In the Linux kernel, the ethtool tsinfo routine contains a flaw: when the preparation stage fails, the code wrongly passes an error pointer to genlmsg_cancel, causing the function to attempt to cancel a message that was never started. This improper error handling, an instance of CWE‑476 Null Pointer Dereference, leads to a kernel panic and renders the system unavailable, constituting a denial‑of‑service weakness.

All Linux kernels that include the generic ethtool implementation before the commit referenced in the kernel git history are affected. Users who run the ethtool utility to query tsinfo on any network device on such systems are at risk; the specific kernel releases are not enumerated but any kernel prior to the patch may contain the flaw.

Based on the description, it is inferred that the likely attack vector is local execution of ethtool or privilege escalation enabling such execution. The CVSS score of 5.5 indicates a medium severity, while the EPSS score is below 1 %, indicating a very low probability of exploitation. The vulnerability is not listed in the CISA KEV catalog. Attackers would need the ability to invoke ethtool on the target system, which typically requires local privilege or the ability to execute the command. Once triggered, the kernel crash causes an immediate denial of service, terminating all processes until a reboot occurs.