INFO: task syz.4.1382:15133 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1382      state:D stack:24960 pid:15133 tgid:15130 ppid:13223  task_flags:0x400040 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
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x540/0x9e0
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74c899c799
RSP: 002b:00007f74c97c9028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f74c8c15fa0 RCX: 00007f74c899c799
RDX: 0000000000000000 RSI: 0000200000002540 RDI: ffffffff80000900
RBP: 00007f74c8a32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74c8c16038 R14: 00007f74c8c15fa0 R15: 00007fff7cfadfc8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5637:
 #0: ffff88817311a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
2 locks held by syz-executor/6690:
3 locks held by kworker/1:8/11496:
 #0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc900078afc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffff8881744c2240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
1 lock held by syz.4.1382/15133:
 #0: ffff8881bc6500e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.7.1466/15361:
 #0: ffff8881bc6500e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.3.1578/16065:
 #0: ffff8881bc6500e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/18473:
1 lock held by syz.5.2117/18649:
 #0: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
2 locks held by dhcpcd/18670:
 #0: ffff8881ad2aa260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10
 #1: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770

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

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+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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 164 Comm: kworker/u9:5 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
Workqueue: writeback wb_workfn (flush-7:9)
RIP: 0010:serial8250_console_write+0x532/0x1ba0
Code: 8d 5f 50 48 89 d8 48 c1 e8 03 48 89 84 24 80 00 00 00 42 80 3c 28 00 74 08 48 89 df e8 77 76 ef fc 48 89 5c 24 78 4d 8b 5f 50 <4c> 89 ff be 01 00 00 00 2e e8 70 b6 70 06 89 44 24 2c 49 8d 8f a8
RSP: 0018:ffffc90003406560 EFLAGS: 00000046
RAX: 1ffffffff34b9d22 RBX: ffffffff9a5ce910 RCX: ffff888105300000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900034066d0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85409fc0 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff9a5cea00 R15: ffffffff9a5ce8c0
FS:  0000000000000000(0000) GS:ffff88818de60000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557444fe5950 CR3: 0000000171810000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 console_flush_all+0x718/0xb20
 console_unlock+0xd1/0x1c0
 vprintk_emit+0x485/0x560
 _printk+0xdd/0x130
 submit_bio_noacct+0x12b6/0x1c20
 __submit_merged_bio+0x256/0x700
 __submit_merged_write_cond+0x3c9/0x4e0
 f2fs_write_data_pages+0x2975/0x35e0
 do_writepages+0x32e/0x550
 __writeback_single_inode+0x133/0x11a0
 writeback_sb_inodes+0x992/0x1a20
 wb_writeback+0x456/0xb70
 wb_workfn+0x414/0xf50
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
