INFO: task kworker/u8:0:12 blocked for more than 147 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D stack:24360 pid:12    tgid:12    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 <TASK>
 __schedule+0x17db/0x58f0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7c1/0x1550
 addrconf_verify_work+0x19/0x30
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
locks held by kworker/0:0/9: 5, last CPU#0:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900000e7c40 ((work_completion)(&helper->damage_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffc900000e7770 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_atomic_helper_dirtyfb+0x106/0xfd0
 #3: ffffc900000e7798 (crtc_ww_class_mutex){+.+.}-{4:4}, at: drm_atomic_helper_dirtyfb+0x106/0xfd0
 #4: ffffffff8eeac3f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
locks held by kworker/0:1/10: 3, on CPU#0:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc900000f7c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902556c0 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
locks held by kworker/u8:0/12: 3, on CPU#1:
 #0: ffff888177433140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000117c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902556c0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30
locks held by pr/ttyS0/16: 3, last CPU#0:
 #0: ffffffff8ec367b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60
 #1: ffffffff8ed5cbe0 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x3de/0x18b0
 #2: ffffffff8ed5cbe0 (rcu_read_lock){....}-{1:3}, at: NF_HOOK+0x9e/0x3c0
locks held by kworker/u9:1/29: 3, last CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000a47c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff888110c707a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xb4/0x420
locks held by kworker/1:1/33: 4, on CPU#1:
 #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000a87c40 (reg_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902556c0 (rtnl_mutex){+.+.}-{4:4}, at: reg_todo+0x1c/0xa40
 #3: ffff8881bd2807a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_process_self_managed_hints+0x8d/0x160
locks held by khungtaskd/35: 1, last CPU#1:
 #0: ffffffff8ed5cbe0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
locks held by kworker/u10:1/37: 3, last CPU#1:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000ad7c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff8881bd2807a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xb4/0x420
locks held by kworker/u9:2/53: 3, last CPU#0:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90000bf7c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff8881bdc4f258 (&devlink->lock_key#2){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40
locks held by kworker/u10:7/1111: 3, last CPU#0:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90006a97c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffff88816e22a258 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40
locks held by klogd/5032: 1, last CPU#1:
 #0: ffffffff8eeac3f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
locks held by udevd/5043: 2, last CPU#1:
 #0: ffffffff8f4f3f78 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_perm+0x251/0x560
 #1: ffffffff8eeac3f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
locks held by dhcpcd/5339: 4, last CPU#1:
 #0: ffffffff8ee36150 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x10f/0x480
 #1: ffff88816b825038 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0
 #2: ffff8881105669b8 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0
 #3: ffffffff8eeac3f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
locks held by getty/5424: 2, on CPU#0:
 #0: ffff8881784990a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
locks held by syz-executor/5577: 2, last CPU#1:
 #0: ffffffff8eeac3f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
 #1: ffffffff8ed5cbe0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550
locks held by syz-executor/5590: 1, on CPU#0:
 #0: ffffffff902556c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
locks held by syz-executor/5592: 1, on CPU#0:
 #0: ffffffff902556c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
locks held by syz-executor/5602: 1, on CPU#0:
 #0: ffffffff902556c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
locks held by kworker/u8:2/5631: 2, last CPU#1:
 #0: ffff888178649140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90004ce7c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
locks held by kworker/1:5/5664: 3, on CPU#1:
 #0: ffff888100069d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90004eb7c40 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902556c0 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0xac/0x1110
locks held by kworker/1:6/5702: 3, on CPU#1:
 #0: ffff888100069d40 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90004fb7c40 ((crda_timeout).work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff902556c0 (rtnl_mutex){+.+.}-{4:4}, at: crda_timeout_work+0x16/0x80
locks held by syz-executor/6170: 2, last CPU#1:
 #0: ffff888110565038 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0
 #1: ffffffff8eeac3f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
locks held by udevd/6172: 4, last CPU#1:
 #0: ffff88810d0d4758 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0
 #1: ffff88811dc08480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420
 #2: ffff88817001cb48 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0xb2/0x420
 #3: ffffffff8eeac3f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
locks held by syz-executor/6173: 6, last CPU#1:
 #0: ffff888176350460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888171dcde20 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x200/0x370
 #2: ffff888176594938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200
 #3: ffff8881b9e0eed8 (&ei->i_data_sem#2){++++}-{4:4}, at: ext4_map_blocks+0x436/0x12c0
 #4: ffffffff8eeac3f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60
 #5: ffffffff8ed5cbe0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550

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

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+0x17d/0x390
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x38b/0x480
 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: 16 Comm: pr/ttyS0 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:debug_lockdep_rcu_enabled+0x18/0x40
Code: ca cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d fb 02 95 04 00 74 1d 83 3d ea 30 95 04 00 74 14 <65> 48 8b 0d 48 e5 af 07 31 c0 83 b9 a4 0b 00 00 00 0f 94 c0 e9 4f
RSP: 0018:ffffc900000075d8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff8880128b4e70 RCX: ffffc900000078c0
RDX: ffffc900000078c6 RSI: 0000000000000100 RDI: ffffc900000077c0
RBP: ffffc90000007830 R08: ffffc900000077bf R09: 0000000000000000
R10: ffffc900000077b0 R11: fffff52000000ef8 R12: ffff8880264f75c6
R13: dffffc0000000000 R14: ffffc900000077b0 R15: ffff8881bc158200
FS:  0000000000000000(0000) GS:ffff88818d6cc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563ffce3fc18 CR3: 000000000eb48000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 nft_do_chain+0x264/0x1b10
 nft_do_chain_inet+0x360/0x4b0
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x21f/0x3c0
 NF_HOOK+0x336/0x3c0
 process_backlog+0xa6b/0x18b0
 __napi_poll+0xaa/0x330
 net_rx_action+0x61d/0xf50
 handle_softirqs+0x226/0x860
 __irq_exit_rcu+0xcb/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80
Code: f7 e8 ad b3 bb f5 f7 c3 00 02 00 00 74 05 e8 b0 f0 e7 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 44 cd ac f5 65 48 8b 05 3c 31 ad 07 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc90000157ca8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000206 RCX: 8000000000000001
RDX: 0000000000000000 RSI: ffffffff8e47a1a9 RDI: 0000000000000001
RBP: ffffc90000157e18 R08: ffffffff907a5c7f R09: 1ffffffff20f4b8f
R10: dffffc0000000000 R11: fffffbfff20f4b90 R12: 0000000000000002
R13: ffff888102ed8000 R14: ffffffff9ad3f080 R15: dffffc0000000000
 nbcon_kthread_func+0x6c4/0x880
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
