INFO: task kworker/u8:5:1137 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5    state:D stack:23080 pid:1137  tgid:1137  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5401 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6790
 __schedule_loop kernel/sched/core.c:6868 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6883
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6940
 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
 f2fs_down_write fs/f2fs/f2fs.h:2229 [inline]
 f2fs_balance_fs+0x558/0x750 fs/f2fs/segment.c:463
 f2fs_write_inode+0x3fb/0x5f0 fs/f2fs/inode.c:819
 write_inode fs/fs-writeback.c:1525 [inline]
 __writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745
 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
 wb_do_writeback fs/fs-writeback.c:2315 [inline]
 wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
4 locks held by kworker/u8:5/1137:
 #0: ffff88801dab0948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801dab0948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc90003ddfbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90003ddfbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffff888031e940e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
 #3: ffff888020ba5410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2229 [inline]
 #3: ffff888020ba5410 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x558/0x750 fs/f2fs/segment.c:463
2 locks held by getty/5596:
 #0: ffff88803533a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by syz.0.21/6102:
2 locks held by syz-executor/6276:
 #0: ffffffff8e87e368 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline]
 #0: ffffffff8e87e368 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1758
 #1: ffffffff8e144840 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786
1 lock held by syz-executor/7245:
 #0: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
 #0: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998
1 lock held by syz.0.299/8813:
 #0: ffff888031e940e0 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888031e940e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x25c/0x3b0 fs/super.c:121
1 lock held by syz.0.299/8864:
 #0: ffff888031e940e0 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888031e940e0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x25c/0x3b0 fs/super.c:121
2 locks held by syz.2.306/8881:
2 locks held by dhcpcd-run-hook/8889:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5822 Comm: syz-executor Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:dequeue_entity+0xacb/0x1690 kernel/sched/fair.c:5535
Code: b0 01 00 00 4c 89 e8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ef e8 a6 7f 8d 00 4d 89 75 00 89 d8 48 83 c4 58 5b 41 5c 41 5d 41 5e <41> 5f 5d c3 cc cc cc cc cc 49 89 df eb 0c 4d 8b 3f 4d 85 ff 0f 84
RSP: 0018:ffffc9000412f848 EFLAGS: 00000086
RAX: 0000000033deda01 RBX: 0000000000000009 RCX: 0000000000000009
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888033deda80
RBP: dffffc0000000000 R08: ffffffff8fa0bbf7 R09: 1ffffffff1f4177e
R10: dffffc0000000000 R11: fffffbfff1f4177f R12: ffff888033deda80
R13: 1ffff110170e73db R14: ffff888033deda00 R15: ffff8880b8739ed0
FS:  000055556190a500(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556071c5c8 CR3: 000000007b4fa000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 dequeue_entities+0x1fa/0x1510 kernel/sched/fair.c:7094
 dequeue_task_fair+0x205/0x580 kernel/sched/fair.c:7193
 block_task kernel/sched/core.c:2149 [inline]
 try_to_block_task kernel/sched/core.c:6623 [inline]
 __schedule+0x5a7/0x4cb0 kernel/sched/core.c:6739
 __schedule_loop kernel/sched/core.c:6868 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6883
 do_nanosleep+0x1c7/0x600 kernel/time/hrtimer.c:2100
 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2147
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1399 [inline]
 __se_sys_clock_nanosleep+0x2ee/0x380 kernel/time/posix-timers.c:1376
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd8e9fc11a3
Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d 9e 53 1c 00 00 74 14 b8 e6 00 00 00 0f 05 <f7> d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007fff692842c8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd8e9fc11a3
RDX: 00007fff692842e0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 000000000c52de23 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff69284730
R13: 0000000000000004 R14: 00007fff6928431c R15: 00007fff692843b0
 </TASK>