CVE-2024-50187 — Use After Free in Linux

In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Stop the active perfmon before being destroyed Upon closing the file descriptor, the active performance monitor is not stopped. Although all perfmons are destroyed in `vc4_perfmon_close_file()`, the active performance monitor's pointer (`vc4->active_perfmon`) is still retained. If we open a new file descriptor and submit a few jobs with performance monitors, the driver will attempt to stop the active performance moni…