INFO: task kworker/u9:5:7425 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:5    state:D stack:20136 pid:7425  tgid:7425  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:6)
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x883/0x1080
 down_write+0x1bc/0x200
 f2fs_down_write_trace+0x3e/0x1d0
 f2fs_balance_fs+0x60e/0x840
 f2fs_write_inode+0x3fb/0x5f0
 __writeback_single_inode+0x75a/0x10e0
 writeback_sb_inodes+0x979/0x19d0
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x459/0xb00
 wb_workfn+0xb12/0xf10
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 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: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
6 locks held by kworker/u10:4/81:
1 lock held by udevd/5058:
2 locks held by getty/5437:
 #0: ffff88816f0650a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
4 locks held by kworker/u9:5/7425:
 #0: ffff8881626cf940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004bcfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff8881ae9e60d8 (&type->s_umount_key#55){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
 #3: ffff88811dfa94b8 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write_trace+0x3e/0x1d0
5 locks held by syz.6.1392/16749:
1 lock held by syz.3.1827/20696:
2 locks held by syz.1.1829/20704:

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

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+0xfd3/0x1030
 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: 20704 Comm: syz.1.1829 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:__sanitizer_cov_trace_pc+0x0/0x70
Code: 89 fb e8 23 00 00 00 48 8b 3d 44 9e 60 0c 48 89 de 5b e9 e3 ec 5f 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0d 28 6e 73 11 65 8b 15 49 6e 73
RSP: 0018:ffffc90008de7338 EFLAGS: 00000246
RAX: ffffffff821634d6 RBX: 00000000000133d7 RCX: ffff88810cc28000
RDX: 0000000000000002 RSI: 00000000000133d7 RDI: 00000000000133d7
RBP: 00000000000133d7 R08: ffff888100d0337f R09: 1ffff110201a066f
R10: dffffc0000000000 R11: ffffed10201a0670 R12: 000000fffffffe00
R13: ffff8881ad448180 R14: 00080000000133d7 R15: 80000000133d7225
FS:  00007eff222b66c0(0000) GS:ffff8882a928d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007eff17fff000 CR3: 000000016f78a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 vm_normal_page+0x220/0x280
 __zap_vma_range+0x1098/0x4b40
 unmap_vmas+0x379/0x530
 unmap_region+0x208/0x330
 vms_complete_munmap_vmas+0x493/0xc60
 do_vmi_align_munmap+0x3b7/0x4b0
 do_vmi_munmap+0x252/0x2d0
 __vm_munmap+0x22c/0x3d0
 __x64_sys_munmap+0x60/0x70
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7eff2139cc87
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 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:00007eff222b5e08 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007eff2139cc87
RDX: 0000000001000000 RSI: 0000000008400000 RDI: 00007eff17000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 00007eff222b5ee0 R14: 00007eff222b5ea0 R15: 00007eff17000000
 </TASK>
