Re: [PATCH] ntfs: reject zero sectors_per_cluster in the boot sector

[Hyunchul Lee]

Hi Dennis,

> diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
> index d400fea32..48bea5ce1 100644
> --- a/fs/ntfs/super.c
> +++ b/fs/ntfs/super.c
> @@ -557,8 +557,9 @@ static bool is_boot_sector_ntfs(const struct super_block *sb,
>          * Check sectors per cluster value is valid and the cluster size
>          * is not above the maximum (2MB).
>          */
> -       if (b->bpb.sectors_per_cluster > 0x80 &&
> -           b->bpb.sectors_per_cluster < 0xf4)
> +       if (!b->bpb.sectors_per_cluster ||
> +           (b->bpb.sectors_per_cluster > 0x80 &&
> +            b->bpb.sectors_per_cluster < 0xf4))
>                 goto not_ntfs;
>
>         /* Check reserved/unused fields are really zero. */

We need to check whether it is a power of two.

-- 
Thanks,
Hyunchul