CVE-2026-72229 batman-adv: clean untagged VLAN on netdev registration failure
A memory leak in the Linux kernel batman-adv module can lead to resource exhaustion and denial of service when netdev registration fails.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72229?
CVE-2026-72229 is a memory corruption 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:
batman-adv: clean untagged VLAN on netdev registration failure
When an mesh interface is registered, it creates an untagged struct batadv_meshif_vlan on top of it via the NETDEV_REGISTER notifier. But in this process, another receiver of this notification can veto the registration. The netdev registration will be aborted because of this veto.
The register_netdevice() call will try to clean up the net_device using unregister_netdevice_queue() - which only uses the .priv_destructor to free private resources. In this situation, .dellink will not be called.
The cleanup of the untagged batadv_meshif_vlan must thefore be done in the destructor to avoid a leak of this object.
Which versions are affected by CVE-2026-72229?
How do I fix CVE-2026-72229?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-72229 being exploited?
There is no known exploitation of CVE-2026-72229 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72229, DEBIAN-CVE-2026-72229, GHSA-7p74-4rvh-gr76, UBUNTU-CVE-2026-72229.