CVE-2026-63861 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
spi: mtk-snfi: unregister ECC engine on probe failure and remove() callback
mtk_snand_probe() registers the on-host NAND ECC engine, but teardown was missing from both probe unwind and remove-time cleanup. Add a devm cleanup action after successful registration so nand_ecc_unregister_on_host_hw_engine() runs automatically on probe failures and during device removal.
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Analysis
by VulDB Data Team • 07/19/2026
The vulnerability in question pertains to improper resource management within the MediaTek NAND SPI driver of the Linux kernel, specifically affecting the mtk-snfi subsystem. This issue manifests as a failure to properly unregister the on-host NAND ECC engine during both probe failure scenarios and device removal operations. The root cause lies in the incomplete implementation of cleanup routines within the mtk_snand_probe() function which registers the ECC engine but fails to establish proper teardown mechanisms. When probe operations fail or when devices are removed, the registered ECC engine remains active in the system, creating potential resource leaks and inconsistent driver states.
The technical flaw stems from the absence of proper device management cleanup actions following successful registration of the NAND ECC engine. In embedded systems architecture, particularly within the context of storage controllers and memory interfaces, proper resource cleanup is critical for maintaining system stability and preventing memory corruption. The missing devm cleanup action means that while the ECC engine gets registered successfully during probe operations, there's no automatic mechanism to unregister it when the device fails to initialize properly or when the driver module is unloaded. This pattern violates fundamental principles of device management and resource lifecycle handling in kernel space programming.
The operational impact of this vulnerability extends beyond simple resource leakage to potentially compromise system integrity and security. When ECC engines remain registered after probe failures, they continue to occupy system resources and may interfere with subsequent initialization attempts or create unexpected behavior in the storage subsystem. From a cybersecurity perspective, such resource management flaws can serve as potential attack vectors for denial-of-service attacks or may provide adversaries with opportunities to manipulate the device state during driver operations. The vulnerability affects systems using MediaTek NAND controllers where ECC engine registration is critical for data integrity and error correction capabilities.
The proposed solution involves implementing proper devm cleanup actions that automatically invoke nand_ecc_unregister_on_host_hw_engine() when either probe failures occur or during device removal callbacks. This approach aligns with established kernel development practices and follows the principle of automatic resource management through device drivers. The fix ensures that all registered ECC engines are properly unregistered regardless of how the driver lifecycle terminates, thereby preventing resource leaks and maintaining consistent system state. This remediation addresses the underlying issue by establishing proper cleanup mechanisms that are automatically triggered by the kernel's device management subsystem, following the patterns recommended in the Linux kernel documentation for device driver development. The solution directly corresponds to CWE-404, which describes improper resource release or unbalanced resource management, and aligns with ATT&CK techniques related to system resource exploitation where improper cleanup can lead to persistent access vectors within embedded systems environments.