INFO: task kworker/u4:0:12 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc6-syzkaller-00205-g3571e8b091f4 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0    state:D stack:18320 pid:12    tgid:12    ppid:2      task_flags:0x4208160 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578
 f2fs_down_write fs/f2fs/f2fs.h:2191 [inline]
 f2fs_balance_fs+0x5a9/0x810 fs/f2fs/segment.c:454
 f2fs_write_inode+0x3a7/0x540 fs/f2fs/inode.c:803
 write_inode fs/fs-writeback.c:1525 [inline]
 __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745
 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047
 wb_writeback+0x427/0xb80 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+0xb94/0x1080 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u4:0/12:
 #0: ffff888030bf6148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888030bf6148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc900001e7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900001e7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffff88801295c0e0 (&type->s_umount_key#42){.+.+}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562
 #3: ffff888040481350 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2191 [inline]
 #3: ffff888040481350 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x5a9/0x810 fs/f2fs/segment.c:454
1 lock held by khungtaskd/27:
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by getty/5112:
 #0: ffff88801bf210a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000019b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
6 locks held by syz-executor242/5337:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 27 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00205-g3571e8b091f4 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>