CVE-2021-47532: 
Linux Kernel vulnerability analysis and mitigation

CVE-2021-47532 is a vulnerability in the Linux kernel related to a reference count leak in the DRM/MSM devfreq driver. The vulnerability was discovered and reported by Douglas Anderson, with the issue specifically affecting the OPP (Operating Performance Point) reference counting mechanism. The vulnerability was disclosed on May 24, 2024, and affects the Linux kernel's graphics subsystem (Kernel Git).

The vulnerability stems from a reference count leak in the DRM/MSM (Direct Rendering Manager/Mainstream) devfreq driver of the Linux kernel. The issue specifically occurs in the msm_gpu_devfreq.c file where the OPP (Operating Performance Point) reference count was not properly managed when handling idle frequencies. The bug was introduced in commit 9bc95570175a titled 'drm/msm: Devfreq tuning' (Kernel Git).

The vulnerability could lead to a reference count leak in the Linux kernel's graphics subsystem, potentially affecting system stability and resource management (Debian Tracker).

The vulnerability has been fixed through a patch that properly releases the OPP reference count by adding a dev_pm_opp_put(opp) call in the appropriate code path. The fix was implemented in the Linux kernel and is available through the stable kernel release channels (Kernel Git).