linux-kernel - Re: 5.11 new lockdep warning related to led-class code (also may involve ata / piix controller)

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: <f344f1db-1a7a-0a80-1cb1-f9c3fbf83abd@redhat.com>
Date:   Wed, 13 Jan 2021 09:59:44 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Pavel Machek <pavel@....cz>
Cc:     Jens Axboe <axboe@...nel.dk>, Dan Murphy <dmurphy@...com>,
        linux-ide@...r.kernel.org, linux-leds@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: 5.11 new lockdep warning related to led-class code (also may
 involve ata / piix controller)

Hi,

On 1/12/21 11:30 PM, Pavel Machek wrote:
> Hi!
> 
>> Booting a 5.11-rc2 kernel with lockdep enabled inside a virtualbox vm (which still
>> emulates good old piix ATA controllers) I get the below lockdep splat early on during boot:
>>
>> This seems to be led-class related but also seems to have a (P)ATA
>> part to it. To the best of my knowledge this is a new problem in
>> 5.11 .
> 
> This is on my for-next branch:
> 
> commit 9a5ad5c5b2d25508996f10ee6b428d5df91d9160 (HEAD -> for-next, origin/for-next)
> 
>     leds: trigger: fix potential deadlock with libata
>     
>     We have the following potential deadlock condition:
>     
>      ========================================================
>      WARNING: possible irq lock inversion dependency detected
>      5.10.0-rc2+ #25 Not tainted
>      --------------------------------------------------------
>      swapper/3/0 just changed the state of lock:
>      ffff8880063bd618 (&host->lock){-...}-{2:2}, at: ata_bmdma_interrupt+0x27/0x200
>      but this lock took another, HARDIRQ-READ-unsafe lock in the past:
>       (&trig->leddev_list_lock){.+.?}-{2:2}
> 
> If I'm not mistaken, that should fix your issue.

I can confirm that this fixes things, thanks.

I assume that this will be part of some future 5.11 fixes pull-req?

Regards,

Hans