CVE-2026-68331 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
dpaa2-eth: put MAC endpoint device on disconnect
fsl_mc_get_endpoint() returns the MAC endpoint device with a reference taken through device_find_child(). The Ethernet connect path stores that device in mac->mc_dev and keeps it for the lifetime of the connected MAC object.
However, the disconnect path only disconnects and closes the MAC before freeing the dpaa2_mac object. It does not drop the endpoint device reference stored in mac->mc_dev, so every successful connect leaks that device reference when the MAC is later disconnected.
Drop the endpoint device reference after closing the MAC and before freeing the dpaa2_mac object.
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Analysis
by VulDB Data Team • 08/10/2026
This vulnerability resides within the Linux kernel's data path acceleration subsystem specifically affecting the dpaa2-eth driver implementation. The issue manifests as a resource management flaw in the FSL DPAA2 (Design Point Acceleration Architecture 2) Ethernet driver where MAC endpoint devices are not properly released during the disconnect operation. The vulnerability stems from improper reference counting practices within the driver's connect-disconnect lifecycle management, creating a persistent resource leak that accumulates over time. When an Ethernet connection is established through the dpaa2-eth driver, the fsl_mc_get_endpoint() function retrieves the MAC endpoint device and maintains a reference through device_find_child() mechanism. This reference is stored in the mac->mc_dev field of the dpaa2_mac structure and remains held throughout the lifetime of the connected MAC object.
The operational impact of this vulnerability extends beyond simple memory consumption as it represents a classic resource leak pattern that can lead to system instability over extended periods of operation. Each successful connection cycle results in an unreleased device reference, causing the kernel's device reference counting mechanism to maintain unnecessary references to MAC endpoint devices. This behavior violates fundamental resource management principles and can eventually exhaust available device references or cause memory pressure within the kernel's device management subsystem. The vulnerability specifically affects systems utilizing FSL DPAA2 hardware acceleration components where Ethernet connections are frequently established and torn down, such as in high-performance networking appliances or embedded systems with real-time processing requirements.
The technical flaw aligns with CWE-404 weakness category for improper resource release or unmanaged resources, demonstrating a clear failure in reference counting management within the driver's object lifecycle. This vulnerability also maps to ATT&CK technique T1547.001 for hijacking execution flow through kernel module manipulation and represents a potential denial of service vector that could degrade system performance or cause complete system instability if left unaddressed. The fix implements proper reference dropping semantics by ensuring that the endpoint device reference stored in mac->mc_dev is released after closing the MAC connection but before the dpaa2_mac object is freed. This correction follows standard kernel development practices for maintaining proper reference counting and prevents the accumulation of unreleased device references that would otherwise persist until system reboot.
The resolution addresses a fundamental flaw in the driver's resource management architecture by ensuring that all acquired references are properly released during the disconnect path. This fix directly impacts the driver's ability to maintain stable operation over extended periods and prevents the gradual degradation of system resources that would occur from accumulating unreleased device references. The vulnerability demonstrates how seemingly minor reference counting errors can lead to significant operational impacts in kernel drivers, particularly those managing hardware acceleration components where connection cycles are frequent. System administrators should ensure that affected kernel versions receive immediate patch updates to prevent potential resource exhaustion scenarios and maintain optimal system performance in environments utilizing FSL DPAA2 Ethernet hardware acceleration capabilities.