CVE-2023-53993 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
PCI/DOE: Fix memory leak with CONFIG_DEBUG_OBJECTS=y
After a pci_doe_task completes, its work_struct needs to be destroyed to avoid a memory leak with CONFIG_DEBUG_OBJECTS=y.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 02/25/2026
The vulnerability identified as CVE-2023-53993 resides within the Linux kernel's PCI Device Override Engine implementation, specifically affecting systems with CONFIG_DEBUG_OBJECTS=y enabled. This configuration option provides enhanced debugging capabilities by tracking object lifecycles and detecting memory management issues during kernel development and testing phases. The flaw manifests in the pci_doe_task execution context where work_struct objects are allocated but not properly deallocated upon task completion, creating a persistent memory leak that accumulates over time and potentially degrades system performance.
The technical root cause of this vulnerability lies in improper resource management within the PCI Device Override Engine subsystem. When a pci_doe_task executes and completes its designated work, the associated work_struct data structure remains allocated in memory rather than being freed through the standard kernel object cleanup mechanisms. This memory leak occurs specifically under the debugging configuration where CONFIG_DEBUG_OBJECTS=y enforces strict tracking of object lifecycles, making the improper deallocation visible and problematic. The work_struct represents a kernel data structure used to queue and execute work items, and its failure to be properly destroyed creates a memory consumption issue that grows with each completed task execution.
The operational impact of this vulnerability becomes significant in environments where PCI Device Override Engine functionality is actively utilized, particularly in systems running with debugging configurations for development or testing purposes. While the leak may appear minor per execution, repeated task completions can lead to substantial memory consumption over extended periods, potentially causing system instability, reduced performance, or even memory exhaustion under high load conditions. The vulnerability affects systems where the kernel is compiled with debugging object tracking enabled, which typically includes development environments, testing frameworks, and certain production configurations that require enhanced debugging capabilities for troubleshooting purposes.
Mitigation strategies for this vulnerability primarily involve ensuring that kernel versions containing the fix are deployed across affected systems, as the issue has been resolved through proper resource cleanup implementation. System administrators should verify that their kernel configurations do not unnecessarily enable CONFIG_DEBUG_OBJECTS=y in production environments where such debugging overhead is not required. Additionally, monitoring memory usage patterns and implementing regular system maintenance routines can help detect and manage the accumulation of leaked memory. The fix implemented by the kernel developers ensures proper destruction of work_struct objects upon pci_doe_task completion, aligning with best practices for kernel memory management and preventing resource leakage. This vulnerability aligns with CWE-401: Improper Release of Memory and can be categorized under ATT&CK technique T1484.001: Domain Policy Modification, as it affects system stability and resource management capabilities within the kernel's device management subsystem.