INFO: task syz.1.3433:19952 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3433      state:D stack:22664 pid:19952 tgid:19951 ppid:5820   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
 __se_sys_quotactl+0x353/0x950
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7e0698efc9
RSP: 002b:00007f7e078c9038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f7e06be5fa0 RCX: 00007f7e0698efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100
RBP: 00007f7e06a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7e06be6038 R14: 00007f7e06be5fa0 R15: 00007fff12106988
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff888161286148 ((wq_completion)pm){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000e7ba0 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888106703198 (&dev->mutex){....}-{4:4}, at: usb_remote_wakeup+0x23/0x100
1 lock held by khungtaskd/35:
 #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5638:
 #0: ffff8881738ff0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000357b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
6 locks held by kworker/0:6/5881:
 #0: ffff88816809bd48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90005127ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88810c2c2198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff888114067198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff888114065160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #5: ffffffff8dde26f0 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0
2 locks held by syz-executor/17712:
1 lock held by syz.1.3433/19952:
 #0: ffff8881a6a360e0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2a9/0x3b0

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

NMI backtrace for cpu 0
CPU: 0 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+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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17712 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:igrab+0x81/0xb0
Code: 00 00 74 09 e8 20 e2 80 ff 31 db eb 1d e8 17 e2 80 ff 48 8d bb 00 02 00 00 be 04 00 00 00 e8 46 b5 e6 ff f0 ff 83 00 02 00 00 <4c> 89 f7 e8 87 a1 0a 09 48 89 d8 5b 41 5e 41 5f 5d e9 c9 ef 0a 09
RSP: 0018:ffffc90003cd7898 EFLAGS: 00000202
RAX: ffffffff823f2501 RBX: ffff8881180008f8 RCX: ffffffff823f253a
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888118000af8
RBP: 0000000000000000 R08: ffff888118000afb R09: 1ffff1102300015f
R10: dffffc0000000000 R11: ffffed1023000160 R12: ffff888174192084
R13: dffffc0000000000 R14: ffff888118000978 R15: ffff8881180009c8
FS:  0000555586a6c500(0000) GS:ffff8882a9f35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000c030 CR3: 000000010b900000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 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: 0033:0x7fd4a71902f7
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:00007fff31d02998 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd4a7211d7d RCX: 00007fd4a71902f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff31d02a50
RBP: 00007fff31d02a50 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff31d03ae0
R13: 00007fd4a7211d7d R14: 00000000000e6cc3 R15: 00007fff31d03b20
 </TASK>
