Re: thunderbolt: NULL deref in nhi_remove() from pciehp during shutdown (Titan Ridge, ThinkPad P1 Gen 3)

Re: thunderbolt: NULL deref in nhi_remove() from pciehp during shutdown (Titan Ridge, ThinkPad P1 Gen 3)

[Mika Westerberg]

Hi,

On Fri, Nov 06, 2026 at 07:46:16PM -0800, Alex wrote:
> Hi Mika,
> 
> I'm not a kernel developer, so apologies if this isn't the right way to report
> this.
> 
>  My ThinkPad P1 Gen 3 has been hanging instead of turning off
> for most of this year whenever it powers itself off on a low battery.
> I had an AI assistant (Claude Code) dig into it, and it found what
> looks like a double teardown of the Thunderbolt NHI during shutdown.
> The info dump below and a suggested patch are AI-generated, so please treat
> them that way.
> 
> I applied the patch and it fixed the problem, and it looks like from research
> that this issue was called out as a bit of a concern when it was comitted back
> in the day, so thought I would share in case you want to fix it. 
> 
> Thanks,
> -Alex
> 
> ------
> 
> Hardware: ThinkPad P1 Gen 3 (20TH0037US), BIOS N2VET36W (1.21)
> 2021-12-27, Titan Ridge JHL7540 behind root port 00:1c.0 (pciehp,
> HotPlug+ Surprise+). Firmware connection manager. Ubuntu 24.04, kernel
> 6.8.0-138 at the time of this dump. The nvidia and ZFS modules are
> loaded, hence the taint.

Can you try with a newer kernel and see if the problem still happens?
Something like v7.3 would be good. If it does then please provide dump.