INFO: task kworker/R-netns:8 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/R-netns state:D stack:26696 pid:8     tgid:8     ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7282
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
 netdev_wait_allrefs_any net/core/dev.c:11588 [inline]
 netdev_run_todo+0x690/0xde0 net/core/dev.c:11708
 ops_exit_rtnl_list net/core/net_namespace.c:189 [inline]
 ops_undo_list+0x3d8/0x940 net/core/net_namespace.c:248
 cleanup_net+0x56b/0x800 net/core/net_namespace.c:702
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 rescuer_thread+0x827/0x1130 kernel/workqueue.c:3609
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245