CVE-2026-72022 llc: fix SAP refcount leak in llc_ui_autobind()
A refcount leak in the Linux kernel LLC subsystem allows local attackers to exhaust dynamic SAP values, causing denial of service for subsequent socket operations.
- 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-2026-72022?
CVE-2026-72022 is a denial of service vulnerability in Linux, published on 15 Aug 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:
llc: fix SAP refcount leak in llc_ui_autobind()
llc_ui_autobind() opens a SAP after choosing a dynamic LSAP. llc_sap_open() returns a reference owned by the caller, and llc_sap_add_socket() takes a second reference for the socket's membership in the SAP hash tables.
llc_ui_bind() drops the caller's reference after adding the socket, but llc_ui_autobind() keeps it. When the socket is closed, llc_sap_remove_socket() releases only the socket reference, leaving the SAP on llc_sap_list with sk_count == 0.
This is user-visible because repeated autobind and close cycles can consume all dynamic SAP values and make later autobinds fail with -EUSERS.
Drop the caller's reference after a successful autobind, matching llc_ui_bind()'s ownership model.
Which versions are affected by CVE-2026-72022?
How do I fix CVE-2026-72022?
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-2026-72022 being exploited?
There is no known exploitation of CVE-2026-72022 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-72022, GHSA-8wqh-fvw2-pqc7, UBUNTU-CVE-2026-72022.