The Register reports
from Jiří Benc’s DevConf.cz talk on the making of the CentOS Stream
kernel.

So, what the team are working on is a Frankenstein’s monster, sewn
together from different codebases. Although the base kernel is
still version 5.14, it is full of backports from upstream. It has
the XFS filesystem code from kernel 6.0, the USB subsystem –
complete with drivers – and BPF subsystem from kernel 6.2, the
wireless stack and all drivers from kernel 6.3, and the multipath
TCP/IP code from kernel 6.4 – which at the time of the talk hadn’t
even been released upstream yet.

Source: LWN.net – What it takes to keep an enterprise ‘Frankenkernel’ alive (Register)