On disconnect drm_atomic_helper_disable_all() is called which sets both the fb and crtc for a plane to NULL before invoking a commit.

This causes a kernel oops on every display disconnect.

Add guards for those dereferences.

Cc: stable@vger.kernel.org # 6.18.x Signed-off-by: Shenghao Yang me@shenghaoyang.info --- drivers/gpu/drm/gud/gud_pipe.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c index 76d77a736d84..4b77be94348d 100644 --- a/drivers/gpu/drm/gud/gud_pipe.c +++ b/drivers/gpu/drm/gud/gud_pipe.c @@ -457,27 +457,20 @@ int gud_plane_atomic_check(struct drm_plane *plane, struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane); struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane); struct drm_crtc *crtc = new_plane_state->crtc; - struct drm_crtc_state *crtc_state; + struct drm_crtc_state *crtc_state = NULL; const struct drm_display_mode *mode; struct drm_framebuffer *old_fb = old_plane_state->fb; struct drm_connector_state *connector_state = NULL; struct drm_framebuffer *fb = new_plane_state->fb; - const struct drm_format_info *format = fb->format; + const struct drm_format_info *format; struct drm_connector *connector; unsigned int i, num_properties; struct gud_state_req *req; int idx, ret; size_t len;

- if (drm_WARN_ON_ONCE(plane->dev, !fb)) - return -EINVAL; - - if (drm_WARN_ON_ONCE(plane->dev, !crtc)) - return -EINVAL; - - crtc_state = drm_atomic_get_new_crtc_state(state, crtc); - - mode = &crtc_state->mode; + if (crtc) + crtc_state = drm_atomic_get_new_crtc_state(state, crtc);

ret = drm_atomic_helper_check_plane_state(new_plane_state, crtc_state, DRM_PLANE_NO_SCALING, @@ -492,6 +485,9 @@ int gud_plane_atomic_check(struct drm_plane *plane, if (old_plane_state->rotation != new_plane_state->rotation) crtc_state->mode_changed = true;

+ mode = &crtc_state->mode; + format = fb->format; + if (old_fb && old_fb->format != format) crtc_state->mode_changed = true;

@@ -598,7 +594,7 @@ void gud_plane_atomic_update(struct drm_plane *plane, struct drm_atomic_helper_damage_iter iter; int ret, idx;

- if (crtc->state->mode_changed || !crtc->state->enable) { + if (!crtc || crtc->state->mode_changed || !crtc->state->enable) { cancel_work_sync(&gdrm->work); mutex_lock(&gdrm->damage_lock); if (gdrm->fb) {