CVE-2026-74534

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.