Please backport the
f4eb17e1efe538d4da7d574bedb00a8dafcc26b7 ("Revert "sit: reload iphdr
in ipip6_rcv"") to 4.4.y.
It has been applied to 4.9.112 recently, but in 4.4.y the problem still exists.
The original commit was CCed to 'stable' but the reversal wasn't.
It causes a regression with non-working ping6 and log spam from sit.
