CVE Published: 25/03/2024 |
CVE Updated: 04/11/2024 |
CVE Year: 2021 Source: Linux |
Vendor: Linux |
Product: Linux Status : PUBLISHED
CVE-2021-47163 Description
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().