diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index f955edb..2fb5013 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -75,6 +75,7 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
 	image = rom;
 	do {
 		void __iomem *pds;
+		u16 length;
 		/* Standard PCI ROMs start out with these bytes 55 AA */
 		if (readb(image) != 0x55) {
 			dev_err(&pdev->dev, "Invalid ROM contents\n");
@@ -93,8 +94,10 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
 		if (readb(pds + 3) != 'R')
 			break;
 		last_image = readb(pds + 21) & 0x80;
-		/* this length is reliable */
-		image += readw(pds + 16) * 512;
+		length = readw(pds + 16);
+		if (!length)
+			break;
+		image += length * 512;
 	} while (!last_image);
 
 	/* never return a size larger than the PCI resource window */