CVE-2025-39930 in Linux
Summary
by MITRE • 04/18/2025
In the Linux kernel, the following vulnerability has been resolved:
ASoC: simple-card-utils: Don't use __free(device_node) at graph_util_parse_dai()
commit 419d1918105e ("ASoC: simple-card-utils: use __free(device_node) for device node") uses __free(device_node) for dlc->of_node, but we need to keep it while driver is in use.
Don't use __free(device_node) in graph_util_parse_dai().
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 05/24/2026
The vulnerability CVE-2025-39930 represents a critical memory management flaw in the Linux kernel's Advanced SoC (ASoC) subsystem, specifically within the simple-card-utils component that handles audio device node parsing. This issue manifests in the graph_util_parse_dai() function where improper memory deallocation occurs, potentially leading to system instability or denial of service conditions. The vulnerability arises from an incorrect implementation that attempts to free device node memory structures while the driver is still actively utilizing them, creating a race condition that can result in dangling pointer references and subsequent kernel crashes.
The technical root cause stems from commit 419d1918105e which introduced a flawed approach to device node memory management by applying __free(device_node) to dlc->of_node references. This change violates fundamental memory management principles by deallocating memory that remains in active use by the audio subsystem driver. The device node structures contain essential configuration data and topology information required for proper audio device operation, and prematurely freeing these structures causes the kernel to attempt accessing freed memory locations. This pattern directly corresponds to CWE-415: Double Free and CWE-416: Use After Free vulnerabilities, where improper memory lifecycle management leads to system instability.
The operational impact of this vulnerability extends beyond simple system crashes to potentially compromise audio functionality across embedded systems and mobile devices running Linux kernels. Systems utilizing the ASoC framework for audio processing, including smartphones, tablets, automotive infotainment systems, and embedded audio appliances, may experience complete audio subsystem failures or unexpected reboots when the affected code path is triggered. The vulnerability is particularly concerning in automotive environments where audio system reliability is critical for safety and user experience. Attackers could potentially exploit this weakness to cause denial of service conditions, making audio services unavailable during critical operations.
Mitigation strategies for CVE-2025-39930 require immediate kernel updates that revert the problematic commit 419d1918105e and implement proper memory lifecycle management for device node structures. System administrators should prioritize applying security patches from their respective kernel maintainers, as the vulnerability affects the core audio subsystem functionality. Additionally, implementing monitoring solutions to detect unusual audio subsystem behavior or kernel oops messages can help identify exploitation attempts. The fix should ensure that device node references remain valid throughout the driver's operational lifetime while properly cleaning up memory only when the driver is completely unloaded. This approach aligns with ATT&CK technique T1499.004: Endpoint Denial of Service to prevent unauthorized disruption of audio services. Organizations should also consider implementing kernel hardening measures such as stack canaries and memory protection mechanisms to further reduce the attack surface and prevent exploitation of similar memory management vulnerabilities in the ASoC subsystem.