INFO: task kworker/0:8:5963 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:23000 pid:5963 tgid:5963 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events rfkill_sync_work Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776 device_lock include/linux/device.h:895 [inline] nfc_dev_down+0x2d/0x310 net/nfc/core.c:143 nfc_rfkill_set_block+0x39/0x110 net/nfc/core.c:179 rfkill_set_block+0x1fe/0x550 net/rfkill/core.c:346 rfkill_sync+0x10a/0x1c0 net/rfkill/core.c:379 rfkill_sync_work+0x27/0x40 net/rfkill/core.c:1056 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task kworker/0:11:17108 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:11 state:D stack:23768 pid:17108 tgid:17108 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events rfkill_global_led_trigger_worker Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776 rfkill_global_led_trigger_worker+0x1b/0x160 net/rfkill/core.c:182 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task syz.4.4108:19623 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.4108 state:D stack:26664 pid:19623 tgid:19623 ppid:15593 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 __flush_work+0x7d7/0xcc0 kernel/workqueue.c:4277 __cancel_work_sync kernel/workqueue.c:4397 [inline] cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4434 rfkill_unregister+0x95/0x2c0 net/rfkill/core.c:1139 nfc_unregister_device+0x94/0x390 net/nfc/core.c:1167 virtual_ncidev_close+0x4b/0xa0 drivers/nfc/virtual_ncidev.c:172 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe24278f749 RSP: 002b:00007ffd0e65f748 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fe2429e7da0 RCX: 00007fe24278f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fe2429e7da0 R08: 0000000000000148 R09: 0000000f0e65fa3f R10: 00000000003ffc94 R11: 0000000000000246 R12: 00000000000d3e22 R13: 00007fe2429e6090 R14: ffffffffffffffff R15: 00007ffd0e65f860 INFO: task syz-executor:19854 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:27368 pid:19854 tgid:19854 ppid:1 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776 rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 hci_register_dev+0x3cc/0xce0 net/bluetooth/hci_core.c:2631 __vhci_create_device+0x357/0x880 drivers/bluetooth/hci_vhci.c:451 vhci_create_device drivers/bluetooth/hci_vhci.c:479 [inline] vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline] vhci_write+0x2c0/0x480 drivers/bluetooth/hci_vhci.c:616 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7d3/0x11d0 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f691c98e1c0 RSP: 002b:00007ffd0afb6db8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f691c98e1c0 RDX: 0000000000000002 RSI: 00007ffd0afb6dca RDI: 00000000000000ca RBP: 00007f691cbe67b8 R08: 0000000000000000 R09: 00007f691d71d6c0 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffd0afb7118 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5569: #0: ffff88814d0890a0 (&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/0x1510 drivers/tty/n_tty.c:2211 4 locks held by kworker/0:8/5963: #0: ffff88813ff51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000425fc90 ((work_completion)(&rfkill->sync_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff905ef048 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_sync_work+0x1b/0x40 net/rfkill/core.c:1055 #3: ffff88807c811100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88807c811100 (&dev->mutex){....}-{4:4}, at: nfc_dev_down+0x2d/0x310 net/nfc/core.c:143 2 locks held by kworker/u8:22/6593: #0: ffff88801dbf9148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000cacfc90 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 3 locks held by kworker/0:11/17108: #0: ffff88813ff51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000258fc90 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff905ef048 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x1b/0x160 net/rfkill/core.c:182 1 lock held by syz.4.4108/19623: #0: ffff88807c811100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #0: ffff88807c811100 (&dev->mutex){....}-{4:4}, at: nfc_unregister_device+0x60/0x390 net/nfc/core.c:1165 2 locks held by syz-executor/19854: #0: ffff888034cbe118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:478 [inline] #0: ffff888034cbe118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline] #0: ffff888034cbe118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:616 #1: ffffffff905ef048 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz.1.4299/20223: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 #1: ffffffff905ef048 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_open+0x136/0x750 net/rfkill/core.c:1178 1 lock held by syz.2.4302/20233: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz.0.4304/20237: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz.0.4304/20238: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz.5.4307/20246: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20251: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20252: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20254: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20256: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20262: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20266: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20267: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20268: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20270: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/20276: #0: ffffffff8f09fd48 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 ============================================= 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 10/25/2025 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] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 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 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 06 60 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 13 59 13 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 000000000283c5a5 RBX: 0000000000000000 RCX: ffffffff8b7706d9 RDX: 0000000000000000 RSI: ffffffff8dac200a RDI: ffffffff8bf24280 RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000 R13: ffffffff8e097b40 R14: ffffffff9087f7d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124909000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f10764e8f9a CR3: 000000000e184000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3ef/0x4d0 init/main.c:1206 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148