Merge branch 'tcp-take-care-of-another-syzbot-issue'

Eric Dumazet says:

====================
tcp: take care of another syzbot issue

This is a minor issue: It took months for syzbot to find a C repro,
and even with it, I had to spend a lot of time to understand KFENCE
was a prereq. With the default kfence 500ms interval, I had to be
very patient to trigger the kernel warning and perform my analysis.

This series targets net-next tree, because I added a new generic helper
in the first patch, then fixed the issue in the second one.
They can be backported once proven solid.
====================

Link: https://lore.kernel.org/r/20220222032113.4005821-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>