Re: [PATCH v2] PCI: vmd: Fix wrong kfree() in vmd_msi_free()

[Nam Cao <namcao@linutronix.de>]

Bjorn Helgaas <helgaas@kernel.org> writes:
> On Thu, Aug 07, 2025 at 10:10:51AM +0200, Nam Cao wrote:
>> vmd_msi_alloc() allocates struct vmd_irq and stashes it into
>> irq_data->chip_data associated with the VMD's interrupt domain.
>> vmd_msi_free() extracts the pointer by calling irq_get_chip_data() and
>> frees it.
>> 
>> irq_get_chip_data() returns the chip_data associated with the top interrupt
>> domain. This worked in the past, because VMD's interrupt domain was the top
>> domain.
>> 
>> But since commit d7d8ab87e3e7 ("PCI: vmd: Switch to
>> msi_create_parent_irq_domain()") changed the interrupt domain hierarchy,
>> VMD's interrupt domain is not the top domain anymore. irq_get_chip_data()
>> now returns the chip_data at the MSI devices' interrupt domains. It is
>> therefore broken for vmd_msi_free() to kfree() this chip_data.
>> 
>> Fix this issue, correctly extract the chip_data associated with the VMD's
>> interrupt domain.
...
>
> Applied to pci/for-linus for v6.17, thanks!
>
> I assume you checked the other msi_create_parent_irq_domain() changes
> for similar problems?

Not before you reminded me :(

But yes, none of the similar PCI patches has the same problem.

Nam