INFO: task kworker/u8:1:13 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:1    state:D stack:23816 pid:13    tgid:13    ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 wg_destruct+0x25/0x2f0
 netdev_run_todo+0xcd7/0xea0
 default_device_exit_batch+0x81e/0x890
 ops_undo_list+0x525/0x990
 cleanup_net+0x4d8/0x820
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000c7bc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f0cc8c8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
4 locks held by kworker/u8:1/13:
 #0: ffff88801aef7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90000107bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f0bf9f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820
 #3: ffffffff8f0cc8c8 (rtnl_mutex){+.+.}-{4:4}, at: wg_destruct+0x25/0x2f0
1 lock held by khungtaskd/34:
 #0: ffffffff8dd3aca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kswapd0/83:
2 locks held by kswapd1/84:
2 locks held by kworker/1:3/2332:
 #0: ffff888136639fd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff888136624048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
3 locks held by syslogd/5255:
5 locks held by udevd/5273:
2 locks held by getty/5651:
 #0: ffff888108ed10a0 (&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
3 locks held by kworker/u8:2/5654:
 #0: ffff88802135e148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002cafbc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f0cc8c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
3 locks held by kworker/0:6/5888:
 #0: ffff88801a082148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003a4fbc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f0cc8c8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x95/0xf30
1 lock held by syz.1.243/6592:
 #0: ffffffff8f0cc8c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
1 lock held by syz.0.1188/8932:
 #0: ffffffff8f0cc8c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
1 lock held by syz.5.3098/13475:
 #0: ffffffff8f0cc8c8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
3 locks held by syz-executor/14088:
1 lock held by dhcpcd-run-hook/14218:
3 locks held by syz-executor/14226:
3 locks held by syz-executor/14230:

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

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+0x439/0x7d0
 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: 84 Comm: kswapd1 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
RIP: 0010:unwind_next_frame+0x348/0x2390
Code: 48 81 fb 70 0a 6a 8f 0f 83 48 11 00 00 48 c7 c0 70 0a 6a 8f 49 29 c5 48 c7 c6 94 35 e1 8f 49 c1 fd 02 4a 8d 14 6d 00 00 00 00 <4c> 01 ea 48 01 d2 48 01 f2 48 bd 00 00 00 00 00 fc ff df 0f 84 37
RSP: 0018:ffffc9000174eaf8 EFLAGS: 00000246
RAX: ffffffff8f7271e4 RBX: ffffffff8f7271e8 RCX: ffffffff8f7271ec
RDX: 0000000000000000 RSI: ffffffff8fedd0c8 RDI: ffffffff8b9e6f80
RBP: ffffffff8f7271ec R08: 0000000000000001 R09: ffffffff81722195
R10: ffffc9000174ec18 R11: ffffffff81aaa4d0 R12: ffffffff81a4e846
R13: 0000000000000000 R14: ffffc9000174ebc8 R15: ffffffff8f7271e8
FS:  0000000000000000(0000) GS:ffff8880b8d7e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557af9e350 CR3: 00000000280d6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 __destroy_inode+0x2da/0x670
 evict+0x797/0x9c0
 __dentry_kill+0x209/0x660
 shrink_kill+0xa9/0x2c0
 shrink_dentry_list+0x2e0/0x5e0
 prune_dcache_sb+0x10e/0x180
 super_cache_scan+0x369/0x4b0
 do_shrink_slab+0x6ef/0x1110
 shrink_slab+0xd74/0x10d0
 shrink_one+0x28a/0x7c0
 shrink_node+0x314e/0x3760
 kswapd+0x147c/0x2830
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
