INFO: task syz.4.337:8619 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.337       state:D stack:24328 pid:8619  tgid:8618  ppid:7788   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x98/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9fff18ebe9
RSP: 002b:00007f9ffff73038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f9fff3c5fa0 RCX: 00007f9fff18ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f9fff3c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9fff3c6038 R14: 00007f9fff3c5fa0 R15: 00007ffcc8aea4b8
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
3 locks held by kworker/u10:0/27:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000060fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5595:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
2 locks held by getty/5677:
 #0: ffff888027af60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by kworker/u8:4/5879:
3 locks held by syz-executor/6179:
4 locks held by kworker/0:8/7468:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffff888122b18fe0 (&r->consumer_lock#2){+.+.}-{3:3}, at: wg_packet_decrypt_worker+0x87a/0xd10
 #3: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
1 lock held by syz.4.337/8619:
 #0: ffff8880226620e0 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.3.374/9008:
 #0: ffff8880226620e0 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.450/9803:
 #0: ffff8880226620e0 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/10987:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
1 lock held by syz-executor/11210:
1 lock held by syz-executor/11373:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:lockdep_hardirqs_on_prepare+0x107/0x2a0
Code: f0 0a 00 00 45 31 ff 4d 89 f4 eb 13 49 ff c7 48 63 83 e8 0a 00 00 49 83 c4 28 49 39 c7 7d 44 49 83 ff 31 73 2d 41 8b 44 24 20 <a9> 00 00 04 00 74 db 25 00 00 03 00 83 f8 01 ba 03 00 00 00 83 da
RSP: 0018:ffffc900000f70b0 EFLAGS: 00000083
RAX: 0000000000040b2a RBX: ffff88801c685640 RCX: ffffffff9351f410
RDX: 0000000000000002 RSI: ffff88801c686130 RDI: ffff88801c685640
RBP: 0000000000000000 R08: ffffffff8fa39037 R09: 1ffffffff1f47206
R10: dffffc0000000000 R11: fffffbfff1f47207 R12: ffff88801c686158
R13: 0000000000000000 R14: ffff88801c686130 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558281f5c8 CR3: 000000001f970000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 trace_hardirqs_on+0x28/0x40
 irqentry_exit+0x74/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110
Code: 74 05 e8 eb f9 4a f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 53 9f 13 f6 65 8b 05 0c 22 24 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900000f71a0 EFLAGS: 00000206
RAX: 30d770c5f28ddc00 RBX: 0000000000000a02 RCX: 30d770c5f28ddc00
RDX: 0000000000000006 RSI: ffffffff8d9b8241 RDI: 0000000000000001
RBP: ffffc900000f7220 R08: ffffffff8fa39037 R09: 1ffffffff1f47206
R10: dffffc0000000000 R11: fffffbfff1f47207 R12: dffffc0000000000
R13: ffff8880454d78f0 R14: ffffffff99d4d9f0 R15: 1ffff9200001ee34
 debug_check_no_obj_freed+0x451/0x470
 kmem_cache_free+0x113/0x400
 netlink_broadcast_filtered+0x1188/0x12c0
 nlmsg_notify+0xf0/0x1a0
 inetdev_event+0x77f/0x15b0
 notifier_call_chain+0x1b6/0x3e0
 unregister_netdevice_many_notify+0x14d7/0x1ff0
 default_device_exit_batch+0x819/0x890
 ops_undo_list+0x525/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
