CVE-2023-53666 in Linux
Summary
by MITRE • 10/07/2025
In the Linux kernel, the following vulnerability has been resolved:
ASoC: codecs: wcd938x: fix missing mbhc init error handling
MBHC initialisation can fail so add the missing error handling to avoid dereferencing an error pointer when later configuring the jack:
Unable to handle kernel paging request at virtual address fffffffffffffff8
pc : wcd_mbhc_start+0x28/0x380 [snd_soc_wcd_mbhc]
lr : wcd938x_codec_set_jack+0x28/0x48 [snd_soc_wcd938x]
Call trace: wcd_mbhc_start+0x28/0x380 [snd_soc_wcd_mbhc]
wcd938x_codec_set_jack+0x28/0x48 [snd_soc_wcd938x]
snd_soc_component_set_jack+0x28/0x8c [snd_soc_core]
qcom_snd_wcd_jack_setup+0x7c/0x19c [snd_soc_qcom_common]
sc8280xp_snd_init+0x20/0x2c [snd_soc_sc8280xp]
snd_soc_link_init+0x28/0x90 [snd_soc_core]
snd_soc_bind_card+0x628/0xbfc [snd_soc_core]
snd_soc_register_card+0xec/0x104 [snd_soc_core]
devm_snd_soc_register_card+0x4c/0xa4 [snd_soc_core]
sc8280xp_platform_probe+0xf0/0x108 [snd_soc_sc8280xp]
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Analysis
by VulDB Data Team • 03/01/2026
The vulnerability CVE-2023-53666 represents a critical error handling flaw in the Linux kernel's audio subsystem, specifically within the wcd938x codec driver component. This issue manifests in the Advanced SoC (ASoC) framework where the MBHC (Microphone Bias High Compliance) initialization process can fail without proper error propagation. The flaw occurs when the wcd938x_codec_set_jack function attempts to configure jack detection hardware without verifying that the MBHC initialization completed successfully, leading to a scenario where an error pointer gets dereferenced during kernel execution.
The technical implementation of this vulnerability stems from inadequate error checking during the MBHC initialization sequence within the snd_soc_wcd_mbhc module. When the wcd_mbhc_start function fails to properly initialize the microphone bias hardware, it returns an error code rather than a valid pointer reference. However, the subsequent wcd938x_codec_set_jack function does not validate this error condition before proceeding with jack configuration operations. This failure to implement proper error handling creates a path where the kernel attempts to access virtual memory address ffffffffffffff8, which represents an invalid memory location that triggers a kernel paging fault.
The operational impact of this vulnerability extends beyond simple system instability, as it can lead to complete system crashes or kernel oops conditions that require manual intervention to recover from. The call trace demonstrates a clear execution path from the hardware platform probe function through multiple layers of the sound subsystem, ultimately failing during the jack setup process. This vulnerability affects devices using the sc8280xp platform and Qualcomm's wcd938x codec drivers, potentially impacting a wide range of mobile devices, tablets, and embedded systems that rely on these audio components. The error handling deficiency creates a condition where the kernel cannot properly manage the audio jack detection subsystem, leading to unpredictable behavior during audio device initialization.
From a cybersecurity perspective, this vulnerability aligns with CWE-252, which describes "Unchecked Return Value" conditions where functions that can fail are called without checking their return values. The flaw also relates to ATT&CK technique T1490, "Inhibit System Recovery," as system crashes can occur during normal audio initialization processes. The vulnerability represents a classic example of how insufficient error handling in kernel drivers can create exploitable conditions, particularly when dealing with hardware initialization sequences that must complete successfully before subsequent operations can proceed. The fix implemented addresses this by ensuring proper error propagation from the MBHC initialization function to prevent the execution of subsequent code that would operate on an invalid pointer reference. This remediation follows security best practices by implementing defensive programming techniques that validate all critical function return values before proceeding with dependent operations.