PCI: vmd: Fix wrong kfree() in vmd_msi_free()

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 d7d8ab8 ("PCI: vmd: Switch to msi_create_parent_irq_domain()")
changed the interrupt domain hierarchy so 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 by extracting the chip_data associated with the VMD's interrupt domain.

Fixes: d7d8ab8 ("PCI: vmd: Switch to msi_create_parent_irq_domain()")
Reported-by: Kenneth Crudup <[email protected]>
Closes: https://lore.kernel.org/linux-pci/[email protected]/
Reported-by: Ammar Faizi <[email protected]>
Closes: https://lore.kernel.org/linux-pci/ed53280ed15d1140700b96cca2734bf327ee92539e5eb68e80f5bbbf0f01@linux.gnuweeb.org/
Tested-by: Ammar Faizi <[email protected]>
Tested-by: Kenneth Crudup <[email protected]>
Signed-off-by: Nam Cao <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Reviewed-by: Jinjie Ruan <[email protected]>
Acked-by: Manivannan Sadhasivam <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: covanam

drivers/pci/controller/vmd.c

@@ -280,10 +280,12 @@ static int vmd_msi_alloc(struct irq_domain *domain, unsigned int virq,
 static void vmd_msi_free(struct irq_domain *domain, unsigned int virq,
 			 unsigned int nr_irqs)
 {
+	struct irq_data *irq_data;
 	struct vmd_irq *vmdirq;
 
 	for (int i = 0; i < nr_irqs; ++i) {
-		vmdirq = irq_get_chip_data(virq + i);
+		irq_data = irq_domain_get_irq_data(domain, virq + i);
+		vmdirq = irq_data->chip_data;
 
 		synchronize_srcu(&vmdirq->irq->srcu);