INFO: task kworker/1:0:21 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:24720 pid: 21 ppid: 2 flags:0x00004000 Workqueue: events_long flush_mdb 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 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit_lock+0xbc/0x1a0 kernel/sched/wait_bit.c:90 out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117 lock_buffer include/linux/buffer_head.h:402 [inline] hfs_mdb_commit+0x113/0x1110 fs/hfs/mdb.c:271 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 INFO: task syz-executor:4796 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21968 pid: 4796 ppid: 1 flags:0x00004002 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 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 bit_wait_io+0xd/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit_lock+0xbc/0x1a0 kernel/sched/wait_bit.c:90 out_of_line_wait_on_bit_lock+0x138/0x190 kernel/sched/wait_bit.c:117 lock_buffer include/linux/buffer_head.h:402 [inline] hfs_mdb_commit+0xc53/0x1110 fs/hfs/mdb.c:325 hfs_sync_fs+0x11/0x20 fs/hfs/super.c:35 sync_filesystem+0xe6/0x220 fs/sync.c:56 generic_shutdown_super+0x6b/0x300 fs/super.c:448 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x626/0x20c0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f0c58876429 RSP: 002b:00007ffeba115278 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f0c588f8a37 RCX: 00007f0c58876429 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000002 R08: 0000000000000000 R09: 00007f0c588f8a12 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffeba116530 R13: 00007f0c588f8a12 R14: 0000000000017a43 R15: 00007ffeba1175f0 Showing all locks held in the system: 2 locks held by kworker/1:0/21: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90000db7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/1:2/1111: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90004b77d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by getty/3951: #0: ffff88814d4f0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 2 locks held by kworker/1:5/4239: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000300fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/1:13/4247: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000309fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/1:14/4248: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900030bfd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/1:15/4290: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000317fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 1 lock held by syz-executor/4796: #0: ffff88807d7ac0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 4 locks held by kworker/0:6/4992: #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffff8880b9027888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x499/0x7d0 kernel/sched/psi.c:882 #2: ffff8880b90280d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:946 #3: ffffffff964aff90 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x63/0x4e0 lib/debugobjects.c:694 2 locks held by kworker/0:8/4996: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90002e2fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/0:15/5006: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900031afd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/0:16/5007: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000321fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/0:17/5008: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000324fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/0:19/5010: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000326fd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 1 lock held by syz-executor/5199: #0: ffff88802399a0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/5483: #0: ffff88807bcf40e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/5771: #0: ffff8880603800e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/6065: #0: ffff8880203a60e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/6363: #0: ffff8880782a60e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/6657: #0: ffff88807ec200e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/6959: #0: ffff888079f200e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/7261: #0: ffff88801da780e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/7564: #0: ffff88807e4c20e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by dhcpcd/7857: #0: ffff8880789f4120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff8880789f4120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 2 locks held by dhcpcd/7858: #0: ffff88801a1bc120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88801a1bc120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3212 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3852 Comm: dhcpcd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0033:0x7f890370f4e0 Code: 84 99 fe ff ff f3 0f bc c0 31 c9 40 3a 34 02 75 c4 48 01 d0 e9 15 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 f9 6e c6 89 f8 25 ff 0f 00 00 c4 e2 7d 78 c0 c5 f1 ef c9 3d e0 RSP: 002b:00007fff073df2c8 EFLAGS: 00000202 RAX: 00007fff073dfcf0 RBX: 00007fff073df7d0 RCX: 0000000000000000 RDX: 00007fff073dfcd0 RSI: 0000000000000025 RDI: 000055ef60576a48 RBP: 000055ef60576a48 R08: 000000000edf2075 R09: 000000002cbba98b R10: 000000859e136354 R11: 0000000000000217 R12: 00007fff073dfcd0 R13: 00007fff073dfcd0 R14: 0000000000000001 R15: 000055ef60576a48 FS: 00007f89035b3740 GS: 0000000000000000