INFO: task syz-executor:6242 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:6242  ppid:1      flags:0x00000009
Call trace:
 __switch_to+0x2f4/0x550 arch/arm64/kernel/process.c:555
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0xdb4/0x1a6c kernel/sched/core.c:6562
 schedule+0xc4/0x170 kernel/sched/core.c:6638
 wb_wait_for_completion+0x158/0x29c fs/fs-writeback.c:191
 sync_inodes_sb+0x188/0x81c fs/fs-writeback.c:2756
 sync_filesystem+0x160/0x218 fs/sync.c:64
 generic_shutdown_super+0x74/0x32c fs/super.c:474
 kill_block_super+0x78/0xe0 fs/super.c:1470
 deactivate_locked_super+0xb4/0x128 fs/super.c:332
 deactivate_super+0xe4/0x104 fs/super.c:363
 cleanup_mnt+0x3a8/0x430 fs/namespace.c:1191
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198
 task_work_run+0x1f4/0x280 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
 el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffff800015507db0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xc48 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffff8000155085d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xc48 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffff800015507440 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
2 locks held by getty/4082:
 #0: ffff0000c0936098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001f9b62f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2e8/0xfa8 drivers/tty/n_tty.c:2198
4 locks held by kworker/u4:18/4787:
2 locks held by syz-executor/6242:
 #0: ffff0000d2aa80e0 (&type->s_umount_key#30){++++}-{3:3}, at: deactivate_super+0xdc/0x104 fs/super.c:362
 #1: ffff0000ced9c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff0000ced9c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x170/0x81c fs/fs-writeback.c:2754
3 locks held by syz-executor/6800:
 #0: ffff0000d2c3c460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402
 #1: ffff0000fac76de0 (&type->i_mutex_dir_key#5/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
 #1: ffff0000fac76de0 (&type->i_mutex_dir_key#5/1){+.+.}-{3:3}, at: do_unlinkat+0x184/0x504 fs/namei.c:4381
 #2: ffff80001c7a5520 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x80/0x4c0 lib/debugobjects.c:698
2 locks held by syz.1.1325/9437:
2 locks held by syz.8.1348/9500:
1 lock held by syz.7.1349/9503:
1 lock held by syz.5.1351/9508:
1 lock held by syz.4.1352/9509:
 #0: ffff80001550d0f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #0: ffff80001550d0f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3f8/0x780 kernel/rcu/tree_exp.h:962
3 locks held by syz.8.1350/9512:

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