From: Joe Moriarty <joe.moriarty@xxxxxxxxxx> [ Upstream commit 22a07038c0eaf4d1315a493ce66dcd255accba19 ] The Parfait (version 2.1.0) static code analysis tool found the following NULL pointer derefernce problem. - drivers/gpu/drm/drm_dp_mst_topology.c The call to drm_dp_calculate_rad() in function drm_dp_port_setup_pdt() could result in a NULL pointer being returned to port->mstb due to a failure to allocate memory for port->mstb. Signed-off-by: Joe Moriarty <joe.moriarty@xxxxxxxxxx> Reviewed-by: Steven Sistare <steven.sistare@xxxxxxxxxx> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20180212195144.98323-3-joe.moriarty@xxxxxxxxxx Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> --- drivers/gpu/drm/drm_dp_mst_topology.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 93f2033b414a2..a38be6dd7cfb1 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1052,10 +1052,12 @@ static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port) lct = drm_dp_calculate_rad(port, rad); port->mstb = drm_dp_add_mst_branch_device(lct, rad); - port->mstb->mgr = port->mgr; - port->mstb->port_parent = port; + if (port->mstb) { + port->mstb->mgr = port->mgr; + port->mstb->port_parent = port; - send_link = true; + send_link = true; + } break; } return send_link; -- 2.25.1
