On Thu, 23 Feb 2023 21:41:01 +0100, Ard Biesheuvel wrote:
> Our virtual KASLR displacement is a randomly chosen multiple of
> 2 MiB plus an offset that is equal to the physical placement modulo 2
> MiB. This arrangement ensures that we can always use 2 MiB block
> mappings (or contiguous PTE mappings for 16k or 64k pages) to map the
> kernel.
>
> This means that a KASLR offset of less than 2 MiB is simply the product
> of this physical displacement, and no randomization has actually taken
> place. Currently, we use 'kaslr_offset() > 0' to decide whether or not
> randomization has occurred, and so we misidentify this case.
>
> [...]
Applied to arm64 (for-next/core), thanks!
[1/1] arm64: kaslr: don't pretend KASLR is enabled if offset < MIN_KIMG_ALIGN
https://git.kernel.org/arm64/c/010338d729c1
--
Catalin
