INFO: task kworker/u8:3:5671 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3    state:D stack:22424 pid:5671  tgid:5671  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 addrconf_verify_work+0x19/0x30
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/0:3/5427:
2 locks held by getty/5443:
 #0: ffff8881122740a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
2 locks held by kworker/u8:2/5507:
3 locks held by kworker/u8:3/5671:
 #0: ffff88817487a140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900049cfc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
5 locks held by kworker/0:6/6032:
3 locks held by kworker/0:13/6040:
 #0: ffff888100069d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90007ca7c40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xab/0x10d0
3 locks held by kworker/0:14/6041:
3 locks held by kworker/1:15/6045:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90007d07c40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x19/0x3c0
3 locks held by syz.0.1304/10849:
1 lock held by syz-executor/10886:
 #0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
1 lock held by syz-executor/10889:
 #0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz-executor/10906:
 #0: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0
1 lock held by syz-executor/10912:
 #0: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0
1 lock held by syz-executor/10917:
 #0: ffffffff8fdd0300 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 6032 Comm: kworker/0:6 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: events_long defense_work_handler
RIP: 0010:clockevents_program_event+0x1d7/0x630
Code: c2 48 c1 ea 20 b9 e0 06 00 00 0f 30 4c 8b 64 24 10 43 c6 44 2c 04 f8 31 c0 48 c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 <65> 48 8b 0d 61 80 83 11 48 3b 4c 24 60 0f 85 0b 03 00 00 48 8d 65
RSP: 0018:ffffc90000007180 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888121023e40 RCX: ffff88810b1e5880
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007238 R08: ffffffff81b2dfc5 R09: ffffffff9a493588
R10: 0000000000000003 R11: ffffffff817446c0 R12: 1ffff92000000e34
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888121023e8c
FS:  0000000000000000(0000) GS:ffff88818dc87000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33c13ff8 CR3: 000000000e74a000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __hrtimer_rearm_deferred+0x270/0x450
 irqentry_exit+0x6a0/0x730
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90
Code: 89 44 11 20 e9 09 e4 e6 09 cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 15 48 cc 73 11 65 8b 0d 69 cc 73 11 81 e1 00 01 ff 00 74
RSP: 0018:ffffc90000007398 EFLAGS: 00000246
RAX: ffffffff8a6c9faa RBX: 000000000000001f RCX: 0000000000000000
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000007590 R08: ffffc9000000750f R09: 0000000000000000
R10: ffffc900000074f0 R11: fffff52000000ea2 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000001 R15: 0000000000000000
 ip6t_do_table+0x1ca/0x1560
 ip6table_mangle_hook+0x2b3/0x740
 nf_hook_slow+0xc5/0x220
 br_nf_pre_routing_ipv6+0x59f/0x6f0
 br_handle_frame+0x1277/0x1510
 __netif_receive_skb_core+0x98f/0x3170
 process_backlog+0x76d/0x1950
 __napi_poll+0xae/0x340
 net_rx_action+0x627/0xf70
 handle_softirqs+0x22a/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__schedule+0x17bc/0x5680
Code: d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 fa 57 86 f6 4c 89 23 4c 89 ef 4c 89 e6 e8 3c 9c 88 f5 48 89 c7 e8 b4 4c ea f5 <31> ff 4d 39 e5 40 0f 95 c7 e8 96 58 ea f5 48 8b 84 24 00 01 00 00
RSP: 0018:ffffc90007bef760 EFLAGS: 00000202
RAX: 000000000019dd37 RBX: ffff88812103ae88 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8dfaaec4 RDI: ffffffff8c28ade0
RBP: ffffc90007bef970 R08: ffffffff9030def7 R09: 1ffffffff2061bde
R10: dffffc0000000000 R11: fffffbfff2061bdf R12: ffff88810b1e5880
R13: ffff88810b1e5880 R14: dffffc0000000000 R15: ffff88812103b9f8
 preempt_schedule_irq+0x4d/0xa0
 irqentry_exit+0x14f/0x730
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x221/0x350
Code: ff ff ff e8 51 04 08 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 3b df 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d c8 8b 92
RSP: 0018:ffffc90007befaa0 EFLAGS: 00000286
RAX: b5d7468da9cea900 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000000316da00 RSI: ffffffff8e21f5e0 RDI: ffffffff8c28ade0
RBP: ffffffff818e9580 R08: ffffffff818e9580 R09: ffffc90007befc40
R10: dffffc0000000000 R11: fffffbfff2061bdf R12: 0000000000000000
R13: ffffc90007befc40 R14: 0000000000000001 R15: 0000000000000246
 process_scheduled_works+0xa8d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
