INFO: task kworker/u8:1:13 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:1    state:D stack:24928 pid:13    tgid:13    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 ipmr_net_exit_batch+0x20/0x90
 ops_undo_list+0x52b/0x940
 cleanup_net+0x56b/0x800
 process_scheduled_works+0xb02/0x1830
