CVE-2025-40343 nvmet-fc: avoid scheduling association deletion twice
A race condition in the Linux kernel nvmet-fc driver allows double scheduling of association deletion, potentially causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40343?
CVE-2025-40343 is a critical vulnerability in Linux, published on 9 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
nvmet-fc: avoid scheduling association deletion twice
When forcefully shutting down a port via the configfs interface, nvmet_port_subsys_drop_link() first calls nvmet_port_del_ctrls() and then nvmet_disable_port(). Both functions will eventually schedule all remaining associations for deletion.
The current implementation checks whether an association is about to be removed, but only after the work item has already been scheduled. As a result, it is possible for the first scheduled work item to free all resources, and then for the same work item to be scheduled again for deletion.
Because the association list is an RCU list, it is not possible to take a lock and remove the list entry directly, so it cannot be looked up again. Instead, a flag (terminating) must be used to determine whether the association is already in the process of being deleted.
Which versions are affected by CVE-2025-40343?
How do I fix CVE-2025-40343?
Apply the vendor's patch.
Is CVE-2025-40343 being exploited?
There is no known exploitation of CVE-2025-40343 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40343, DEBIAN-CVE-2025-40343, GHSA-247j-3qhv-rpc8, ROOT-OS-DEBIAN-11-CVE-2025-40343, ROOT-OS-DEBIAN-12-CVE-2025-40343, ROOT-OS-DEBIAN-13-CVE-2025-40343 and 3 more.