CVE-2025-38091: Linux Kernel AMD GPU Display Driver False Positive Warning
This blog post discusses a resolved issue in the Linux kernel related to the AMD GPU display driver. Specifically, it addresses a false positive warning that could occur during certain operations, enhancing system stability by preventing unnecessary alerts.
Vulnerability Details
- CVE ID: CVE-2025-38091
- Description: A false positive warning was identified in the AMD GPU display driver (DML21) within the Linux kernel. This warning arose due to insufficient checks when querying the
plane_id. The issue was triggered during mode resets, specifically when executingcat /sys/kernel/debug/dri/1/amdgpu_gpu_recover. - CVSS Score and Vector: Awaiting Analysis.
- Exploit Requirements: The warning is a false positive and does not represent an exploitable vulnerability. It is triggered during specific debugging operations.
- Affected Vendor, Product, Version: Linux Kernel, specifically the AMD GPU display driver component. The fix has been applied to the kernel version mentioned in the commit logs.
- CWE: This is not an exploitable vulnerability, but it can be related to CWE-703 (Improper Handling of Error Conditions) as it involves an incorrect warning being generated.
Timeline of Events
- Reported: Unknown
- Patch Applied: 2025-07-02 (Based on CVE Publication Date)
- Analyzed: 2025-07-02 (Based on CVE Publication Date)
Exploitability & Real-World Risk
Since this issue is a false positive warning, there is no real-world exploitability or risk associated with it. The patch primarily addresses a noisy debugging output, preventing unnecessary alerts that could mislead developers and system administrators. The practical impact is reduced noise in system logs and improved clarity during debugging sessions.
Recommendations
Users running affected Linux kernels should update to a version that includes the fix. This can be achieved through standard system update procedures. Specifically, ensure that the following commit is included in your kernel version: f8ad62c0a93e5dd94243e10f1b742232e4d6411e.
Technical Insight
The issue stemmed from missing checks in the DML21 wrapper when querying the plane_id. The fix introduces the necessary checks to prevent the false positive warning during mode resets, ensuring that the warning is only triggered when an actual error condition exists. This prevents debug logs from being flooded with irrelevant warnings.
Credit to Researcher(s)
The resolution of this issue is credited to the developers who contributed to the AMD GPU display driver in the Linux kernel.
References
Tags
Linux, Kernel, AMD, GPU, Display Driver, DML21, CVE-2025-38091, False Positive, Warning
Summary: A false positive warning was identified and resolved in the AMD GPU display driver (DML21) of the Linux kernel. This fix prevents unnecessary warning messages during mode resets, improving system stability and debugging clarity.
CVE ID: CVE-2025-38091
Risk Analysis: The risk is minimal as it only resulted in misleading debug information and not a system compromise.
Recommendation: Update to a Linux kernel version including the fix: commit f8ad62c0a93e5dd94243e10f1b742232e4d6411e.
Timeline
- 2025-07-02: CVE Published and fix analyzed.