PCI/MSI: Destroy sysfs before freeing entries

commit 3735459 upstream. 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 Signed-off-by: Greg Kroah-Hartman <[email protected]>
hnonly · Nov 21, 2021 · 9b61500 · 9b61500
1 parent c49bfdf
commit 9b61500
Showing 1 changed file with 12 additions and 12 deletions.
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
@@ -396,18 +396,6 @@ 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));
 
-	pci_msi_teardown_msi_irqs(dev);
-
-	list_for_each_entry_safe(entry, tmp, msi_list, list) {
-		if (entry->msi_attrib.is_msix) {
-			if (list_is_last(&entry->list, msi_list))
-				iounmap(entry->mask_base);
-		}
-
-		list_del(&entry->list);
-		free_msi_entry(entry);
-	}
-
 	if (dev->msi_irq_groups) {
 		sysfs_remove_groups(&dev->dev.kobj, dev->msi_irq_groups);
 		msi_attrs = dev->msi_irq_groups[0]->attrs;
@@ -423,6 +411,18 @@ static void free_msi_irqs(struct pci_dev *dev)
 		kfree(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) {
+		if (entry->msi_attrib.is_msix) {
+			if (list_is_last(&entry->list, msi_list))
+				iounmap(entry->mask_base);
+		}
+
+		list_del(&entry->list);
+		free_msi_entry(entry);
+	}
 }
 
 static void pci_intx_for_msi(struct pci_dev *dev, int enable)