CVE-2026-72442 netfilter: flowtable: fix and simplify IP6IP6 tunnel handling

In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: fix and simplify IP6IP6 tunnel handling Fix nfflowip6tunnelproto to use pskbmaypull instead of skbheaderpointer to ensure the outer IPv6 header is in the skb headroom, which is required for subsequent packet...