INFO: task syz.8.756:11988 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.756       state:D stack:25128 pid:11988 tgid:11987 ppid:11760  task_flags:0x400140 flags:0x00004004
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
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa65238ec29
RSP: 002b:00007fa653179038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fa6525d5fa0 RCX: 00007fa65238ec29
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: ffffffff80000801
RBP: 00007fa652411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000002c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa6525d6038 R14: 00007fa6525d5fa0 R15: 00007ffc9b8a1788
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u10:5/1090:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90007137bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by dhcpcd/5594:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50
2 locks held by getty/5675:
 #0: ffff888022ed10a0 (&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 syz-executor/8144:
1 lock held by syz.8.756/11988:
 #0: ffff888022bf00e0 (&type->s_umount_key#64){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by syz-executor/12915:
1 lock held by syz.4.996/14326:
 #0: ffff888022bf00e0 (&type->s_umount_key#64){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz-executor/14817:
 #0: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
1 lock held by syz.2.1054/14846:
 #0: ffff888022bf00e0 (&type->s_umount_key#64){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz.5.1057/14865:

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

NMI backtrace for cpu 0
CPU: 0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8144 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:__might_resched+0x1af/0x610
Code: 00 00 02 74 43 4c 8d 7a 2c 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 89 03 00 00 41 f6 07 02 75 25 4c 8d ba 80 0a 00 00 <4c> 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 90 03 00 00 41 83
RSP: 0018:ffffc900039ff840 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff9200073ff10 RCX: 9a64dc035a2aa600
RDX: ffff88810846d640 RSI: ffffffff8dba996e RDI: ffffffff8be33f80
RBP: ffffc900039ff950 R08: ffff88802e5893f3 R09: 1ffff11005cb127e
R10: dffffc0000000000 R11: ffffed1005cb127f R12: 1ffff1102108db50
R13: dffffc0000000000 R14: ffff88810846da84 R15: ffff88810846e0c0
FS:  0000555585b4f500(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f38805ff000 CR3: 0000000038732000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 f2fs_write_checkpoint+0x50d/0x1df0
 kill_f2fs_super+0x2c3/0x6c0
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf7e18ff57
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:00007fff51225b18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fcf7e211c2d RCX: 00007fcf7e18ff57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff51225bd0
RBP: 00007fff51225bd0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff51226c60
R13: 00007fcf7e211c2d R14: 0000000000027002 R15: 00007fff51226ca0
 </TASK>
