Kernel panic via incomplete PMU probe rollback

Denial of service in the Linux kernel Arm NI driver allows local users to interrupt service through a kernel panic after probe failure. The arm_ni_probe error path leaves PMUs from earlier clock domains registered when a later domain's resource request fails, so a subsequent registration corrupts the PMU list. Reachability requires low-privileged local access, an affected Arm NI device, and an allocation failure during probing; the reported consequence is a host crash.