INFO: task syz-executor:4250 blocked for more than 143 seconds. Not tainted 6.1.134-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20312 pid:4250 ppid:1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6561 schedule+0xbf/0x180 kernel/sched/core.c:6637 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa6e/0x26a0 kernel/exit.c:871 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f04cf98e169 RSP: 002b:00007ffcc793da18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f04cfa108c6 RCX: 00007f04cf98e169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000010 R08: 00007ffcc793b7b6 R09: 00007ffcc793ecd0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcc793ecd0 R13: 00007f04cfa10854 R14: 00005555835794a8 R15: 00007ffcc793fda0 Showing all locks held in the system: 2 locks held by kworker/0:0/7: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc900000c7d20 (drain_vmap_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 3 locks held by kworker/u4:0/9: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32e910 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32f110 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 3 locks held by kworker/0:2/126: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffff8880b8e27788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x419/0x790 kernel/sched/psi.c:999 #2: ffff88805f1c9240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x316/0x41f0 drivers/net/netdevsim/fib.c:1491 2 locks held by getty/4005: #0: ffff888030f37098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198 2 locks held by syz-executor/4250: #0: ffff888077f1c0e0 (&type->s_umount_key#32){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffff8881443c87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8881443c87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737 1 lock held by kworker/u4:7/4341: #0: ffff8880b8e3a998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:545 4 locks held by kworker/u4:15/4681: #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90003597d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e544210 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xd20 net/core/net_namespace.c:594 #3: ffffffff8d333c40 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5f0 kernel/rcu/tree.c:4019 2 locks held by kworker/1:8/4797: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90003867d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 2 locks held by syz.3.150/4999: #0: ffff888073b3e460 (sb_writers#3){.+.+}-{0:0}, at: do_sendfile+0x5f4/0xff0 fs/read_write.c:1254 #1: ffff888077f1c0e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755 4 locks held by syz-executor/5443: #0: ffff888057c010b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff888057c010b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2707 #1: ffff888057c00078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0xfc0 net/bluetooth/hci_sync.c:5165 #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1799 [inline] #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2503 #3: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #3: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962 3 locks held by syz-executor/5874: #0: ffff888051b250b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff888051b250b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2707 #1: ffff888051b24078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0xfc0 net/bluetooth/hci_sync.c:5165 #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962 3 locks held by syz-executor/6045: #0: ffff8880291750b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff8880291750b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2707 #1: ffff888029174078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0xfc0 net/bluetooth/hci_sync.c:5165 #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1799 [inline] #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2503 3 locks held by syz-executor/6101: #0: ffff88807cd310b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff88807cd310b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2707 #1: ffff88807cd30078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0xfc0 net/bluetooth/hci_sync.c:5165 #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1799 [inline] #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2503 3 locks held by syz-executor/6298: #0: ffff88807cf4d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff88807cf4d0b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2707 #1: ffff88807cf4c078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0xfc0 net/bluetooth/hci_sync.c:5165 #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1799 [inline] #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2503 3 locks held by dhcpcd-run-hook/6453: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.134-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ca/0x430 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4294 Comm: kworker/0:4 Not tainted 6.1.134-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events pwq_unbound_release_workfn RIP: 0010:remove_class_from_lock_chains kernel/locking/lockdep.c:5990 [inline] RIP: 0010:zap_class+0x37c/0x830 kernel/locking/lockdep.c:6033 Code: 08 00 00 00 e8 e5 10 76 00 48 0f ab 5d 00 48 ff 05 e9 ea c3 11 4c 8b 64 24 08 49 83 c7 08 4c 89 f8 48 c1 e8 03 42 80 3c 30 00 <0f> 84 bd fd ff ff 4c 89 ff e8 16 0f 76 00 e9 b0 fd ff ff 44 89 f9 RSP: 0018:ffffc90004677ae8 EFLAGS: 00000046 RAX: 1ffffffff2272389 RBX: 000000000001d67d RCX: 000000000001d67c RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff91289c18 RBP: ffffffff9023ae18 R08: dffffc0000000000 R09: fffffbfff2251384 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000c0a R13: 1ffffffff2272388 R14: dffffc0000000000 R15: ffffffff91391c48 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f85dcb1a290 CR3: 000000000d08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lockdep_free_key_range kernel/locking/lockdep.c:6159 [inline] lockdep_unregister_key+0x3c8/0x600 kernel/locking/lockdep.c:6361 wq_unregister_lockdep kernel/workqueue.c:3500 [inline] pwq_unbound_release_workfn+0x23d/0x290 kernel/workqueue.c:3738 process_one_work+0x917/0x1260 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295