CVE-2023-53993: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53993 is a memory leak vulnerability in the Linux kernel's PCI/DOE (Data Object Exchange) subsystem. The flaw occurs because after a pci_doe_task completes, its associated work_struct is not properly destroyed, resulting in a memory leak when the kernel is compiled with CONFIG_DEBUG_OBJECTS=y. The vulnerability was published on December 24, 2025, and affects Linux kernel versions in the 6.x range (specifically prior to patch commits targeting stable branches 6.1.24, 6.2.11, and 6.3). No CVSS score has been assigned by NVD at this time, and the EPSS score is 0.00017 (very low) (Feedly, EUVD).

The root cause is improper resource cleanup (CWE category: memory management/resource leak) in the Linux kernel's PCI DOE implementation. When a pci_doe_task finishes execution, the kernel fails to call the appropriate destructor for the embedded work_struct, which under CONFIG_DEBUG_OBJECTS=y tracking leads to a detectable memory leak. The bug is confined to the kernel's PCI subsystem and is only observable as a leak under debug object tracking configurations; it does not represent a typical exploitable memory corruption condition. Fixes were applied to three stable kernel branches via commits 2a0e0f47, 95628b83, and abf04be0 (kernel.org patch 1, kernel.org patch 2, kernel.org patch 3).

The primary impact of this vulnerability is a kernel memory leak, which can gradually degrade system stability and availability on affected Linux systems over time, particularly those running debug-enabled kernel builds (CONFIG_DEBUG_OBJECTS=y). There is no evidence of confidentiality or integrity impact, and the vulnerability does not enable privilege escalation, remote code execution, or lateral movement. The practical risk is limited to resource exhaustion in long-running systems with PCI DOE activity (Feedly).

The fix has been applied to Linux stable kernel branches: version 6.1.24, 6.2.11, and 6.3 (via commits 2a0e0f47, 95628b83, and abf04be0 respectively). Users running affected kernel versions should update to a patched stable release. As a short-term workaround, systems not requiring PCI DOE functionality or not compiled with CONFIG_DEBUG_OBJECTS=y are not practically impacted by the memory leak in production environments (kernel.org patch 1, kernel.org patch 2, kernel.org patch 3).