Service interruption via leaked PHY clock resources

Resource leak in the Linux kernel MediaTek T-PHY driver allows local users to interrupt service through failed PHY initialization. The mtk_phy_init error path enables the PHY reference clock but returns without calling clk_disable_unprepare when initialization fails, leaving the clock resource enabled. Reachability requires local low-privileged access, compatible MediaTek hardware, and a T-PHY configuration that enters the failing initialization path; repeated failures exhaust resources and interrupt service.