CVE-2022-48738 in Linux
Summary
by MITRE • 06/20/2024
In the Linux kernel, the following vulnerability has been resolved:
ASoC: ops: Reject out of bounds values in snd_soc_put_volsw()
We don't currently validate that the values being set are within the range we advertised to userspace as being valid, do so and reject any values that are out of range.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/29/2025
The vulnerability described in CVE-2022-48738 represents a critical security flaw within the Linux kernel's Advanced Sound Architecture (ASoC) subsystem that affects how volume control operations are handled. This issue specifically targets the snd_soc_put_volsw() function which is responsible for managing volume switch operations in audio subsystems. The flaw stems from the absence of proper input validation mechanisms that should ensure all volume values fall within the predefined acceptable ranges communicated to user space applications. This validation gap creates an opportunity for malicious actors to manipulate audio parameters beyond their intended boundaries, potentially leading to system instability or unintended behavior in audio processing pipelines.
The technical implementation of this vulnerability resides in the ASoC framework's volume control handling mechanism where the kernel fails to perform bounds checking on volume values before applying them to audio hardware components. When user space applications attempt to set volume parameters through the sound subsystem interface, the kernel should verify that these values conform to the documented range specifications that were advertised during the device initialization process. However, the absence of this validation allows out-of-bounds values to be processed, which could cause unpredictable behavior in the audio driver stack. The vulnerability manifests as a lack of input sanitization that should have been implemented according to standard security practices for kernel subsystems handling user-provided data. This flaw directly relates to CWE-129 Input Validation and Output Processing, specifically addressing the failure to validate input data ranges before processing.
The operational impact of this vulnerability extends beyond simple audio quality issues to potentially compromise system stability and security. When out-of-bounds volume values are accepted and processed, they can cause audio drivers to behave erratically, leading to system crashes, audio distortion, or even potential privilege escalation scenarios. The vulnerability affects any system running a Linux kernel version that includes the affected ASoC subsystem code, particularly impacting devices with audio hardware that relies on the snd_soc_put_volsw() function for volume control operations. Attackers could exploit this weakness by crafting malicious audio control commands that push volume values beyond acceptable ranges, potentially causing the audio subsystem to malfunction or providing a vector for more sophisticated attacks against the kernel's audio processing capabilities. This vulnerability aligns with ATT&CK technique T1068, which involves exploiting vulnerabilities in system services to gain elevated privileges.
Mitigation strategies for CVE-2022-48738 focus on implementing proper bounds checking within the kernel's audio subsystem. The primary solution involves adding input validation to the snd_soc_put_volsw() function to ensure all volume values are within the range previously advertised to user space applications. This validation should occur before any hardware operations are performed, preventing out-of-bounds values from being processed. System administrators should prioritize updating to kernel versions that include the patched ASoC subsystem code, as this vulnerability was resolved through the implementation of proper input validation mechanisms. Organizations running embedded systems or devices with audio capabilities should conduct thorough testing of their audio subsystems after applying the patch to ensure no regression issues are introduced. Additionally, monitoring for unusual audio subsystem behavior or system crashes following audio parameter changes can help identify potential exploitation attempts, while maintaining up-to-date kernel versions remains the most effective long-term mitigation approach. The fix demonstrates proper adherence to security principles by implementing defensive programming techniques that validate all inputs before processing them within kernel space.