Re: [PATCH] mm/slub, kasan: fix checking page_alloc allocations on free

From: Shakeel Butt
Date: Tue Aug 10 2021 - 20:18:46 EST


On Tue, Aug 10, 2021 at 4:47 PM <andrey.konovalov@xxxxxxxxx> wrote:
>
> From: Andrey Konovalov <andreyknvl@xxxxxxxxx>
>
> A fix for stat counters f227f0faf63b ("slub: fix unreclaimable slab stat
> for bulk free") used page_address(page) as kfree_hook() argument instead
> of object. While the change is technically correct, it breaks KASAN's
> ability to detect improper (unaligned) pointers passed to kfree() and
> causes the kmalloc_pagealloc_invalid_free test to fail.
>
> This patch changes free_nonslab_page() to pass object to kfree_hook()
> instead of page_address(page) as it was before the fix.
>
> Fixed: f227f0faf63b ("slub: fix unreclaimable slab stat for bulk free")
> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>

The fix is already in the mm tree:
https://lkml.kernel.org/r/20210802180819.1110165-1-shakeelb@xxxxxxxxxx