from mail-wr1-x42d.google.com (mail-wr1-x42d.google.com [IPv6:2a00:1450:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76FE9C05CB82 for ; Wed, 9 Feb 2022 07:59:52 -0800 (PST) Received: by mail-wr1-x42d.google.com with SMTP id q7so4781566wrc.13 for ; Wed, 09 Feb 2022 07:59:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=Wf8pBHPnIbwBS8l1ga7IlePPb2NVs+dEhjuVljUBPL0=; b=uoZQFZFTh4MWC1dtmAROvUGhJHmAVYXfRYOAWo8gKyK62YWvPbxBb/FtR7u0hgWHM+ pIHKzcAPIBus0KV7+mL3D5j14qeOkWhNlhbJ27iaSBhTl/LjI4HHKacQLeaP0W27kYi4 S3IY7DwzPAuE8oLpegUUjChlpPOLw2uSQqJ+5BKLAuffbk7cd8egzMzWrTEY9KtgoRa8 lhCJFlR9ZXDT3UoxC0gXTD0HcsmKfyMcum4z3NXlytG7Avl6gstXNUE/R3zGzn6Ti6rI nfSuSby+RBkqpUK/2NHWt/I4qhdA9CqPByEjJEcUJtu45v7exquNrCxUmMMhRNRl4LwZ 9QKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=Wf8pBHPnIbwBS8l1ga7IlePPb2NVs+dEhjuVljUBPL0=; b=Mr26fAmEOSXWiq5foEZxFlLd7wTav0dFYxwvQjcOb20M7DCSDS9lyf4lmmAVfm4YQJ +jaDUQd7GmB4v8UMllnrJ1GwGU5iMI9Oe9kTLkjx9onMjVox8gbU2zAPoqFiYgsn4Fje R7IpTZQvWTruue9gYZXb4ouYloHwjsWBtbSgi4L7MjCwT6f2g70v0V+/eEO3p6tn4tOV pMismlmk8d6t3A6vNTL3Vwex7GdXQS0kfavK7N4+HTfaAH/FzajS1pbUA53KrMrrdGpO 2ra0H3THPChKWIlnHPni4UINJDFbDQVDfsXFzZqWtS7jYJHcCAZhPjiXPiW/U/ueBgIm kbkw== X-Gm-Message-State: AOAM530TGibC2yZfVLsW2o0iY4T35Hu4Te6z1dIo0RA/3RuiSCMWDl2i YO5FxLIyK3FOCqqJrUJQJSrhtg== X-Google-Smtp-Source: ABdhPJzrsU/yGaq1wonWpTsPZOGFI2x3Kw84cs8UYaEe/84fhhkIxX9wA9KdK4C49JCW0SYDnFQlaw== X-Received: by 2002:a05:6000:1548:: with SMTP id 8mr2519928wry.504.1644422390765; Wed, 09 Feb 2022 07:59:50 -0800 (PST) Received: from google.com (cpc155339-bagu17-2-0-cust87.1-3.cable.virginm.net. [86.27.177.88]) by smtp.gmail.com with ESMTPSA id g22sm5098170wmh.7.2022.02.09.07.59.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Feb 2022 07:59:50 -0800 (PST) Date: Wed, 9 Feb 2022 15:59:48 +0000 From: Lee Jones To: Christoph Hellwig Cc: 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220209150904.GA22025@lst.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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. -- Lee Jones [李琼斯] Principal Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog