CVE-2026-10647 Deadlock denial of service in USB CDC-NCM device class on TX enqueue failure

The USB CDC-NCM device class subsys/usb/devicenext/class/usbdcdcncm.c ignores the return value of usbdepenqueue in its ethernet transmit callback cdcncmsend. When the enqueue fails, the function still calls ksemtake&data-syncsem, KFOREVER, blocking on a completion semaphore that is only ever...