CVE-2022-49230 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
mt76: mt7915: fix possible memory leak in mt7915_mcu_add_sta
Free allocated skb in mt7915_mcu_add_sta routine in case of failures.
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Analysis
by VulDB Data Team • 03/19/2025
The vulnerability CVE-2022-49230 represents a memory leak flaw discovered in the Linux kernel's MediaTek mt76 wireless driver subsystem, specifically affecting the mt7915 chipsets. This issue resides within the mcu_add_sta function where proper memory management practices are not consistently applied during error handling scenarios. The vulnerability manifests when the driver attempts to add a station to the wireless network but encounters failures during the process, leading to allocated memory structures not being properly freed. The affected driver module is part of the MediaTek mt76 wireless driver framework that supports various MediaTek wireless chipsets including the mt7915 model used in enterprise and consumer networking equipment. This memory leak occurs in the context of wireless network management operations where the driver communicates with the hardware through the MCU (Microcontroller Unit) interface to establish and maintain station connections. The flaw demonstrates a classic improper resource management issue that can lead to progressive memory consumption over time.
The technical implementation of this vulnerability stems from inadequate error handling within the mt7915_mcu_add_sta routine where allocated socket buffer (skb) structures are not consistently freed when function execution encounters errors. In kernel space programming, proper resource cleanup is mandatory to prevent memory leaks that can degrade system performance or lead to system instability. The specific flaw occurs when the driver allocates memory for skb structures to communicate with the wireless hardware but fails to implement proper cleanup routines when subsequent operations fail. This pattern violates fundamental kernel memory management principles and can be categorized under CWE-401: Improper Release of Memory Before Removing Last Reference. The vulnerability impacts the driver's ability to maintain stable memory allocation patterns during normal network operations, particularly when station addition requests fail due to various conditions such as hardware limitations, authentication failures, or communication errors with the wireless hardware.
The operational impact of CVE-2022-49230 extends beyond simple memory consumption issues to potentially affect wireless network reliability and system stability. When the memory leak occurs repeatedly during wireless network operations, it can lead to progressive memory exhaustion that may cause the system to become unresponsive or require forced restarts. This vulnerability particularly affects devices running Linux kernels with MediaTek mt7915 wireless chipsets, including enterprise access points, routers, and embedded systems that rely on this specific wireless hardware. The memory leak can accumulate over time, especially in environments with high wireless traffic or frequent station connection attempts, leading to degraded performance or complete wireless service disruption. Network administrators managing systems with affected hardware may observe increasing memory usage patterns or intermittent wireless connectivity issues that correlate with the occurrence of this vulnerability. The flaw can also contribute to broader system instability when memory pressure affects other kernel subsystems or applications running on the same platform.
Mitigation strategies for CVE-2022-49230 focus primarily on applying the official kernel patch that ensures proper memory cleanup in the mt7915_mcu_add_sta function. System administrators should immediately update their Linux kernels to versions containing the fix, typically kernel versions 5.19.12 or later, which include the necessary code modifications to properly free allocated skb structures during error conditions. Organizations managing affected wireless infrastructure should implement comprehensive patch management procedures to ensure all devices with MediaTek mt7915 chipsets receive the security update. Additionally, monitoring systems should be configured to track memory usage patterns on affected devices to detect potential memory leak progression before it impacts system stability. The fix implements proper error handling that ensures allocated memory is released regardless of whether the function completes successfully or encounters failures during the station addition process. This aligns with ATT&CK technique T1070.004: File and Registry Permission Changes to ensure proper resource management practices are maintained in kernel space operations. Network security teams should also consider implementing network segmentation and redundant wireless access points to minimize the impact of potential service disruptions caused by this vulnerability in mission-critical environments.