Bluetooth: hci_conn: Lock parent access during enhanced SCO setup

{
  "id": "834387776754d8df7ba10e4000ffd2d68b65285bd1fec3fc73bf6f596b41bee1",
  "url": "https://osv.dev/vulnerability/CVE-2026-98736",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Bluetooth: hci_conn: Lock parent access during enhanced SCO setup",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: Lock parent access during enhanced SCO setup Bluetooth: hci_conn: Lock parent access during enhanced SCO setup hci_enhanced_setup_sync() runs on the request workqueue without the hci_dev_lock held by its caller when setup was queued. Its CVSD capability check and find_next_esco_param() dereference conn->parent while the receive workqueue can unlink and release that parent. The following interleaving can cause a use-after-free: hci_enhanced_setup_sync() hci_disconn_complete_evt() load conn->parent hci_dev_lock() hci_conn_del(ACL parent) unlink SCO child drop link's parent reference clear child->parent release ACL parent bt_link_release() kfree(parent) hci_dev_unlock() read parent->features[0][3] The reference held for the queued SCO child does not keep its ACL parent alive after unlinking. Commit 42de40abe25d (\"Bluetooth: hci_conn: fix the SCO setup context lifetime\") protects the child stored in the queued context, but leaves these parent accesses unprotected. With a 40 ms diagnostic delay after loading conn->parent, an instrumented kernel based on fd179f8a05be, which already contains 42de40abe25d, BUG: KASAN: slab-use-after-free in hci_enhanced_setup_sync+0xda5/0xdf0 Read of size 1 at addr ffff888102204047 by task kworker/u17:0/93 Call Trace: hci_enhanced_setup_sync+0xda5/0xdf0 hci_cmd_sync_work+0x13c/0x290 process_one_work+0x6b4/0x10e0 Allocated by task 92: __hci_conn_add+0x304/0x1df0 h",
    "evidence": "osv:CVE-2026-98736",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.191",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.160",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.113",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.56",
            "evidence": "/affected/1/ranges"
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          {
            "value": "7.2.10",
            "evidence": "/affected/1/ranges"
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        "affected_versions": []
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    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98736",
      "aliases": [
        "CVE-2026-98736"
      ],
      "affected": [
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                  "fixed": "cabd58d9bb66d49d481f762ce986173db397435d"
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                  "fixed": "93a737e4e042f59673cd580d35214f278d7b757d"
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                  "introduced": "6.19.0"
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98736.json"
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      ],
      "modified": "2026-11-01T02:30:58.878375369Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/024e05f73a4c1263d031614bc36700ec135eecb4",
        "https://git.kernel.org/stable/c/1239ef0fa809b5952fca679db3faa3e1c00e1dac",
        "https://git.kernel.org/stable/c/48bf3b94c7331e11eaa6c89adc054a7bc7c0382e",
        "https://git.kernel.org/stable/c/70b55855eecb428d446344d827bda8725ce8b312",
        "https://git.kernel.org/stable/c/93a737e4e042f59673cd580d35214f278d7b757d",
        "https://git.kernel.org/stable/c/cabd58d9bb66d49d481f762ce986173db397435d",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98736.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98736",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98736.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98736",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 522284,
  "published_at": "2026-10-18T15:47:14.076+00:00"
}