Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com> Thanks, Andrey On 11/27/2017 09:57 AM, Gustavo A. R. Silva wrote: > dm_new_crtc_state->stream and disconnected_acrtc are being dereferenced > before they are null checked, hence there is a potential null pointer > dereference. > > Fix this by null checking such pointers before they are dereferenced. > > Addresses-Coverity-ID: 1423745 ("Dereference before null check") > Addresses-Coverity-ID: 1423833 ("Dereference before null check") > Fixes: e7b07ceef2a6 ("drm/amd/display: Merge amdgpu_dm_types and amdgpu_dm") > Fixes: 54d765752467 ("drm/amd/display: Unify amdgpu_dm state variable namings.") > Signed-off-by: Gustavo A. R. Silva <garsilva at embeddedor.com> > --- > drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > index 889ed24..3bdd137 100644 > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > @@ -4190,6 +4190,9 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) > > dm_new_crtc_state = to_dm_crtc_state(new_crtc_state); > > + if (!dm_new_crtc_state->stream) > + continue; > + > update_stream_scaling_settings(&dm_new_con_state->base.crtc->mode, > dm_new_con_state, (struct dc_stream_state *)dm_new_crtc_state->stream); > > @@ -4197,9 +4200,6 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) > WARN_ON(!status); > WARN_ON(!status->plane_count); > > - if (!dm_new_crtc_state->stream) > - continue; > - > /*TODO How it works with MPO ?*/ > if (!dc_commit_planes_to_stream( > dm->dc, > @@ -4332,9 +4332,11 @@ void dm_restore_drm_connector_state(struct drm_device *dev, > return; > > disconnected_acrtc = to_amdgpu_crtc(connector->encoder->crtc); > - acrtc_state = to_dm_crtc_state(disconnected_acrtc->base.state); > + if (!disconnected_acrtc) > + return; > > - if (!disconnected_acrtc || !acrtc_state->stream) > + acrtc_state = to_dm_crtc_state(disconnected_acrtc->base.state); > + if (!acrtc_state->stream) > return; > > /*