Re: [PATCH v2 1/3] PCI/sysfs: Fix null pointer dereference during hotplug

[duziming]

在 2025/12/30 1:31, Bjorn Helgaas 写道:
> On Wed, Dec 24, 2025 at 05:27:17PM +0800, Ziming Du wrote:
> > During the concurrent process of creating and rescanning in VF, the
> > resource files for the same pci_dev may be created twice. The second
> > creation attempt fails, resulting the res_attr in pci_dev to kfree(),
> > but the pointer is not set to NULL. This will subsequently lead to
> > dereferencing a null pointer when removing the device.
> >
> > When we perform the following operation:
> >    echo $vfcount > /sys/class/net/"$pfname"/device/sriov_numvfs &
> Is the value of $vfcount relevant here?  Can you use the actual values
> here instead of the variables so this is more useful to others?

In fact, we directly use sriov_totalvfs here. In my opinion, the larger 
this value is,

the more likely it is to cause the issue.

> >    sleep 0.5
> >    echo 1 > /sys/bus/pci/rescan
> >    pci_remove "$pfname"
> > system will crash as follows: