Loongson64 Finally Seeing KASLR With Mainline Linux 5.11 Kernel

While the Linux kernel has supported Kernel Address Space Layout Randomization (KASLR) for a decade and a half in varying forms, it hasn't been supported for all hardware targets. Only in 2021 is the mainline Linux kernel seeing KASLR working for the MIPS-based Loongson64 platform.

The Chinese-made Loongson MIPS64 processors have been popular in some circles for their Linux usage and the Loongson-powered Lemote hardware even popular with Richard Stallman for a time due to fully open-source firmware. But surprisingly it has taken until now for enabling the common KASLR functionality for Loongson64.

With this simple patch finally from a Loongson engineer now in MIPS-next ahead of Linux 5.11, Loongson64 is supported as a relocatable kernel build and meets the setup for providing kernel address space layout randomization. This is basically about randomizing the position within the system memory where the kernel code and data is placed in order to fend off exploits relying upon the known positions within memory.

Other MIPS hardware has supported KASLR for a while with the mainline Linux KASLR support dating back to 2005.

The Linux 5.11 cycle is kicking off soon while the 5.11 stable release should be out in February.