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Subject: Re: [PATCH] mm/page_alloc: __alloc_pages_bulk(): do bounds check
 before accessing array
To:     Mel Gorman <mgorman@techsingularity.net>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Alexander Lobakin <alobakin@pm.me>,
        Vlastimil Babka <vbabka@suse.cz>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
References: <20210507064504.1712559-1-linux@rasmusvillemoes.dk>
 <20210507102634.GD9524@techsingularity.net>
From:   Rasmus Villemoes <linux@rasmusvillemoes.dk>
Message-ID: <387ca68d-7c59-b316-7d95-cf13a3b26770@rasmusvillemoes.dk>
Date:   Mon, 21 Jun 2021 18:01:17 +0200
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On 07/05/2021 12.26, Mel Gorman wrote:
> On Fri, May 07, 2021 at 08:45:03AM +0200, Rasmus Villemoes wrote:
>> In the event that somebody would call this with an already fully
>> populated page_array, the last loop iteration would do an access
>> beyond the end of page_array.
>>
>> It's of course extremely unlikely that would ever be done, but this
>> triggers my internal static analyzer. Also, if it really is not
>> supposed to be invoked this way (i.e., with no NULL entries in
>> page_array), the nr_populated<nr_pages check could simply be removed
>> instead.
>>
>> Fixes: 0f87d9d30f21 (mm/page_alloc: add an array-based interface to the bulk page allocator)
>> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> 
> Acked-by: Mel Gorman <mgorman@techsingularity.net>
> 

Andrew, will you get this to Linus before 5.13 is released? I got a mail
on May 9 that it had been added to your queue, but I don't see it in
master yet.

Rasmus