Re: [PATCH v3] block: add capacity validation in bdev_add_partition()

[Damien Le Moal]

On 6/17/23 02:19, min.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.
> 
> Signed-off-by: min.li <min15.li@xxxxxxxxxxx>

I am guessing this should be:

Signed-off-by: Min Li <min15.li@xxxxxxxxxxx>

No ? The signed-off-by tag, and any other tag, must have your full name
correctly written.

> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> 
> ---
> Changes from v1:
> 
> - Check for overflows of the start + length value.
> - Place the capacity check at the beginning of the function.
> 
> Changes from v2:
> 
> - Place the assignment on the first line and merge the two lines into one.
> - Modify the singed name.
> ---
>  block/partitions/core.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/block/partitions/core.c b/block/partitions/core.c
> index 49e0496ff23c..b511f88bf558 100644
> --- a/block/partitions/core.c
> +++ b/block/partitions/core.c
> @@ -436,10 +436,21 @@ static bool partition_overlaps(struct gendisk *disk, sector_t start,
>  int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
>  		sector_t length)
>  {
> +	sector_t capacity = get_capacity(disk), end;
>  	struct block_device *part;
>  	int ret;
>  
>  	mutex_lock(&disk->open_mutex);
> +	if (check_add_overflow(start, length, &end)) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (start >= capacity || end > capacity) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
>  	if (!disk_live(disk)) {
>  		ret = -ENXIO;
>  		goto out;

-- 
Damien Le Moal
Western Digital Research