Sorry, did non see the already existing bug. I created a new one 1127670 tldr: the breaking commit is not the one mentioned (this was also my first guess, but the issue is in the rx path, not the tx)
the actual issue is https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/net/ ipv6/ip6_tunnel.c?id=81c734dae203757fb3c9eee6f9896386940776bd reverting this fixes 6.12.69 (at least for me) As said I don't really understand why this fails on 6.12 but works on 6.19. Also running the testcase that should trigger the bug this fix fixes does not create a stacktrace on my system, so maybe 6.12 is not affected??
