INFO: task syz.7.714:10446 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.714       state:D stack:24040 pid:10446 tgid:10445 ppid:8504   task_flags:0x400140 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
 __iterate_supers+0x126/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7fd678ec29
RSP: 002b:00007f7fd757a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f7fd69d5fa0 RCX: 00007f7fd678ec29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f7fd69d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7fd69d6038 R14: 00007f7fd69d5fa0 R15: 00007ffdc557a2c8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by klogd/5287:
 #0: ffff888136639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
2 locks held by getty/5676:
 #0: ffff8880222730a0 (&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
3 locks held by syz-executor/6022:
2 locks held by syz-executor/7372:
1 lock held by syz.7.714/10446:
 #0: ffff88810ae5e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
3 locks held by syz.1.892/11716:

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 6022 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+0x72e/0xd20
Code: 3e 8b 9f e8 0a 00 00 48 85 db 0f 84 81 00 00 00 83 fb 31 0f 83 e0 05 00 00 48 8d 04 9b 45 8b 66 20 48 8b 4c 24 10 8b 44 c1 f8 <44> 31 e0 25 00 60 00 00 31 c9 89 c2 f7 da 48 19 c9 49 09 cf 85 c0
RSP: 0018:ffffc90004cdf790 EFLAGS: 00000087
RAX: 00000000000408af RBX: 0000000000000002 RCX: ffff888021916130
RDX: 0000000000000008 RSI: ffff888021916180 RDI: ffff888021915640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff840a310c
R10: dffffc0000000000 R11: ffffed1020c27939 R12: 00000000000408b6
R13: 0000000000000004 R14: ffff888021916180 R15: de4f3e632bce623e
FS:  0000555578ad9500(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000287000 CR3: 0000000027d5c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 down_write+0x96/0x1f0
 f2fs_write_checkpoint+0x51c/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: 0033:0x7f6b49b8ff57
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:00007ffe4dbbb0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f6b49c11c2d RCX: 00007f6b49b8ff57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe4dbbb180
RBP: 00007ffe4dbbb180 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe4dbbc210
R13: 00007f6b49c11c2d R14: 000000000001fb38 R15: 00007ffe4dbbc250
 </TASK>
