Re: [PATCH v1] drivers/md/md-bitmap: check the return value of md_bitmap_get_counter()

[Song Liu]

On Thu, Sep 8, 2022 at 9:09 PM Li Zhong <floridsleeves@xxxxxxxxx> wrote:
>
> Check the return value of md_bitmap_get_counter() in case it returns
> NULL pointer, which will result in a null pointer dereference.
>
> Signed-off-by: Li Zhong <floridsleeves@xxxxxxxxx>

Somehow I didn't get v2 of this in my inbox. So replying to v1:

Applied v2 to md-next.

Thanks,
Song

> ---
>  drivers/md/md-bitmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
> index bf6dffadbe6f..06ab1098ff99 100644
> --- a/drivers/md/md-bitmap.c
> +++ b/drivers/md/md-bitmap.c
> @@ -2195,7 +2195,7 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
>
>                 if (set) {
>                         bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
> -                       if (*bmc_new == 0) {
> +                       if (bmc_new && *bmc_new == 0) {
>                                 /* need to set on-disk bits too. */
>                                 sector_t end = block + new_blocks;
>                                 sector_t start = block >> chunkshift;
> --
> 2.25.1
>