CVE-2023-53181 in Linux
Summary
by MITRE • 09/15/2025
In the Linux kernel, the following vulnerability has been resolved:
dma-buf/dma-resv: Stop leaking on krealloc() failure
Currently dma_resv_get_fences() will leak the previously allocated array if the fence iteration got restarted and the krealloc_array() fails.
Free the old array by hand, and make sure we still clear the returned *fences so the caller won't end up accessing freed memory. Some (but not all) of the callers of dma_resv_get_fences() seem to still trawl through the array even when dma_resv_get_fences() failed. And let's zero out *num_fences as well for good measure.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/10/2026
The vulnerability described in CVE-2023-53181 resides within the Linux kernel's dma-buf subsystem, specifically in the dma-resv component responsible for managing reservation objects and fence operations. This issue represents a memory management flaw that occurs during the execution of the dma_resv_get_fences() function, which is critical for coordinating access to DMA buffers across different hardware components. The vulnerability manifests when the system attempts to reallocate memory for fence arrays during iteration processes, creating a potential memory leak scenario that could lead to resource exhaustion over time. The flaw is particularly concerning because it operates at the kernel level where memory management errors can have cascading effects on system stability and security.
The technical root cause of this vulnerability stems from improper error handling during memory reallocation operations. When krealloc_array() fails to allocate additional memory during fence iteration, the existing allocated array is not properly freed, resulting in a memory leak. This failure occurs because the code does not implement proper cleanup mechanisms when the reallocation operation encounters an error condition. The vulnerability is classified as a memory leak under CWE-401 and represents a classic case of resource management failure where allocated memory is not properly released, potentially leading to denial of service conditions. The function fails to maintain proper state management during error conditions, leaving the system in an inconsistent state where previously allocated memory remains accessible but unreferenced.
The operational impact of this vulnerability extends beyond simple memory consumption issues to potentially compromise system stability and availability. When the memory leak occurs repeatedly during active DMA buffer operations, it can gradually consume available system memory, leading to performance degradation or even system crashes. The vulnerability affects any system utilizing the Linux kernel's DMA buffer management subsystem, particularly those running graphics-intensive applications, network drivers, or storage systems that rely heavily on DMA operations. Attackers could potentially exploit this memory leak to cause denial of service conditions by triggering repeated allocation failures, exhausting system resources and making the system unresponsive to legitimate operations. The vulnerability also creates potential security implications as memory leaks can sometimes be leveraged to expose sensitive information or facilitate further exploitation attempts.
Mitigation strategies for CVE-2023-53181 involve implementing proper error handling and resource cleanup mechanisms within the dma_resv_get_fences() function. The fix requires explicit freeing of previously allocated memory arrays when krealloc_array() operations fail, ensuring that no memory leaks occur during error conditions. Additionally, the implementation should clear the returned fence pointers and zero out the number of fences counter to prevent callers from accessing freed memory locations. System administrators should ensure their kernels are updated to versions containing the patched implementation, which addresses the memory leak through proper resource management practices. The fix aligns with ATT&CK technique T1499.004 for resource exhaustion and follows best practices for kernel memory management as outlined in the Linux kernel security documentation. Organizations should monitor their systems for continued operation of the patched kernel versions and implement proper memory monitoring to detect potential issues related to resource exhaustion that could result from similar memory management errors.