INFO: task kworker/u4:1:136 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1    state:D stack:    0 pid:  136 ppid:     2 flags:0x00000008
Workqueue: writeback wb_workfn (flush-7:0)
Call trace:
 __switch_to+0x2f4/0x540 arch/arm64/kernel/process.c:521
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0xdfc/0x1bc4 kernel/sched/core.c:6395
 schedule+0x11c/0x1c8 kernel/sched/core.c:6478
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6537
 __mutex_lock_common+0xac8/0x1f14 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743
 hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
 hfsplus_cat_write_inode+0x1cc/0x750 fs/hfsplus/inode.c:613
 hfsplus_write_inode+0x154/0x4d0 fs/hfsplus/super.c:179
 write_inode fs/fs-writeback.c:1505 [inline]
 __writeback_single_inode+0x560/0x11c8 fs/fs-writeback.c:1715
 writeback_sb_inodes+0x830/0x13a8 fs/fs-writeback.c:1940
 __writeback_inodes_wb+0x110/0x394 fs/fs-writeback.c:2011
 wb_writeback+0x400/0xe64 fs/fs-writeback.c:2116
 wb_check_background_flush fs/fs-writeback.c:2182 [inline]
 wb_do_writeback fs/fs-writeback.c:2270 [inline]
 wb_workfn+0xae8/0xe44 fs/fs-writeback.c:2298
 process_one_work+0x79c/0x1138 kernel/workqueue.c:2310
 worker_thread+0x8f4/0x1034 kernel/workqueue.c:2457
 kthread+0x374/0x454 kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:856

Showing all locks held in the system:
4 locks held by kworker/u4:0/9:
 #0: ffff0000c1e37938 (
(wq_completion)writeback){+.+.}-{0:0}
, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: 
ffff80001b407c00
 (
(work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}
, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: 
ffff0000ec03a0e0 (&type->s_umount_key
#52){.+.+}-{3:3}
, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: ffff0000d94980b0 (
&tree->tree_lock){+.+.}-{3:3}
, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
1 lock held by khungtaskd/27:
 #0: ffff800014471360 (
rcu_read_lock){....}-{1:2}
, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:312
4 locks held by kworker/u4:1/136:
 #0: 
ffff0000c1e37938
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: 
ffff80001be97c00
 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: 
ffff0000d5d7a0e0
 (
&type->s_umount_key
#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: ffff0000ceb2e0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
4 locks held by kworker/u4:2/148:
 #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: ffff80001bf57c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: ffff0000d5c4e0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: ffff0000c87e00b0 (
&tree->tree_lock
){+.+.}-{3:3}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
4 locks held by kworker/u4:4/1605:
 #0: 
ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: ffff800023bc7c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: ffff0000d6a400e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: ffff0000cf1cc0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
4 locks held by kworker/u4:5/1618:
 #0: ffff0000c1e37938 (
(wq_completion)writeback){+.+.}-{0:0}
, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: 
ffff800023c87c00
 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: 
ffff0000cab280e0
 (
&type->s_umount_key
#52){.+.+}-{3:3}
, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: 
ffff0000cab2c0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
4 locks held by kworker/u4:6/1797:
 #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: ffff800023e67c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: 
ffff0000ef6800e0 (
&type->s_umount_key
#52
){.+.+}-{3:3}
, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: 
ffff0000ef6d60b0
 (
&tree->tree_lock
){+.+.}-{3:3}
, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
2 locks held by getty/3806:
 #0: ffff0000d3b07098
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001bcfe2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2f0/0xf6c drivers/tty/n_tty.c:2158
6 locks held by syz.0.16/4926:
6 locks held by syz.1.17/4948:
6 locks held by syz.2.18/4967:
6 locks held by syz.3.19/4982:
6 locks held by syz.4.20/5014:
4 locks held by kworker/u4:9/5040:
 #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: ffff80001fe07c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: ffff0000ef3340e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: ffff0000c613e0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
6 locks held by syz.5.21/5042:
4 locks held by kworker/u4:10/5056:
 #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: 
ffff800020027c00
 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}
, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: ffff0000ce21a0e0 (&type->s_umount_key#52){.+.+}-{3:3}, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: ffff0000ce21e0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
6 locks held by syz.6.22/5068:
4 locks held by kworker/u4:11/5083:
 #0: ffff0000c1e37938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1138 kernel/workqueue.c:2283
 #1: ffff80001ffe7c00
 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}
, at: process_one_work+0x6b8/0x1138 kernel/workqueue.c:2285
 #2: ffff0000ec0760e0
 (
&type->s_umount_key
#52
){.+.+}-{3:3}
, at: trylock_super+0x24/0xf4 fs/super.c:418
 #3: ffff0000ed90e0b0 (&tree->tree_lock){+.+.}-{3:3}
, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
6 locks held by syz.7.23/5096:
6 locks held by syz.8.24/5128:
6 locks held by syz.9.25/5155:

=============================================