--- a/drivers/bus/pci/pdo.c
+++ b/drivers/bus/pci/pdo.c
@@ -359,6 +359,7 @@ PdoGetRangeLength(PPDO_DEVICE_EXTENSION DeviceExtension,
     *Base = ((OriginalValue.Bar & PCI_ADDRESS_IO_SPACE)
              ? (OriginalValue.Bar & PCI_ADDRESS_IO_ADDRESS_MASK_64)
              : (OriginalValue.Bar & PCI_ADDRESS_MEMORY_ADDRESS_MASK_64));
+    *Base &= 0xFFFFFFFF;
 
     Size = (NewValue.Bar & PCI_ADDRESS_IO_SPACE)
            ? (NewValue.Bar & PCI_ADDRESS_IO_ADDRESS_MASK_64)