From: Mario Limonciello mario.limonciello@amd.com

[WHY] Although unlikely drm_atomic_get_new_connector_state() or drm_atomic_get_old_connector_state() can return NULL.

[HOW] Check returns before dereference.

Cc: Mario Limonciello mario.limonciello@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Reviewed-by: Harry Wentland harry.wentland@amd.com Signed-off-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Alex Hung alex.hung@amd.com --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 176f420effd9..b944abea306d 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -7836,6 +7836,9 @@ amdgpu_dm_connector_atomic_check(struct drm_connector *conn, struct amdgpu_dm_connector *aconn = to_amdgpu_dm_connector(conn); int ret;

+ if (WARN_ON(unlikely(!old_con_state || !new_con_state))) + return -EINVAL; + trace_amdgpu_dm_connector_atomic_check(new_con_state);

if (conn->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {