Re: [PATCH] maple_tree: Fix allocation in mas_sparse_area()

From: Andrew Morton
Date: Wed Apr 19 2023 - 15:49:11 EST


On Wed, 19 Apr 2023 17:36:25 +0800 Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx> wrote:

> In the case of reverse allocation, mas->index and mas->last do not point
> to the correct allocation range, which will cause users to get incorrect
> allocation results, so fix it. If the user does not use it in a specific
> way, this bug will not be triggered.

Please describe the user-visible effects of the bug. I assume "none",
because there are presently no callers which can trigger it?

> Also re-checks whether the size is still satisfied after the lower bound
> was increased, which is a corner case and is incorrect in previous versions.

Again, what are the user-visible effects of the bug?