{"cve":"CVE-2021-47163","nvd":{"published":"2024-03-25T10:15:08.530","modified":"2026-08-04T10:16:49.993","status":"Modified","description":"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().","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986","https://git.kernel.org/stable/c/5195ec5e365a2a9331bfeb585b613a6e94f98dba","https://git.kernel.org/stable/c/b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d","https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa","https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:47:51.568503435+00:00"},"epss":{"cve":"CVE-2021-47163","score":0.00187,"percentile":0.08353,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}