CVE-2022-49616 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
ASoC: rt7*-sdw: harden jack_detect_handler
Realtek headset codec drivers typically check if the card is instantiated before proceeding with the jack detection.
The rt700, rt711 and rt711-sdca are however missing a check on the card pointer, which can lead to NULL dereferences encountered in driver bind/unbind tests.
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Analysis
by VulDB Data Team • 10/23/2025
The vulnerability identified as CVE-2022-49616 affects the Linux kernel's sound subsystem, specifically within the Advanced SoC (ASoC) framework that manages audio codec drivers for Realtek headset codecs. This issue resides in the rt7*-sdw driver implementations which handle the rt700, rt711, and rt711-sdca audio codec variants. The core problem manifests when the jack detection handler function processes headset insertion or removal events without proper validation of the card structure pointer, creating a potential null pointer dereference condition that can crash the system or allow unauthorized access to kernel memory.
The technical flaw represents a classic null pointer dereference vulnerability classified under CWE-476, where the driver fails to validate that the card structure pointer is valid before attempting to access its members during jack detection operations. This occurs specifically in the jack_detect_handler function within the Realtek codec drivers, which are part of the Linux kernel's sound subsystem that manages audio hardware configuration and device management. The absence of proper pointer validation creates an exploitable condition that can be triggered through driver bind/unbind operations or normal headset insertion/removal events, making it particularly dangerous in production environments where audio hardware is frequently connected and disconnected.
The operational impact of this vulnerability extends beyond simple system crashes, as it represents a potential privilege escalation vector that could allow malicious actors to gain unauthorized access to kernel memory spaces. When the card pointer is NULL during jack detection, the driver attempts to dereference this invalid pointer, potentially causing kernel oops, system panics, or in more sophisticated attack scenarios, enabling code execution with kernel privileges. This vulnerability directly impacts systems running Linux kernels that utilize Realtek audio codecs, particularly in laptops, desktops, and embedded systems where audio hardware is frequently managed through dynamic driver loading and unloading processes, making it a significant concern for both enterprise and consumer environments.
Mitigation strategies for CVE-2022-49616 involve applying the official kernel patch that implements proper NULL pointer validation before accessing the card structure in the jack detection handler function. System administrators should prioritize updating to kernel versions that include the fix, typically those released after the vulnerability disclosure date, which aligns with the ATT&CK framework's defense evasion techniques where kernel-level vulnerabilities represent critical attack surfaces. Organizations should also implement monitoring for unusual system behavior or kernel oops messages that might indicate exploitation attempts, as well as maintain regular kernel update schedules to ensure protection against similar vulnerabilities in the ASoC subsystem. The fix demonstrates the importance of proper input validation in kernel drivers and aligns with security best practices outlined in the Linux kernel security documentation, emphasizing the need for robust error handling in device driver code to prevent null pointer dereferences that can compromise system integrity and security.