CVE-2026-90078 net/sched: act_skbmod: fix length calculations and avoid invalid header warnings

In the Linux kernel, the following vulnerability has been resolved: net/sched: actskbmod: fix length calculations and avoid invalid header warnings syzbot reported a warning in skbnetworkheaderlen triggered by tcfskbmodact: !skbtransportheaderwassetskb WARNING: CPU: 0 PID: 14949 at...