After years of countless reviews, discussions, and code rewrites, Linus Torvalds approved on Saturday a new security feature for the Linux kernel, named “lockdown.”
The new feature will ship as a LSM (Linux Security Module) in the soon-to-be-released Linux kernel 5.4 branch, where it will be turned off by default; usage being optional due to the risk of breaking existing systems.
PUTTING A LEASH ON THE ROOT ACCOUNT
The new feature’s primary function will be to strengthen the divide between userland processes and kernel code by preventing even the root account from interacting with kernel code — something that it’s been able to do, by design, until now.
When enabled, the new “lockdown” feature will restrict some kernel functionality, even for the root user, making it harder for compromised root accounts to compromise the rest of the OS.
“The lockdown module is intended to allow for kernels to be locked down early in [the] boot [process],” said Matthew Garrett, the Google engineer who proposed the feature a few years back.
By Catalin Cimpanu
September 29, 2019