This patch add checks for NULL drm_[connector/crtc/plane]_helper_funcs pointers before derefrencing the variable to avoid NULL pointer dereference and make the helper functions as optional as possible. Signed-off-by: Haneen Mohammed <hamohammed.sa@xxxxxxxxx> --- drivers/gpu/drm/drm_atomic_helper.c | 42 +++++++++++++++-------------- drivers/gpu/drm/drm_probe_helper.c | 11 ++++---- 2 files changed, 28 insertions(+), 25 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index c35654591c12..52092deb741d 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -112,9 +112,9 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state, if (!new_conn_state->crtc) continue; - if (funcs->atomic_best_encoder) + if (funcs && funcs->atomic_best_encoder) new_encoder = funcs->atomic_best_encoder(connector, new_conn_state); - else if (funcs->best_encoder) + else if (funcs && funcs->best_encoder) new_encoder = funcs->best_encoder(connector); else new_encoder = drm_atomic_helper_best_encoder(connector); @@ -308,10 +308,10 @@ update_connector_routing(struct drm_atomic_state *state, funcs = connector->helper_private; - if (funcs->atomic_best_encoder) + if (funcs && funcs->atomic_best_encoder) new_encoder = funcs->atomic_best_encoder(connector, new_connector_state); - else if (funcs->best_encoder) + else if (funcs && funcs->best_encoder) new_encoder = funcs->best_encoder(connector); else new_encoder = drm_atomic_helper_best_encoder(connector); @@ -438,7 +438,7 @@ mode_fixup(struct drm_atomic_state *state) continue; funcs = crtc->helper_private; - if (!funcs->mode_fixup) + if (!funcs || !funcs->mode_fixup) continue; ret = funcs->mode_fixup(crtc, &new_crtc_state->mode, @@ -639,7 +639,7 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, new_crtc_state->connectors_changed = true; } - if (funcs->atomic_check) + if (funcs && funcs->atomic_check) ret = funcs->atomic_check(connector, new_connector_state); if (ret) return ret; @@ -681,7 +681,7 @@ drm_atomic_helper_check_modeset(struct drm_device *dev, if (connectors_mask & BIT(i)) continue; - if (funcs->atomic_check) + if (funcs && funcs->atomic_check) ret = funcs->atomic_check(connector, new_connector_state); if (ret) return ret; @@ -972,14 +972,16 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state) /* Right function depends upon target state. */ - if (new_crtc_state->enable && funcs->prepare) - funcs->prepare(crtc); - else if (funcs->atomic_disable) - funcs->atomic_disable(crtc, old_crtc_state); - else if (funcs->disable) - funcs->disable(crtc); - else - funcs->dpms(crtc, DRM_MODE_DPMS_OFF); + if (funcs) { + if (new_crtc_state->enable && funcs->prepare) + funcs->prepare(crtc); + else if (funcs->atomic_disable) + funcs->atomic_disable(crtc, old_crtc_state); + else if (funcs->disable) + funcs->disable(crtc); + else + funcs->dpms(crtc, DRM_MODE_DPMS_OFF); + } if (!(dev->irq_enabled && dev->num_crtcs)) continue; @@ -1093,7 +1095,7 @@ crtc_set_mode(struct drm_device *dev, struct drm_atomic_state *old_state) funcs = crtc->helper_private; - if (new_crtc_state->enable && funcs->mode_set_nofb) { + if (new_crtc_state->enable && funcs && funcs->mode_set_nofb) { DRM_DEBUG_ATOMIC("modeset on [CRTC:%d:%s]\n", crtc->base.id, crtc->name); @@ -1197,7 +1199,7 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev, funcs = crtc->helper_private; - if (new_crtc_state->enable) { + if (funcs && new_crtc_state->enable) { DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n", crtc->base.id, crtc->name); @@ -2117,7 +2119,7 @@ int drm_atomic_helper_prepare_planes(struct drm_device *dev, funcs = plane->helper_private; - if (funcs->prepare_fb) { + if (funcs && funcs->prepare_fb) { ret = funcs->prepare_fb(plane, new_plane_state); if (ret) goto fail; @@ -2135,7 +2137,7 @@ int drm_atomic_helper_prepare_planes(struct drm_device *dev, funcs = plane->helper_private; - if (funcs->cleanup_fb) + if (funcs && funcs->cleanup_fb) funcs->cleanup_fb(plane, new_plane_state); } @@ -2412,7 +2414,7 @@ void drm_atomic_helper_cleanup_planes(struct drm_device *dev, funcs = plane->helper_private; - if (funcs->cleanup_fb) + if (funcs && funcs->cleanup_fb) funcs->cleanup_fb(plane, plane_state); } } diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 527743394150..42507aa7f763 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -272,9 +272,9 @@ drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force) retry: ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx); if (!ret) { - if (funcs->detect_ctx) + if (funcs && funcs->detect_ctx) ret = funcs->detect_ctx(connector, &ctx, force); - else if (connector->funcs->detect) + else if (connector->funcs && connector->funcs->detect) ret = connector->funcs->detect(connector, force); else ret = connector_status_connected; @@ -320,9 +320,9 @@ drm_helper_probe_detect(struct drm_connector *connector, if (ret) return ret; - if (funcs->detect_ctx) + if (funcs && funcs->detect_ctx) return funcs->detect_ctx(connector, ctx, force); - else if (connector->funcs->detect) + else if (connector->funcs && connector->funcs->detect) return connector->funcs->detect(connector, force); else return connector_status_connected; @@ -480,7 +480,8 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector, goto prune; } - count = (*connector_funcs->get_modes)(connector); + if (connector_funcs && connector_funcs->get_modes) + count = (*connector_funcs->get_modes)(connector); if (count == 0 && connector->status == connector_status_connected) count = drm_add_modes_noedid(connector, 1024, 768); 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