CVE-2022-50844: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50844 is a type mismatch vulnerability in the Linux kernel's drm/amdgpu driver, specifically in the odn_edit_dpm_table() callback within the AMD GPU power management subsystem. The flaw involves an incompatible function pointer type for the second parameter — one implementation uses enum PP_OD_DPM_TABLE_COMMAND while another uses u32 — which can cause undefined behavior or a kernel panic when Clang's kernel Control Flow Integrity (kCFI, CONFIG_CFI_CLANG) is enabled. It was published on December 30, 2025, and affects the Linux kernel's amdgpu driver. The CVSS category is estimated as Medium, with an EPSS score of 0.000180 (Feedly, VulDB).

The root cause is an incompatible function pointer type mismatch (CWE-704: Incorrect Type Conversion or Cast) in the struct amd_pm_funcs definition within drivers/gpu/drm/amd/amdgpu/../pm/swsmu/amdgpu_smu.c. The two implementations of ->odn_edit_dpm_table() — smu_od_edit_dpm_table() and pp_odn_edit_dpm_table() — differ in the type of their second parameter (enum PP_OD_DPM_TABLE_COMMAND vs. u32/uint32_t). When kCFI is active, indirect calls are validated against the expected function pointer prototype at runtime; a mismatch results in a kernel panic or the calling thread being killed. The fix involves aligning the second parameter type across all implementations to eliminate the incompatibility (Feedly).

Exploitation of this vulnerability on a system with CONFIG_CFI_CLANG enabled can result in a kernel panic (denial of service) or abnormal termination of the thread invoking the mismatched callback, affecting system availability. The scope is limited to systems running the Linux kernel with the amdgpu driver and Clang's kCFI enabled; confidentiality and integrity impacts are minimal, as the primary consequence is a crash rather than code execution or data exposure (Feedly, VulDB).

The fix is to align the second parameter type of all ->odn_edit_dpm_table() implementations in struct amd_pm_funcs to use a consistent type, resolving the function pointer incompatibility. Patches have been submitted to the Linux kernel stable tree (commits 24cba9d865157c9e23128fbcf8b86f5da9570edd, 36217f676b55932a12d6732c95388150015fdee6, e4d0ef752081e7aa6ffb7ccac11c499c732a2e05, and f9084e9930db562bdcd47fa199a66fb45e16dab5). Users should update to a patched kernel version that includes these fixes; as a temporary workaround, disabling CONFIG_CFI_CLANG will prevent the runtime panic, though this reduces kernel security hardening (Feedly, Kernel Git).