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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65C9DC28EB5 for ; Thu, 6 Jun 2019 21:46:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3BDCA208C0 for ; Thu, 6 Jun 2019 21:46:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559857606; bh=e8zSxF2YstjZdXDoPM2QroSTxqWSMLpjdXaDzNM/bHM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=UdRNMGCj+NEL1WIFXxNzOwibJQK64naoLR8itWpOYaX2sMU6XXLTiejhgwDe6dgyY nOSSIhy5dRSiVKv3qUbh5aG62CWb3KrwG7rnwjCnIOxtjHeHVI5t8p9oE1dDPSkXx4 Zztn5PW91h8gVMuxEF/Mbbd/NPa9yejWV3Q8bapg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728664AbfFFVqp (ORCPT ); Thu, 6 Jun 2019 17:46:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:40324 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726157AbfFFVqp (ORCPT ); Thu, 6 Jun 2019 17:46:45 -0400 Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 309C320673; Thu, 6 Jun 2019 21:46:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559857604; bh=e8zSxF2YstjZdXDoPM2QroSTxqWSMLpjdXaDzNM/bHM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=dfZnA3LoZI3kcekTvMdg7vm4wyUFToyxp29Scm6Cs7omCJytnHlzwlMXFqlGds2ht tKZ/OehCLO9EzgtHqjvJGedCRwMgeIGQKU+kGulTg4LF9TrwyYbFy3R+yo1Vi1wg+x L5CEq0PQe3DdZ/43QWfXSG4GV8UOuKXGuJHoNWd0= Date: Thu, 6 Jun 2019 14:46:43 -0700 From: Andrew Morton To: Dan Williams Cc: stable@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, osalvador@suse.de, mhocko@suse.com Subject: Re: [PATCH v9 11/12] libnvdimm/pfn: Fix fsdax-mode namespace info-block zero-fields Message-Id: <20190606144643.4f3363db9499ebbf8f76e62e@linux-foundation.org> In-Reply-To: <155977193862.2443951.10284714500308539570.stgit@dwillia2-desk3.amr.corp.intel.com> References: <155977186863.2443951.9036044808311959913.stgit@dwillia2-desk3.amr.corp.intel.com> <155977193862.2443951.10284714500308539570.stgit@dwillia2-desk3.amr.corp.intel.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 05 Jun 2019 14:58:58 -0700 Dan Williams wrote: > At namespace creation time there is the potential for the "expected to > be zero" fields of a 'pfn' info-block to be filled with indeterminate > data. While the kernel buffer is zeroed on allocation it is immediately > overwritten by nd_pfn_validate() filling it with the current contents of > the on-media info-block location. For fields like, 'flags' and the > 'padding' it potentially means that future implementations can not rely > on those fields being zero. > > In preparation to stop using the 'start_pad' and 'end_trunc' fields for > section alignment, arrange for fields that are not explicitly > initialized to be guaranteed zero. Bump the minor version to indicate it > is safe to assume the 'padding' and 'flags' are zero. Otherwise, this > corruption is expected to benign since all other critical fields are > explicitly initialized. > > Fixes: 32ab0a3f5170 ("libnvdimm, pmem: 'struct page' for pmem") > Cc: > Signed-off-by: Dan Williams The cc:stable in [11/12] seems odd. Is this independent of the other patches? If so, shouldn't it be a standalone thing which can be prioritized?