INFO: task kworker/0:4:9830 blocked for more than 143 seconds.
      Not tainted 5.3.0-rc6 #120
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:4     D25696  9830      2 0x80004000
Workqueue: events linkwatch_event
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x755/0x1580 kernel/sched/core.c:3880
 schedule+0xd9/0x260 kernel/sched/core.c:3947
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4006
 __mutex_lock_common kernel/locking/mutex.c:1007 [inline]
 __mutex_lock+0x7b0/0x13c0 kernel/locking/mutex.c:1077
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1092
 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72
 linkwatch_event+0xf/0x70 net/core/link_watch.c:242
 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
INFO: task syz-executor.3:31350 blocked for more than 143 seconds.
      Not tainted 5.3.0-rc6 #120
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D27208 31350   9821 0x20024004
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x755/0x1580 kernel/sched/core.c:3880
 schedule+0xd9/0x260 kernel/sched/core.c:3947
 exp_funnel_lock kernel/rcu/tree_exp.h:308 [inline]
 synchronize_rcu_expedited+0x544/0x5b0 kernel/rcu/tree_exp.h:816
 synchronize_net+0x3b/0x60 net/core/dev.c:9264
 rollback_registered_many+0xa37/0xdd0 net/core/dev.c:8232
 rollback_registered+0x109/0x1d0 net/core/dev.c:8243
 unregister_netdevice_queue net/core/dev.c:9290 [inline]
 unregister_netdevice_queue+0x1ee/0x2c0 net/core/dev.c:9283
 unregister_netdevice include/linux/netdevice.h:2631 [inline]
 __tun_detach+0xd8a/0x1040 drivers/net/tun.c:723
 tun_detach drivers/net/tun.c:740 [inline]
 tun_chr_close+0xe0/0x180 drivers/net/tun.c:3442
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_32_irqs_on arch/x86/entry/common.c:347 [inline]
 do_fast_syscall_32+0xb87/0xdb3 arch/x86/entry/common.c:403
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7faca29
Code: Bad RIP value.
RSP: 002b:000000000847fbfc EFLAGS: 00000212 ORIG_RAX: 0000000000000006
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000005 RSI: 000000000816b680 RDI: 0000000008170b30
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 1058 Comm: khungtaskd Not tainted 5.3.0-rc6 #120
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0x9d0/0xef0 kernel/hung_task.c:289
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60