CVE-2026-64021 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/oa: Fix exec_queue leak on width check in stream open
In xe_oa_stream_open_ioctl(), when param.exec_q->width > 1 the function returns -EOPNOTSUPP directly, skipping the existing err_exec_q cleanup path. The exec_queue reference obtained by xe_exec_queue_lookup() is leaked.
The exec queue holds a reference on the xe_file, which is only dropped during queue teardown. The leaked lookup ref is not on the file's exec_queue xarray, so file close cannot release it. This keeps both the exec queue and the file private state pinned indefinitely.
Jump to err_exec_q instead of returning directly so the reference is released.
(cherry picked from commit 339fa0be9e4a5d69fa47e91f4a36574224fb478f)
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Analysis
by VulDB Data Team • 07/19/2026
This vulnerability exists within the Intel Xeon Edge graphics driver component of the Linux kernel, specifically in the drm/xe/oa subsystem responsible for managing performance monitoring streams. The issue manifests as a resource leak during the execution queue management process when handling stream open operations. The flaw occurs in the xe_oa_stream_open_ioctl() function where improper error handling leads to persistent memory allocation issues that can accumulate over time and potentially impact system stability.
The technical implementation flaw stems from conditional logic that bypasses proper cleanup procedures when processing execution queues with width parameters exceeding one. When param.exec_q->width > 1, the function immediately returns -EOPNOTSUPP without executing the established error handling path that would normally release references through err_exec_q label. This direct return path prevents the proper invocation of xe_exec_queue_lookup() cleanup mechanisms that would otherwise release the acquired execution queue reference.
The operational impact of this vulnerability creates a persistent memory leak scenario where execution queues remain indefinitely pinned in kernel memory. The leaked exec_queue reference maintains an active reference to the xe_file structure, which is only properly released during queue teardown operations. Since this reference is not maintained within the file's exec_queue xarray data structure, standard file closure procedures cannot trigger the necessary cleanup, resulting in both the execution queue and associated private file state remaining allocated indefinitely.
This resource leak vulnerability aligns with CWE-404, which specifically addresses improper resource management where allocated resources are not properly released. The issue demonstrates poor defensive programming practices in error handling paths where developers failed to ensure all allocated resources are properly cleaned up regardless of execution flow. From an attack surface perspective, this vulnerability could potentially be exploited to cause gradual memory exhaustion on systems running Intel Xeon Edge graphics hardware.
The recommended mitigation involves modifying the function behavior to jump to the err_exec_q cleanup label instead of returning directly when encountering width parameter violations. This ensures that all references obtained through xe_exec_queue_lookup() are properly released through established cleanup pathways. The fix maintains the intended error return value while ensuring proper resource management, following best practices for kernel development where error handling paths must always clean up allocated resources before returning to prevent memory leaks and maintain system stability.
This vulnerability type represents a common class of issues in kernel drivers where improper error handling can lead to resource leaks that accumulate over time. The fix demonstrates the importance of maintaining consistent resource management patterns throughout all code paths, particularly in kernel subsystems where resource exhaustion can severely impact system performance and availability. The solution approach follows established kernel development practices for ensuring proper cleanup in error conditions while preserving the intended functional behavior of rejecting unsupported width parameters.
The vulnerability affects systems utilizing Intel Xeon Edge graphics hardware running Linux kernels with the drm/xe/oa subsystem, particularly those implementing performance monitoring features. Regular kernel updates and patch application are essential to prevent potential accumulation of leaked resources that could eventually impact system responsiveness or cause unexpected behavior in graphics-intensive applications. System administrators should prioritize applying this specific fix to maintain optimal resource utilization and prevent long-term stability issues in environments relying on Intel graphics hardware for performance monitoring capabilities.
This type of resource leak vulnerability is particularly concerning in server and enterprise environments where continuous operation and resource efficiency are critical requirements. The indefinite pinning of execution queues and file state references can compound over time, especially in systems with high graphics processing workloads or frequent stream open/close operations. Proper implementation of cleanup paths in error conditions represents a fundamental requirement for kernel subsystems to maintain predictable resource behavior and prevent gradual degradation of system performance.