Re: [PATCH 1/3] rbd: fix null dereference in dout

[Alex Elder <alex.elder@linaro.org>]

On 08/29/2013 01:24 AM, Josh Durgin wrote:
> The order parameter is sometimes NULL in _rbd_dev_v2_snap_size(), but
> the dout() always derefences it. Move this to another dout() protected
> by a check that order is non-NULL.

Looks good.

Reviewed-by: Alex Elder <elder@linaro.org>

> Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
> ---
>  drivers/block/rbd.c |    8 +++++---
>  1 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 80f787b..fef3687 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -3702,12 +3702,14 @@ static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
>  	if (ret < sizeof (size_buf))
>  		return -ERANGE;
>  
> -	if (order)
> +	if (order) {
>  		*order = size_buf.order;
> +		dout("  order %u", (unsigned int)*order);
> +	}
>  	*snap_size = le64_to_cpu(size_buf.size);
>  
> -	dout("  snap_id 0x%016llx order = %u, snap_size = %llu\n",
> -		(unsigned long long)snap_id, (unsigned int)*order,
> +	dout("  snap_id 0x%016llx snap_size = %llu\n",
> +		(unsigned long long)snap_id,
>  		(unsigned long long)*snap_size);
>  
>  	return 0;
>