commit dfee0a725bb027b749ffdd318eb48b91d564b266
Author: Olaf Kirch <olaf.kirch@oracle.com>
Date:   Fri Mar 9 13:55:38 2007 -0800

    [IPV6]: Fix for ipv6_setsockopt NULL dereference
    
    I came across this bug in http://bugzilla.kernel.org/show_bug.cgi?id=8155
    
    Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
    Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
    Signed-off-by: David S. Miller <davem@davemloft.net>

Index: linux-2.6.18/net/ipv6/ipv6_sockglue.c
===================================================================
--- linux-2.6.18.orig/net/ipv6/ipv6_sockglue.c
+++ linux-2.6.18/net/ipv6/ipv6_sockglue.c
@@ -408,7 +408,7 @@ static int do_ipv6_setsockopt(struct soc
 		}
 
 		/* routing header option needs extra check */
-		if (optname == IPV6_RTHDR && opt->srcrt) {
+		if (optname == IPV6_RTHDR && opt && opt->srcrt) {
 			struct ipv6_rt_hdr *rthdr = opt->srcrt;
 			if (rthdr->type)
 				goto sticky_done;