INFO: task kworker/u9:6:3642 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:6    state:D stack:19752 pid:3642  tgid:3642  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x872/0xfe0
 down_write+0x1ab/0x1f0
 f2fs_balance_fs+0x5ab/0x7f0
 f2fs_write_inode+0x3fb/0x5f0
 __writeback_single_inode+0x6f1/0xff0
 writeback_sb_inodes+0x6c7/0x1010
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x44f/0xaf0
 wb_workfn+0xaef/0xef0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
1 lock held by ksoftirqd/1/23:
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/u9:3/135:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900025ffbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
4 locks held by kworker/u9:6/3642:
 #0: ffff88801b37e148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90001c2fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8881104fc0e0 (&type->s_umount_key#94){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
 #3: ffff888012689410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x5ab/0x7f0
2 locks held by getty/5676:
 #0: ffff88810ccd20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
6 locks held by syz.3.1147/11410:
2 locks held by syz.0.1963/14957:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0
 #1: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

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

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: 11410 Comm: syz.3.1147 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:__lock_acquire+0x899/0xd20
Code: 00 0f 85 36 02 00 00 48 83 7c 24 28 00 0f 84 bc 01 00 00 41 8b 46 f8 25 ff 1f 00 00 48 0f a3 05 1d da 0a 12 0f 83 5a 01 00 00 <48> 69 c0 c8 00 00 00 48 8d 80 10 43 49 93 e9 87 01 00 00 e8 8f 4b
RSP: 0018:ffffc900033ee1c8 EFLAGS: 00000003
RAX: 00000000000010a4 RBX: 0000000000000006 RCX: 000000009d80ac4d
RDX: 00000000b296174e RSI: 00000000d73bac40 RDI: ffff888106a33980
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8172c195
R10: ffffc900033ee418 R11: ffffffff81ac3aa0 R12: 000000007c2929ae
R13: ffff888106a34470 R14: ffff888106a34560 R15: 293723cf9d80ac4d
FS:  00007fde2314b6c0(0000) GS:ffff8881a3c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8d5a1ffe00 CR3: 000000012554c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 kmem_cache_free+0x309/0x400
 f2fs_read_end_io+0x360/0x980
 f2fs_submit_page_read+0x116/0x190
 f2fs_get_read_data_folio+0x4a4/0x7d0
 f2fs_get_lock_data_folio+0x54/0x1f0
 do_garbage_collect+0x3061/0x6410
 f2fs_gc+0xc87/0x2590
 f2fs_balance_fs+0x5f7/0x7f0
 f2fs_map_blocks+0x345f/0x4130
 f2fs_expand_inode_data+0x5af/0xa60
 f2fs_fallocate+0x4f5/0x990
 vfs_fallocate+0x669/0x7e0
 file_ioctl+0x611/0x780
 do_vfs_ioctl+0xb33/0x1430
 __se_sys_ioctl+0x82/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fde2238ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fde2314b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fde225c6090 RCX: 00007fde2238ebe9
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 000000000000000d
RBP: 00007fde22411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fde225c6128 R14: 00007fde225c6090 R15: 00007ffe02e1bfb8
 </TASK>
