CVE-2026-74534 is a vulnerability in Linux Kernel
Published on August 15, 2026
Bluetooth: ISO: fix refcounting of iso_conn
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.
Products Associated with CVE-2026-74534
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Affected Versions
Linux:- Version dc26097bdb864a0d5955b9a25e43376ffc1af99b and below 3b921533e8aa95b77aadcf31737595578e735f3c is affected.
- Version dc26097bdb864a0d5955b9a25e43376ffc1af99b and below 8208b4939afb0a1977fffe902c3ca42fe0f3baaa is affected.
- Version dc26097bdb864a0d5955b9a25e43376ffc1af99b and below fdfde532ab1caa165fcd8985001157ac8b4db365 is affected.
- Version f53e7489273dc2bb307bf50f319b3762d45534f0 is affected.
- Version a58d0f5dac322e16cc75334d000666512341bde5 is affected.
- Version 6.11.11 and below 6.12 is affected.
- Version 6.12.2 and below 6.13 is affected.
- Version 6.13 is affected.
- Before 6.13 is unaffected.
- Version 6.18.44, <= 6.18.* is unaffected.
- Version 7.1.8, <= 7.1.* is unaffected.
- Version 7.2-rc6, <= * is unaffected.