Linux stable kernel maintainer Greg Kroah-Hartman declared at Open Source Summit India 2026 that the Linux kernel is moving toward Rust, calling the language a permanent part of the project rather than an experiment. Kroah-Hartman, who oversees the kernel's CVE process, said Rust could eliminate about 80% of the roughly 13 CVEs the kernel sees daily, most of which stem from simple C memory-safety mistakes.
Rust's safety benefits for kernel development
Kroah-Hartman, once a C skeptic, now champions Rust for its ownership and type system that catches common errors at compile time. "Rust makes my life so much easier," he said, noting that most kernel vulnerabilities are not exotic attacks but trivial bugs like unchecked pointers and forgotten unlocks. He estimates 80% of kernel CVEs would be prevented by Rust's safety guarantees, leaving maintainers to focus on logic bugs rather than memory-safety issues.
Linux has over 5,000 developers but only about 150 core maintainers who review most code changes. Kroah-Hartman emphasized that language choices are optimized for reviewers, not developers: "If it builds as a reviewer, I know it's OK. I can look at the logic." Rust's ability to enforce locking and lifetime rules at build time reduces reviewer workload significantly.
Rust becoming default for new subsystems
The kernel community officially ended the "Rust experiment" last year, declaring Rust a first-class language. New drivers for complex subsystems like graphics will only be accepted in Rust. The Android IPC mechanism Binder now has parallel C and Rust implementations, with the C version expected to be removed soon, leaving Rust as the bedrock for billions of Android devices.
Kroah-Hartman stressed that existing C code will not be rewritten: "We don't want rewrites. Leave existing C code alone, and let's evolve forward." However, the Rust effort has already improved C APIs in the kernel, adding guard and scoped-allocation mechanisms inspired by Rust's automatic cleanup. "If Rust were to disappear tomorrow, the kernel's better off for it," he said.
Acknowledging the challenge of change
Despite his enthusiasm, Kroah-Hartman acknowledged that transitioning from C is difficult for a community that has used it for decades, including himself: "I like C. I've been doing C for many, many, many years. It's hard." Yet he returned to the theme that first convinced him: "Rust makes coding fun again. I can focus on logic, and that's the beauty of it." He concluded that Rust makes Linux more secure for users and more enjoyable for maintainers, adding with a smile: "World domination is proceeding as planned."