> -----Original Message----- > From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf > Of Drew Davenport > Sent: Saturday, October 28, 2017 12:05 AM > To: amd-gfx at lists.freedesktop.org > Cc: Deucher, Alexander <Alexander.Deucher at amd.com>; Drew Davenport > <ddavenport at chromium.org> > Subject: [PATCH] amdgpu/dc: Avoid dereferencing NULL pointer > > crtc is dereferenced from within drm_atomic_get_new_crtc_state, so > check for NULL before initializing new_crtc_state. > > Signed-off-by: Drew Davenport <ddavenport at chromium.org> Reviewed-by: Shirish S <shirish.s at amd.com> > --- > drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 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 d0ee1b3b8b5c..5a440fadbe18 100644 > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > @@ -3874,8 +3874,7 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, > /* update planes when needed */ > for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) { > struct drm_crtc *crtc = new_plane_state->crtc; > - struct drm_crtc_state *new_crtc_state = > - drm_atomic_get_new_crtc_state(state, crtc); > + struct drm_crtc_state *new_crtc_state; > struct drm_framebuffer *fb = new_plane_state->fb; > bool pflip_needed; > struct dm_plane_state *dm_new_plane_state = > to_dm_plane_state(new_plane_state); > @@ -3885,7 +3884,11 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state, > continue; > } > > - if (!fb || !crtc || pcrtc != crtc || !new_crtc_state->active) > + if (!fb || !crtc || pcrtc != crtc) > + continue; > + > + new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc); > + if (!new_crtc_state->active) > continue; > > pflip_needed = !state->allow_modeset;
