Linux Kernel up to 7.2.6/7.3-rc1 stmmac stmmac_tso_xmit memory leak

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 7.2.6/7.3-rc1. Affected is the function stmmac_tso_xmit of the component stmmac. Such manipulation leads to memory leak. This vulnerability is listed as CVE-2026-98131. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2.6/7.3-rc1. It has been rated as very critical. Affected by this issue is the function stmmac_tso_xmit of the component stmmac. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-98131 since 09/25/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/25/2026). This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 7.2.7 or 7.3-rc2 eliminates this vulnerability. Applying the patch e85adaac3dc6317cae902372c6849189ec62cf7d/a5d946466a95621fa2769720d59ea336003aa1a5 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.3-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

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