CVE-2026-98817 in Linux
Summary
by MITRE • 10/18/2026
In the Linux kernel, the following vulnerability has been resolved:
ASoC: SDCA: Add better pm_runtime error handling in func probe
Add a common error path in probe that balances the runtime PM reference.
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Analysis
by VulDB Data Team • 10/18/2026
The identified issue resides within the Advanced System Control Architecture (SDCA) subsystem of the Linux kernel's ALSA SoC audio framework, specifically affecting the device probing mechanism during driver initialization. SDCA is an industry standard for managing high-performance digital microphones and speakers in modern computing devices, requiring precise power management to ensure system stability and energy efficiency. The vulnerability stems from improper handling of runtime power management references when a probe operation encounters an error condition. In Linux kernel drivers, the pm_runtime_get_sync function or similar primitives are typically invoked during device initialization to increment the usage counter for the device's power state, ensuring that necessary clocks and hardware resources remain active while the driver binds to the device. When this binding process fails due to configuration errors, missing dependencies, or other transient faults, the original code path failed to invoke the corresponding pm_runtime_put_sync function to decrement this reference count. This oversight results in a persistent imbalance where the kernel believes the device is still actively in use and powered on, even though the driver has detached from it or failed to initialize properly.
This technical flaw constitutes an improper resource management error that leads to a power state inconsistency within the system's runtime PM framework. From a security and stability perspective, such imbalances can cause significant operational disruptions. If the reference count is not decremented upon failure, the device remains in a powered-on state indefinitely until the next explicit suspend cycle or reboot occurs. This prevents the system from entering low-power states efficiently, leading to increased battery drain on mobile devices and higher thermal output on stationary systems. Furthermore, if multiple probe attempts fail without releasing these references, it can exhaust the available power management resources for that device type, potentially causing subsequent initialization attempts of other SDCA-compliant peripherals to hang or fail entirely due to resource contention. In severe cases, this could lead to a denial-of-service condition where audio functionality becomes unresponsive until a system restart is performed.
The vulnerability aligns with CWE-401, which describes the missing release of memory after successful allocation, and more specifically CWE-756, which covers improper use of customized or non-standard mechanisms for resource management. In terms of attack vectors and behavioral analysis, this flaw relates to ATT&CK technique T1499, Endpoint Denial of Service, as it can be leveraged by a local attacker with the ability to trigger device probe failures repeatedly to degrade system performance or cause audio subsystem instability. While typically not exploitable for remote code execution due to its nature as a resource leak rather than a memory corruption issue, it represents a significant reliability concern that undermines the robustness of the kernel's power management infrastructure. The flaw highlights the critical importance of maintaining symmetric reference counting in driver probe functions, where every acquisition of a runtime PM reference must have a corresponding release path for all possible exit points, including error returns.
To mitigate this vulnerability and restore proper system behavior, it is essential to implement a common error handling path within the SDCA device probe function that ensures the pm_runtime_put_sync call is executed whenever an error occurs after the initial power management references are acquired. This involves refactoring the driver code to use goto statements or structured cleanup functions that guarantee the decrement of the usage counter before returning an error code from the probe routine. By balancing the runtime PM reference, the kernel can correctly transition the device back to a suspended state if initialization fails, allowing other drivers and system processes to proceed without interference. This fix ensures compliance with Linux kernel coding standards for power management and maintains the integrity of the SDCA subsystem's operational stability across various hardware configurations.