INFO: task syz.0.476:9949 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.476       state:D stack:28480 pid:9949  tgid:9946  ppid:9593   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: 0033:0x7f704a99c799
RSP: 002b:00007f704b80e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f704ac16090 RCX: 00007f704a99c799
RDX: 0000000000000000 RSI: 0000200000002c40 RDI: ffffffff80000802
RBP: 00007f704aa32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000002c80 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f704ac16128 R14: 00007f704ac16090 R15: 00007fffb97c8538
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/9:
 #0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc900000e7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffff888101b51240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
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/5634:
 #0: ffff88811221e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900035762f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
3 locks held by syz-executor/5812:
2 locks held by syz-executor/6133:
3 locks held by syz-executor/8842:
1 lock held by syz.0.476/9949:
 #0: ffff88811061a0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.3.559/10612:
 #0: ffff8881112a80e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.9.723/11980:
 #0: ffff88811061a0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.1.737/12072:
 #0: ffff8881a92940e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by udevd/12078:
 #0: ffff88816b8dd358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by syz.2.740/12168:
 #0: ffff88811061a0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/12182:
1 lock held by syz.0.771/12515:
 #0: ffff88811061a0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x289/0x3d0
3 locks held by syz.3.812/12842:
4 locks held by syz.5.813/12908:
3 locks held by dhcpcd-run-hook/12921:

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

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: 12908 Comm: syz.5.813 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:wq_watchdog_touch+0x27/0x160
Code: 90 90 90 0f 1f 40 d6 55 41 57 41 56 41 55 41 54 53 89 fb 49 bf 00 00 00 00 00 fc ff df e8 a1 30 37 00 4c 6b 25 d9 56 d1 0c 64 <4c> 8b 2d f2 56 d1 0c 48 c7 c0 80 12 41 8e 48 c1 e8 03 42 80 3c 38
RSP: 0018:ffffc90005f16de8 EFLAGS: 00000002
RAX: ffffffff818e703f RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc90026842000 RSI: 000000000003b888 RDI: 000000000003b889
RBP: ffffc90005f16f90 R08: ffffffff81a4a983 R09: ffffffff8e750a80
R10: dffffc0000000000 R11: ffffffff853f6d50 R12: 00000000000036b0
R13: dffffc0000000000 R14: ffffffff9a5cebb8 R15: dffffc0000000000
FS:  00007f5afb46c6c0(0000) GS:ffff88818de60000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005617d0118950 CR3: 000000011a170000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0xc3/0x1ba0
 console_flush_all+0x718/0xb20
 console_unlock+0xd1/0x1c0
 vprintk_emit+0x485/0x560
 _printk+0xdd/0x130
 f2fs_printk+0x48a/0x520
 f2fs_recover_fsync_data+0x2c3/0x8b80
 f2fs_fill_super+0x64b5/0x7740
 get_tree_bdev_flags+0x431/0x4f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x341/0xd30
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5afa59da0a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5afb46be58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5afb46bee0 RCX: 00007f5afa59da0a
RDX: 0000200000000140 RSI: 00002000000000c0 RDI: 00007f5afb46bea0
RBP: 0000200000000140 R08: 00007f5afb46bee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000c0
R13: 00007f5afb46bea0 R14: 0000000000005512 R15: 00002000000004c0
 </TASK>
