CVE-2026-43447

A flaw was found in the Linux kernel's iavf driver. A race condition exists where the Precision Time Protocol (PTP) worker attempts to access adapter resources that have already been freed during a reset or disable operation. This use-after-free vulnerability can lead to a system crash, resulting in a Denial of Service (DoS).

A use-after-free flaw was found in the Linux kernel's iavf driver, which Red Hat Product Security rates as Moderate. A race condition exists in the PTP (Precision Time Protocol) teardown path: the worker that periodically caches PHC time is not stopped during adapter reset or VF disable, so iavf_reset_task() or iavf_disable_vf() can free adapter resources (such as Admin Queue state and locks) while the worker is still running. If the worker queues a PTP command during teardown, it accesses freed memory and locks, causing a kernel crash and a local denial of service. Exploitation requires local access with the ability to influence the timing of a reset or disable operation, and the narrow race window makes reliable exploitation difficult; this is reflected in Red Hat's Moderate severity (CVSS 6.5, AV:L/AC:H/PR:L), which is lower than the upstream CVEORG rating of Important (7.8) that assumes broader confidentiality and integrity impact from the use-after-free. Within Red Hat Enterprise Linux, the vulnerable code is present only in the RHEL 9.7 and RHEL 10.1 kernels, where the resolution was delegated and the associated trackers were closed as Won't Do, so those streams retain the residual risk of a crash triggered by this race. All other Red Hat Enterprise Linux streams, including kernel-rt and Red Hat In-Vehicle OS, are not affected because the vulnerable code is not present.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.