INFO: task kworker/0:3:1346 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:3 state:D stack:24272 pid: 1346 ppid: 2 flags:0x00004000 Workqueue: events_long flush_mdb Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 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+0xb7/0x1a0 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+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task syz-executor:4924 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:22192 pid: 4924 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 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+0xb7/0x1a0 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+0xc51/0x1110 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+0x426/0x4d0 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+0x635/0x2110 kernel/exit.c:884 do_group_exit+0x12c/0x2f0 kernel/exit.c:998 __do_sys_exit_group kernel/exit.c:1009 [inline] __se_sys_exit_group kernel/exit.c:1007 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1007 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: 0033:0x7f9947f4c429 RSP: 002b:00007ffdbfe91328 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f9947fcea37 RCX: 00007f9947f4c429 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000002 R08: 0000000000000000 R09: 00007f9947fcea12 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdbfe925e0 R13: 00007f9947fcea12 R14: 000000000001c473 R15: 00007ffdbfe936a0 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+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90000db7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by kworker/1:1/23: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90000ddfd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 1 lock held by khungtaskd/27: #0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/0:3/1346: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90005bf7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by kworker/1:3/2290: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90006cdfd00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by getty/3950: #0: ffff88814ca77098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900021ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 2 locks held by kworker/1:4/4220: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002307d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by kworker/0:18/4400: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900029a7d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by kworker/0:20/4404: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900029b7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by kworker/0:24/4409: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900024d7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by kworker/1:5/4478: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002277d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by kworker/1:6/4854: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc900023d7d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 2 locks held by kworker/1:8/4856: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002477d00 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 1 lock held by syz-executor/4924: #0: ffff888023fa80e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/5355: #0: ffff88807dfd40e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/5628: #0: ffff88802b8c20e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/5917: #0: ffff88807481a0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/6202: #0: ffff88802290a0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/6497: #0: ffff88805fbcc0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/6790: #0: ffff88805da140e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/7087: #0: ffff888025e9a0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/7384: #0: ffff888073d4e0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/7685: #0: ffff8880791e20e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by dhcpcd/7968: #0: ffff88807e5ca120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88807e5ca120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3218 #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 2 locks held by dhcpcd/7969: #0: ffff88807f134120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline] #0: ffff88807f134120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3218 #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c3239a8 (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 05/09/2026 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+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/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: 3544 Comm: syslogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__lock_acquire+0xe5f/0x7b50 kernel/locking/lockdep.c:-1 Code: 0f b6 04 00 84 c0 0f 85 67 5c 00 00 49 83 ff ff 0f 94 c0 83 3d e1 33 d0 14 00 b1 01 0f 84 54 4c 00 00 84 c9 0f 84 56 4c 00 00 <48> 89 9c 24 a0 00 00 00 48 8b 5c 24 68 48 89 d8 48 c1 e8 03 42 80 RSP: 0018:ffffc900022074a0 EFLAGS: 00000002 RAX: 1ffff1100fc2215c RBX: ffff88807e110ae0 RCX: ffffffff815ceb27 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901cb0c0 RBP: ffffc900022076d0 R08: dffffc0000000000 R09: 1ffffffff2039618 R10: dffffc0000000000 R11: fffffbfff2039619 R12: ffff88807e110b38 R13: ffff88807e110000 R14: 0000000000000001 R15: 4ef885bbd51f08e5 FS: 00007f0321505c80(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557a7fad0168 CR3: 000000002b5bc000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] unix_write_space+0x1a/0x340 net/unix/af_unix.c:462 sock_wfree+0x123/0x1f0 net/core/sock.c:2233 unix_destruct_scm+0x211/0x290 net/unix/scm.c:152 skb_release_head_state+0xf6/0x240 net/core/skbuff.c:729 skb_release_all net/core/skbuff.c:740 [inline] __kfree_skb net/core/skbuff.c:756 [inline] consume_skb+0x72/0x100 net/core/skbuff.c:914 skb_free_datagram+0x25/0xe0 net/core/datagram.c:325 __unix_dgram_recvmsg+0x9dc/0xd50 net/unix/af_unix.c:2395 sock_recvmsg_nosec net/socket.c:969 [inline] sock_recvmsg net/socket.c:987 [inline] sock_read_iter+0x2c2/0x380 net/socket.c:1068 call_read_iter include/linux/fs.h:2167 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x75e/0xd50 fs/read_write.c:485 ksys_read+0x153/0x260 fs/read_write.c:623 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: 0033:0x7f0321655407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffced61b8a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f0321505c80 RCX: 00007f0321655407 RDX: 00000000000000ff RSI: 000055f4e686c950 RDI: 0000000000000000 RBP: 000055f4e686c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055f4e686c996 R13: 0000000000000000 R14: 000055f4e686c950 R15: 000055f4af1fdd98