CVE-2025-40171 nvmet-fc: move lsop put work to nvmet_fc_ls_req_op
A reference counting bug in the Linux kernel's nvmet-fc driver can lead to resource leaks and potential 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-2025-40171?
CVE-2025-40171 is a high-severity denial of service vulnerability in Linux, published on 12 Nov 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: move lsop put work to nvmet_fc_ls_req_op
It’s possible for more than one async command to be in flight from __nvmet_fc_send_ls_req. For each command, a tgtport reference is taken.
In the current code, only one put work item is queued at a time, which results in a leaked reference.
To fix this, move the work item to the nvmet_fc_ls_req_op struct, which already tracks all resources related to the command.
Which versions are affected by CVE-2025-40171?
How do I fix CVE-2025-40171?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-40171 being exploited?
There is no known exploitation of CVE-2025-40171 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40171, DEBIAN-CVE-2025-40171, GHSA-j97x-pm24-3q67, ROOT-OS-DEBIAN-13-CVE-2025-40171, ROOT-OS-UBUNTU-2404-CVE-2025-40171, UBUNTU-CVE-2025-40171.