Linux Kernel up to 6.18.10/6.19.0 bus driver_override_show use after free

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.18.10/6.19.0. This affects the function driver_override_show of the component bus. The manipulation results in use after free. This vulnerability is cataloged as CVE-2026-23221. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.10/6.19.0. It has been classified as critical. Affected is the function driver_override_show of the component bus. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: bus: fsl-mc: fix use-after-free in driver_override_show() The driver_override_show() function reads the driver_override string without holding the device_lock. However, driver_override_store() uses driver_set_override(), which modifies and frees the string while holding the device_lock. This can result in a concurrent use-after-free if the string is freed by the store function while being read by the show function. Fix this by holding the device_lock around the read operation.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-23221 since 01/13/2026. The exploitability is told to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 03/19/2026).

The vulnerability scanner Nessus provides a plugin with the ID 299442 (Linux Distros Unpatched Vulnerability : CVE-2026-23221), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.11 or 6.19.1 eliminates this vulnerability. Applying the patch 1d6bd6183e723a7b256ff34bbb5b498b5f4f2ec0/a2ae33e1c6361e960a4d00f7cf75d880b54f9528 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (299442) and CERT Bund (WID-SEC-2026-0462). Once again VulDB remains the best source for vulnerability data.

Affected

• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.0
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5
• 6.6
• 6.7
• 6.8
• 6.9
• 6.10
• 6.11
• 6.12
• 6.13
• 6.14
• 6.15
• 6.16
• 6.17
• 6.18
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.19.0

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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