INFO: task kworker/0:0:8176 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:0 D28808 8176 2 0x80000000 Workqueue: events_long flush_mdb Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 io_schedule+0xb5/0x120 kernel/sched/core.c:5181 bit_wait_io+0x12/0x90 kernel/sched/wait_bit.c:207 __wait_on_bit_lock+0xb5/0x170 kernel/sched/wait_bit.c:89 out_of_line_wait_on_bit_lock+0xd2/0x100 kernel/sched/wait_bit.c:116 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline] __lock_buffer+0x52/0x60 fs/buffer.c:65 lock_buffer include/linux/buffer_head.h:374 [inline] hfs_mdb_commit+0x55e/0x11e0 fs/hfs/mdb.c:319 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 1 lock held by khungtaskd/1570: #0: 000000002e56a843 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by systemd-journal/4679: #0: 00000000b9c69cdb (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9702 [inline] #0: 00000000b9c69cdb (&rq->lock){-.-.}, at: pick_next_task_fair+0x556/0x1570 kernel/sched/fair.c:6841 1 lock held by in:imklog/7806: #0: 00000000eadc87c2 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by kworker/0:0/8176: #0: 0000000053c54be6 ((wq_completion)"events_long"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000f22088ba ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 2 locks held by syz-executor295/15193: #0: 00000000e77b2216 (&type->i_mutex_dir_key#7){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #0: 00000000e77b2216 (&type->i_mutex_dir_key#7){+.+.}, at: lock_mount+0xcc/0x4a0 fs/namespace.c:2075 #1: 00000000cd5ad5e7 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #1: 00000000cd5ad5e7 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10 Comm: rcu_preempt Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:2318 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:2337 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:2391 [inline] RIP: 0010:__lock_acquire+0xbed/0x3ff0 kernel/locking/lockdep.c:3416 Code: db 74 55 48 83 eb 08 74 4f 48 bd 00 00 00 00 00 fc ff df eb 06 48 83 eb 08 74 3d 48 8d 7b 18 48 89 f8 48 c1 e8 03 80 3c 28 00 <0f> 85 8c 1e 00 00 4c 3b 63 18 0f 84 f1 fc ff ff 48 8d 7b 08 48 89 RSP: 0018:ffff8880b5a679e0 EFLAGS: 00000046 RAX: 1ffffffff18e2a5b RBX: ffffffff8c7152c0 RCX: 0000000000005d11 RDX: 1ffffffff19a8bb9 RSI: 00000000f59a8c27 RDI: ffffffff8c7152d8 RBP: dffffc0000000000 R08: ffffffff8cd45dc8 R09: 0000000000000000 R10: ffff8880b5a4eb08 R11: 0000000000000000 R12: 577f4c272808619f R13: ffff8880b5a4e280 R14: ffff8880b5a4eb20 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1fd89c4000 CR3: 00000000a1986000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 del_timer_sync+0xab/0x270 kernel/time/timer.c:1295 schedule_timeout+0x4d7/0xfe0 kernel/time/timer.c:1819 rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415