From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:34127 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751761AbcFDUyu (ORCPT ); Sat, 4 Jun 2016 16:54:50 -0400 Subject: Patch "drm/atomic: Verify connector->funcs != NULL when clearing states" has been added to the 4.4-stable tree To: cpaul@redhat.com, airlied@linux.ie, daniel.vetter@ffwll.ch, gregkh@linuxfoundation.org Cc: , From: Date: Sat, 04 Jun 2016 13:54:49 -0700 In-Reply-To: <1464713347-28982-5-git-send-email-cpaul@redhat.com> Message-ID: <14650736898454@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 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 4.4-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-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From cpaul@redhat.com Sat Jun 4 13:44:11 2016 From: Lyude Date: Tue, 31 May 2016 12:49:07 -0400 Subject: drm/atomic: Verify connector->funcs != NULL when clearing states To: stable@vger.kernel.org, Greg Kroah-Hartman Cc: Lyude , David Airlie , dri-devel@lists.freedesktop.org (open list:DRM DRIVERS), linux-kernel@vger.kernel.org (open list) Message-ID: <1464713347-28982-5-git-send-email-cpaul@redhat.com> From: Lyude 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 Signed-off-by: Lyude --- 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 @@ -150,7 +150,7 @@ 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@redhat.com are queue-4.4/drm-i915-fbdev-fix-num_connector-references-in-intel_fb_initial_config.patch queue-4.4/drm-fb_helper-fix-references-to-dev-mode_config.num_connector.patch queue-4.4/drm-atomic-verify-connector-funcs-null-when-clearing-states.patch