diff -Nuar iproute2-4.1.1.orig/misc/ss.c iproute2-4.1.1/misc/ss.c
--- iproute2-4.1.1.orig/misc/ss.c	2015-07-06 17:57:34.000000000 -0400
+++ iproute2-4.1.1/misc/ss.c	2015-08-20 10:37:17.615100588 -0400
@@ -1023,6 +1023,8 @@
 	if (ifindex) {
 		ifname   = ll_index_to_name(ifindex);
 		est_len -= strlen(ifname) + 1;  /* +1 for percent char */
+		if (est_len < 0)
+			est_len = 0;
 	}
 
 	sock_addr_print_width(est_len, ap, ":", serv_width, resolve_service(port),