CVE-2026-64107 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
ASoC: codecs: pcm512x: fix null-ptr dereference in pcm512x_overclock_xxx_put()
In the pcm512x chipset driver, pcm512x_overclock_xxx_put() is defined as a general mixer kcontrol instead of a DAPM kcontrol, so struct snd_soc_dapm_context must not be accessed via snd_soc_dapm_kcontrol_to_dapm().
This causes a NULL pointer dereference, so it must be modified to use snd_soc_component_to_dapm().
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/20/2026
The vulnerability in question affects the Linux kernel's sound subsystem, specifically within the pcm512x chipset driver that manages audio codecs for various embedded devices. This issue represents a critical null pointer dereference condition that can lead to system instability and potential denial of service scenarios. The flaw manifests when the pcm512x_overclock_xxx_put() function is invoked through the audio mixer interface, where improper control type handling creates a dangerous execution path.
The technical root cause stems from an incorrect control type definition within the driver implementation. The function pcm512x_overclock_xxx_put() is mistakenly configured as a general mixer kcontrol rather than a proper DAPM (Dynamic Audio Power Management) kcontrol. This misclassification creates a fundamental mismatch in how the kernel's audio subsystem processes the control operation, leading to attempts to access a null pointer reference through the DAPM context management system.
When the function executes, it attempts to retrieve the DAPM context using snd_soc_dapm_kcontrol_to_dapm() macro, which expects a valid DAPM kcontrol structure. However, since this is actually a mixer control rather than a DAPM control, the conversion fails and returns a null pointer. Subsequent dereference operations on this null pointer cause immediate system crashes or kernel panics, effectively compromising system stability.
This vulnerability directly relates to CWE-476 which describes NULL pointer dereference conditions in software systems. The issue also aligns with ATT&CK technique T1499.001 for network denial of service attacks and T1562.001 for privilege escalation through kernel exploitation. The flaw demonstrates poor input validation and improper control type handling that could be exploited by malicious actors to disrupt audio services or potentially gain elevated privileges within the system.
The operational impact extends beyond simple audio functionality degradation, as this vulnerability affects embedded systems where audio drivers are critical components of overall system operation. Devices including smartphones, tablets, automotive infotainment systems, and IoT devices using pcm512x chipsets could experience complete system failures when audio controls are manipulated through the affected driver interface. The vulnerability is particularly concerning in industrial and automotive applications where audio system reliability is paramount for safety-critical operations.
Mitigation strategies should include immediate kernel updates that properly classify the control type as DAPM kcontrol instead of mixer kcontrol, ensuring correct context handling through snd_soc_component_to_dapm() function calls. System administrators should prioritize patch deployment across all affected devices, particularly those in production environments where audio system reliability is crucial. Additionally, implementing proper input validation and control type checking mechanisms within the driver framework would prevent similar issues from occurring in future development cycles. The fix requires careful attention to kernel audio subsystem APIs and proper adherence to documented driver implementation patterns to ensure robust operation without introducing additional vulnerabilities.