INFO: task syz.0.364:7364 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.364 state:D stack:27512 pid:7364 tgid:7359 ppid:5841 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 __schedule_loop kernel/sched/core.c:7049 [inline] schedule+0x164/0x360 kernel/sched/core.c:7064 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7121 __mutex_lock_common kernel/locking/mutex.c:710 [inline] __mutex_lock+0x856/0x1420 kernel/locking/mutex.c:794 bdev_open+0xe0/0xd30 block/bdev.c:953 bdev_file_open_by_dev+0x1be/0x240 block/bdev.c:1067 setup_bdev_super+0x5a/0x5b0 fs/super.c:1612 get_tree_bdev_flags+0x389/0x4f0 fs/super.c:1692 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4399 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f286a99c819 RSP: 002b:00007f286b8bd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f286ac16090 RCX: 00007f286a99c819 RDX: 00002000000000c0 RSI: 0000200000000080 RDI: 00002000000002c0 RBP: 00007f286aa32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000008010 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f286ac16128 R14: 00007f286ac16090 R15: 00007ffe91b64b98 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e95d260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:8/1159: #0: ffff88801ae8c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801ae8c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc9000584fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc9000584fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8fdcce80 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by getty/5598: #0: ffff888037c0a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by kworker/1:4/5845: #0: ffff88813fe4f140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88813fe4f140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc900045c7c40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc900045c7c40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 5 locks held by kworker/0:4/5926: #0: ffff8880226d3540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff8880226d3540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90005207c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90005207c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff88802b10a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:995 [inline] #2: ffff88802b10a1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff88802b118560 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff88802b118560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #3: ffff88802b118560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #3: ffff88802b118560 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #3: ffff88802b118560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x217a/0x4f30 drivers/usb/core/hub.c:5953 #4: ffff88802b065f60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline] #4: ffff88802b065f60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #4: ffff88802b065f60 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #4: ffff88802b065f60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21a2/0x4f30 drivers/usb/core/hub.c:5953 3 locks held by kworker/0:5/5941: 1 lock held by udevd/6094: #0: ffff888027c4b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953 2 locks held by syz.0.364/7364: #0: ffff8880786ce0d8 (&type->s_umount_key#30/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345 #1: ffff888027c4b350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953 2 locks held by syz.4.601/8380: #0: ffffffff8fdcce80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fdcce80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e963568 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e963568 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 4 locks held by syz-executor/9288: #0: ffff88803226cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff88803226cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff88803226c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5356 #2: ffffffff8ff59520 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8ff59520 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2650 #3: ffff8880223572f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x92/0x570 net/bluetooth/l2cap_core.c:1777 1 lock held by syz.6.764/9314: #0: ffffffff8e963568 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e963568 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.4.766/9320: #0: ffffffff8fdcce80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fdcce80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 1 lock held by syz.1.765/9330: #0: ffffffff8fdcce80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fdcce80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 3 locks held by syz.7.768/9338: #0: ffff888043554ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff888043554ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff8880435540b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5356 #2: ffffffff8ff59520 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8ff59520 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2650 1 lock held by dhcpcd/9357: #0: ffff88802a1ea260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88802a1ea260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3198 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: ac 78 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 21 1a 00 fb f4 3c f0 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000242 RAX: 00000000008b4af1 RBX: ffffffff819b142a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dfc0ce0 RDI: ffffffff8c287de0 RBP: ffffc90000197f10 R08: ffff8880b87339db R09: 1ffff110170e673b R10: dffffc0000000000 R11: ffffed10170e673c R12: 0000000000000001 R13: 1ffff11003bd4000 R14: 0000000000000001 R15: 1ffff11003bd4000 FS: 0000000000000000(0000) GS:ffff88812535c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005575c559a660 CR3: 000000000e74a000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147