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 d7d8ab87e3e7 ("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: d7d8ab87e3e7 ("PCI: vmd: Switch to msi_create_parent_irq_domain()")
Reported-by: Kenneth Crudup <kenny@panix.com>
Closes: https://lore.kernel.org/linux-pci/dfa40e48-8840-4e61-9fda-25cdb3ad81c1@panix.com/
Reported-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Closes: https://lore.kernel.org/linux-pci/ed53280ed15d1140700b96cca2734bf327ee92539e5eb68e80f5bbbf0f01@linux.gnuweeb.org/
Tested-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Tested-by: Kenneth Crudup <kenny@panix.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20250807081051.2253962-1-namcao@linutronix.de

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 9bbb0ff4cc15b31f5693b88a92827899b4042e0c..b679c7f28f51c13468b60f1e6481a26d5967d4eb 100644 (file)
--- a/drivers/pci/controller/vmd.c
+++ b/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);