Index: usr.sbin/efibootmgr/efibootmgr.c
===================================================================
--- usr.sbin/efibootmgr/efibootmgr.c
+++ usr.sbin/efibootmgr/efibootmgr.c
@@ -737,6 +737,7 @@
 	return 0;
 }
 
+#define EFIDP_MAX(dp, edp) ((uintptr_t)edp - (uintptr_t)dp)
 
 static void
 print_loadopt_str(uint8_t *data, size_t datalen)
@@ -779,11 +780,10 @@
 	 * optlen = ep - walker;
 	 */
 	indent = 1;
-	while (dp < edp) {
-		efidp_format_device_path(buf, sizeof(buf), dp,
-		    (intptr_t)(void *)edp - (intptr_t)(void *)dp);
+	while (dp < edp && EFIDP_MAX(dp, edp) > sizeof(efidp_header)) {
+		efidp_format_device_path(buf, sizeof(buf), dp, EFIDP_MAX(dp, edp));
 		printf("%*s%s\n", indent, "", buf);
-		indent = 10 + len + 1;
+		indent = 11 + len + 1;
 		rv = efivar_device_path_to_unix_path(dp, &dev, &relpath, &abspath);
 		if (rv == 0) {
 			printf("%*s%s:%s %s\n", indent + 4, "", dev, relpath, abspath);