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.
On every embedded including a few IoT devices I worked on, every single time the IPv6 is either outright disabled, ignored, or treated like IPv4 even when telling my client what they want is not how IPv6 is designed.
May not be the same everywhere, just my anecdotal experience.
I’ve been doing this at home. So far, none of my phones or access points use IPv4. I should be able to get the desktops off it soon. Microsoft finally got it working in Windows after decades of (stalled) development.
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.
On every embedded including a few IoT devices I worked on, every single time the IPv6 is either outright disabled, ignored, or treated like IPv4 even when telling my client what they want is not how IPv6 is designed.
May not be the same everywhere, just my anecdotal experience.
Also remember:
I’ve been doing this at home. So far, none of my phones or access points use IPv4. I should be able to get the desktops off it soon. Microsoft finally got it working in Windows after decades of (stalled) development.
I disable IPv6 to reduce the vector