Please be aware that https://www.kernel.org/pub/linux/kernel/ primary mirror (including cdn.kernel.org) was accidentally emptied - restore is in progress. This affects also most secondary mirrors (many promptly deleted their /kernel/ too).
Details are on: https://lwn.net/Articles/1081015/
According to https://status.linuxfoundation.org/incidents/3y1k8b4ky71t - restore is still in progress (my last visit at Jul 03, 4:21 UTC):
I’m publishing it here because major media (Phoronix, Slashdot) are quiet on that topic.