diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index 0decf0d81cf589c0b142aef74ff3a6aac865fc9c..1f5e6af96c834307c8acf0afcab4b8b437fb3226 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -156,8 +156,13 @@ void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
 	 * True size is important if the ROM is going to be copied.
 	 */
 	*size = pci_get_rom_size(pdev, rom, *size);
+	if (!*size)
+		goto invalid_rom;
+
 	return rom;
 
+invalid_rom:
+	iounmap(rom);
 err_ioremap:
 	/* restore enable if ioremap fails */
 	if (!(res->flags & IORESOURCE_ROM_ENABLE))