diff --git a/drivers/pci/pci-stub.c b/drivers/pci/pci-stub.c
index 4c0336b31cafb5fa3b0c00d51b9f7ab03bbb5c8c..775e933c222547d14c30840daebd16b5a438be72 100644
--- a/drivers/pci/pci-stub.c
+++ b/drivers/pci/pci-stub.c
@@ -58,6 +58,9 @@ static int __init pci_stub_init(void)
 			subdevice = PCI_ANY_ID, class=0, class_mask=0;
 		int fields;
 
+		if (!strlen(id))
+			continue;
+
 		fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
 				&vendor, &device, &subvendor, &subdevice,
 				&class, &class_mask);