Bugzilla – Bug 1221980
VUL-0: CVE-2021-47163: kernel: tipc: wait and exit until all work queues are done
Last modified: 2024-07-03 05:39:10 UTC
In the Linux kernel, the following vulnerability has been resolved: tipc: wait and exit until all work queues are done On some host, a crash could be triggered simply by repeating these commands several times: # modprobe tipc # tipc bearer enable media udp name UDP1 localip 127.0.0.1 # rmmod tipc [] BUG: unable to handle kernel paging request at ffffffffc096bb00 [] Workqueue: events 0xffffffffc096bb00 [] Call Trace: [] ? process_one_work+0x1a7/0x360 [] ? worker_thread+0x30/0x390 [] ? create_worker+0x1a0/0x1a0 [] ? kthread+0x116/0x130 [] ? kthread_flush_work_fn+0x10/0x10 [] ? ret_from_fork+0x35/0x40 When removing the TIPC module, the UDP tunnel sock will be delayed to release in a work queue as sock_release() can't be done in rtnl_lock(). If the work queue is schedule to run after the TIPC module is removed, kernel will crash as the work queue function cleanup_beareri() code no longer exists when trying to invoke it. To fix it, this patch introduce a member wq_count in tipc_net to track the numbers of work queues in schedule, and wait and exit until all work queues are done in tipc_exit_net(). References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-47163 https://git.kernel.org/stable/c/5195ec5e365a2a9331bfeb585b613a6e94f98dba https://git.kernel.org/stable/c/b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d https://git.kernel.org/stable/c/04c26faa51d1e2fe71cf13c45791f5174c37f986 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2021/CVE-2021-47163.mbox https://git.kernel.org/stable/c/d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa https://www.cve.org/CVERecord?id=CVE-2021-47163 https://bugzilla.redhat.com/show_bug.cgi?id=2271452
Offending commit (d0f91938bede) found in: - ALP-current - cve/linux-4.4-LTSS - cve/linux-5.3-LTSS - cve/linux-5.14-LTSS - SLE12-SP2-LTSS - SLE12-SP3-LTSS - SLE12-SP3-TD - SLE12-SP4-LTSS - SLE12-SP5 - SLE15-LTSS - SLE15-SP1-LTSS - SLE15-SP2-LTSS - SLE15-SP3-LTSS - SLE15-SP4-LTSS - SLE15-SP5 - SLE15-SP6 - stable Fixing commit (b9f5b7ad4ac3) found in: - ALP-current - cve/linux-5.14-LTSS - SLE15-SP4-LTSS - SLE15-SP5 - SLE15-SP6 - stable Tracking as affected: - cve/linux-4.4-LTSS - cve/linux-5.3-LTSS - SLE12-SP2-LTSS - SLE12-SP3-LTSS - SLE12-SP3-TD - SLE12-SP4-LTSS - SLE12-SP5 - SLE15-LTSS - SLE15-SP1-LTSS - SLE15-SP2-LTSS - SLE15-SP3-LTSS
This is low score, so not really LTSS material. so we should only patch - SLE12-SP5 I'll handle the backport.
Michal, actually can you take this one? It needs a custom fix to avoid ABI breakages, so I'd rather have an expert on this code to decide on the fix.