Linux Kernel up to 7.2.7/7.3-rc3 dsa mxl862xx_setup race condition

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 7.2.7/7.3-rc3. This issue affects the function mxl862xx_setup of the component dsa. Such manipulation leads to race condition. This vulnerability is uniquely identified as CVE-2026-98305. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2.7/7.3-rc3. It has been rated as very critical. Affected by this issue is the function mxl862xx_setup of the component dsa. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net: dsa: mxl862xx: disable the stats poll on teardown mxl862xx_setup() arms the stats poll before mxl862xx_setup_mdio(), and nothing stops it until dsa_register_switch() has returned an error to mxl862xx_probe(). DSA frees the dsa_port list before it returns, so a poll that fires once .setup or a later step of dsa_tree_setup() has failed walks freed ports. On shutdown the user ports stay registered, and the WORK_STOPPED flag test in mxl862xx_get_stats64() is not atomic with the cancel in mxl862xx_shutdown(), so a re-arm that read the flag before it was set queues the poll after cancel_delayed_work_sync() has returned. Arm the poll once .setup has succeeded and stop it from a .teardown op, which DSA calls on unregister and after a failed registration, in both cases before it frees the ports. Use disable_delayed_work_sync() there and in shutdown(): it drains a running poll as the cancel did and turns every later attempt to queue the work into a no-op, so the re-arm cannot bring the poll back. remove() and the probe error path only set WORK_STOPPED, which crc_err_work tests before it walks the ports.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-98305 since 09/25/2026. The exploitation is known to be easy. The attack may be launched remotely. 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 10/06/2026).

Upgrading to version 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch 97df811a11d4f76bc2ffe67b6bf730263f56c668/9e92ad4630f5dd1838ce6bbe6b1bd2c73d34de36 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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
• 7.2.7
• 7.3-rc1
• 7.3-rc2
• 7.3-rc3

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

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