FKIE_CVE-2026-64206
Vulnerability from fkie_nvd - Published: 2026-07-20 17:18 - Updated: 2026-07-20 17:18
Severity
Summary
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.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/bluetooth/l2cap_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "d5616beb3355b5fca2280d796c1cf7ada4ee6551",
"status": "affected",
"version": "7ab56c3a6eccb215034b0cb096e0313441cbf2a4",
"versionType": "git"
},
{
"lessThan": "e96fbac8d3a73b0bc165383c092a30628561d320",
"status": "affected",
"version": "7ab56c3a6eccb215034b0cb096e0313441cbf2a4",
"versionType": "git"
},
{
"lessThan": "2641a9e0a1dd4af2e21995470a21d55dd35e5203",
"status": "affected",
"version": "7ab56c3a6eccb215034b0cb096e0313441cbf2a4",
"versionType": "git"
},
{
"status": "affected",
"version": "ee805f9499ebd0edf0877990968543c752043b59",
"versionType": "git"
},
{
"lessThan": "3.16",
"status": "affected",
"version": "3.15.5",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/bluetooth/l2cap_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.16"
},
{
"lessThan": "3.16",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2-rc3",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"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-\u003elock\n\nl2cap_conn_del() takes conn-\u003elock 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() -\u003e queue_work(...,\n\u0026conn-\u003epending_rx_work) submit path, the l2cap_conn_del() -\u003e\ncancel_work_sync(\u0026conn-\u003epending_rx_work) teardown path, and the\nprocess_pending_rx() -\u003e mutex_lock(\u0026conn-\u003elock) 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-\u003elock, 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-\u003elock has been acquired."
}
],
"id": "CVE-2026-64206",
"lastModified": "2026-07-20T17:18:22.620",
"metrics": {},
"published": "2026-07-20T17:18:22.620",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2641a9e0a1dd4af2e21995470a21d55dd35e5203"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d5616beb3355b5fca2280d796c1cf7ada4ee6551"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e96fbac8d3a73b0bc165383c092a30628561d320"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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