diff --git a/drivers/pci/hotplug/ibmphp_ebda.c b/drivers/pci/hotplug/ibmphp_ebda.c
index 5becbdee4027019a5c584df5ff5fb3cc99b04cc3..2850e64dedae3e0cb9e258d113b75156aff891d3 100644
--- a/drivers/pci/hotplug/ibmphp_ebda.c
+++ b/drivers/pci/hotplug/ibmphp_ebda.c
@@ -276,6 +276,12 @@ int __init ibmphp_access_ebda (void)
 
 	for (;;) {
 		offset = next_offset;
+
+		/* Make sure what we read is still in the mapped section */
+		if (WARN(offset > (ebda_sz * 1024 - 4),
+			 "ibmphp_ebda: next read is beyond ebda_sz\n"))
+			break;
+
 		next_offset = readw (io_mem + offset);	/* offset of next blk */
 
 		offset += 2;