INFO: task syz.4.162:7272 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.162       state:D stack:17384 pid:7272  tgid:7271  ppid:7172   task_flags:0x400140 flags:0x00080002
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/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda2598ec29
RSP: 002b:00007fda23bee038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fda25bd5fa0 RCX: 00007fda2598ec29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fda25bd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda25bd6038 R14: 00007fda25bd5fa0 R15: 00007ffeba692318
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff88801baff148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000f7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f72dbd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820
 #3: ffffffff8f73ad08 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990
1 lock held by khungtaskd/34:
 #0: ffffffff8e33d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:2/53:
 #0: ffff88801ac89948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900007dfba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f73ad08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by dhcpcd/5593:
 #0: ffffffff8f73ad08 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50
2 locks held by getty/5676:
 #0: ffff888021dfb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900028fe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz-executor/5855:
3 locks held by kworker/0:4/5903:
 #0: ffff88801ac75948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003487ba0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f73ad08 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20
3 locks held by kworker/0:5/5916:
 #0: ffff88801ac75948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003497ba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88810edf1240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0
1 lock held by syz.4.162/7272:
 #0: ffff888034a760e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.396/8988:
 #0: ffff888034a760e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.396/8990:
 #0: ffff888034a760e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_lock+0x25c/0x3b0
2 locks held by syz-executor/10563:
 #0: ffffffff8f72dbd0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0
 #1: ffffffff8f73ad08 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x80/0x210
1 lock held by syz.0.563/10575:

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

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+0xf60/0xfa0
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 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: 5855 Comm: syz-executor 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:mark_lock+0x3c/0x190
Code: 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 89 d9 d3 e5 25 ff 1f 00 00 48 0f a3 05 d4 fb 2a 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 30 23 6a 93 eb 48 83 3d 3b 8b
RSP: 0018:ffffc900031b7720 EFLAGS: 00000003
RAX: 000000000000097c RBX: 0000000000000002 RCX: 0000000000000002
RDX: 0000000000000002 RSI: ffff88801bb0c5a8 RDI: ffff88801bb0ba00
RBP: 0000000000000004 R08: 0000000000000000 R09: ffffffff823de811
R10: dffffc0000000000 R11: fffff52000636f08 R12: 0000000000000003
R13: 0000000000000003 R14: ffff88801bb0c5a8 R15: ffff88801bb0c5c8
FS:  000055557d5b6500(0000) GS:ffff8880b840a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd13f5ff000 CR3: 0000000029012000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __lock_acquire+0x9b6/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock+0x2e/0x40
 igrab+0x21/0xb0
 f2fs_write_checkpoint+0xad2/0x2440
 kill_f2fs_super+0x2cc/0x6d0
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xe9/0x130
 do_syscall_64+0x2bd/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc109d8ff57
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fffb93b9928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fc109e11c2d RCX: 00007fc109d8ff57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffb93b99e0
RBP: 00007fffb93b99e0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffb93baa70
R13: 00007fc109e11c2d R14: 0000000000018743 R15: 00007fffb93baab0
 </TASK>
