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Date:   Tue, 13 Jul 2021 19:12:44 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc:     Mina Almasry <almasrymina@google.com>,
        YueHaibing <yuehaibing@huawei.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Peter Xu <peterx@redhat.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: Make copy_huge_page() always available
Message-Id: <20210713191244.553680171f9fab3bf6e0889b@linux-foundation.org>
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On Mon, 12 Jul 2021 16:32:07 +0100 "Matthew Wilcox (Oracle)" <willy@infradead.org> 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?