Re: [PATCH v2] block: add capacity validation in bdev_add_partition()

[Christoph Hellwig]

On Fri, Jun 16, 2023 at 11:05:57AM +0000, min15.li wrote:
> In the function bdev_add_partition(),there is no check that the start
> and end sectors exceed the size of the disk before calling add_partition.
> When we call the block's ioctl interface directly to add a partition,
> and the capacity of the disk is set to 0 by driver,the command will
> continue to execute.
> v1->v2: check for overflows of the start + length value and put
> the capacity check at the beginning of the function.
> 
> Signed-off-by: min15.li <min15.li@xxxxxxxxxxx>
> ---
>  block/partitions/core.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/block/partitions/core.c b/block/partitions/core.c
> index 49e0496ff23c..3546b43d5124 100644
> --- a/block/partitions/core.c
> +++ b/block/partitions/core.c
> @@ -438,8 +438,20 @@ int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
>  {
>  	struct block_device *part;
>  	int ret;
> +	sector_t end;
> +	sector_t capacity = get_capacity(disk);

Very minor nitpick, but I think this would read nicer as:

+	sector_t capacity = get_capacity(disk), end;
  	struct block_device *part;
  	int ret;

Otherwise this looks good:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>