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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 817CCC4332D for ; Fri, 20 Mar 2020 05:41:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55B2B2072D for ; Fri, 20 Mar 2020 05:41:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="U3bFLpxB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726448AbgCTFle (ORCPT ); Fri, 20 Mar 2020 01:41:34 -0400 Received: from mail-oi1-f193.google.com ([209.85.167.193]:42712 "EHLO mail-oi1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726030AbgCTFld (ORCPT ); Fri, 20 Mar 2020 01:41:33 -0400 Received: by mail-oi1-f193.google.com with SMTP id 13so5325763oiy.9 for ; Thu, 19 Mar 2020 22:41:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=k688XzVuSNLYe3/7qT3llYLpqx6g5F7Zxm3QiJQLoqY=; b=U3bFLpxB0E1piwMeEM1qfe+GRCdtO2Zd+VZHSSx23ldLwDnUzwMpzAXvR1kOHbKj+B xKbk7Zpg2hzEba4e0Wpr5j3U1iuse35Pg3BjUk9FeiFJqCUYiVW8En0IOtYxR18FolS2 yszGygfmtACg2iotXT1BcwP4sfHv0odRerjm5yH1YXwv16JZGtPf4yERkzMdli43CrDk FY0AyUjYHXOy8OYF3KvhYydasPnvmHtGkpH5KM7J9aBPwJ3OZpiKEqBAZ6OxVb4YBcxH onVmOv3DTBNJuunCPjM6jgMe6pyERoNBLdNFFr0OPNOVaoWXDzBGWKXLf8Itu9umML3Y xRmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=k688XzVuSNLYe3/7qT3llYLpqx6g5F7Zxm3QiJQLoqY=; b=O8AMfSpOq6LIr5fp7PkeJ69rQKKnxyutjYcmogq5ZMV/30uyIUCEWxoQitmQuT9pKi UpZh5PUiiAxbZO93e5rbMFqXzMcyH1mMh27mLpwEdvwWlZUExWcCxsI5PZU9QajNNLoB 5rU011kzrdDlTGs0cB2qB7jGb8J9+UZzUxKI9UrVVTdFeqDpqitm1Ql1en0QQ3sxh170 K4HGouw67soBB+vHZzmWoLkqhXlgSPzDvNkmTB4RN+Ur+dXQevD3zvTtQChDqohL7cWv 7Tk5AcumcbxOc0vGIx60Ywfgxm+qqv27V/VyEGZxy2ZVsPl08CQO32zH1uGIfJzKyOIk k2pw== X-Gm-Message-State: ANhLgQ2DjqnMZQupem7ytBGSFkfeSqwgaj0S5q6dvCoNZsq/MiFUzGBw 2/9Jwx7BVX7tfVv8LogORXK6P3zD X-Google-Smtp-Source: ADFU+vvFDokCzqit29Qie6+1WIDzfxJZRMxfsKeN7TY4kM1M+mqPRrakJbqHnnpj/+3ibRHL47N1SQ== X-Received: by 2002:aca:3302:: with SMTP id z2mr333039oiz.3.1584682892690; Thu, 19 Mar 2020 22:41:32 -0700 (PDT) Received: from ubuntu-m2-xlarge-x86 ([2604:1380:4111:8b00::1]) by smtp.gmail.com with ESMTPSA id 103sm1613439oty.36.2020.03.19.22.41.31 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 19 Mar 2020 22:41:31 -0700 (PDT) Date: Thu, 19 Mar 2020 22:41:30 -0700 From: Nathan Chancellor To: Ben Hutchings Cc: Greg Kroah-Hartman , Sasha Levin , Sasha Levin , stable Subject: Re: [stable] locks: fix a potential use-after-free problem when wakeup a waiter Message-ID: <20200320054130.GA9611@ubuntu-m2-xlarge-x86> References: <2082b1e11fdbf3b64f0da022fb15a8b615c3678c.camel@codethink.co.uk> <20200318222906.GJ4189@sasha-vm> <20200319063742.GB3274814@kroah.com> <500c8174c171378e8b6802ad70b4bf5563b3fab0.camel@codethink.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <500c8174c171378e8b6802ad70b4bf5563b3fab0.camel@codethink.co.uk> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, Mar 19, 2020 at 07:27:56PM +0000, Ben Hutchings wrote: > 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. > Looks like a fix for the performance regression was committed yesterday to mainline. dcf23ac3e846c ("locks: reinstate locks_delete_block optimization") Cheers, Nathan