Re: [PATCH 1/1] media: v4l: subdev: Make link validation safer

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Tomi,

On Fri, Mar 03, 2023 at 10:41:27AM +0200, Tomi Valkeinen wrote:
> On 02/03/2023 22:22, Sakari Ailus wrote:
> > Link validation currently accesses invalid pointers if the link passed to it
> > is not between two sub-devices. This is of course a driver bug.
> > 
> > Ignore the error but print a debug message, as this is how it used to work
> > previously.
> > 
> > Fixes: a6b995ed03ff ("media: subdev: use streams in v4l2_subdev_link_validate()")
> > Reported-by: Hans de Goede <hdegoede@redhat.com>
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > ---
> > Hi Hans,
> > 
> > Could you test this?
> > 
> > The bug is of course in the ImgU driver and this reverts to the old
> > pre-streams behaviour. It silently fails instead of oopsing. The ImgU driver
> > needs to be fixed and I think we could make this return an error at the same
> > time. Right now I can't be sure the ImgU driver is the only one suffering
> > from this, but if so, it's likely to be broken anyway.
> 
> Maybe it should be at least a warn? How do we catch other broken drivers
> otherwise?

The purpose of this patch is just to restore the old behaviour, and merge
it as a fix to v6.3 (via Cc'ing stable). I agree this should be made an
error but I'd like that change to be present in the media tree for some
time first.

> 
> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

Thanks!

-- 
Kind regards,

Sakari Ailus