CVE-2026-23064 net/sched: act_ife: avoid possible NULL deref

In the Linux kernel, the following vulnerability has been resolved: net/sched: actife: avoid possible NULL deref tcfifeencode must make sure ifeencode does not return NULL. syzbot reported: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 1 SMP KASAN NOP...