diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -1211,7 +1211,7 @@
 		 * Note that the order of the headers remains in
 		 * the chain of ancillary data.
 		 */
-		while (1) {	/* is explicit loop prevention necessary? */
+		for (int loopcnt = 0; loopcnt < 64; loopcnt++) { /* explicit loop prevention */
 			struct ip6_ext *ip6e = NULL;
 			int elen;
 #ifdef PULLDOWN_TEST