INFO: task syz.3.34:6123 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.34        state:D stack:24960 pid:6123  tgid:6122  ppid:5944   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x61e/0x920
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 __iterate_supers+0x126/0x290
 __se_sys_quotactl+0x3a7/0x9e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcfa079c799
RSP: 002b:00007fcfa16bd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fcfa0a15fa0 RCX: 00007fcfa079c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100
RBP: 00007fcfa0832c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcfa0a16038 R14: 00007fcfa0a15fa0 R15: 00007fff830b7c08
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e3e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5632:
 #0: ffff88810ccd30a0 (&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/5805:
1 lock held by syz.3.34/6123:
 #0: ffff8881749ca0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.301/8124:
 #0: ffff8881749ca0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.301/8125:
 #0: 
ffff8881749ca0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/9347:
 #0: ffffffff8e764678 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz.3.503/9541:
 #0: ffff8881749ca0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.3.503/9543:
 #0: ffff8881749ca0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by dhcpcd/9620:
 #0: ffff88816e888260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10

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

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: 9347 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:io_serial_out+0x7c/0xc0
Code: d9 84 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cc 22 ef fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 c7 78 70 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9002a55e5d0 EFLAGS: 00000006
RAX: 0000000000000005 RBX: 0000000000000005 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f9 R08: ffff8881036f8237 R09: 1ffff110206df046
R10: dffffc0000000000 R11: ffffffff8540cf50 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff9a5cf9e0 R15: 0000000000000000
FS:  000055555b37c500(0000) GS:ffff8882a945f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff42269448 CR3: 0000000115166000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0x108f/0x1ba0
 console_flush_all+0x718/0xb20
 console_unlock+0xd1/0x1c0
 vprintk_emit+0x485/0x560
 _printk+0xdd/0x130
 f2fs_printk+0x48a/0x520
 f2fs_write_end_io+0xcdb/0xff0
 __submit_merged_bio+0x256/0x700
 __submit_merged_write_cond+0x3c9/0x4e0
 f2fs_write_data_pages+0x2975/0x35e0
 do_writepages+0x32e/0x550
 filemap_fdatawrite+0x1e9/0x2f0
 f2fs_sync_dirty_inodes+0x30e/0x860
 f2fs_write_checkpoint+0x9df/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: 0033:0x7f2ec959d9d7
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:00007ffc4e840738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f2ec9632050 RCX: 00007f2ec959d9d7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc4e8407f0
RBP: 00007ffc4e8407f0 R08: 00007ffc4e8417f0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc4e841880
R13: 00007f2ec9632050 R14: 000000000003b115 R15: 00007ffc4e8418c0
 </TASK>
