

IPv6 is not affected by this race because the kernel copies the options for IPv6 connections.
It’s been a slow-going effort to get a compile flag into the kernel that disables IPv4, but this is precisely the type of bug which that flag would have avoided. When devices choose to natively use IPv6-only – eg IoT – they really shouldn’t have to also accept an increased attack surface from Legacy IP, something that is increasingly unnecessary.
Disabling IPv4 when it’s unneeded is good security posture, but such a choice is not available yet in Linux.


How is this different than Fabrice Bellard’s achievement in 2011? https://bellard.org/jslinux/