Rusting the Linux Kernel - A Sysadmin's Cautious Optimism (2024)

The debate around incorporating Rust code into the Linux kernel has been heating up recently. As a system administrator who cares deeply about security, I have mixed feelings on the matter.

On one hand, Rust offers some clear security benefits over C, the main language currently used in the Linux kernel. Rust is designed to be memory-safe, preventing entire classes of bugs like buffer overflows that have led to vulnerabilities in C code. The ownership and borrowing system in Rust also makes it harder for developers to introduce other types of errors like use-after-free. For a critical system component like the kernel, building more reliability and security into the codebase is extremely attractive.

However, rewriting or porting a significant portion of the kernel from C to Rust would be an enormous undertaking. The Linux kernel codebase stretches over 20 million lines of code that has been developed and refined for decades. Introducing a new language like Rust in a piecemeal fashion may create more problems than it solves, at least in the short term. There is a risk of introducing new bugs any time major changes are made to complex, interconnected systems.

As a system administrator, stability and reliability are some of my top concerns. While I'm eager for improvements to security, I'm hesitant about changes that could temporarily destabilize systems that are currently running smoothly. Of course, software has to evolve and improve over time, but my preference would be for a cautious, incremental approach to adopting Rust rather than a rapid rewrite of core components.

I also have some concerns about the impact on the contributor community. C has been the primary development language for the kernel for a long time, and many of the top contributors are C experts. Rust has a learning curve that may discourage participation from some veteran developers. Maintaining a healthy, active contributor base is crucial for the long-term sustainability of an open-source project like Linux.

That said, integrating some Rust components carefully and strategically could be a good path forward. For instance, it may make sense to use Rust for newer subsystems and self-contained components rather than recoding central kernel functions. Allowing Rust and C to coexist for some time while the community gains more experience with Rust may be the safest approach.

As a system administrator, I see the clear benefits of Rust but also understand the risks of rapid change to this mission-critical software. My preference would be to take a balanced, incremental approach so we can enhance security without jeopardizing stability or community participation. I'm optimistic that Linux will continue to evolve and improve safely over time through the combined efforts of its maintainers and contributor community.