CVE-2022-49331 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
nfc: st21nfca: fix memory leaks in EVT_TRANSACTION handling
Error paths do not free previously allocated memory. Add devm_kfree() to those failure paths.
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Analysis
by VulDB Data Team • 04/17/2025
The vulnerability identified as CVE-2022-49331 resides within the Linux kernel's NFC subsystem, specifically affecting the st21nfca driver implementation. This issue manifests as a memory leak condition that occurs during error handling scenarios within the NFC transaction event processing functionality. The st21nfca driver is responsible for managing NFC communication with STMicroelectronics ST21NFCA NFC controllers, which are commonly found in various mobile devices and embedded systems requiring NFC capabilities. The vulnerability represents a critical flaw in resource management practices within the kernel's device driver architecture.
The technical root cause of this vulnerability stems from improper memory deallocation within error handling code paths. When the NFC driver encounters failures during transaction event processing, the existing code fails to properly release previously allocated memory resources through the devm_kfree() function. This memory management oversight occurs specifically during event handling routines where the driver processes various NFC transaction events. The flaw demonstrates a classic resource leak pattern where allocated kernel memory remains unreleased even when error conditions are encountered, leading to gradual memory consumption that can eventually impact system stability and performance.
From an operational impact perspective, this vulnerability creates a persistent memory leak condition that can accumulate over time, particularly in systems with high NFC transaction activity or continuous NFC operations. The memory consumption grows incrementally with each error path execution, potentially leading to system performance degradation, reduced available memory for other kernel operations, and in extreme cases, system instability or crashes. The vulnerability affects systems running Linux kernels with the st21nfca NFC driver implementation, particularly those utilizing NFC-enabled devices such as smartphones, tablets, and embedded systems with NFC capabilities. The issue is particularly concerning in embedded environments where memory resources are constrained and system reliability is paramount.
The mitigation strategy for this vulnerability involves implementing proper memory deallocation within all error handling paths of the NFC driver. The fix requires adding devm_kfree() calls to previously unmanaged memory allocation failure paths, ensuring that all allocated memory resources are properly released regardless of execution flow. This approach aligns with established kernel development practices and security guidelines for resource management. The solution directly addresses the memory leak pattern by incorporating proper cleanup mechanisms into the driver's error handling routines, thereby preventing accumulation of unreleased memory blocks. This fix demonstrates adherence to secure coding principles and follows the recommended practices outlined in the Linux kernel security documentation and vulnerability management protocols.
This vulnerability classification aligns with CWE-401, which identifies improper resource management as a fundamental security weakness. The memory leak scenario represents a direct violation of proper resource cleanup practices within kernel space programming. From an attack surface perspective, while this vulnerability does not directly enable privilege escalation or remote code execution, it can contribute to system instability and potentially facilitate denial-of-service conditions. The vulnerability's impact is consistent with ATT&CK technique T1499.004, which addresses resource exhaustion through memory leaks and other resource management flaws. The fix addresses the underlying memory management issue by ensuring proper kernel memory cleanup during error conditions, which is essential for maintaining system stability and preventing potential exploitation through resource exhaustion attacks.