INFO: task syz.4.1506:11549 blocked for more than 143 seconds. Not tainted 6.14.0-rc6-syzkaller-00244-g31d7109a19f6 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1506 state:D stack:22816 pid:11549 tgid:11549 ppid:6394 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 request_wait_answer fs/fuse/dev.c:453 [inline] __fuse_request_send fs/fuse/dev.c:467 [inline] __fuse_simple_request+0xe2a/0x1850 fs/fuse/dev.c:561 fuse_simple_request fs/fuse/fuse_i.h:1197 [inline] fuse_flush+0x6c0/0x990 fs/fuse/file.c:557 filp_flush+0xb7/0x190 fs/open.c:1540 filp_close+0x1e/0x40 fs/open.c:1553 __range_close fs/file.c:746 [inline] __do_sys_close_range fs/file.c:805 [inline] __se_sys_close_range+0x38b/0x6d0 fs/file.c:769 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb38558d169 RSP: 002b:00007fff0e308c98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007fb3857a7ba0 RCX: 00007fb38558d169 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fb3857a7ba0 R08: 0000000000018aa4 R09: 0000001e0e308f8f R10: 00007fb3857a7ac0 R11: 0000000000000246 R12: 00000000000af7cf R13: 00007fb3857a6160 R14: ffffffffffffffff R15: 00007fff0e308db0 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: #0: ffff88801bef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801bef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000127c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000127c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8feb76d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17a/0xd60 net/core/net_namespace.c:606 #3: ffffffff8fec3f08 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x880 net/core/dev.c:12420 1 lock held by khungtaskd/31: #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by getty/5589: #0: ffff888031bea0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:5/5880: 3 locks held by kworker/1:3/5882: #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc900041bfc60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900041bfc60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #2: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996 3 locks held by kworker/u8:12/6010: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90004517c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90004517c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fec3f08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285 3 locks held by syz.7.1315/10793: #0: ffff888061f80d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888061f80d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2678 #1: ffff888061f80078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60d/0x1260 net/bluetooth/hci_sync.c:5185 #2: ffffffff900298a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2041 [inline] #2: ffffffff900298a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2698 3 locks held by syz-executor/11683: #0: ffff888030594d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888030594d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2678 #1: ffff888030594078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60d/0x1260 net/bluetooth/hci_sync.c:5185 #2: ffffffff900298a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2041 [inline] #2: ffffffff900298a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2698 1 lock held by syz.9.1831/13004: #0: ffffffff8fec3f08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fec3f08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 4 locks held by syz.8.1832/12992: #0: ffff8880340c8d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff8880340c8d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2678 #1: ffff8880340c8078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60d/0x1260 net/bluetooth/hci_sync.c:5185 #2: ffffffff900298a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2041 [inline] #2: ffffffff900298a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2698 #3: ffff8880246d2338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1761 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00244-g31d7109a19f6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.14.0-rc6-syzkaller-00244-g31d7109a19f6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: netns cleanup_net RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:409 Code: 70 7e 45 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 51 30 aa fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c RSP: 0018:ffffc90000126a78 EFLAGS: 00000002 RAX: 1ffffffff352c700 RBX: ffffffff9a963ec0 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff857c60f6 R09: 1ffff11004a5a046 R10: dffffc0000000000 R11: ffffffff857c60b0 R12: 0000000000000020 R13: 1ffffffff352c82a R14: 00000000000003fd R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32c02ff8 CR3: 000000000e938000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x1b1/0x320 drivers/tty/serial/8250/8250_port.c:2100 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3357 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3380 [inline] serial8250_console_write+0x134c/0x1e00 drivers/tty/serial/8250/8250_port.c:3465 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432 _printk+0xd5/0x120 kernel/printk/printk.c:2457 netdev_info+0x122/0x170 net/core/dev.c:12354 __dev_set_promiscuity+0x1c1/0x5a0 net/core/dev.c:9046 __dev_set_rx_mode+0x197/0x280 dev_uc_del+0xc2/0x110 net/core/dev_addr_lists.c:715 macsec_dev_stop+0x330/0x430 drivers/net/macsec.c:3679 __dev_close_many+0x216/0x350 net/core/dev.c:1719 dev_close_many+0x24e/0x4c0 net/core/dev.c:1744 unregister_netdevice_many_notify+0x52d/0x1f10 net/core/dev.c:11859 unregister_netdevice_many net/core/dev.c:11951 [inline] default_device_exit_batch+0x7ff/0x880 net/core/dev.c:12434 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x8ad/0xd60 net/core/net_namespace.c:652 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244