INFO: task kworker/u4:5:4337 blocked for more than 143 seconds.
      Not tainted 6.1.53-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:5    state:D stack:0     pid:4337  ppid:2      flags:0x00000008
Workqueue: writeback wb_workfn (flush-7:1)
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xee4/0x1c98 kernel/sched/core.c:6554
 schedule+0xc4/0x170 kernel/sched/core.c:6630
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6689
 __mutex_lock_common+0xbd8/0x21a0 kernel/locking/mutex.c:679
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 exfat_write_inode+0x70/0x114 fs/exfat/inode.c:94
 write_inode fs/fs-writeback.c:1443 [inline]
 __writeback_single_inode+0x614/0x1770 fs/fs-writeback.c:1655
 writeback_sb_inodes+0x978/0x16c0 fs/fs-writeback.c:1881
 __writeback_inodes_wb+0x110/0x39c fs/fs-writeback.c:1952
 wb_writeback+0x428/0x1130 fs/fs-writeback.c:2057
 wb_check_background_flush fs/fs-writeback.c:2123 [inline]
 wb_do_writeback fs/fs-writeback.c:2211 [inline]
 wb_workfn+0xc98/0x1034 fs/fs-writeback.c:2238
 process_one_work+0x7ac/0x1404 kernel/workqueue.c:2292
 worker_thread+0x8e4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015a84ef0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffff800015a856f0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffff800015a84d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:305
2 locks held by getty/3984:
 #0: ffff0000d7a58098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001bd202f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1214 drivers/tty/n_tty.c:2188
1 lock held by syz-fuzzer/4220:
2 locks held by syz-fuzzer/15930:
1 lock held by syz-executor.5/4257:
 #0: ffff800015a8a2f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
 #0: ffff800015a8a2f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3e0/0x768 kernel/rcu/tree_exp.h:950
2 locks held by kworker/0:4/4314:
 #0: ffff0000c0021d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: ffff80001e437c20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
4 locks held by kworker/u4:5/4337:
 #0: ffff0000c2e3d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: ffff80001e567c20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
 #2: ffff000131b380e0 (&type->s_umount_key#86){++++}-{3:3}, at: trylock_super+0x28/0xf8 fs/super.c:415
 #3: ffff0001285160e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_write_inode+0x70/0x114 fs/exfat/inode.c:94
5 locks held by syz-executor.1/14513:
2 locks held by syz-executor.0/17673:
2 locks held by syz-executor.2/17675:

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