CVE-2025-21917 is a medium severity vulnerability in the Linux kernel's Renesas USBHS driver. It causes a kernel crash due to a NULL pointer dereference when performing continuous unbind/bind operations on USB drivers for the Renesas RZ/G2L SoC. The issue is related to the usbhsc_notify_hotplug() function and is resolved by flushing the delayed work to prevent execution when driver resources are unavailable.