INFO: task syz-executor:4321 blocked for more than 143 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:4321  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+0xdd0/0x1b0c kernel/sched/core.c:6562
 schedule+0xc4/0x170 kernel/sched/core.c:6638
 wb_wait_for_completion+0x150/0x29c fs/fs-writeback.c:191
 __writeback_inodes_sb_nr+0x1b4/0x224 fs/fs-writeback.c:2670
 writeback_inodes_sb_nr fs/fs-writeback.c:2687 [inline]
 writeback_inodes_sb+0x78/0x8c fs/fs-writeback.c:2702
 sync_filesystem+0xa0/0x218 fs/sync.c:54
 generic_shutdown_super+0x70/0x324 fs/super.c:474
 kill_block_super+0x70/0xdc fs/super.c:1470
 deactivate_locked_super+0xac/0x120 fs/super.c:332
 deactivate_super+0xe4/0x104 fs/super.c:363
 cleanup_mnt+0x390/0x418 fs/namespace.c:1191
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198
 task_work_run+0x1ec/0x278 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 do_notify_resume+0x1fa0/0x2aa4 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: ffff8000153e7c30 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xbb4 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffff8000153e8450 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x40/0xbb4 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffff8000153e72c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
1 lock held by udevd/3935:
2 locks held by getty/4078:
 #0: ffff0000d6d7c098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80001cfe62f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2ec/0xfa0 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4321:
 #0: ffff0000ca36e0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xdc/0x104 fs/super.c:362
2 locks held by kworker/u4:7/4647:
2 locks held by kworker/u4:12/7093:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x6b8/0x13a4 kernel/workqueue.c:2265
 #1: ffff800020cf7c20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x6fc/0x13a4 kernel/workqueue.c:2267
2 locks held by kworker/1:10/8004:
 #0: ffff0000c0021938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x6b8/0x13a4 kernel/workqueue.c:2265
 #1: ffff800021787c20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x6fc/0x13a4 kernel/workqueue.c:2267
2 locks held by kworker/u4:13/8086:
 #0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x6b8/0x13a4 kernel/workqueue.c:2265
 #1: ffff800021827c20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x6fc/0x13a4 kernel/workqueue.c:2267
2 locks held by syz.4.877/8248:
 #0: ffff80001787f188 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:74
 #1: ffff8000153ecf78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #1: ffff8000153ecf78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3fc/0x77c kernel/rcu/tree_exp.h:962

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