Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752791AbcKHOJE (ORCPT ); Tue, 8 Nov 2016 09:09:04 -0500 Received: from mxi.iteg.at ([185.35.182.175]:38406 "EHLO mxi.iteg.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751455AbcKHOJC (ORCPT ); Tue, 8 Nov 2016 09:09:02 -0500 X-Greylist: delayed 331 seconds by postgrey-1.27 at vger.kernel.org; Tue, 08 Nov 2016 09:09:01 EST X-Spam-Score: -1.9 X-Spam-Report: * -0.0 NO_RELAYS Informational: message was not relayed via SMTP * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.0 NO_RECEIVED Informational: message has no Received headers X-Recvd: from [192.168.52.43] (fw05.crs.iteg.at [83.175.111.149]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: christoph.lechleitner@iteg.at) by mxi.iteg.at (Postfix) with ESMTPSA id B724CC0240; Tue, 8 Nov 2016 15:03:03 +0100 (CET) Subject: Re: [PATCH] drbd: Fix kernel_sendmsg() usage To: Jens Axboe , linux-kernel@vger.kernel.org, stable@vger.kernel.org, drbd-dev@lists.linbit.com, philipp.reisner@linbit.com, viro@zeniv.linux.org.uk, Richard Weinberger , wolfgang.glas@iteg.at References: <1478601789-15060-1-git-send-email-richard@nod.at> <1478601789-15060-1-git-send-email-richard@nod.at> From: Christoph Lechleitner Message-ID: <43450517-c3c5-bbcb-8d9b-cbe2a0b25542@iteg.at> Date: Tue, 8 Nov 2016 15:03:08 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <1478601789-15060-1-git-send-email-richard@nod.at> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1130 Lines: 26 Am 2016-11-08 um 14:43 schrieb Lars Ellenberg: > From 3a5859e696178e31a25e65de58c461046fc52beb Mon Sep 17 00:00:00 2001 > From: Richard Weinberger > Date: Tue, 8 Nov 2016 11:43:09 +0100 > Subject: [PATCH] drbd: Fix kernel_sendmsg() usage - potential NULL deref > drbd: Fix kernel_sendmsg() usage - potential NULL deref > Even with this error exposed, to trigger the bug, we would need to have > an environment (config or otherwise) causing us to not use sendpage() > for larger transfers, a flaky connection, and have it fail "just at the > right time". Apparently that was unlikely enough for most, so this went > unnoticed for years. Our drbd configuration was created some 8 years ago. Maybe I should have read more migration tips when upgrading again and again, sorry ;-) But a 30cm Cat6 cable directly connecting 2 dedicated ethernet ports should not match the term "flaky connection". FYI: I co-own the company that hired Richard to track down this bug, that repeatedly (~15 times) forced us to hard-reset servers hosting tens of virtual root servers for our customers. Regards, Christoph Lechleitner