CVE-2025-21768 net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels Some lwtunnels have a dst cache for post-transformation dst. If the packet destination did not change we may end up recording a reference to the lwtunnel in its own...