INFO: task syz.7.695:11609 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.695       state:D stack:17448 pid:11609 tgid:11608 ppid:10164  task_flags:0x400140 flags:0x00004006
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: 0033:0x7facfb38eba9
RSP: 002b:00007facfc196038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007facfb5d5fa0 RCX: 00007facfb38eba9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007facfb5d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007facfb5d6038 R14: 00007facfb5d5fa0 R15: 00007fff9b0262f8
 </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
2 locks held by getty/5682:
 #0: ffff8881096e40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by syz-executor/5853:
3 locks held by syz-executor/7611:
1 lock held by syz.7.695/11609:
 #0: ffff8881120ac0e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.1.818/12466:
 #0: ffff8881120ac0e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by kworker/u8:5/12647:
 #0: ffff888136639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffffc90004397bc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
1 lock held by syz.3.846/12672:
 #0: ffff8880330600e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.2.889/13319:
 #0: ffff8881120ac0e0 (&type->s_umount_key#52){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
1 lock held by syz.6.899/13370:

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

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+0x439/0x7d0
 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: 13370 Comm: syz.6.899 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:io_serial_in+0x77/0xc0
Code: e8 8e e5 6f fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 0f 83 d3 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 1a 94 2d 06 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90002ade638 EFLAGS: 00000006
RAX: 1ffffffff33bec05 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000033c7b RDI: 0000000000033c7c
RBP: ffffc90002ade810 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff854fd780 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff99df6440 R15: 0000000000000000
FS:  00007f52054586c0(0000) GS:ffff8880b8614000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f51fa23f000 CR3: 000000012ad1e000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0x584/0x1ba0
 console_flush_all+0x728/0xc40
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 _printk+0xcf/0x120
 submit_bio_noacct+0x109a/0x1a50
 __submit_merged_bio+0x27a/0x6a0
 __submit_merged_write_cond+0x255/0x530
 f2fs_write_data_pages+0x261d/0x3000
 do_writepages+0x32e/0x550
 filemap_write_and_wait_range+0x21f/0x320
 f2fs_file_write_iter+0x832/0x2410
 iter_file_splice_write+0x975/0x10e0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x5a8/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f520458eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5205458038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f52047d5fa0 RCX: 00007f520458eba9
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000006
RBP: 00007f5204611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020fffe82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52047d6038 R14: 00007f52047d5fa0 R15: 00007fffaf7dd2e8
 </TASK>
