CVE-2026-64206 Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock
A race condition in the Linux kernel Bluetooth L2CAP module can cause a deadlock during connection teardown, leading to a denial of service.
- 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-2026-64206?
CVE-2026-64206 is a high-severity vulnerability in Linux kernel, published on 20 Jul 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:
Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock
l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for pending_rx_work. process_pending_rx() takes the same mutex, so teardown can deadlock against the worker it is flushing.
This issue was found by our static analysis tool and then manually reviewed against the current tree.
The grounded PoC kept the l2cap_conn_ready() -> queue_work(..., &conn->pending_rx_work) submit path, the l2cap_conn_del() -> cancel_work_sync(&conn->pending_rx_work) teardown path, and the process_pending_rx() -> mutex_lock(&conn->lock) worker edge. Lockdep
WARNING: possible circular locking dependency detected process_pending_rx+0x21/0x2a [vuln_msv] l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv] *** DEADLOCK ***
Cancel pending_rx_work before taking conn->lock, matching the existing lock-before-drain ordering used for the two delayed works in the same teardown path. The pending_rx queue is still purged after the work has been cancelled and conn->lock has been acquired.
Weakness: CWE-362
Which versions are affected by CVE-2026-64206?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64206?
Apply the vendor's patch.
Is CVE-2026-64206 being exploited?
There is no known exploitation of CVE-2026-64206 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-92865, BELL-CVE-2026-64206, DEBIAN-CVE-2026-64206, GHSA-4pqq-whjc-554c, ROOT-OS-DEBIAN-11-CVE-2026-64206, ROOT-OS-DEBIAN-12-CVE-2026-64206 and 3 more.