CVE-2026-31499

About vulnerability

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix deadlock in l2cap_conn_del() l2cap_conn_del() calls cancel_delayed_work_sync() for both info_timer and id_addr_timer while holding conn->lock. However, the work functions l2cap_info_timeout() and l2cap_conn_update_id_addr() both acquire conn->lock, creating a potential AB-BA deadlock if the work is already executing when l2cap_conn_del() takes the lock. Move the work cancellations before acquiring conn->lock and use disable_delayed_work_sync() to additionally prevent the works from being rearmed after cancellation, consistent with the pattern used in hci_conn_del(). A flaw was found in the Linux kernel’s Bluetooth L2CAP component. A deadlock can occur in the l2cap_conn_del() function when canceling delayed work, specifically info_timer and id_addr_timer. This happens because l2cap_conn_del() holds a lock while attempting to cancel work functions that also acquire the same lock, creating a circular waiting condition. This concurrency issue can lead to a Denial of Service (DoS), making the system unresponsive.

Live-patch status from KernelCare for each operating system.