Re: [BUG] PCI/DPC: NULL pointer dereference in pci_bus_read_config_dword during DPC recovery racing with hotplug

[Lukas Wunner]

On Wed, Jan 14, 2026 at 09:49:44AM +0000, Kangfenglong wrote:
> Kernel Version: 5.10.0

That's ancient.

The bug you're seeing was fixed upstream with 11a1f4bc4736 ("PCI/DPC:
Fix use-after-free on concurrent DPC and hot-removal").  It was
backported to 5.10.224.

> 1. Existing synchronization between DPC and hotplug?

That was introduced by a97396c6eb13 ("PCI: pciehp: Ignore Link Down/Up
caused by DPC"), which went into v5.14.

Thanks,

Lukas