INFO: task kworker/0:8:5994 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:8 state:D stack:22312 pid:5994 tgid:5994 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events rfkill_global_led_trigger_worker Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 rfkill_global_led_trigger_worker+0x1b/0x160 net/rfkill/core.c:182 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.4.1090:10609 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1090 state:D stack:26264 pid:10609 tgid:10609 ppid:6088 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 rfkill_unregister+0xec/0x2c0 net/rfkill/core.c:1145 nfc_unregister_device+0x94/0x330 net/nfc/core.c:1167 virtual_ncidev_close+0x4b/0xa0 drivers/nfc/virtual_ncidev.c:172 __fput+0x3ff/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d0bd8ebe9 RSP: 002b:00007fff8235aa38 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f0d0bfc7da0 RCX: 00007f0d0bd8ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f0d0bfc7da0 R08: 0000000000000204 R09: 0000001e8235ad2f R10: 00007f0d0bfc7cb0 R11: 0000000000000246 R12: 000000000007b2a5 R13: 00007f0d0bfc6090 R14: ffffffffffffffff R15: 00007fff8235ab50 INFO: task syz.4.1090:10612 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1090 state:D stack:25376 pid:10612 tgid:10609 ppid:6088 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 device_lock include/linux/device.h:911 [inline] nfc_dev_down+0x2d/0x2e0 net/nfc/core.c:143 nfc_rfkill_set_block+0x39/0xe0 net/nfc/core.c:179 rfkill_set_block+0x1fb/0x550 net/rfkill/core.c:346 rfkill_fop_write+0x2c0/0x580 net/rfkill/core.c:1301 vfs_write+0x29d/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d0bd8ebe9 RSP: 002b:00007f0d0cbec038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0d0bfc5fa0 RCX: 00007f0d0bd8ebe9 RDX: 0000000000000008 RSI: 0000200000000080 RDI: 000000000000000f RBP: 00007f0d0be11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0d0bfc6038 R14: 00007f0d0bfc5fa0 R15: 00007fff8235a8d8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:3/49: #0: ffff88801c6f4148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000b97d10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff9036dd90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:658 #3: ffffffff8e5cc6c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3815 2 locks held by getty/5610: #0: ffff88803604d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5844: #0: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xec/0x2c0 net/rfkill/core.c:1145 3 locks held by kworker/0:8/5994: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000424fd10 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x1b/0x160 net/rfkill/core.c:182 1 lock held by syz.1.402/7798: #0: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xec/0x2c0 net/rfkill/core.c:1145 2 locks held by syz.4.1090/10609: #0: ffff8880309ad100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #0: ffff8880309ad100 (&dev->mutex){....}-{4:4}, at: nfc_unregister_device+0x60/0x330 net/nfc/core.c:1165 #1: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xec/0x2c0 net/rfkill/core.c:1145 2 locks held by syz.4.1090/10612: #0: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_write+0x166/0x580 net/rfkill/core.c:1293 #1: ffff8880309ad100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #1: ffff8880309ad100 (&dev->mutex){....}-{4:4}, at: nfc_dev_down+0x2d/0x2e0 net/nfc/core.c:143 2 locks held by syz-executor/10786: #0: ffff888072073918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:470 [inline] #0: ffff888072073918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:528 [inline] #0: ffff888072073918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:608 #1: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz.2.1206/11096: #0: ffff88807a50a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz.2.1206/11098: #0: ffff88807a50a1c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: __tty_hangup.part.0+0xda/0x8c0 drivers/tty/tty_io.c:581 #1: ffff88807a50a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #1: ffff88807a50a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock+0x65/0xb0 drivers/tty/tty_ldisc.c:313 2 locks held by syz-executor/11265: #0: ffff888078567918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:470 [inline] #0: ffff888078567918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:528 [inline] #0: ffff888078567918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:608 #1: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz-executor/11371: #0: ffff88805caf1118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:470 [inline] #0: ffff88805caf1118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:528 [inline] #0: ffff88805caf1118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:608 #1: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz-executor/11807: #0: ffff88805c75d118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:470 [inline] #0: ffff88805c75d118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:528 [inline] #0: ffff88805c75d118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:608 #1: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz-executor/11883: #0: ffff88803533e918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:470 [inline] #0: ffff88803533e918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:528 [inline] #0: ffff88803533e918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:608 #1: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz-executor/11893: #0: ffff888059e34918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:470 [inline] #0: ffff888059e34918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:528 [inline] #0: ffff888059e34918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:608 #1: ffffffff90821028 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 1 lock held by syz.0.1449/12053: #0: ffffffff8e5cc7f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 0c 62 02 c3 cc cc cc cc 0f 1f 00 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 53 03 16 00 fb f4 8c 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c2 RAX: 000000000270741b RBX: 0000000000000000 RCX: ffffffff8b940c29 RDX: 0000000000000000 RSI: ffffffff8de513c8 RDI: ffffffff8c162b00 RBP: fffffbfff1c52ef8 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8e2977c0 R14: ffffffff90ab5c90 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881246b8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9bc034a6b0 CR3: 000000000e380000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:744 start_kernel+0x3ee/0x4d0 init/main.c:1097 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148