Hello Dan Williams, This is a semi-automatic email about new static checker warnings. The patch 8c2f7e8658df: "libnvdimm: infrastructure for btt devices" from Jun 25, 2015, leads to the following Smatch complaint: drivers/nvdimm/region_devs.c:461 nd_region_notify_driver_action() error: we previously assumed 'dev->parent' could be null (see line 453) drivers/nvdimm/region_devs.c 452 } 453 if (dev->parent && is_nd_blk(dev->parent) && probe) { ^^^^^^^^^^^ New check. 454 nd_region = to_nd_region(dev->parent); 455 nvdimm_bus_lock(dev); 456 if (nd_region->ns_seed == dev) 457 nd_region_create_blk_seed(nd_region); 458 nvdimm_bus_unlock(dev); 459 } 460 if (is_nd_btt(dev) && probe) { 461 nd_region = to_nd_region(dev->parent); ^^^^^^^^^^^ New unchecked dereference inside function call.