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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 2AF81C4332E for ; Thu, 19 Mar 2020 19:28:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0284F2071C for ; Thu, 19 Mar 2020 19:28:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726934AbgCST2C (ORCPT ); Thu, 19 Mar 2020 15:28:02 -0400 Received: from imap3.hz.codethink.co.uk ([176.9.8.87]:59188 "EHLO imap3.hz.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726785AbgCST2C (ORCPT ); Thu, 19 Mar 2020 15:28:02 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126] helo=xylophone) by imap3.hz.codethink.co.uk with esmtpsa (Exim 4.92 #3 (Debian)) id 1jF0ph-0007ul-Eo; Thu, 19 Mar 2020 19:27:57 +0000 Message-ID: <500c8174c171378e8b6802ad70b4bf5563b3fab0.camel@codethink.co.uk> Subject: Re: [stable] locks: fix a potential use-after-free problem when wakeup a waiter From: Ben Hutchings To: Greg Kroah-Hartman , Sasha Levin Cc: Sasha Levin , stable Date: Thu, 19 Mar 2020 19:27:56 +0000 In-Reply-To: <20200319063742.GB3274814@kroah.com> References: <2082b1e11fdbf3b64f0da022fb15a8b615c3678c.camel@codethink.co.uk> <20200318222906.GJ4189@sasha-vm> <20200319063742.GB3274814@kroah.com> Organization: Codethink Ltd. Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, 2020-03-19 at 07:37 +0100, Greg Kroah-Hartman wrote: > On Wed, Mar 18, 2020 at 06:29:06PM -0400, Sasha Levin wrote: > > On Wed, Mar 18, 2020 at 10:09:20PM +0000, Ben Hutchings wrote: > > > This commit (included in 5.6-rc5) seems to be needed for 5.4 and 5.5 > > > branches: > > > > > > commit 6d390e4b5d48ec03bb87e63cf0a2bff5f4e116da > > > Author: yangerkun > > > Date: Wed Mar 4 15:25:56 2020 +0800 > > > > > > locks: fix a potential use-after-free problem when wakeup a waiter > > > > I've queued it up for 5.5 and 5.4, thanks! > > > > > I'm a bit surprised that it hasn't yet been applied, while some fixes > > > from 5.6-rc6 have. > > > > Greg, I wonder if it makes sense to have you push a "Greg is here > > --->" "bookmark" in the form of a tag/branch on linux-stable-rc.git? at > > the very least it'll make it easy to see if something was missed or > > still waiting in the queue. > > To quote Jeff Layton: > > Hi Greg, there is a performance regression with this patch. We're > sorting through potential ways to address it at the moment, but you may > want to hold off until we have a fix for that merged. > > Sorry for the hassle! > > Which is why I dropped it for now. > > I'll go drop it again :) I didn't see any mention of this on the stable list though. I also don't think that a performance regression outweighs the seriousness of the bug being fixed. Ben. -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom