From sudipm.mukherjee at gmail.com  Fri May  8 03:27:56 2026
From: sudipm.mukherjee at gmail.com (Sudip Mukherjee)
Date: Fri, 8 May 2026 11:27:56 +0100
Subject: [Linux-parport] [PATCH] parport: Fix race between port and
 client registration
In-Reply-To: <afo6uBv68GDevbMD@decadent.org.uk>
References: <afo6uBv68GDevbMD@decadent.org.uk>
Message-ID: <CADVatmM8DECzSBq4pCUUrLksa0YEBck9xDmKVYZw4cagv26GCQ@mail.gmail.com>

On Tue, 5 May 2026 at 19:45, Ben Hutchings <benh at debian.org> wrote:
>
> The parport subsystem registers port devices before they are fully
> initialised, resulting in a race condition where client drivers such
> as lp can attach to ports that are not completely initialised or even
> being torn down.

Thanks Ben.

>
> When the port and client drivers are built as modules and loaded
> around the same time during boot, this occasionally results in a
> crash.  I was able to make this happen reliably in a VM with a
> PC-style parallel port by patching parport_pc to fail probing:

<snip>

>
> Fixes: 6fa45a226897 ("parport: add device-model to parport subsystem")
> Closes: https://bugs.debian.org/1130365
> Closes: https://lore.kernel.org/all/6ba903ad-9897-42bb-8c2d-337385cc3746 at molgen.mpg.de/
> Cc: stable at vger.kernel.org
> Signed-off-by: Ben Hutchings <benh at debian.org>

Acked-by: Sudip Mukherjee <sudipm.mukherjee at gmail.com>


-- 
Regards
Sudip