On Thu, Feb 22, 2018 at 08:12:48AM +0200, Oleksandr Andrushchenko wrote: > On 02/22/2018 08:09 AM, Oleksandr Andrushchenko wrote: > > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > > > > It is possible that drm_simple_kms_plane_atomic_check called > > with no CRTC set, e.g. when user-space application sets CRTC_ID/FB_ID > > to 0 before doing any actual drawing. This leads to NULL pointer > > dereference because in this case new CRTC state is NULL and must be > > checked before accessing. > > > > Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx> > > Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > > > > --- > > Changes since initial: > > - re-worked checks for null CRTC as suggested by Daniel Vetter > > --- > > drivers/gpu/drm/drm_simple_kms_helper.c | 10 +++------- > > 1 file changed, 3 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c > > index 9ca8a4a59b74..4a1dbd88b1ec 100644 > > --- a/drivers/gpu/drm/drm_simple_kms_helper.c > > +++ b/drivers/gpu/drm/drm_simple_kms_helper.c > > @@ -121,12 +121,6 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane, > > pipe = container_of(plane, struct drm_simple_display_pipe, plane); > > crtc_state = drm_atomic_get_new_crtc_state(plane_state->state, > > &pipe->crtc); > > - if (!crtc_state->enable) > > - return 0; /* nothing to check when disabling or disabled */ > > - > > - if (crtc_state->enable) > > - drm_mode_get_hv_timing(&crtc_state->mode, > > - &clip.x2, &clip.y2); > > ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state, > > &clip, > > @@ -137,7 +131,9 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane, > > return ret; > > if (!plane_state->visible) > > - return -EINVAL; > Daniel, I have put your R-b tag, but I had removed suggested > "WARN_ON(crtc_state && crtc_state->enable);" > here as it fires each time when crtc_state is not NULL. > Please let me know if this is not ok and you want me to remove > your R-b tag. I'm a bit confused why that fires, but oh well. Applied, thanks for your patch. -Daniel > > + return 0; > > + > > + drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2); > > if (!pipe->funcs || !pipe->funcs->check) > > return 0; > Thank you, > Oleksandr > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
