{"id":"CVE-2021-47163","details":"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().","modified":"2026-03-23T05:02:38.852486Z","published":"2024-03-25T10:15:08.530Z","related":["SUSE-SU-2024:4100-1","SUSE-SU-2025:0034-1","SUSE-SU-2025:01633-1","SUSE-SU-2025:1574-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986"},{"type":"FIX","url":"https://git.kernel.org/stable/c/5195ec5e365a2a9331bfeb585b613a6e94f98dba"},{"type":"FIX","url":"https://git.kernel.org/stable/c/b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d"},{"type":"FIX","url":"https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47163.json","unresolved_ranges":[{"events":[{"introduced":"4.1"},{"fixed":"5.4.124"}]},{"events":[{"introduced":"5.5"},{"fixed":"5.10.42"}]},{"events":[{"introduced":"5.11"},{"fixed":"5.12.9"}]},{"events":[{"introduced":"0"},{"last_affected":"5.13-rc1"}]},{"events":[{"introduced":"0"},{"last_affected":"5.13-rc2"}]},{"events":[{"introduced":"0"},{"last_affected":"5.13-rc3"}]}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}