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.
Published: 2026-09-25
Score: n/a
EPSS: n/a
KEV: No
Impact: Denial of Service via DMA mapping resource exhaustion
Action: Update Kernel
AI Analysis

Impact

In the Linux kernel, the stmmac_tso_xmit() function failed to unmap DMA buffers when a fragment mapping failed, causing the linear part and previously mapped fragments to remain mapped. This leak of DMA descriptors can exhaust kernel resources, potentially leading to network failure or a kernel panic. The underlying weakness is a resource leak as defined by CWE‑401 and CWE‑772.

Affected Systems

Linux kernel users who run the stmmac network driver before the stmmac_tso_xmit() fix. Any kernel version that includes the stmmac driver without the fixed DMA mapping release is affected. The issue is not vendor‑specific beyond the Linux kernel community; it impacts all distributions that ship the affected driver code.

Risk and Exploitability

The EPSS score is not available and the vulnerability is not listed in the CISA KEV catalog. Because the bug causes a DMA mapping leak, repeated failures can drain system resources and lead to denial of service. The likely attack vector, inferred from the driver behavior, is sending crafted network traffic that forces a DMA mapping failure during packet transmission, thereby draining the mapping pool. No publicly disclosed exploit exists, but the kernel‑level nature of the defect and the high potential impact warrant careful monitoring.

Generated by OpenCVE AI on September 25, 2026 at 12:25 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade Linux kernel to a version that includes the stmmac_tso_xmit() fix.
  • Apply any vendor or distribution patches that address the stmmac driver.
  • Disable or remove the stmmac network driver, or limit network interfaces that rely on it, if an immediate kernel update is not available.

Generated by OpenCVE AI on September 25, 2026 at 12:25 UTC.

Tracking

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Advisories

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History

Fri, 25 Sep 2026 12:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-401
CWE-772

Fri, 25 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
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.
Title net: stmmac: fix dma mapping leak in stmmac_tso_xmit()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-25T10:36:11.043Z

Reserved: 2026-09-25T10:25:14.318Z

Link: CVE-2026-98131

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-25T11:17:44.500

Modified: 2026-09-25T11:17:44.500

Link: CVE-2026-98131

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-25T13:30:18Z

Weaknesses
  • CWE-401

    Missing Release of Memory after Effective Lifetime

  • CWE-772

    Missing Release of Resource after Effective Lifetime