Re: kernel NULL pointer dereference on hotplug

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi,

On Wed, Feb 07, 2024 at 10:12:07AM +0100, Thorsten Leemhuis wrote:
> On 07.02.24 07:13, Linux regression tracking (Thorsten Leemhuis) wrote:
> > 
> > On 04.02.24 07:40, Mika Westerberg wrote:
> >> On Fri, Feb 02, 2024 at 05:47:01PM +0100, Olliver Schinagl wrote:
> >>>
> >>> I noticed this nasty kernel NULL pointer dereference yesterday on
> >>> 6.7.2-arch1-1 (haven't done this in a while) but also today, after updating
> >>> to 6.7.3-arch1-1 it's still there, so dumping the panic here. Hopefully
> >>> it'll be resolved by 6.7.4-arch1-1.
> >>
> >> Thanks for the report.
> >>
> >>> The thunderbolt gbit adapter always worked in the past, so this seems like a
> >>> regression. Anyway, here's the log.
> 
> FWIW, Leon Weiß (BCCed) just posted another NULL pointer deference issue
> in 6.7 and found the culprit; for details see:
> https://lore.kernel.org/all/38c253ea42072cc825dc969ac4e6b9b600371cc8.camel@ruhr-uni-bochum.de/
>
> Sadly Leon's report lacks a backtrace we had in this thread (
> https://lore.kernel.org/all/c24c7882-6254-4e68-8f22-f3e8f65dc84f@schinagl.nl/
> ), so it might be something totally different. Leon's problem afaics
> also happens on unplug while this one on hotplug. But well, I thought I
> better quickly mention it here anyway so everyone is aware of it.

Thanks for the information. 

As you mention, this seems to be unrelated. The one above is about DRM
and graphics, the one Olliver reported is about Thunderbolt (okay there
is Thunderbolt device involved in both but this one seems to be purely
DP thing).