Re: [PATCH] mm/page_alloc: __alloc_pages_bulk(): do bounds check before accessing array

From: Rasmus Villemoes
Date: Mon Jun 21 2021 - 12:01:23 EST


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@xxxxxxxxxxxxxxxxxx>
>
> Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
>

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