[PATCH RESEND] drm/sti: avoid potential dereference of error pointers

[Alain Volmat]

Hi,

I probably went a bit fast on the commit message.  It seems to me that
the Fixes line would be probably better with below one instead.

Fixes: dd86dc2f9ae1 ("drm/sti: implement atomic_check for the planes")

The same fix is actually necessary for all planes (cursor / gdp / hqvdp),
which is related to the same original commit.  Hence sti_cursor/sti_gdp
and sti_hqvdp.

Would you be ok to have those 3 fixes within a commit ?

Regards,
Alain

On Tue, Sep 10, 2024 at 07:25:43PM +0200, Alain Volmat wrote:
> Hi,
> 
> Thanks for your patch.
> 
> Acked-by: Alain Volmat <alain.volmat at foss.st.com>
> 
> Regards,
> Alain
> 
> On Mon, Aug 26, 2024 at 01:26:52PM +0800, Ma Ke wrote:
> > The return value of drm_atomic_get_crtc_state() needs to be
> > checked. To avoid use of error pointer 'crtc_state' in case
> > of the failure.
> > 
> > Cc: stable at vger.kernel.org
> > Fixes: dec92020671c ("drm: Use the state pointer directly in planes atomic_check")
> > 
> > Signed-off-by: Ma Ke <make24 at iscas.ac.cn>
> > ---
> >  drivers/gpu/drm/sti/sti_cursor.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/sti/sti_cursor.c b/drivers/gpu/drm/sti/sti_cursor.c
> > index db0a1eb53532..e460f5ba2d87 100644
> > --- a/drivers/gpu/drm/sti/sti_cursor.c
> > +++ b/drivers/gpu/drm/sti/sti_cursor.c
> > @@ -200,6 +200,8 @@ static int sti_cursor_atomic_check(struct drm_plane *drm_plane,
> >  		return 0;
> >  
> >  	crtc_state = drm_atomic_get_crtc_state(state, crtc);
> > +	if (IS_ERR(crtc_state))
> > +		return PTR_ERR(crtc_state);
> >  	mode = &crtc_state->mode;
> >  	dst_x = new_plane_state->crtc_x;
> >  	dst_y = new_plane_state->crtc_y;
> > -- 
> > 2.25.1
> >