CVE-2026-43447 iavf: fix PTP use-after-free during reset
A race condition in the Linux kernel iavf driver causes a use-after-free crash during adapter reset, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43447?
CVE-2026-43447 is a high-severity use after free vulnerability in Linux kernel, published on 8 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-416
Which versions are affected by CVE-2026-43447?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43447?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-43447 being exploited?
There is no known exploitation of CVE-2026-43447 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43447, DEBIAN-CVE-2026-43447, GHSA-7qq3-fmc6-w4w4, UBUNTU-CVE-2026-43447.