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Date: Sat, 26 Sep 2026 13:53:38 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Cc: "Liam R. Howlett" <liam@infradead.org>, Vlastimil Babka
 <vbabka@kernel.org>, Jann Horn <jannh@google.com>, Pedro Falcato
 <pfalcato@suse.de>, Brian Geffon <bgeffon@google.com>, Minchan Kim
 <minchan@kernel.org>, Kiryl Shutsemau <kas@kernel.org>, linux-mm@kvack.org,
 linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 0/2] mm/mremap: fix two issues with MREMAP_DONTUNMAP
Message-Id: <20260926135338.7d7ea1d29a89351c964e5897@linux-foundation.org>
In-Reply-To: <20260920-fix-dontunmap-partial-self-merge-v1-0-6ffb556f8f8b@kernel.org>
References: <20260920-fix-dontunmap-partial-self-merge-v1-0-6ffb556f8f8b@kernel.org>
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On Sun, 20 Sep 2026 15:13:09 +0100 "Lorenzo Stoakes (ARM)" <ljs@kernel.org> wrote:

> The MREMAP_DONTUNMAP feature is highly unusual in that it permits mremap()
> operations that keep the original VMA in place.
> 
> Historically this has led to a lot of bugs where non-obvious interactions
> occur between existing mremap() operations and the original VMA.
> 
> ...
> 
> Both issues can be fixed by treating the source range as distinct from the
> destination range, which is the definition of what MREMAP_DONTUNMAP does so
> is appropriate.

Can we please have some review of these two cc:stable hotfixes?

Thanks.