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HighFix available

Bluetooth: ISO: fix refcounting of iso_conn

Type: advisorySources: OSV

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
Kernel
Affected versions
Not specified
Fixed versions
6.12.113, 6.18.44, 7.1.8
CVEs
CVE-2026-74534
Confirmed fixed CVEs
Not specified
Updated in this feed
8 Nov 2026, 03:40 UTC · Revision 1

Source evidence

Bluetooth: ISO: fix refcounting of iso_conn

core-osv · Original source

Published 15 Aug 2026, 12:27 UTC

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.

osv:CVE-2026-74534

Kernel

Fixed versions: 6.12.113, 6.18.44, 7.1.8

Complete source record
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  "url": "https://osv.dev/vulnerability/CVE-2026-74534",
  "method": "structured",
  "payload": {
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    "title": "Bluetooth: ISO: fix refcounting of iso_conn",
    "summary": "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.",
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      ],
      "modified": "2026-10-28T02:30:53.218274970Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/3b921533e8aa95b77aadcf31737595578e735f3c",
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  "source_id": "core-osv",
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  "published_at": "2026-08-15T12:27:47.831+00:00"
}