CVE-2026-72120 can: bcm: add missing rcu list annotations and operations
A race condition in the Linux kernel CAN BCM module due to missing RCU list operations can lead to system instability or crashes.
- 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-2026-72120?
CVE-2026-72120 is a high-severity 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:
can: bcm: add missing rcu list annotations and operations
sashiko-bot remarked the missing use of list_add_rcu() in bcm_[rx|tx]_setup() to have a proper initialized bcm_op structure when bcm_proc_show() traverses the bcm_op's under rcu_read_lock().
To cover all initial settings of the bcm_op's the list_add_rcu() calls are moved to the end of the setup code.
While at it, also fix the mirroring removal side: bcm_release() called bcm_remove_op() - which frees the op via call_rcu() - on ops that were still linked in bo->tx_ops/bo->rx_ops, without list_del_rcu() first. Unlink each op with list_del_rcu() before handing it to bcm_remove_op(), matching the existing pattern in bcm_delete_tx_op()/bcm_delete_rx_op().
Which versions are affected by CVE-2026-72120?
How do I fix CVE-2026-72120?
Apply the vendor's patch.
Is CVE-2026-72120 being exploited?
There is no known exploitation of CVE-2026-72120 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72120, DEBIAN-CVE-2026-72120, GHSA-v4mr-5hv5-p6wp, UBUNTU-CVE-2026-72120.