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Commit acdbd4bc authored by Imre Deak's avatar Imre Deak Committed by Greg Kroah-Hartman
Browse files

drm/mst: Avoid dereferencing a NULL mstb in drm_dp_mst_handle_up_req() 



commit 7f8b3987da54cb4d41ad2545cd4d7958b9a36bdf upstream.

In case of an unknown broadcast message is sent mstb will remain unset,
so check for this.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Lyude <lyude@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Reviewed-by: default avatarLyude <lyude@redhat.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170719114330.26540-3-imre.deak@intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 36ad1e78

drivers/gpu/drm/drm_dp_mst_topology.c

+3 −1
Original line number Diff line number Diff line
@@ -2209,7 +2209,9 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) 
			DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);

		}



		if (mstb)

			drm_dp_put_mst_branch_device(mstb);



		memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));

	}

	return ret;