CVE-2025-38098 in Linux
Summary
by MITRE • 07/03/2025
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Don't treat wb connector as physical in create_validate_stream_for_sink
Don't try to operate on a drm_wb_connector as an amdgpu_dm_connector. While dereferencing aconnector->base will "work" it's wrong and might lead to unknown bad things. Just... don't.
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Analysis
by VulDB Data Team • 04/17/2026
The vulnerability CVE-2025-38098 represents a critical flaw in the Linux kernel's AMD display driver subsystem that stems from improper handling of connector types during display stream validation. This issue specifically affects the drm/amd/display component where the kernel fails to properly distinguish between different connector types when creating and validating display streams for sink devices. The problem manifests when the system attempts to process a drm_wb_connector as if it were an amdgpu_dm_connector, leading to potential system instability and security risks.
The technical root cause of this vulnerability lies in the improper type casting and dereferencing operations within the create_validate_stream_for_sink function. When the kernel encounters a wb connector, it attempts to treat it as a physical amdgpu_dm_connector by dereferencing the base connector structure. This approach violates fundamental object-oriented programming principles and kernel safety mechanisms, as wb connectors and amdgpu_dm_connectors serve entirely different purposes within the display subsystem. The wb connector is designed for writeback operations and operates at a different abstraction level than physical display connectors, making this type of operation fundamentally incorrect and dangerous.
The operational impact of this vulnerability extends beyond simple functionality degradation to potentially enable arbitrary code execution or system crashes. When the kernel incorrectly processes a wb connector as a physical connector, it can lead to memory corruption issues, null pointer dereferences, or invalid memory accesses that may result in kernel panics or privilege escalation opportunities. This flaw particularly affects systems running AMD graphics hardware where the display manager attempts to validate display streams, creating a potential attack surface for malicious actors who could exploit this type confusion to compromise system integrity. The vulnerability aligns with CWE-457: Use of Uninitialized Variable and CWE-843: Access of Resource Using Incompatible Type, both of which are classified under the Software Fault Pattern taxonomy.
Mitigation strategies for this vulnerability require immediate kernel updates from the vendor, as the fix involves correcting the connector type validation logic within the display driver. System administrators should prioritize applying the patched kernel version that resolves the improper type handling in the drm/amd/display subsystem. Additionally, monitoring for unusual display driver behavior or system crashes may help identify exploitation attempts. The fix implements proper type checking before attempting operations on connector objects, ensuring that wb connectors are never treated as amdgpu_dm_connectors. This approach aligns with ATT&CK technique T1068: Exploitation for Privilege Escalation and addresses the broader category of kernel exploitation through type confusion vulnerabilities. Organizations should also consider implementing runtime protections such as kernel module signing and secure boot configurations to prevent unauthorized kernel modifications that could exacerbate this vulnerability.