CVE-2026-64557

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb()

l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after

release_sock(parent). Once the parent lock is dropped the newly

enqueued child socket sk is reachable via the accept queue, so another

task can accept and free it before the callback dereferences sk,

resulting in a use-after-free.

Rework the ->new_connection() op so the core, rather than the callback,

owns the child channel's lifetime. The op now receives a pre-allocated

new_chan and returns an errno instead of allocating and returning a

channel. l2cap_new_connection() allocates the child channel and links

it into the conn list via __l2cap_chan_add() before invoking the

callback, so the conn-list reference keeps the channel alive once

release_sock(parent) exposes the socket to other tasks.

Channel configuration that was duplicated in l2cap_sock_init() and the

various new_connection

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References