This is a note to let you know that I've just added the patch titled drm/i915: Fix possible race in intel_dp_add_mst_connector() to the 4.19-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-i915-fix-possible-race-in-intel_dp_add_mst_connector.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 7c4512300cfa5a4dcc8c1c52ae61e3fa4bd11a39 Mon Sep 17 00:00:00 2001 From: Lyude Paul <lyude@xxxxxxxxxx> Date: Tue, 6 Nov 2018 16:30:12 -0500 Subject: drm/i915: Fix possible race in intel_dp_add_mst_connector() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Lyude Paul <lyude@xxxxxxxxxx> commit 7c4512300cfa5a4dcc8c1c52ae61e3fa4bd11a39 upstream. This hasn't caused any issues yet that I'm aware of, but as Ville Syrjälä pointed out - we need to make sure that intel_connector->mst_port is set before initializing MST connectors, since in theory we could potentially check intel_connector->mst_port in i915_hpd_poll_init_work() after registering the connector but before having written it's value. Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://patchwork.freedesktop.org/patch/msgid/20181106213017.14563-2-lyude@xxxxxxxxxx (cherry picked from commit 66a5ab1034be801630816d1fa6cfc30db1a2f0b0) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_dp_mst.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/gpu/drm/i915/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/intel_dp_mst.c @@ -458,6 +458,10 @@ static struct drm_connector *intel_dp_ad if (!intel_connector) return NULL; + intel_connector->get_hw_state = intel_dp_mst_get_hw_state; + intel_connector->mst_port = intel_dp; + intel_connector->port = port; + connector = &intel_connector->base; ret = drm_connector_init(dev, connector, &intel_dp_mst_connector_funcs, DRM_MODE_CONNECTOR_DisplayPort); @@ -468,10 +472,6 @@ static struct drm_connector *intel_dp_ad drm_connector_helper_add(connector, &intel_dp_mst_connector_helper_funcs); - intel_connector->get_hw_state = intel_dp_mst_get_hw_state; - intel_connector->mst_port = intel_dp; - intel_connector->port = port; - for_each_pipe(dev_priv, pipe) { struct drm_encoder *enc = &intel_dp->mst_encoders[pipe]->base.base; Patches currently in stable-queue which might be from lyude@xxxxxxxxxx are queue-4.19/drm-atomic_helper-disallow-new-modesets-on-unregistered-connectors.patch queue-4.19/drm-i915-fix-hpd-handling-for-pins-with-two-encoders.patch queue-4.19/drm-i915-dp-restrict-link-retrain-workaround-to-external-monitors.patch queue-4.19/drm-nouveau-fix-nv50_mstc-best_encoder.patch queue-4.19/drm-i915-skip-vcpi-allocation-for-mstb-ports-that-are-gone.patch queue-4.19/drm-amdgpu-suppress-keypresses-from-acpi_video-events.patch queue-4.19/drm-i915-dp-fix-link-retraining-comment-in-intel_dp_long_pulse.patch queue-4.19/drm-i915-don-t-unset-intel_connector-mst_port.patch queue-4.19/drm-i915-fix-possible-race-in-intel_dp_add_mst_connector.patch queue-4.19/drm-nouveau-check-backlight-ids-are-0-not-0.patch queue-4.19/drm-i915-fix-null-deref-when-re-enabling-hpd-irqs-on-systems-with-mst.patch queue-4.19/drm-dp_mst-check-if-primary-mstb-is-null.patch