UBUNTU-CVE-2021-47163
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().
02 / AFFECTED SOFTWARE
Affected packages
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
6 explicit affected versions
2 explicit affected versions
7 explicit affected versions
28 explicit affected versions
71 explicit affected versions
35 explicit affected versions
18 explicit affected versions
102 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
107 explicit affected versions
1 explicit affected versions
1 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
12 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
30 explicit affected versions
38 explicit affected versions
12 explicit affected versions
30 explicit affected versions
106 explicit affected versions
10 explicit affected versions
174 explicit affected versions
37 explicit affected versions
10 explicit affected versions
1 explicit affected versions
26 explicit affected versions
13 explicit affected versions
1 explicit affected versions
29 explicit affected versions
13 explicit affected versions
1 explicit affected versions
33 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
100 explicit affected versions
11 explicit affected versions
12 explicit affected versions
123 explicit affected versions
7 explicit affected versions
12 explicit affected versions
31 explicit affected versions
2 explicit affected versions
116 explicit affected versions
151 explicit affected versions
137 explicit affected versions
26 explicit affected versions
10 explicit affected versions
26 explicit affected versions
13 explicit affected versions
123 explicit affected versions
16 explicit affected versions
3 explicit affected versions
77 explicit affected versions
1 explicit affected versions
51 explicit affected versions
76 explicit affected versions
12 explicit affected versions
27 explicit affected versions
1 explicit affected versions
1 explicit affected versions
81 explicit affected versions
8 explicit affected versions
5 explicit affected versions
20 explicit affected versions
8 explicit affected versions
1 explicit affected versions
21 explicit affected versions
10 explicit affected versions
13 explicit affected versions
1 explicit affected versions
7 explicit affected versions
78 explicit affected versions
10 explicit affected versions
12 explicit affected versions
19 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
37 explicit affected versions
38 explicit affected versions
9 explicit affected versions
11 explicit affected versions
21 explicit affected versions
7 explicit affected versions
84 explicit affected versions
4 explicit affected versions
127 explicit affected versions
106 explicit affected versions
4 explicit affected versions
99 explicit affected versions
20 explicit affected versions
43 explicit affected versions
1 explicit affected versions
130 explicit affected versions
151 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
23 explicit affected versions
4 explicit affected versions
10 explicit affected versions
1 explicit affected versions
53 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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().
05 / REFERENCES
Further evidence
- 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://ubuntu.com/security/CVE-2021-47163
- https://ubuntu.com/security/notices/USN-7496-1
- https://ubuntu.com/security/notices/USN-7496-3
- https://ubuntu.com/security/notices/USN-7496-4
- https://ubuntu.com/security/notices/USN-7496-5
- https://ubuntu.com/security/notices/USN-7506-1
- https://ubuntu.com/security/notices/USN-7506-2
- https://ubuntu.com/security/notices/USN-7506-3
- https://ubuntu.com/security/notices/USN-7506-4
- https://www.cve.org/CVERecord?id=CVE-2021-47163