Re: [PATCH v2 2/3] x86/mm/pat: fix VM_PAT handling in COW mappings

From: Andrew Morton
Date: Thu Apr 04 2024 - 16:01:12 EST


On Thu, 4 Apr 2024 21:20:06 +0200 David Hildenbrand <david@xxxxxxxxxx> wrote:

> >> Reported-by: Wupeng Ma <mawupeng1@xxxxxxxxxx>
> >> Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@xxxxxxxxxx
> >> Fixes: b1a86e15dc03 ("x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines")
> >> Fixes: 5899329b1910 ("x86: PAT: implement track/untrack of pfnmap regions for x86 - v3")
> >
> > These are really old. Should we backport this?
>
> I was asking that question myself.
>
> With the reproducer, the worst thing that happens on most systems is the
> warning. On !RAM and with PAT, there could be memory leaks and other
> surprises.
>
> Likely, we should just backport it to stable. Should not be too hard to
> backport to stable kernels I guess/hope.

OK, thanks, I added the cc:stable tag.