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        "category": "legal_disclaimer",
        "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.",
        "title": "Terms of Use"
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        "url": "https://security.tuxcare.com/csaf/v2/els_os/ubuntu16.04els/vex/2021/cve-2021-47163-els_os-ubuntu16_04els.json"
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    "title": "Security update on CVE-2021-47163",
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  "vulnerabilities": [
    {
      "cve": "CVE-2021-47163",
      "cwe": {
        "id": "CWE-667",
        "name": "Improper Locking"
      },
      "notes": [
        {
          "category": "description",
          "text": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: wait and exit until all work queues are done\n\nOn some host, a crash could be triggered simply by repeating these\ncommands several times:\n\n  # modprobe tipc\n  # tipc bearer enable media udp name UDP1 localip 127.0.0.1\n  # rmmod tipc\n\n  [] BUG: unable to handle kernel paging request at ffffffffc096bb00\n  [] Workqueue: events 0xffffffffc096bb00\n  [] Call Trace:\n  []  ? process_one_work+0x1a7/0x360\n  []  ? worker_thread+0x30/0x390\n  []  ? create_worker+0x1a0/0x1a0\n  []  ? kthread+0x116/0x130\n  []  ? kthread_flush_work_fn+0x10/0x10\n  []  ? ret_from_fork+0x35/0x40\n\nWhen removing the TIPC module, the UDP tunnel sock will be delayed to\nrelease in a work queue as sock_release() can't be done in rtnl_lock().\nIf the work queue is schedule to run after the TIPC module is removed,\nkernel will crash as the work queue function cleanup_beareri() code no\nlonger exists when trying to invoke it.\n\nTo fix it, this patch introduce a member wq_count in tipc_net to track\nthe numbers of work queues in schedule, and  wait and exit until all\nwork queues are done in tipc_exit_net().",
          "title": "Vulnerability description"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
      "product_status": {
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          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2021-47163"
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          "summary": "https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986",
          "url": "https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986"
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          "summary": "https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa",
          "url": "https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa"
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      "release_date": "2024-03-25T10:15:00",
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            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 5.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
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