Re: [PATCH v6 13/20] md: check for failure when adding pages in alloc_behind_master_bio

[Song Liu <song@kernel.org>]

On Tue, May 30, 2023 at 8:50 AM Johannes Thumshirn
<johannes.thumshirn@wdc.com> wrote:
>
> alloc_behind_master_bio() can possibly add multiple pages to a bio, but it
> is not checking for the return value of bio_add_page() if adding really
> succeeded.
>
> Check if the page adding succeeded and if not bail out.
>
> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Acked-by: Song Liu <song@kernel.org>

> ---
>  drivers/md/raid1.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
> index 68a9e2d9985b..8283ef177f6c 100644
> --- a/drivers/md/raid1.c
> +++ b/drivers/md/raid1.c
> @@ -1147,7 +1147,10 @@ static void alloc_behind_master_bio(struct r1bio *r1_bio,
>                 if (unlikely(!page))
>                         goto free_pages;
>
> -               bio_add_page(behind_bio, page, len, 0);
> +               if (!bio_add_page(behind_bio, page, len, 0)) {
> +                       free_page(page);
> +                       goto free_pages;
> +               }
>
>                 size -= len;
>                 i++;
> --
> 2.40.1
>