INFO: task kworker/u10:1:36 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:1   state:D stack:20840 pid:36    tgid:36    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:8)
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x87d/0x1080
 down_write+0x1bc/0x200
 f2fs_down_write_trace+0x34/0x1f0
 f2fs_issue_checkpoint+0x414/0x6f0
 f2fs_balance_fs_bg+0x573/0x990
 f2fs_write_node_pages+0x158/0x700
 do_writepages+0x338/0x560
 __writeback_single_inode+0x12e/0xf90
 writeback_sb_inodes+0x9de/0x1b00
 __writeback_inodes_wb+0x114/0x240
 wb_writeback+0x42f/0xad0
 wb_workfn+0xc92/0x10f0
 process_scheduled_works+0xa8e/0x14e0
 worker_thread+0xa47/0xfb0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e959c20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/u10:1/36:
 #0: ffff88816268f940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #1: ffffc90000ac7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0
 #2: ffff8881053920d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
 #3: ffff8881141ed4b8 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write_trace+0x34/0x1f0
2 locks held by getty/5437:
 #0: ffff8881741f20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034762e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360
4 locks held by syz-executor/17181:
4 locks held by syz.8.1194/17541:
1 lock held by syz.8.1424/20002:
 #0: ffff8881053920d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x289/0x3d0
1 lock held by syz.0.1433/20051:
 #0: ffff8881094380d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.1499/20847:
 #0: ffff8881094380d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.5.1576/21632:
 #0: ffff8881094380d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.8.1639/22118:
 #0: ffff8881053920d8 (&type->s_umount_key#62){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.6.1648/22164:
2 locks held by syz.6.1648/22170:
1 lock held by syz.7.1650/22167:
 #0: ffffffff8e95ff28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770
1 lock held by syz.7.1650/22169:

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

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/0x380
 sys_info+0x135/0x170
 watchdog+0xfd7/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 1112 Comm: kworker/u10:4 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: events_unbound nsim_dev_trap_report_work
RIP: 0010:do_raw_spin_lock+0x138/0x2f0
Code: df be 04 00 00 00 49 89 d6 e8 64 33 91 00 48 8d 7c 24 40 be 04 00 00 00 e8 55 33 91 00 8b 44 24 40 b9 01 00 00 00 f0 0f b1 0b <0f> 85 20 01 00 00 43 c6 44 34 04 f8 65 8b 1d a9 da 9c 11 43 0f b6
RSP: 0000:ffffc90006f977a0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff9a76e830 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90006f977e0
RBP: ffffc90006f97850 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000df2efc R12: 1ffff92000df2ef8
R13: ffffffff9a76e838 R14: dffffc0000000000 R15: 1ffffffff34edd07
FS:  0000000000000000(0000) GS:ffff8882a9226000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe5ecbdf000 CR3: 000000011e71c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _raw_spin_lock_irqsave+0x4c/0x60
 debug_check_no_obj_freed+0xcb/0x450
 kfree+0x13e/0x640
 skb_release_data+0x85e/0xab0
 __kfree_skb+0x5d/0x210
 nsim_dev_trap_report_work+0x7ac/0xb40
 process_scheduled_works+0xa8e/0x14e0
 worker_thread+0xa47/0xfb0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
