INFO: task syz.7.3532:29973 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.3532      state:D stack:22584 pid:29973 tgid:29970 ppid:29052  task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 super_lock+0x25c/0x3b0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x4da/0x950
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa2aa18ebe9
RSP: 002b:00007fa2ab013038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fa2aa3c5fa0 RCX: 00007fa2aa18ebe9
RDX: 000000000000ee01 RSI: 0000200000000040 RDI: ffffffff80000302
RBP: 00007fa2aa211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa2aa3c6038 R14: 00007fa2aa3c5fa0 R15: 00007ffefee5c158
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5676:
 #0: ffff88810d19a0a0 (&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
4 locks held by syz-executor/25191:
1 lock held by syz.7.3532/29973:
 #0: ffff88802ccf80e0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x25c/0x3b0
1 lock held by syz.2.3872/32222:
 #0: ffff88802ccf80e0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.5.3894/32404:
2 locks held by syz.3.3895/32406:

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

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+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 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: 25191 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+0x334/0xd20
Code: 09 d5 09 cd 44 09 f5 41 89 6c c7 20 45 89 44 c7 24 4c 89 7c 24 10 4d 8d 34 c7 81 e5 ff 1f 00 00 48 0f a3 2d 3e 0f 0b 12 73 10 <48> 69 c5 c8 00 00 00 48 8d 80 10 73 49 93 eb 40 83 3d a5 9e 0e 18
RSP: 0018:ffffc900035e7590 EFLAGS: 00000003
RAX: 000000000000000f RBX: ffff88802b77e340 RCX: 0000000000000910
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88804aacb980
RBP: 0000000000000910 R08: 0000000000000000 R09: ffffffff824207c8
R10: dffffc0000000000 R11: fffff520006bcebc R12: 0000000000000000
R13: 0000000000000000 R14: ffff88804aacc4e8 R15: ffff88804aacc470
FS:  000055557a681500(0000) GS:ffff8880b8615000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b5fb733e0 CR3: 000000001bf46000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 _raw_spin_lock+0x2e/0x40
 writeback_single_inode+0x218/0x6a0
 sync_inode_metadata+0xb9/0x110
 f2fs_write_checkpoint+0xb06/0x1df0
 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: 0033:0x7fad5c98ff17
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:00007fffe0c42f28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fad5ca11c05 RCX: 00007fad5c98ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffe0c42fe0
RBP: 00007fffe0c42fe0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffe0c44070
R13: 00007fad5ca11c05 R14: 00000000000f39d5 R15: 00007fffe0c440b0
 </TASK>
