INFO: task syz.1.808:10876 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.808       state:D stack:25256 pid:10876 tgid:10875 ppid:10458  task_flags:0x400040 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: 0033:0x7f584a78ebe9
RSP: 002b:00007f584b6d0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f584a9b5fa0 RCX: 00007f584a78ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffff80000402
RBP: 00007f584a811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f584a9b6038 R14: 00007f584a9b5fa0 R15: 00007ffcf02c9f68
 </TASK>
INFO: lockdep is turned off.
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: 6215 Comm: syz.1.42 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:check_preemption_disabled+0x6/0x120
Code: c7 c6 60 36 e3 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 <48> 83 ec 10 65 48 8b 05 be be 26 07 48 89 44 24 08 65 8b 05 c6 be
RSP: 0018:ffffc90004eaf1f8 EFLAGS: 00000283
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8be33660 RDI: ffffffff8be33620
RBP: ffffffff8241f985 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f47067 R12: 0000000000000000
R13: ffff88803a039b80 R14: 0000000000000000 R15: 0000000000000001
FS:  00007fcefcc616c0(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f17f8887e20 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 rcu_is_watching+0x15/0xb0
 lock_acquire+0x5f/0x360
 _raw_spin_lock+0x2e/0x40
 writeback_single_inode+0x205/0x6a0
 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
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcefbdc14a5
Code: Unable to access opcode bytes at 0x7fcefbdc147b.
RSP: 002b:00007fcefcc60f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fcefbfb5fa0 RCX: 00007fcefbdc14a5
RDX: 00007fcefcc60fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fcefbe11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007fcefbfb6038 R14: 00007fcefbfb5fa0 R15: 00007ffd7e8dc2f8
 </TASK>
