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=-2.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham 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 EF2A9C65BAF for ; Wed, 12 Dec 2018 23:14:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A83532084E for ; Wed, 12 Dec 2018 23:14:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544656484; bh=R++n8pMaT8jzbJRCkS942AUnQg8hVklSl0keFhlKwR4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=GJDCenIlOg2soQXYago1ZUBxFFP+4chMIB36NYAfet1RfpyR2+jttCjmkkvxy+XKZ vuhPi1wEVADpN/VpFMQR2b+y4ZR9Cd7S+w7WXvM8NzEnCr+NbyxwBB6BMgYK7hlGYp TPIWGEfGMCHNXZnjMZDaP1rAPCxhpLx5ua3wBz18= DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A83532084E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728493AbeLLXOn (ORCPT ); Wed, 12 Dec 2018 18:14:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:44668 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726253AbeLLXOn (ORCPT ); Wed, 12 Dec 2018 18:14:43 -0500 Received: from localhost (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 5A8042084E; Wed, 12 Dec 2018 23:14:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544656482; bh=R++n8pMaT8jzbJRCkS942AUnQg8hVklSl0keFhlKwR4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qqmJgJLIeKt3W8OFrFrmKeQwDD8ZtxZDNnyFkjGUx7CXk3BNYrDnsOES/zbkrzwG1 1zhAziRwY0BxH98nuyKsjKuNGaNnA7bi+REX3Aj+Yw+GVrxdQhTwfh2/1fu0js/FCQ 6HEXzrWZZFsnGq/SYSNVeFN7LjfKafsWTDjFzxDY= Date: Wed, 12 Dec 2018 18:14:41 -0500 From: Sasha Levin To: Kees Cook Cc: "# 3.4.x" , LKML Subject: Re: [PATCH AUTOSEL 4.19 104/123] pstore/ram: Correctly calculate usable PRZ bytes Message-ID: <20181212231441.GG2746@sasha-vm> References: <20181205093555.5386-1-sashal@kernel.org> <20181205093555.5386-104-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 05, 2018 at 02:57:08PM -0800, Kees Cook wrote: >On Wed, Dec 5, 2018 at 1:41 AM Sasha Levin wrote: >> >> From: Kees Cook >> >> [ Upstream commit 89d328f637b9904b6d4c9af73c8a608b8dd4d6f8 ] >> >> The actual number of bytes stored in a PRZ is smaller than the >> bytes requested by platform data, since there is a header on each >> PRZ. Additionally, if ECC is enabled, there are trailing bytes used >> as well. Normally this mismatch doesn't matter since PRZs are circular >> buffers and the leading "overflow" bytes are just thrown away. However, in >> the case of a compressed record, this rather badly corrupts the results. >> >> This corruption was visible with "ramoops.mem_size=204800 ramoops.ecc=1". >> Any stored crashes would not be uncompressable (producing a pstorefs >> "dmesg-*.enc.z" file), and triggering errors at boot: >> >> [ 2.790759] pstore: crypto_comp_decompress failed, ret = -22! >> >> Backporting this depends on commit 70ad35db3321 ("pstore: Convert console >> write to use ->write_buf") > >Please note the above. If this gets backported, this one is needed too. Okay, I've added 70ad35db3321 for 4.9, 4.4, and 3.18. -- Thanks, Sasha