CVE-2026-93195 in Linux
Summary
by MITRE • 09/18/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/bridge: synopsys: dw-dp: Support unregistering the AUX channel
The DisplayPort AUX channel gets initialized and registered during dw_dp_bind(), but it is never unregistered, which may lead to resource leaks and/or use-after-free.
Add the missing dw_dp_unbind() function to allow the users of the library to handle the required cleanup, i.e. unregister the AUX adapter.
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Analysis
by VulDB Data Team • 09/18/2026
The Linux kernel's DisplayPort subsystem contains a critical resource management flaw within the Synopsys DesignWare DisplayPort driver component known as dw-dp. This vulnerability stems from an incomplete implementation of the device lifecycle management routines, specifically concerning the initialization and teardown phases of the AUX channel infrastructure. During normal operation, when the driver binds to its hardware or platform data via the dw_dp_bind function, it successfully initializes and registers a DisplayPort AUX adapter. This adapter is essential for communication between the host system and connected display devices over the auxiliary channel used for link training, configuration, and status reporting. However, the corresponding unbind routine lacked the necessary logic to unregister this adapter when the device was removed or suspended, creating a significant gap in resource cleanup procedures.
This omission results in two primary technical consequences: memory leaks and potential use-after-free conditions. When the driver is unloaded or the hardware is detached without proper deregistration, the kernel retains references to the AUX channel structures that are no longer actively managed by the device instance. If subsequent operations attempt to access these stale pointers, such as during a hot-plug event or system suspend-resume cycle where drivers may be re-initialized while old resources remain allocated in memory pools, it can lead to undefined behavior. In worst-case scenarios involving concurrent access patterns, this could allow an attacker with local privileges to exploit the dangling pointer to execute arbitrary code or cause a kernel panic by corrupting critical data structures within the DRM subsystem.
From a classification perspective, this issue aligns with CWE-401, which describes missing release of memory after effective usage, and CWE-755, concerning improper handling of unusual or exceptional input conditions related to resource cleanup failures. In terms of attack vectorization under the MITRE ATT&CK framework for enterprise environments, this flaw relates to T1059 Command Line Interface abuse if an attacker leverages local privilege escalation through kernel memory corruption, though it primarily represents a stability and reliability risk rather than a direct remote exploitation path. The vulnerability highlights the importance of symmetric resource management in kernel drivers where every allocation must have a corresponding deallocation triggered by appropriate lifecycle events.
To mitigate this vulnerability, system administrators should ensure that their Linux distributions are updated with patches containing the dw_dp_unbind implementation. This fix introduces the missing cleanup logic into the driver's unbind callback, ensuring that when the device is detached or the module is unloaded, the AUX adapter is properly deregistered from the kernel subsystems. For developers integrating this library, it is imperative to verify that their platform code correctly invokes the new unbind function during removal sequences. Regular auditing of driver lifecycle functions against industry standards for resource management can prevent similar oversights in other components of the graphics stack, maintaining system integrity and preventing potential denial-of-service conditions caused by kernel memory exhaustion or crashes due to invalid memory access patterns.