Re: [PATCH] mm/vmalloc.c: Fix potential memory leak

From: Uladzislau Rezki
Date: Thu Jan 07 2021 - 08:14:58 EST


> In VM_MAP_PUT_PAGES case, we should put pages and free array in vfree. But
> we missed to set area->nr_pages in vmap(). So we would failed to put pages
> in __vunmap() because area->nr_pages = 0.
>
> Fixes: b944afc9d64d ("mm: add a VM_MAP_PUT_PAGES flag for vmap")
> Signed-off-by: Shijie Luo <luoshijie1@xxxxxxxxxx>
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
> mm/vmalloc.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 6507a579ff88..8ab83fbecadd 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -2421,8 +2421,10 @@ void *vmap(struct page **pages, unsigned int count,
> return NULL;
> }
>
> - if (flags & VM_MAP_PUT_PAGES)
> + if (flags & VM_MAP_PUT_PAGES) {
> area->pages = pages;
> + area->nr_pages = count;
> + }
> return area->addr;
> }
> EXPORT_SYMBOL(vmap);
> --
> 2.19.1
>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>

--
Vlad Rezki