CVE-2026-74534

/// Technical description

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

Bluetooth: ISO: fix refcounting of iso_conn

iso_conn_del() and iso_chan_del() have a race that results to double-put

of iso_conn:

[Task hdev->workqueue] [Task 2]

iso_conn_del iso_chan_del

iso_conn_hold_unless_zero iso_conn_lock

iso_conn_lock conn->sk = NULL

iso_conn_unlock

sk = iso_sock_hold(conn) <---------´

if (!sk) iso_conn_put iso_conn_put

iso_conn_put /* UAF */

The extra put for !sk in iso_conn_del() is currently required since

failing iso_chan_add() may leave iso_conn not associated with any sk.

Fix by having iso_pi(sk)->conn own refcount when non-NULL, so

iso_conn_del does not need to put it. Adjust the iso_conn_add()

refcounting so that conn is put if it does not get associated with an

sk.

/// 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