INFO: task kworker/u10:5:1110 blocked in I/O wait for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:5   state:D stack:23352 pid:1110  tgid:1110  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 io_schedule+0x7f/0xd0
 txBegin+0x27d/0xc00
 jfs_commit_inode+0x1b3/0x530
 jfs_write_inode+0x145/0x220
 __writeback_single_inode+0x75a/0x10e0
 writeback_sb_inodes+0x979/0x19d0
 wb_writeback+0x445/0xb00
 wb_workfn+0x3f8/0xf10
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz-executor:7741 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22424 pid:7741  tgid:7741  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 wb_wait_for_completion+0x3e8/0x790
 __writeback_inodes_sb_nr+0x24b/0x2c0
 sync_filesystem+0xa3/0x230
 generic_shutdown_super+0x77/0x2d0
 kill_block_super+0x44/0x90
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x437/0x4d0
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0xed/0x480
 do_syscall_64+0x33e/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7f9839e017
RSP: 002b:00007fff28f1f178 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f7f98432120 RCX: 00007f7f9839e017
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff28f1f230
RBP: 00007fff28f1f230 R08: 00007fff28f20230 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff28f202c0
R13: 00007f7f98432120 R14: 00000000000273ce R15: 00007fff28f20300
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/u10:5/1110:
 #0: ffff888162a90140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc9000736fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
2 locks held by getty/5437:
 #0: ffff888100f680a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000346b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by syz-executor/7741:
 #0: ffff8881753e20d8 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
8 locks held by kworker/u8:5/9530:
 #0: ffff8881012b5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90006517c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdc1708 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800
 #3: ffff8881bef8d128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420
 #4: ffff88816d243258 (&devlink->lock_key#18){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420
 #5: ffffffff8fdd03c0 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x13a/0x830
 #6: ffff8881a9dbcdc8 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1197/0x22c0
 #7: ffffffff8e9630a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770

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

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+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: 9530 Comm: kworker/u8:5 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:__bfs+0xf5/0x290
Code: 0d 20 dd 9f 14 4d 85 ed 0f 84 61 01 00 00 49 8b 45 10 48 85 c0 0f 84 3c 01 00 00 8b 0d 0c dd 9f 14 39 48 5c 0f 84 6f ff ff ff <89> 48 5c 49 8b 45 30 48 85 c0 74 23 41 0f b6 4d 2a 89 ca 80 e2 fa
RSP: 0018:ffffc90006516c80 EFLAGS: 00000083
RAX: ffffffff93e93e88 RBX: 0000000000000020 RCX: 00000000000614c5
RDX: 0000000000000008 RSI: ffff888021a74758 RDI: ffffffff96ce3950
RBP: ffffffff81a20c90 R08: ffffc90006516d20 R09: 0000000000000020
R10: ffffc90006517040 R11: ffffffff81a20c90 R12: ffffffff96ce3a30
R13: ffffffff96da49a0 R14: 0000000000000000 R15: ffffffff93e63550
FS:  0000000000000000(0000) GS:ffff88818dc91000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f373dfe8158 CR3: 0000000174c92000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 check_path+0x21/0x40
 check_noncircular+0xda/0x150
 __lock_acquire+0x15a5/0x2cf0
 lock_acquire+0x106/0x350
 __mutex_lock+0x1a3/0x1550
 ipv6_mc_down+0x27/0x5a0
 ipv6_mc_destroy_dev+0x2c/0x5a0
 addrconf_ifdown+0x1561/0x1a40
 addrconf_notify+0x1bc/0x1050
 notifier_call_chain+0x1ad/0x3d0
 unregister_netdevice_many_notify+0x17a5/0x22c0
 unregister_netdevice_queue+0x31f/0x360
 nsim_destroy+0x24e/0x830
 __nsim_dev_port_del+0x14f/0x200
 nsim_dev_reload_destroy+0x288/0x490
 nsim_dev_reload_down+0x8a/0xc0
 devlink_reload+0x1eb/0x8c0
 devlink_pernet_pre_exit+0x1ff/0x420
 ops_undo_list+0x187/0x940
 cleanup_net+0x56b/0x800
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
