KVM Linear Address Space Separation (LASS)

[Paul Lai]

Enable Linear Address Space Separation (LASS) to defend against address space layout probes. LASS Is a new ISA extension to defend against variety of techniques used to expose layout of the kernel address space that are used as a precursor to build targeted exploits for the kernel.

Defends against KASLR subversion and speculative execution side channel techniques by partitioning the 64-bit canonical linear address space into two halves – user and supervisor address spaces – to stop attempt to probe supervisor address space by user mode and vice versa: Prevents a class of attacks using TLB as a side Channel