INFO: task syz-executor:4705 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:4705  tgid:4705  ppid:4701   task_flags:0x400140 flags:0x00800010
Call trace:
 __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T)
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1c04/0x2db8 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x13c/0x20c kernel/sched/core.c:7283
 wb_wait_for_completion+0x15c/0x210 fs/fs-writeback.c:227
 __writeback_inodes_sb_nr+0x1d0/0x23c fs/fs-writeback.c:2847
 writeback_inodes_sb_nr fs/fs-writeback.c:2864 [inline]
 writeback_inodes_sb+0x78/0x8c fs/fs-writeback.c:2879
 sync_filesystem+0xa0/0x210 fs/sync.c:54
 generic_shutdown_super+0x7c/0x2c0 fs/super.c:625
 kill_block_super+0x48/0x94 fs/super.c:1725
 ext4_kill_sb+0x68/0xa4 fs/ext4/super.c:7492
 deactivate_locked_super+0xcc/0x148 fs/super.c:476
 deactivate_super+0xd8/0xf8 fs/super.c:509
 cleanup_mnt+0x318/0x3a8 fs/namespace.c:1312
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1319
 task_work_run+0x1cc/0x25c kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x10c/0x17c kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 arm64_syscall_exit_to_user_mode arch/arm64/kernel/entry-common.c:88 [inline]
 el0_svc+0x18c/0x260 arch/arm64/kernel/entry-common.c:737
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594

Showing all locks held in the system:
2 locks held by kworker/0:0/9:
3 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/15:
4 locks held by kworker/1:1/26:
 #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3397
 #1: ffff80008ec37c40 (reg_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #1: ffff80008ec37c40 (reg_work){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3397
 #2: ffff800089cca300 (rtnl_mutex