2.4 routing table DOS flaw question

Here is a nadvisory http://rhn.redhat.com/errata/RHSA-2003-172.html that describes a flaw in 2.4.x kernel routing hash table. Do i need to patch my kernel and restart the box (and loose my heavy uptime) even if iptables filters all packets come in and are not related to a self established connection? In other words, if a router serves nothing and incoming packets are blocked, the routing table comes not in the game and i dont need to patch? AND - is there a way using iptools (ip route) to circumvent the problem? Regards Michael