INFO: task syz-executor:5833 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21384 pid:5833 tgid:5833 ppid:1 task_flags:0x40054c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 hci_unregister_dev+0x374/0x510 net/bluetooth/hci_core.c:2732 vhci_release+0x152/0x1a0 drivers/bluetooth/hci_vhci.c:690 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x110 kernel/entry/common.c:40 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+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbcc8d8d8dc RSP: 002b:00007fff110844d0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007fbcc8d8d8dc RDX: 0000000000000030 RSI: 00007fff11084590 RDI: 00000000000000f9 RBP: 00007fff1108453c R08: 0000000000000000 R09: 00007fff11084247 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000258 R13: 00000000000927c0 R14: 0000000000047e68 R15: 00007fff11084590 INFO: task syz-executor:5835 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20600 pid:5835 tgid:5835 ppid:1 task_flags:0x40054c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 hci_unregister_dev+0x374/0x510 net/bluetooth/hci_core.c:2732 vhci_release+0x152/0x1a0 drivers/bluetooth/hci_vhci.c:690 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x110 kernel/entry/common.c:40 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+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9c88385017 RSP: 002b:00007fff64bcd6c0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 0000000000000694 RCX: 00007f9c88385017 RDX: 0000000040000000 RSI: 00007fff64bcd72c RDI: 00000000ffffffff RBP: 00007fff64bcd72c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000022a R13: 00005555879de590 R14: 0000000000046bf6 R15: 00007fff64bcd780 INFO: task kworker/0:4:5904 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:22504 pid:5904 tgid:5904 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events rfkill_global_led_trigger_worker Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.0.2772:15509 blocked for more than 144 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2772 state:D stack:25864 pid:15509 tgid:15506 ppid:5835 task_flags:0x40054c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 nfc_unregister_device+0x96/0x2a0 net/nfc/core.c:1167 virtual_ncidev_close+0x56/0x90 drivers/nfc/virtual_ncidev.c:172 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x110 kernel/entry/common.c:40 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+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9c88390d5c RSP: 002b:00007f9c892afec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: 000000000000001c RBX: 00007f9c892affc0 RCX: 00007f9c88390d5c RDX: 000000000000001c RSI: 00007f9c892b0010 RDI: 000000000000000e RBP: 0000000000000000 R08: 00007f9c892aff14 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000000e R13: 00007f9c892aff68 R14: 00007f9c892b0010 R15: 0000000000000000 INFO: task syz.1.2775:15529 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2775 state:D stack:24280 pid:15529 tgid:15528 ppid:5834 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 device_lock include/linux/device.h:914 [inline] nfc_dev_down net/nfc/core.c:143 [inline] nfc_rfkill_set_block+0x50/0x2e0 net/nfc/core.c:179 rfkill_set_block+0x1cf/0x440 net/rfkill/core.c:346 rfkill_fop_write+0x44b/0x570 net/rfkill/core.c:1301 vfs_write+0x27e/0xb30 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f518c38eec9 RSP: 002b:00007f518a5f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f518c5e5fa0 RCX: 00007f518c38eec9 RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007f518c411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f518c5e6038 R14: 00007f518c5e5fa0 R15: 00007ffe324188b8 INFO: task syz-executor:15778 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:28040 pid:15778 tgid:15778 ppid:1 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 rfkill_register+0x37/0x8e0 net/rfkill/core.c:1071 hci_register_dev+0x3f5/0x890 net/bluetooth/hci_core.c:2631 __vhci_create_device drivers/bluetooth/hci_vhci.c:451 [inline] vhci_create_device+0x39c/0x650 drivers/bluetooth/hci_vhci.c:479 vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline] vhci_write+0x3ce/0x4a0 drivers/bluetooth/hci_vhci.c:616 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c6/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fac29d8d940 RSP: 002b:00007ffc3c6188a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fac29d8d940 RDX: 0000000000000002 RSI: 00007ffc3c6188ba RDI: 00000000000000ca RBP: 00007fac29fe67b8 R08: 0000000000000000 R09: 00007fac2ab1d6c0 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8dd3a860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dd3a860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8dd3a860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5598: #0: ffff88814e07f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5833: #0: ffffffff8f3948c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 1 lock held by syz-executor/5835: #0: ffffffff8f3948c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 3 locks held by kworker/0:4/5904: #0: ffff88801a081148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a081148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000a597bc0 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000a597bc0 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f3948c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182 2 locks held by syz.0.2772/15509: #0: ffff88807c422100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff88807c422100 (&dev->mutex){....}-{4:4}, at: nfc_unregister_device+0x63/0x2a0 net/nfc/core.c:1165 #1: ffffffff8f3948c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 2 locks held by syz.1.2775/15529: #0: ffffffff8f3948c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_write+0x191/0x570 net/rfkill/core.c:1293 #1: ffff88807c422100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #1: ffff88807c422100 (&dev->mutex){....}-{4:4}, at: nfc_dev_down net/nfc/core.c:143 [inline] #1: ffff88807c422100 (&dev->mutex){....}-{4:4}, at: nfc_rfkill_set_block+0x50/0x2e0 net/nfc/core.c:179 2 locks held by syz-executor/15778: #0: ffff88805494a918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device+0x34/0x650 drivers/bluetooth/hci_vhci.c:478 #1: ffffffff8f3948c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x37/0x8e0 net/rfkill/core.c:1071 3 locks held by syz.3.2832/15796: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 #1: ffff8880549fd100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #1: ffff8880549fd100 (&dev->mutex){....}-{4:4}, at: nfc_register_device+0xa1/0x320 net/nfc/core.c:1128 #2: ffffffff8f3948c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x37/0x8e0 net/rfkill/core.c:1071 1 lock held by syz-executor/15801: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15802: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz.2.2849/15857: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz.2.2849/15858: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15868: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15870: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15872: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15879: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15880: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15882: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15884: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 drivers/char/misc.c:125 1 lock held by syz-executor/15886: #0: ffffffff8e556f88 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x330 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 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/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+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 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 08/18/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 13 e8 02 00 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 93 c9 15 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8da07d80 EFLAGS: 000002c6 RAX: 101b946c49b5a900 RBX: ffffffff81953917 RCX: 101b946c49b5a900 RDX: 0000000000000001 RSI: ffffffff8d50d356 RDI: ffffffff8b9ec4e0 RBP: ffffffff8da07eb8 R08: ffff8880b8832fdb R09: 1ffff110171065fb R10: dffffc0000000000 R11: ffffed10171065fc R12: ffffffff8f5b8630 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b52a28 FS: 0000000000000000(0000) GS:ffff88812639b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d7f02fe000 CR3: 000000000db36000 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+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:745 start_kernel+0x3ae/0x410 init/main.c:1099 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147