Re: [PATCH 4/7] media-entity: set ent_enum->bmap to NULL after freeing it

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Hans,

Thank you for the patch.

On Thu, Feb 21, 2019 at 03:21:45PM +0100, Hans Verkuil wrote:
> Ensure that this pointer is set to NULL after it is freed.
> The vimc driver has a static media_entity and after
> unbinding and rebinding the vimc device the media code will
> try to free this pointer again since it wasn't set to NULL.

As this fixes a problem in vimc, should you add a Fixes: tag ? To avoid
other similar problems, I think the vimc driver should allocate the
media_device and other device data dynamically at probe time. Bundling
them with the platform_device in struct vimc_device isn't a good idea.

> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> ---
>  drivers/media/media-entity.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
> index 0b1cb3559140..7b2a2cc95530 100644
> --- a/drivers/media/media-entity.c
> +++ b/drivers/media/media-entity.c
> @@ -88,6 +88,7 @@ EXPORT_SYMBOL_GPL(__media_entity_enum_init);
>  void media_entity_enum_cleanup(struct media_entity_enum *ent_enum)
>  {
>  	kfree(ent_enum->bmap);
> +	ent_enum->bmap = NULL;
>  }
>  EXPORT_SYMBOL_GPL(media_entity_enum_cleanup);
>  

-- 
Regards,

Laurent Pinchart