Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user_CVE-2026-23461

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user\n\nAfter commit ab4eedb790ca (\"Bluetooth: L2CAP: Fix corrupted list in\nhci_chan_del\"), l2cap_conn_del() uses conn->lock to protect access to\nconn->users. However, l2cap_register_user() and l2cap_unregister_user()\ndon't use conn->lock, creating a race condition where these functions can\naccess conn->users and conn->hchan concurrently with l2cap_conn_del().\n\nThis can lead to use-after-free and list corruption bugs, as reported\nby syzbot.\n\nFix this by changing l2cap_register_user() and l2cap_unregister_user()\nto use conn->lock instead of hci_dev_lock(), ensuring consistent locking\nfor the l2cap_conn structure.",
    "published": "2026-04-03T15:15:41.051Z",
    "modified": "2026-04-27T14:02:38.897Z",
    "type": "cve",
    "title": "Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/11a87dd5df428a4b79a84d2790cac7f3c73f1f0d\nhttps://git.kernel.org/stable/c/c22a5e659959eb77c2fbb58a5adfaf3c3dab7abf\nhttps://git.kernel.org/stable/c/da3000cbe4851458a22be38bb18c0689c39fdd5f\nhttps://git.kernel.org/stable/c/71030f3b3015a412133a805ff47970cdcf30c2b8\nhttps://git.kernel.org/stable/c/752a6c9596dd25efd6978a73ff21f3b592668f4a",
    "id": "CVE-2026-23461",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux efc30877bd4bc85fefe98d80af60fafc86e5775e\nLinux Linux f87271d21dd4ee83857ca11b94e7b4952749bbae\nLinux Linux ab4eedb790cae44313759b50fe47da285e2519d5\nLinux Linux ab4eedb790cae44313759b50fe47da285e2519d5\nLinux Linux ab4eedb790cae44313759b50fe47da285e2519d5\nLinux Linux 18ab6b6078fa8191ca30a3065d57bf35d5635761\nLinux Linux 6.14",
    "sourceHref": "",
    "cvss": {
        "score": 8.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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            "privilegesRequired": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "efc30877bd4bc85fefe98d80af60fafc86e5775e",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
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    "ai_score": 0
}