INFO: task syz-executor:6552 blocked for more than 148 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:6552  tgid:6552  ppid:1      task_flags:0x400140 flags:0x00000011
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x13b0/0x2864 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:7026
 wb_wait_for_completion+0x150/0x280 fs/fs-writeback.c:216
 __writeback_inodes_sb_nr+0x1b0/0x218 fs/fs-writeback.c:2787
 writeback_inodes_sb_nr fs/fs-writeback.c:2804 [inline]
 writeback_inodes_sb+0x78/0x8c fs/fs-writeback.c:2819
 sync_filesystem+0xa0/0x218 fs/sync.c:54
 generic_shutdown_super+0x70/0x2b8 fs/super.c:621
 kill_anon_super+0x4c/0x7c fs/super.c:1281
 btrfs_kill_super+0x40/0x58 fs/btrfs/super.c:2134
 deactivate_locked_super+0xc4/0x12c fs/super.c:473
 deactivate_super+0xe0/0x100 fs/super.c:506
 cleanup_mnt+0x31c/0x3ac fs/namespace.c:1327
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1334
 task_work_run+0x1dc/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xfc/0x178 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:103 [inline]
 el0_svc+0x170/0x254 arch/arm64/kernel/entry-common.c:747
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:765
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Showing all locks held in the system:
1 lock held by kthreadd/2:
3 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/15:
2 locks held by kworker/1:1/26:
1 lock held by khungtaskd/32:
 #0: ffff80008f76b5a0 (rcu_read_lock
){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
2 locks held by kworker/R-write/34:
3 locks held by kworker/u8:2/41:
3 locks held by kworker/u8:3/42:
3 locks held by kworker/u8:4/353:
3 locks held by kworker/u8:5/2013:
3 locks held by kworker/u8:6/2088:
3 locks held by kworker/u8:7/2115:
2 locks held by kworker/u8:8/2152:
 #0: ffff0000c0031148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x63c/0x155c kernel/workqueue.c:3237
 #1: ffff8000a1127be0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x6d4/0x155c kernel/workqueue.c:3237
3 locks held by kworker/R-ipv6_/4236:
 #0: ffff0000d3b3e948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x63c/0x155c kernel/workqueue.c:3237
 #1: ffff8000a0ca7bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6d4/0x155c kernel/workqueue.c:3237
 #2: ffff8000928570a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
4 locks held by kworker/R-bat_e/4312:
1 lock held by jbd2/nvme0n1p2-/6157:
1 lock held by klogd/6181:
1 lock held by dhcpcd/6246:
3 locks held by dhcpcd/6247:
1 lock held by crond/6321:
2 locks held by getty/6336:
 #0: ffff0000d3a0b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009bb2b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfa4 drivers/tty/n_tty.c:2222
1 lock held by udevd/6542:
2 locks held by syz-executor/6550:
1 lock held by syz-executor/6551:
1 lock held by syz-executor/6552:
 #0: ffff0000dc6280e0
 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd8/0x100 fs/super.c:505
3 locks held by syz-executor/6558:
1 lock held by syz-executor/6561:
4 locks held by kworker/0:4/6597:
 #0: ffff0000c0029948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x63c/0x155c kernel/workqueue.c:3237
 #1: ffff8000a4427be0 (reg_work){+.+.}-{0:0}, at: process_one_work+0x6d4/0x155c kernel/workqueue.c:3237
 #2: ffff8000928570a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
 #3: ffff0000d6498788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline]
 #3: ffff0000d6498788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_process_self_managed_hints+0xc8/0x1dc net/wireless/reg.c:3179
2 locks held by kworker/1:3/6608:
2 locks held by kworker/1:4/6622:
2 locks held by kworker/1:5/6662:
1 lock held by udevd/6712:
1 lock held by udevd/6951:
4 locks held by btrfs-transacti/7092:
 #0: ffff0000f7454850 (&fs_info->transaction_kthread_mutex){+.+.}-{4:4}, at: transaction_kthread+0xc8/0x430 fs/btrfs/disk-io.c:1562