CVE-2024-46716 in Linux
Summary
by MITRE • 09/18/2024
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: altera-msgdma: properly free descriptor in msgdma_free_descriptor
Remove list_del call in msgdma_chan_desc_cleanup, this should be the role of msgdma_free_descriptor. In consequence replace list_add_tail with list_move_tail in msgdma_free_descriptor.
This fixes the path: msgdma_free_chan_resources -> msgdma_free_descriptors -> msgdma_free_desc_list -> msgdma_free_descriptor
which does not correctly free the descriptors as first nodes were not removed from the list.
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Analysis
by VulDB Data Team • 04/05/2026
The vulnerability identified as CVE-2024-46716 affects the Linux kernel's dmaengine subsystem, specifically within the altera-msgdma driver implementation. This issue represents a memory management flaw that occurs during the cleanup process of DMA descriptors in the message DMA channel implementation. The defect manifests in the improper handling of descriptor list operations during resource deallocation, creating a potential memory leak scenario that could impact system stability and resource utilization over time.
The technical root cause of this vulnerability lies in the incorrect sequence of list manipulation operations within the descriptor cleanup functions. The flaw specifically occurs in the msgdma_chan_desc_cleanup function where the list_del operation has been removed, shifting this responsibility to the msgdma_free_descriptor function. This change creates a mismatch in how descriptors are managed within the linked list structure, as the original implementation failed to properly remove nodes from the list before attempting to free them. The vulnerability stems from improper list management practices that violate standard kernel memory management protocols.
The operational impact of this vulnerability extends beyond simple memory leaks to potentially affect system reliability and performance in embedded systems utilizing Altera message DMA controllers. When the descriptor cleanup path executes through msgdma_free_chan_resources, msgdma_free_descriptors, msgdma_free_desc_list, and finally msgdma_free_descriptor, the improper list handling prevents proper descriptor removal from the active list structure. This results in descriptors remaining in memory structures even after they should have been freed, creating a gradual accumulation of unreclaimed memory resources that could eventually lead to system instability or resource exhaustion.
The fix implemented addresses this issue by modifying the list manipulation operations within the descriptor cleanup process. Specifically, the solution replaces list_add_tail with list_move_tail operations in the msgdma_free_descriptor function, ensuring that descriptors are properly moved rather than added to the list structure. This change aligns the cleanup process with proper list management practices and ensures that nodes are correctly removed from their original list positions before being freed. The remediation follows established kernel development best practices for memory management and list handling operations.
This vulnerability type maps to CWE-404, which describes improper resource management or improper handling of resources, and specifically relates to improper cleanup or deallocation of resources. The flaw demonstrates poor list management practices that could potentially enable memory corruption or resource exhaustion scenarios. From an ATT&CK perspective, this vulnerability could be leveraged in resource exhaustion attacks or could serve as a stepping stone for more sophisticated exploitation techniques targeting kernel memory management subsystems. The fix ensures proper adherence to kernel memory management standards and prevents the accumulation of stale descriptor references that could impact system stability during extended operation periods.
The resolution of CVE-2024-46716 demonstrates the critical importance of proper list management in kernel space programming and highlights the need for careful attention to resource cleanup operations in device driver implementations. This vulnerability serves as a reminder of the potential for seemingly minor changes in list manipulation to create significant stability issues in kernel subsystems, particularly those handling DMA operations where proper resource management is essential for system reliability. The fix ensures that the altera-msgdma driver properly maintains list integrity during descriptor cleanup operations, preventing memory leaks and maintaining system stability during extended usage scenarios.