CVE-2025-40045 in Linux
Summary
by MITRE • 10/28/2025
In the Linux kernel, the following vulnerability has been resolved:
ASoC: codecs: wcd937x: set the comp soundwire port correctly
For some reason we endup with setting soundwire port for HPHL_COMP and HPHR_COMP as zero, this can potentially result in a memory corruption due to accessing and setting -1 th element of port_map array.
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Analysis
by VulDB Data Team • 05/20/2026
The vulnerability identified as CVE-2025-40045 affects the Linux kernel's Advanced SoC Audio Codec subsystem specifically within the wcd937x codec driver implementation. This issue resides in the soundwire port configuration mechanism where the driver incorrectly initializes certain audio component ports, particularly HPHL_COMP and HPHR_COMP which represent left and right headphone amplifier components. The flaw occurs during the audio codec initialization process when the driver attempts to configure the soundwire port mapping for these headphone amplifier components.
The technical root cause of this vulnerability stems from improper array indexing logic within the driver's port configuration routine. When the system attempts to set up the soundwire port for headphone amplifier components, the code inadvertently assigns a value of zero to the port configuration for HPHL_COMP and HPHR_COMP. This incorrect assignment leads to a critical memory corruption scenario where the driver attempts to access an invalid memory location within the port_map array. Specifically, the code tries to reference the -1th element of the port_map array, which represents an out-of-bounds memory access that violates standard memory management practices and can result in unpredictable system behavior.
The operational impact of this vulnerability extends beyond simple audio functionality degradation to potentially compromise system stability and security. Memory corruption resulting from invalid array indexing can lead to system crashes, audio distortion, or more concerning exploitation opportunities for malicious actors. The vulnerability affects systems running Linux kernels with the wcd937x codec driver implementation, particularly those utilizing soundwire interfaces for audio component communication. Attackers could potentially leverage this memory corruption to execute arbitrary code or escalate privileges within the kernel space, making it a significant concern for embedded systems, mobile devices, and automotive infotainment systems that rely on this codec architecture.
This vulnerability aligns with CWE-129, which addresses improper validation of array indices, and CWE-787, which covers out-of-bounds write operations. The flaw demonstrates characteristics consistent with ATT&CK technique T1068, which involves exploiting local privileges to gain system-level access through kernel vulnerabilities. The memory corruption aspect of this vulnerability also relates to ATT&CK technique T1203, which involves exploitation of system memory access patterns. Mitigation strategies should focus on implementing proper input validation for array indices, ensuring that all port configuration values fall within valid bounds before array access operations. The fix involves correcting the initialization logic to properly set the soundwire port values for headphone amplifier components, preventing the invalid -1th element access that leads to memory corruption. System administrators should prioritize applying the kernel patches that address this specific driver initialization issue, particularly in environments where audio stability and system security are paramount considerations.