INFO: task syz.4.77:6481 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.77        state:D stack:24648 pid:6481  tgid:6480  ppid:6297   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x9a/0x270
 wait_for_completion+0x2bf/0x5d0
 f2fs_issue_checkpoint+0x376/0x570
 f2fs_do_sync_file+0x869/0x1860
 f2fs_file_write_iter+0x753/0x2410
 vfs_write+0x5c9/0xb30
 __x64_sys_pwrite64+0x193/0x220
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f55d0b8ebe9
RSP: 002b:00007f55d192a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f55d0dc5fa0 RCX: 00007f55d0b8ebe9
RDX: 000000000000fdef RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007f55d0c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000e7c R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55d0dc6038 R14: 00007f55d0dc5fa0 R15: 00007ffd86cb3448
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
 #0: ffff888107d8e948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
 #2: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0
3 locks held by kworker/1:0/24:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900001c7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u9:5/3956:
 #0: ffff88801b347148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000f647bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888110e4e0e0 (&type->s_umount_key#65){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
2 locks held by getty/5678:
 #0: ffff8880204940a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/0:3/5896:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003d4fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8880234e8240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x26b/0x3180
2 locks held by syz-executor/5992:
1 lock held by syz.4.77/6481:
 #0: ffff888110e4e428 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x211/0xb30
4 locks held by f2fs_ckpt-7:4/6498:
1 lock held by syz-executor/8455:
 #0: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
2 locks held by syz.9.302/8605:
 #0: ffff8881088f5358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
 #1: ffff888023446110 (&cd->lock){+.+.}-{4:4}, at: sr_block_open+0xea/0x170
1 lock held by syz.1.301/8611:

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 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: 8611 Comm: syz.1.301 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:debug_check_no_obj_freed+0x212/0x470
Code: c0 0f 84 45 02 00 00 4d 89 fe 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df 41 80 3c 06 00 74 08 4c 89 ff e8 71 c3 52 fd 49 8b 07 <48> 89 44 24 18 4d 8d 67 18 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00
RSP: 0018:ffffc9000344f898 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: dffffc0000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9000344f780
RBP: ffff8880205e9f08 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000689ef0 R12: ffff888020ebdbe8
R13: ffffc90030807000 R14: 1ffff110041d7b81 R15: ffff888020ebdc08
FS:  00007f279084c6c0(0000) GS:ffff8881a3c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fa0b02ca18 CR3: 0000000111094000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 remove_vm_area+0x1d3/0x300
 vfree+0x63/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 irqentry_exit_to_user_mode+0x81/0x120
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0033:0x7f278f850c38
Code: Unable to access opcode bytes at 0x7f278f850c0e.
RSP: 002b:00007f279084b4a0 EFLAGS: 00000202
RAX: 000000000020f8be RBX: 00007f279084b540 RCX: 0000000000000073
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f279084b5e0
RBP: 0000000000000102 R08: 00007f2785600000 R09: 0000000000000000
R10: 0000000000000000 R11: 00007f279084b550 R12: 0000000000000001
R13: 00007f278fa2da20 R14: 0000000000000000 R15: 00007f279084b5e0
 </TASK>
