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Date:   Thu, 21 Sep 2023 11:25:21 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc:     maple-tree@lists.infradead.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, pedro.falcato@gmail.com,
        stable <stable@kernel.org>
Subject: Re: [PATCH 0/2] maple_tree: Fix mas_prev() state regression.
Message-Id: <20230921112521.fc07c658804f4e188179da77@linux-foundation.org>
In-Reply-To: <20230921181236.509072-1-Liam.Howlett@oracle.com>
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On Thu, 21 Sep 2023 14:12:34 -0400 "Liam R. Howlett" <Liam.Howlett@oracle.com> wrote:

> Pedro Falcato contacted me on IRC with an mprotect regression which was
> bisected back to the iterator changes for maple tree.  Root cause
> analysis showed the mas_prev() running off the end of the VMA space
> (previous from 0) followed by mas_find(), would skip the first value.
> 
> This patch set introduces maple state underflow/overflow so the sequence
> of calls on the maple state will return what the user expects.

It isn't clear what are the user-visible effects of this flaw?  Please
send this along and I'll paste it in.

Patch 1 should be titled "Add mas_is_active ...".

And patch 1 should have had cc:stable in the changelog.

It's stable@vger.kernel.org, although stable@kernel.org works just fine.