CVE-2026-98131

Analyzed Analyzed - Analysis Complete

DMA Mapping Leak in Linux Kernel stmmac Driver

Publication date: 2026-09-25

Last updated on: 2026-10-15

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix dma mapping leak in stmmac_tso_xmit() In stmmac_tso_xmit(), if the DMA mapping of an skb fragment fails, the frame is dropped but the DMA mappings already created for the linear part and for the fragments mapped before the failure are never unmapped, leaking DMA mappings. Fix the leak by walking back over the descriptors used by the frame and releasing each of them with stmmac_free_tx_buffer(). Moreover, release the descriptors with stmmac_release_tx_desc() unmapping the DMA buffers.

CVSS Scores

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Meta Information

Published

2026-09-25

Last Modified

2026-10-15

Generated

2026-10-15

AI Q&A

2026-09-25

EPSS Evaluated

2026-10-14

NVD

CVE-2026-98131

EUVD

EUVD-2026-86962

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.3
linux	linux_kernel	From 4.7 (inc) to 7.2.7 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-401	The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Attack-Flow Graph

Executive Summary

This vulnerability is in the Linux kernel's stmmac network driver. It involves a DMA mapping leak during TSO (TCP Segmentation Offload) transmission. If mapping a skb fragment fails, the driver drops the frame but fails to unmap previously created DMA mappings for the linear part and earlier fragments, causing a resource leak.

Detection Guidance

This vulnerability is specific to the Linux kernel's stmmac driver and involves a DMA mapping leak during TSO (TCP Segmentation Offload) operations. Detection requires checking for DMA mapping leaks in network driver logs or using kernel debugging tools like ftrace or perf to monitor stmmac driver behavior. No direct commands are provided in the context to detect this issue.

Impact Analysis

This could lead to resource exhaustion on systems using the stmmac driver, potentially causing network performance degradation or system instability due to unreleased DMA mappings accumulating over time.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA as it is a technical issue related to DMA mapping leaks in the Linux kernel's stmmac driver. It may indirectly impact compliance if exploited to cause denial of service or data corruption, but no evidence suggests direct regulatory impact.

Mitigation Strategies

Apply the kernel patch that fixes the stmmac_tso_xmit() function to properly unmap DMA buffers. Update to a Linux kernel version that includes the fix. Monitor network driver logs for DMA mapping errors as an indicator of exploitation or misconfiguration.

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