CVE-2026-68333 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
dpaa2-switch: put MAC endpoint device on disconnect
fsl_mc_get_endpoint() returns the MAC endpoint device with a reference taken through device_find_child(). The switch port 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 closes the MAC and frees 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 before freeing the dpaa2_mac object.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability exists within the Linux kernel's dpaa2-switch driver implementation where improper resource management leads to memory leaks and potential system instability. The issue specifically affects the Freescale QorIQ DPAA2 switch driver which handles network switching operations in embedded systems. When a MAC endpoint device is connected through the fsl_mc_get_endpoint() function, it returns a reference to the MAC endpoint device that is subsequently stored in the mac->mc_dev field of the dpaa2_mac object structure. This storage occurs during the connect path operation where the device reference is properly acquired through device_find_child() which increments the device's reference count.
The operational flaw manifests when disconnect operations occur because the disconnect path only executes cleanup operations on the MAC endpoint itself while completely neglecting to release the stored reference to the endpoint device. This oversight means that every successful connection operation results in a leaked device reference that remains unreleased even after the MAC object is freed and destroyed. The reference count of the endpoint device continues to increment with each connection without proper decrementing during disconnection, creating a resource leak scenario where system resources gradually become consumed over time.
This vulnerability directly relates to CWE-404 which identifies improper resource management or resource leaks in software systems, specifically concerning object reference handling and memory management. The flaw also aligns with ATT&CK technique T1490 which describes data destruction through resource exhaustion attacks, as the accumulating device references could eventually lead to system resource depletion. From a security perspective, this represents an information disclosure vulnerability since the leaked references may expose internal kernel structures or provide attackers with insights into system resource allocation patterns.
The impact of this vulnerability extends beyond simple memory consumption as it can contribute to system instability and performance degradation over extended periods of operation. In embedded systems where resources are constrained, such leaks can eventually lead to system crashes or complete service unavailability. The issue affects systems utilizing DPAA2 hardware platforms including various Freescale QorIQ processor-based devices used in networking equipment, telecommunications infrastructure, and industrial automation systems. Mitigation requires implementing proper reference counting management during disconnect operations by ensuring that the device reference stored in mac->mc_dev is released before the dpaa2_mac object is freed, effectively calling dev_put() or equivalent reference decrementing functions to balance the initial device_find_child() reference acquisition.
The fix implementation must be carefully coordinated with existing code patterns and resource management practices within the Linux kernel's device model framework. This includes verifying that all potential disconnect paths properly handle the endpoint device reference cleanup while ensuring no other code paths inadvertently create similar reference counting issues. The vulnerability demonstrates the critical importance of maintaining proper reference count balance in kernel drivers, particularly when dealing with complex device hierarchies and multi-level resource management scenarios that are common in hardware abstraction layers for specialized networking equipment.