HighFix available

Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock iso_sock_close() calls iso_sock_clear_timer() before acquiring lock_sock(sk). iso_sock_clear_timer() reads iso_pi(sk)->conn twice without the socket lock held: if (!iso_pi(sk)->conn) return; cancel_delayed_work(&iso_pi(sk)->conn->timeout_work); Concurrently, iso_conn_del() executes under lock_sock(sk) and calls iso_chan_del(), which sets iso_pi(sk)->conn to NULL and may result in the final reference to the connection being dropped: CPU0 CPU1 ---- ---- iso_sock_clear_timer() if (conn != NULL) ... lock_sock(sk) iso_chan_del() iso_pi(sk)->conn = NULL cancel_delayed_work(conn) /* NULL deref or UAF */ iso_pi(sk)->conn is not stable across the unlock window, causing a NULL pointer dereference or use-after-free. Serialize iso_sock_clear_timer() with the socket lock by moving it inside lock_sock()/release_sock(), matching the pattern used in iso_conn_del() and all other call sites.

Products: Kernel
Affected versions: Not specified
Fixed versions: 6.1.176, 6.12.93, 6.18.35, 6.6.143, 7.0.12
CVEs: CVE-2026-63945
Confirmed fixed CVEs: Not specified
Updated in this feed: 6 Nov 2026, 00:22 UTC · Revision 1

Source evidence

Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock

core-osv · Original source

Published 19 Jul 2026, 14:55 UTC

osv:CVE-2026-63945

Kernel

Fixed versions: 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12

Complete source record

{
  "id": "863bc960042dc2e1ea265dcc77b6b5cc6e75ef61a7b85f3f5dbc9fec470cd793",
  "url": "https://osv.dev/vulnerability/CVE-2026-63945",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock iso_sock_close() calls iso_sock_clear_timer() before acquiring lock_sock(sk). iso_sock_clear_timer() reads iso_pi(sk)->conn twice without the socket lock held: if (!iso_pi(sk)->conn) return; cancel_delayed_work(&iso_pi(sk)->conn->timeout_work); Concurrently, iso_conn_del() executes under lock_sock(sk) and calls iso_chan_del(), which sets iso_pi(sk)->conn to NULL and may result in the final reference to the connection being dropped: CPU0 CPU1 ---- ---- iso_sock_clear_timer() if (conn != NULL) ... lock_sock(sk) iso_chan_del() iso_pi(sk)->conn = NULL cancel_delayed_work(conn) /* NULL deref or UAF */ iso_pi(sk)->conn is not stable across the unlock window, causing a NULL pointer dereference or use-after-free. Serialize iso_sock_clear_timer() with the socket lock by moving it inside lock_sock()/release_sock(), matching the pattern used in iso_conn_del() and all other call sites.",
    "evidence": "osv:CVE-2026-63945",
    "products": [
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        "name": {
          "value": "Kernel",
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        "prerequisites": [],
        "fixed_versions": [
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        "affected_versions": []
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    "severity": "high",
    "structured": {
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      "aliases": [
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      "metrics": [
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          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
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      ],
      "modified": "2026-10-28T02:30:45.383110340Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/35f68f36d9883d56dec21cf85f7556d4657fc393",
        "https://git.kernel.org/stable/c/4b5f8e608749b7e8fa386c6e4301cf9272595859",
        "https://git.kernel.org/stable/c/51cb9dcfdf9a1bccf312ab2ae4b62db629f7dcd5",
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        "https://git.kernel.org/stable/c/d9cbf7144ec589a3f0cc91f74a1a1af2d2b14afa",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63945.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-63945",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
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      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63945.json"
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    "related_cves": [
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 513445,
  "published_at": "2026-07-19T14:55:39.859+00:00"
}