INFO: task syz.7.645:11018 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.645       state:D stack:26200 pid:11018 tgid:10997 ppid:10695  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x149b/0x4fd0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x99/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 __se_sys_quotactl+0x353/0x950
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c1638f7c9
RSP: 002b:00007f4c171ce038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f4c165e6090 RCX: 00007f4c1638f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007f4c163f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c165e6128 R14: 00007f4c165e6090 R15: 00007fff17d25b08
 </TASK>
INFO: task syz.7.645:11021 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.645       state:D stack:27472 pid:11021 tgid:10997 ppid:10695  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x149b/0x4fd0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x5fd/0x8f0
 down_read+0x99/0x2e0
 super_lock+0x2a9/0x3b0
 __iterate_supers+0x126/0x290
 __se_sys_quotactl+0x353/0x950
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c1638f7c9
RSP: 002b:00007f4c171ad038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f4c165e6180 RCX: 00007f4c1638f7c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100
RBP: 00007f4c163f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c165e6218 R14: 00007f4c165e6180 R15: 00007fff17d25b08
 </TASK>

Showing all locks held in the system:
1 lock held by ksoftirqd/1/23:
1 lock held by khungtaskd/35:
 #0: ffffffff8df41a20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5658:
 #0: ffff8881750d90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460
2 locks held by syz-executor/10590:
1 lock held by syz.7.645/11018:
 #0: ffff88801eb860e0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.7.645/11021:
 #0: ffff88801eb860e0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by syz-executor/11295:
1 lock held by syz.3.976/13592:
 #0: ffff88801eb860e0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz.2.1079/13912:

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xf95/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x510/0xa50
 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: 10590 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:__lock_acquire+0x570/0x2cf0
Code: 85 c0 74 1c 83 3d a3 59 e4 0d 00 75 13 48 8d 3d c6 6e e7 0d 48 c7 c6 56 06 87 8d 67 48 0f b9 3a 90 31 c9 0f b6 81 c4 00 00 00 <84> c0 0f 84 77 ff ff ff 41 0f b6 f4 0f b6 d0 40 38 c6 0f 42 d6 80
RSP: 0018:ffffc9000964f420 EFLAGS: 00000006
RAX: 0000000000000004 RBX: ffff88817677c5f8 RCX: ffffffff933020e0
RDX: 0000000000000004 RSI: 0000000000000005 RDI: 0000000000000000
RBP: ffff88817677c600 R08: ffffffff8247241b R09: ffff8880202cc898
R10: dffffc0000000000 R11: fffffbfff1f0440f R12: 0000000000000004
R13: ffff88817677c600 R14: ffff88817677ba80 R15: 0000000000000001
FS:  0000555560e6a500(0000) GS:ffff8882a9e21000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32707ff8 CR3: 0000000113ef4000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x107/0x340
 _raw_spin_lock+0x2e/0x40
 writeback_single_inode+0x4ab/0xc70
 sync_inode_metadata+0xb9/0x110
 f2fs_write_checkpoint+0xae9/0x2430
 kill_f2fs_super+0x2d2/0x6c0
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xef/0x4e0
 do_syscall_64+0x2b7/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7966990af7
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:00007ffc98543208 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f79669ee72f RCX: 00007f7966990af7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc985432c0
RBP: 00007ffc985432c0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc98544350
R13: 00007f79669ee72f R14: 000000000003d85d R15: 00007ffc98544390
 </TASK>
