PCI/MSI: Destroy sysfs before freeing entries

free_msi_irqs() frees the MSI entries before destroying the sysfs entries which are exposing them. Nothing prevents a concurrent free while a sysfs file is read and accesses the possibly freed entry. Move the sysfs release ahead of freeing the entries. Fixes: 1c51b50 ("PCI/MSI: Export MSI mode using attributes, not kobjects") Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Greg Kroah-Hartman <[email protected]> Cc: Bjorn Helgaas <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/87sfw5305m.ffs@tglx
pop-os · Nov 11, 2021 · 3735459 · 3735459
1 parent f21082f
commit 3735459
Showing 1 changed file with 5 additions and 5 deletions.
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
@@ -368,6 +368,11 @@ static void free_msi_irqs(struct pci_dev *dev)
 			for (i = 0; i < entry->nvec_used; i++)
 				BUG_ON(irq_has_action(entry->irq + i));
 
+	if (dev->msi_irq_groups) {
+		msi_destroy_sysfs(&dev->dev, dev->msi_irq_groups);
+		dev->msi_irq_groups = NULL;
+	}
+
 	pci_msi_teardown_msi_irqs(dev);
 
 	list_for_each_entry_safe(entry, tmp, msi_list, list) {
@@ -379,11 +384,6 @@ static void free_msi_irqs(struct pci_dev *dev)
 		list_del(&entry->list);
 		free_msi_entry(entry);
 	}
-
-	if (dev->msi_irq_groups) {
-		msi_destroy_sysfs(&dev->dev, dev->msi_irq_groups);
-		dev->msi_irq_groups = NULL;
-	}
 }
 
 static void pci_intx_for_msi(struct pci_dev *dev, int enable)