CVE-2025-21768

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 cache, and the lwtunnel

state will never be freed.

Discovered by the ioam6.sh test, kmemleak was recently fixed

to catch per-cpu memory leaks. I'm not sure if rpl and seg6

can actually hit this, but in principle I don't see why not.