Re: [PATCH 5.15.y v3] mm/kfence: randomize the freelist on initialization

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Feb 05, 2026 at 03:50:55PM +0100, Pimyn Girgis wrote:
> Randomize the KFENCE freelist during pool initialization to make
> allocation patterns less predictable.  This is achieved by shuffling the
> order in which metadata objects are added to the freelist using
> get_random_u32_below().
> 
> Additionally, ensure the error path correctly calculates the address range
> to be reset if initialization fails, as the address increment logic has
> been moved to a separate loop.
> 
> Link: https://lkml.kernel.org/r/20260120161510.3289089-1-pimyn@google.com
> Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure")
> Signed-off-by: Pimyn Girgis <pimyn@google.com>
> Reviewed-by: Alexander Potapenko <glider@google.com>
> Cc: Dmitry Vyukov <dvyukov@google.com>
> Cc: Marco Elver <elver@google.com>
> Cc: Ernesto Martnez Garca <ernesto.martinezgarcia@tugraz.at>
> Cc: Greg KH <gregkh@linuxfoundation.org>
> Cc: Kees Cook <kees@kernel.org>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> (cherry picked from commit 870ff19251bf3910dda7a7245da826924045fedd)
> Signed-off-by: Pimyn Girgis <pimyn@google.com>
> ---
> v2: handle addr calculation for error path  within appropriate loop

What changed in v3?

Yes, it's a nit, but please, we have a process :)

thanks,

greg k-h