This is a note to let you know that I've just added the patch titled drm/atomic: Verify connector->funcs != NULL when clearing states to the 4.5-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-atomic-verify-connector-funcs-null-when-clearing-states.patch and it can be found in the queue-4.5 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From cpaul@xxxxxxxxxx Sat Jun 4 13:44:11 2016 From: Lyude <cpaul@xxxxxxxxxx> Date: Tue, 31 May 2016 12:49:07 -0400 Subject: drm/atomic: Verify connector->funcs != NULL when clearing states To: stable@xxxxxxxxxxxxxxx, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Lyude <cpaul@xxxxxxxxxx>, David Airlie <airlied@xxxxxxxx>, dri-devel@xxxxxxxxxxxxxxxxxxxxx (open list:DRM DRIVERS), linux-kernel@xxxxxxxxxxxxxxx (open list) Message-ID: <1464713347-28982-5-git-send-email-cpaul@xxxxxxxxxx> From: Lyude <cpaul@xxxxxxxxxx> Unfortunately since we don't have Dave's connector refcounting patch here yet, it's very possible that drm_atomic_state_default_clear() could get called by intel_display_resume() when intel_dp_mst_destroy_connector() isn't completely finished destroying an mst connector, but has already finished setting connector->funcs to NULL. As such, we need to treat the connector like it's already been destroyed and just skip it, otherwise we'll end up dereferencing a NULL pointer. This fix is only required for 4.6 and below. David Airlie's patchseries for 4.7 to add connector reference counting provides a more proper fix for this. Changes since v1: - Fix leftover whitespace Upstream fix: 0552f7651bc2 ("drm/i915/mst: use reference counted connectors. (v3)") Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Signed-off-by: Lyude <cpaul@xxxxxxxxxx> --- drivers/gpu/drm/drm_atomic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -138,7 +138,7 @@ void drm_atomic_state_default_clear(stru for (i = 0; i < state->num_connector; i++) { struct drm_connector *connector = state->connectors[i]; - if (!connector) + if (!connector || !connector->funcs) continue; /* Patches currently in stable-queue which might be from cpaul@xxxxxxxxxx are queue-4.5/drm-i915-fbdev-fix-num_connector-references-in-intel_fb_initial_config.patch queue-4.5/drm-i915-psr-try-to-program-link-training-times-correctly.patch queue-4.5/drm-fb_helper-fix-references-to-dev-mode_config.num_connector.patch queue-4.5/drm-atomic-verify-connector-funcs-null-when-clearing-states.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html