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CVE-2026-64206

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for pending_rx_work. process_pending_rx() takes the same mutex, so teardown can deadlock against the worker it is flushing. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the l2cap_conn_ready() -> queue_work(..., &conn->pending_rx_work) submit path, the l2cap_conn_del() -> cancel_work_sync(&conn->pending_rx_work) teardown path, and the process_pending_rx() -> mutex_lock(&conn->lock) worker edge. Lockdep WARNING: possible circular locking dependency detected process_pending_rx+0x21/0x2a [vuln_msv] l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv] *** DEADLOCK *** Cancel pending_rx_work before taking conn->lock, matching the existing lock-before-drain ordering used for the two delayed works in the same teardown path. The pending_rx queue is still purged after the work has been cancelled and conn->lock has been acquired.

Severity
HIGH
CVSS score
8.8 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-20 17:18:22.620000
Last modified
2026-10-19 21:17:26.920000
View original CVE JSON
{
  "id": "CVE-2026-64206",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-20T17:18:22.620",
  "lastModified": "2026-10-19T21:17:26.920",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: cancel pending_rx_work before taking conn->lock\n\nl2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for\npending_rx_work.  process_pending_rx() takes the same mutex, so teardown\ncan deadlock against the worker it is flushing.\n\nThis issue was found by our static analysis tool and then manually\nreviewed against the current tree.\n\nThe grounded PoC kept the l2cap_conn_ready() -> queue_work(...,\n&conn->pending_rx_work) submit path, the l2cap_conn_del() ->\ncancel_work_sync(&conn->pending_rx_work) teardown path, and the\nprocess_pending_rx() -> mutex_lock(&conn->lock) worker edge.  Lockdep\n\n  WARNING: possible circular locking dependency detected\n  process_pending_rx+0x21/0x2a [vuln_msv]\n  l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv]\n  *** DEADLOCK ***\n\nCancel pending_rx_work before taking conn->lock, matching the existing\nlock-before-drain ordering used for the two delayed works in the same\nteardown path.  The pending_rx queue is still purged after the work has\nbeen cancelled and conn->lock has been acquired."
    }
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