CVE-2023-53745 in Linux
Summary
by MITRE • 12/08/2025
In the Linux kernel, the following vulnerability has been resolved:
um: vector: Fix memory leak in vector_config
If the return value of the uml_parse_vector_ifspec function is NULL, we should call kfree(params) to prevent memory leak.
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Analysis
by VulDB Data Team • 02/23/2026
The vulnerability identified as CVE-2023-53745 represents a memory management issue within the Linux kernel's User Mode Linux (UML) subsystem, specifically affecting the vector configuration handling mechanism. This flaw exists in the uml_parse_vector_ifspec function which is responsible for parsing vector interface specifications within the UML framework. The vulnerability manifests when the parsing function returns a NULL value, indicating a failure in the configuration process, yet the system fails to properly release allocated memory resources. The issue resides in the vector_config function where memory allocated to the params structure is not freed when the uml_parse_vector_ifspec function encounters an error condition and returns NULL.
The technical implementation of this vulnerability stems from improper error handling within the kernel's UML vector subsystem. When uml_parse_vector_ifspec fails to parse a vector interface specification and returns NULL, the calling function vector_config does not execute the necessary kfree(params) operation to release the previously allocated memory. This memory leak occurs because the kernel's memory management routines are not properly accounting for error conditions during configuration parsing. The flaw represents a classic case of resource management failure where allocated kernel memory remains unreleased even when function execution paths indicate failure. This type of vulnerability falls under the Common Weakness Enumeration category CWE-401, which specifically addresses improper handling of memory allocation failures and resource leaks.
The operational impact of CVE-2023-53745 extends beyond simple memory consumption issues, potentially leading to system instability and performance degradation over time. In environments where UML instances are frequently created and destroyed, or where vector interface configurations are repeatedly parsed, the cumulative effect of these memory leaks can result in significant memory exhaustion. The vulnerability affects systems running Linux kernels that implement the User Mode Linux subsystem, particularly those utilizing vector-based network interface configurations. Attackers could potentially exploit this memory leak to cause denial of service conditions by exhausting available memory resources through repeated triggering of the faulty code path. The vulnerability's impact is amplified in high-availability systems where memory management is critical for maintaining consistent service delivery.
Mitigation strategies for CVE-2023-53745 require immediate kernel updates from vendors who have addressed this specific memory leak issue in their codebase. System administrators should prioritize applying the relevant kernel patches that implement proper memory cleanup in the vector_config function when uml_parse_vector_ifspec returns NULL. The fix involves adding conditional memory release logic that ensures kfree(params) is called whenever the parsing function fails and returns NULL. Organizations should also implement monitoring solutions to detect unusual memory consumption patterns that might indicate the presence of this vulnerability. Additionally, security teams should consider implementing runtime protections such as memory leak detection tools and regular memory audits to identify potential exploitation attempts. The remediation process should include thorough testing of patched kernels to ensure that the memory management fix does not introduce regressions in UML functionality or network interface handling. The vulnerability's resolution aligns with ATT&CK technique T1070.004 which addresses the use of kernel memory manipulation and resource exhaustion as potential attack vectors in operating system exploitation.