INFO: task syz.6.511:10474 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.511       state:D stack:28000 pid:10474 tgid:10472 ppid:9629   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x899/0x1040
 down_write+0x1bc/0x200
 super_lock+0x289/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x540/0x9e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b9eb9c799
RSP: 002b:00007f1b9fb32028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f1b9ee15fa0 RCX: 00007f1b9eb9c799
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: ffffffff80000301
RBP: 00007f1b9ec32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1b9ee16038 R14: 00007f1b9ee15fa0 R15: 00007ffe281c9718
 </TASK>
INFO: task syz.1.550:10642 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.550       state:D stack:23168 pid:10642 tgid:10641 ppid:10090  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x899/0x1040
 down_write+0x1bc/0x200
 super_lock+0x289/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x540/0x9e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9f739c799
RSP: 002b:00007ff9f8222028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007ff9f7615fa0 RCX: 00007ff9f739c799
RDX: 0000000000000000 RSI: 0000200000000080 RDI: ffffffff80000200
RBP: 00007ff9f7432c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff9f7616038 R14: 00007ff9f7615fa0 R15: 00007ffcea48bf58
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5635:
 #0: ffff8881739f00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
2 locks held by syz-executor/5815:
3 locks held by syz-executor/7110:
1 lock held by syz.6.511/10474:
 #0: ffff88816e13a0e0 (&type->s_umount_key#70){++++}-{4:4}, at: super_lock+0x289/0x3d0
1 lock held by syz.1.550/10642:
 #0: ffff8881bac100e0 (&type->s_umount_key#70){++++}-{4:4}, at: super_lock+0x289/0x3d0
2 locks held by syz.6.897/13529:
2 locks held by syz.1.898/13533:

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd9/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 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: 7110 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+0x74/0x2cf0
Code: df 93 0f 84 da 13 00 00 41 89 cd 41 89 d6 8b 0d 22 3c c1 0c 85 c9 44 0f 44 c1 31 c9 48 3d 50 a4 df 93 41 0f 45 c8 89 4c 24 10 <8b> 0d a6 aa 85 18 85 c9 0f 95 c0 83 fe 08 0f 92 c2 08 c2 0f 84 49
RSP: 0018:ffffc9000893f670 EFLAGS: 00000006
RAX: ffffffff9a438ee0 RBX: 0000000000000246 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881b7cdcc68
RBP: 0000000000000000 R08: 0000000000000001 R09: ffff8881b7cdcc68
R10: dffffc0000000000 R11: ffffed1036f9ba2c R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  000055556630f500(0000) GS:ffff8882a9463000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f574c9e92f8 CR3: 000000016b586000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0xf0/0x2e0
 _raw_spin_lock+0x2e/0x40
 f2fs_write_checkpoint+0xb3b/0x26a0
 kill_f2fs_super+0x314/0x720
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x437/0x4d0
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0xed/0x480
 do_syscall_64+0x32d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f028bb9d9d7
Code: a2 c7 05 1c fd 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 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 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffcdf89c388 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f028bb9d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcdf89c440
RBP: 00007ffcdf89c440 R08: 00007ffcdf89d440 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcdf89d4d0
R13: 00007f028bc32050 R14: 000000000001bed4 R15: 00007ffcdf89d510
 </TASK>
