Linux Kernel up to 6.18.18/6.19.8 iavf_reset_task use after free

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.18.18/6.19.8. Impacted is the function iavf_reset_task. Such manipulation leads to use after free. This vulnerability is referenced as CVE-2026-43447. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.18.18/6.19.8. Affected by this issue is the function iavf_reset_task. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: iavf: fix PTP use-after-free during reset Commit 7c01dbfc8a1c5f ("iavf: periodically cache PHC time") introduced a worker to cache PHC time, but failed to stop it during reset or disable. This creates a race condition where `iavf_reset_task()` or `iavf_disable_vf()` free adapter resources (AQ) while the worker is still running. If the worker triggers `iavf_queue_ptp_cmd()` during teardown, it accesses freed memory/locks, leading to a crash. Fix this by calling `iavf_ptp_release()` before tearing down the adapter. This ensures `ptp_clock_unregister()` synchronously cancels the worker and cleans up the chardev before the backing resources are destroyed.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-43447 since 05/01/2026. The exploitation is known to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 05/22/2026).

Upgrading to version 6.18.19 or 6.19.9 eliminates this vulnerability. Applying the patch 1b034f2429ce6b45ce74dc266175d277acafc5c4/90cc8b2add29b57288025b51c70bc647e7cccb12/efc54fb13d79117a825fef17364315a58682c7ec 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.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 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
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 6.19.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

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