Re: [PATCH] mm: Make copy_huge_page() always available

[Andrew Morton]

On Mon, 12 Jul 2021 16:32:07 +0100 "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> wrote:

> Rewrite copy_huge_page() and move it into mm/util.c so it's always
> available.  Fixes an exposure of uninitialised memory on configurations
> with HUGETLB and UFFD enabled and MIGRATION disabled.

Wait.  Exposing uninitialized memory is serious.  Can we please include
full info on this flaw and decide whether a -stable backport is justified? 
If not, why not, etc?