CVE-2022-50844 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Fix type of second parameter in odn_edit_dpm_table() callback
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals:
drivers/gpu/drm/amd/amdgpu/../pm/swsmu/amdgpu_smu.c:3008:29: error: incompatible function pointer types initializing 'int (*)(void *, uint32_t, long *, uint32_t)' (aka 'int (*)(void *, unsigned int, long *, unsigned int)') with an expression of type 'int (void *, enum PP_OD_DPM_TABLE_COMMAND, long *, uint32_t)' (aka 'int (void *, enum PP_OD_DPM_TABLE_COMMAND, long *, unsigned int)') [-Werror,-Wincompatible-function-pointer-types-strict]
.odn_edit_dpm_table = smu_od_edit_dpm_table, ^~~~~~~~~~~~~~~~~~~~~ 1 error generated.
There are only two implementations of ->odn_edit_dpm_table() in 'struct amd_pm_funcs': smu_od_edit_dpm_table() and pp_odn_edit_dpm_table(). One has a second parameter type of 'enum PP_OD_DPM_TABLE_COMMAND' and the other uses 'u32'. Ultimately, smu_od_edit_dpm_table() calls ->od_edit_dpm_table() from 'struct pptable_funcs' and pp_odn_edit_dpm_table() calls ->odn_edit_dpm_table() from 'struct pp_hwmgr_func', which both have a second parameter type of 'enum PP_OD_DPM_TABLE_COMMAND'.
Update the type parameter in both the prototype in 'struct amd_pm_funcs' and pp_odn_edit_dpm_table() to 'enum PP_OD_DPM_TABLE_COMMAND', which cleans up the warning.
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Analysis
by VulDB Data Team • 04/26/2026
The vulnerability CVE-2022-50844 represents a type mismatch issue within the AMD GPU driver component of the Linux kernel, specifically affecting the drm/amdgpu subsystem. This flaw manifests in the context of kernel control flow integrity mechanisms implemented through clang's kernel control flow integrity (kCFI) framework. The issue arises from an inconsistency in function pointer parameter types that could potentially undermine the security protections designed to prevent return-oriented programming (ROP) attacks and other control flow corruption exploits. The vulnerability impacts systems utilizing AMD graphics hardware through the amdgpu driver, where the kernel's security hardening features are enabled.
The technical root cause involves an incompatible function pointer type declaration within the amd_pm_funcs structure. The odn_edit_dpm_table callback function pointer expects a second parameter of type enum PP_OD_DPM_TABLE_COMMAND, while one of the implementing functions pp_odn_edit_dpm_table() declares its second parameter as uint32_t (u32). This discrepancy creates a mismatch that violates the kCFI validation mechanisms designed to ensure indirect call targets match expected function pointer prototypes. The clang compiler's strict type checking identifies this inconsistency at compile time, generating a warning that would otherwise be suppressed and potentially lead to runtime failures including kernel panics or thread termination.
The operational impact of this vulnerability extends beyond simple compilation warnings to represent a potential security weakness in kernel memory protection mechanisms. When kCFI is enabled through CONFIG_CFI_CLANG, this type mismatch could enable attackers to bypass control flow integrity protections that are specifically designed to prevent exploitation techniques such as ROP and JIT spraying attacks. The vulnerability affects the AMD GPU power management functionality, particularly the on-demand DPM (Dynamic Power Management) table editing capabilities that control GPU performance states and power consumption parameters. This represents a CWE-665 Improper Initialization vulnerability category where function signatures do not properly align with expected interfaces.
The resolution for CVE-2022-50844 involves standardizing parameter types across all implementing functions within the AMD GPU power management subsystem. Both the prototype declaration in struct amd_pm_funcs and the implementation in pp_odn_edit_dpm_table() must be updated to use enum PP_OD_DPM_TABLE_COMMAND for the second parameter. This type consistency ensures that kCFI validation passes correctly and maintains the intended security protections while preserving the functional behavior of the GPU power management system. The fix aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell, specifically addressing the kernel-level execution environment where the vulnerability manifests through function pointer type mismatches that could enable privilege escalation or denial of service attacks. This vulnerability demonstrates the importance of maintaining strict type consistency in kernel interfaces, particularly when security mechanisms like kCFI are employed to protect against sophisticated exploitation techniques targeting kernel memory corruption vulnerabilities.