CVE-2025-38308 in Linux
Summary
by MITRE • 07/10/2025
In the Linux kernel, the following vulnerability has been resolved:
ASoC: Intel: avs: Fix possible null-ptr-deref when initing hw
Search result of avs_dai_find_path_template() shall be verified before being used. As 'template' is already known when avs_hw_constraints_init() is fired, drop the search entirely.
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Analysis
by VulDB Data Team • 12/07/2025
The vulnerability CVE-2025-38308 represents a critical null pointer dereference issue within the Linux kernel's Intel Audio Video Streaming driver component. This flaw exists in the Advanced Sound Architecture (ASoC) subsystem specifically affecting the Intel AVS (Audio Video Streaming) implementation. The vulnerability occurs during the hardware initialization phase of audio device drivers, where the system attempts to initialize hardware constraints for audio data interfaces. The issue stems from improper validation of search results within the avs_dai_find_path_template() function, which is responsible for locating appropriate path templates for audio data interfaces in the AVS subsystem.
The technical root cause of this vulnerability lies in the absence of proper null pointer validation before dereferencing the search result from avs_dai_find_path_template(). When avs_hw_constraints_init() is invoked, the system expects to find a valid template structure but fails to verify whether the search operation successfully located an appropriate template. This oversight creates a condition where a null pointer is dereferenced, leading to potential system crashes or undefined behavior. The vulnerability is particularly concerning because it occurs during the hardware initialization phase, which typically happens early in the system boot process or when audio devices are being configured, making it a prime target for exploitation that could disrupt system stability or enable privilege escalation.
From an operational impact perspective, this vulnerability poses significant risks to systems utilizing Intel AVS audio hardware, particularly those running Linux kernel versions containing the affected code. The null pointer dereference could result in system crashes, audio subsystem failures, or potentially allow attackers to exploit the condition for privilege escalation or denial of service attacks. The vulnerability aligns with CWE-476 which specifically addresses null pointer dereference conditions, and may map to ATT&CK techniques such as T1068 for exploit development or T1499 for system disruption. Systems that rely heavily on audio functionality, including servers, desktops, and embedded devices with Intel AVS audio capabilities, are particularly vulnerable to this issue.
The recommended mitigation strategy involves applying the kernel patch that removes the unnecessary search operation entirely, since the template is already known at the time avs_hw_constraints_init() is called. This approach eliminates the potential for null pointer dereference by avoiding the problematic search altogether. System administrators should prioritize updating their Linux kernel installations to versions containing the fix, particularly in production environments where audio subsystem stability is critical. Additionally, monitoring for unusual system crashes or audio subsystem failures following kernel updates can help identify potential exploitation attempts. Organizations should also consider implementing runtime protections and monitoring mechanisms to detect anomalous behavior patterns that might indicate exploitation attempts targeting this specific vulnerability.