linux-kernel - Re: Crashes with 874bbfe600a6 in 3.18.25

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1454640046.3545.8.camel@gmail.com>
Date:	Fri, 05 Feb 2016 03:40:46 +0100
From:	Mike Galbraith <umgwanakikbuti@...il.com>
To:	Daniel Bilik <daniel.bilik@...system.cz>, Jan Kara <jack@...e.cz>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	LKML <linux-kernel@...r.kernel.org>, stable@...r.kernel.org
Subject: Re: Crashes with 874bbfe600a6 in 3.18.25

On Thu, 2016-02-04 at 17:39 +0100, Daniel Bilik wrote:
> On Thu, 4 Feb 2016 12:20:44 +0100
> Jan Kara <jack@...e.cz> wrote:
> 
> > Thanks for backport Thomas and to Mike for persistence :). I've asked my
> > friend seeing crashes with 3.18.25 to try whether this patch fixes the
> > issues. It may take some time so stay tuned...
> 
> Patch tested and it really fixes the crash we were experiencing on 3.18.25
> with commit 874bbfe+. But it seem to introduce (rather scary) regression.
> Tested host shows abnormal cpu usage in both kernel and userland under the
> same load and traffic pattern. One picture is worth a thousand words, so
> I've taken snapshots of our graphs, see here:
> http://neosystem.cz/test/linux-3.18.25/
> The host was running 3.18.25 with commit 874bbfe+ (1e7af29+ on
> 3.18-stable) reverted. With this commit included, it crashed within
> minutes. Around 13:30 we booted 3.18.25 with commit 874bbfe+ included and
> with the patch from Thomas. And around 15:40 we've booted the host with
> previous kernel, just to ensure this abnormal behaviour was really caused
> by the test kernel.
> Also interesting, in addition to high cpu usage, there is abnormally high
> number of zombie processes reported by the system.

IMHO you should restore the CC list and re-post.  (If I were the
maintainer of either the workqueue code or 3.18-stable, I'd be highly
interested in this finding).

	-Mike