linux-kernel - Re: ltp or kvm triggerable lockdep alloc

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: <20201022164413.tnchtyqbotvbnp2e@linutronix.de>
Date:   Thu, 22 Oct 2020 18:44:13 +0200
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     Mike Galbraith <efault@....de>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-rt-users <linux-rt-users@...r.kernel.org>,
        Steven Rostedt <rostedt@...dmis.org>
Subject: Re: ltp or kvm triggerable lockdep alloc_pid()  deadlock gripe

On 2020-10-22 07:21:13 [+0200], Mike Galbraith wrote:
> Greetings,
Hi,

> The gripe below is repeatable in two ways here, boot with nomodeset so
> nouveau doesn't steal the lockdep show when I then fire up one of my
> (oink) full distro VM's, or from an ltp directory ./runltp -f cpuset
> with the attached subset of controllers file placed in ./runtest dir.
> 
> Method2 may lead to a real deal deadlock, I've got a crashdump of one,
> stack traces of uninterruptible sleepers attached.

Just added commit
	267580db047ef ("seqlock: Unbreak lockdep")

and it is gone.

Sebastian