linux-kernel - Re: [PATCH v2] i2c: rk3x: fix potential spinlock recursion on poll

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: <5e11553952c02ad20591992be4284bbd@manjaro.org>
Date:   Thu, 07 Dec 2023 15:10:29 +0100
From:   Dragan Simic <dsimic@...jaro.org>
To:     Jensen Huang <jensenhuang@...endlyarm.com>
Cc:     Heiko Stuebner <heiko@...ech.de>,
        Andi Shyti <andi.shyti@...nel.org>,
        linux-arm-kernel@...ts.infradead.org,
        linux-rockchip@...ts.infradead.org, linux-i2c@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Dmitry Osipenko <dmitry.osipenko@...labora.com>,
        Chris Morgan <macroalpha82@...il.com>,
        Benjamin Bara <bbara93@...il.com>
Subject: Re: [PATCH v2] i2c: rk3x: fix potential spinlock recursion on poll

On 2023-12-07 10:25, Jensen Huang wrote:
> On Thu, Dec 7, 2023 at 4:37 PM Dragan Simic <dsimic@...jaro.org> wrote:
>> 
>> On 2023-12-07 09:21, Jensen Huang wrote:
>> > Possible deadlock scenario (on reboot):
>> > rk3x_i2c_xfer_common(polling)
>> >     -> rk3x_i2c_wait_xfer_poll()
>> >         -> rk3x_i2c_irq(0, i2c);
>> >             --> spin_lock(&i2c->lock);
>> >             ...
>> >         <rk3x i2c interrupt>
>> >         -> rk3x_i2c_irq(0, i2c);
>> >             --> spin_lock(&i2c->lock); (deadlock here)
>> >
>> > Store the IRQ number and disable/enable it around the polling transfer.
>> > This patch has been tested on NanoPC-T4.
>> 
>> In case you haven't already seen the related discussion linked below,
>> please have a look.  I also added more people to the list of 
>> recipients,
>> in an attempt to make everyone aware of the different approaches to
>> solving this issue.
>> 
>> https://lore.kernel.org/all/655177f4.050a0220.d85c9.3ba0@mx.google.com/T/#m6fc9c214452fec6681843e7f455978c35c6f6c8b
> 
> Thank you for providing the information. I hadn't seen this link 
> before.
> After carefully looking into the related discussion, it appears that
> Dmitry Osipenko is already working on a suitable patch. To avoid 
> duplication
> or conflicts, my patch can be discarded.

Thank you for responding so quickly.  Perhaps it would be best to hear 
from Dmitry as well, before discarding anything.  It's been a while 
since Dmitry wrote about working on the patch, so he might have 
abandoned it.