In a recent development, Microsoft has taken a significant step towards modernizing the kernel used in the Windows Subsystem for Linux (WSL) on WSL2. The company announced plans to upgrade the kernel to a more contemporary version, a move that has generated considerable anticipation among users. However, this upgrade has not yet been implemented in the stable release, and it appears that caution is the order of the day.
What You Need to Know
Microsoft has rolled back the kernel from the newer version 6.6.36.3 to the older 5.15.153.1-2 while debugging issues. The rollback is a precautionary measure to address potential problems that have surfaced. These issues may be linked to iptables, a critical component for the popular containerization tool, Docker.
The decision to revert to the previous kernel version was made in light of several debugging challenges that surfaced during the pre-release candidate phase. The changelog indicates a variety of fixes, including:
- Addressing a race condition that occurs when a WSL2 distribution is stopped.
- Implementing a format attribute to catch printf format errors at compile time.
- Resolving segmentation faults in initialization when the boot.initPath is missing.
- Adding default Hyper-V firewall rules to permit inbound mDNS traffic.
- Updating the Windows SDK to version 26100.
- Refreshing the Microsoft.Windows.ImplementationLibrary to version 1.0.240803.1.
While the changelog does not explicitly detail the issues at hand, there are indications that they may relate to iptables. This is particularly noteworthy as Docker relies heavily on iptables for its operations. A discussion within a WSL Community Telegram group suggested that the shift of some Linux distributions towards nftables could be influencing these complications, although the kernel still maintains support for iptables.
For those utilizing the stable release of WSL2, there is no immediate cause for concern; operations continue as usual. However, users on the pre-release version who have encountered difficulties may want to visit the GitHub page to download the latest release and ensure a smoother experience.
