CVE-2024-50187

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/vc4: Stop the active perfmon before being destroyed<br /> <br /> Upon closing the file descriptor, the active performance monitor is not<br /> stopped. Although all perfmons are destroyed in `vc4_perfmon_close_file()`,<br /> the active performance monitor&amp;#39;s pointer (`vc4-&gt;active_perfmon`) is still<br /> retained.<br /> <br /> If we open a new file descriptor and submit a few jobs with performance<br /> monitors, the driver will attempt to stop the active performance monitor<br /> using the stale pointer in `vc4-&gt;active_perfmon`. However, this pointer<br /> is no longer valid because the previous process has already terminated,<br /> and all performance monitors associated with it have been destroyed and<br /> freed.<br /> <br /> To fix this, when the active performance monitor belongs to a given<br /> process, explicitly stop it before destroying and freeing it.