Lacking to initialize "IP6CB(skb)->nhoff" for ipv6 transmission ?

Hi,

Im using iptables for marking outgoing packets and then divert them to
specific routing tables.
Whenever a flow matches a rule into mangle table it is marked properly
and reaches over the function ip6_route_me_harder.
That function ends up calling xfrm_decode_session and in particular
_decode_session6 for v6 flows.
The latter uses "IP6CB(skb)->nhoff" for locating nextheader value but
on my debugs it was presenting a weird value (96) instead of the
expected (6), since it was a TCP flow.
So I made the decision of initializing "IP6CB(skb)->nhoff" (with the
value offset(struct ipv6hdr, nexthdr) ) in "ip6_xmit" function and
then the (6) started to be shown and the (96) value did not appeared
anymore.
Is this proceeding correct ? (and then that would be a kernel bug ?)

Rgds,
Eduardo Panisset.