INFO: task kworker/u4:3:155 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:24664 pid: 155 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 hfsplus_cat_write_inode+0x21c/0x870 fs/hfsplus/inode.c:613 write_inode fs/fs-writeback.c:1505 [inline] __writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1715 writeback_sb_inodes+0xa4e/0x1680 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011 wb_writeback+0x46f/0xbe0 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+0xbd6/0xf20 fs/fs-writeback.c:2298 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:1/144: #0: ffff8880193c9938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000169fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff888023c360e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff88805d4f20b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 4 locks held by kworker/u4:3/155: #0: ffff8880193c9938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90001fa7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff888079cde0e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff888017a680b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 2 locks held by getty/3945: #0: ffff88802bb79098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 4 locks held by kworker/u4:4/4255: #0: ffff8880193c9938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90002defd00 ((work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff88806129a0e0 (&type->s_umount_key#54){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff88806129e0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 2 locks held by kworker/1:9/4317: #0: ffff888016c72138 ( (wq_completion)rcu_gp ){+.+.}-{0:0} , at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900035afd00 ( (work_completion)(&rew.rew_work) ){+.+.}-{0:0} , at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 4 locks held by kworker/u4:5/4324: #0: ffff8880193c9938 ( (wq_completion)writeback ){+.+.}-{0:0} , at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900034cfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff8880779780e0 ( &type->s_umount_key #54 ){.+.+}-{3:3} , at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff88807797c0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 6 locks held by syz.0.17/5071: 6 locks held by syz.1.18/5089: 2 locks held by kworker/u4:6/5100: 4 locks held by kworker/u4:7/5102: #0: ffff8880193c9938 ((wq_completion)writeback){+.+.}-{0:0} , at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000318fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff888017a620e0 ( &type->s_umount_key #54 ){.+.+}-{3:3} , at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff8880693b80b0 ( &tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 6 locks held by syz.2.19/5113: 6 locks held by syz.3.20/5133: 3 locks held by kworker/u4:8/5143: 4 locks held by kworker/u4:9/5146: #0: ffff8880193c9938 ( (wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000331fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff8880259800e0 (&type->s_umount_key#54 ){.+.+}-{3:3} , at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff8880259840b0 (