INFO: task kworker/1:0:24 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:22232 pid:24 tgid:24 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events rfkill_op_handler Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 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+0x818/0x1060 kernel/locking/mutex.c:760 device_lock include/linux/device.h:914 [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+0x1fe/0x550 net/rfkill/core.c:346 rfkill_epo+0x8e/0x1d0 net/rfkill/core.c:466 __rfkill_handle_global_op net/rfkill/input.c:60 [inline] rfkill_op_handler+0x262/0x280 net/rfkill/input.c:108 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task kworker/1:4:5884 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:21704 pid:5884 tgid:5884 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: events rfkill_global_led_trigger_worker Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 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+0x818/0x1060 kernel/locking/mutex.c:760 rfkill_global_led_trigger_worker+0x1b/0x160 net/rfkill/core.c:182 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.4.3531:14412 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3531 state:D stack:26712 pid:14412 tgid:14412 ppid:5806 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 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+0x818/0x1060 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+0x402/0xb70 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+0xec/0x130 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+0x426/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f65b2b8f6c9 RSP: 002b:00007ffdd1cde108 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f65b2de7da0 RCX: 00007f65b2b8f6c9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f65b2de7da0 R08: 000000000000007c R09: 00000006d1cde3ff R10: 00007f65b2de7cb0 R11: 0000000000000246 R12: 0000000000051794 R13: 00007f65b2de6090 R14: ffffffffffffffff R15: 00007ffdd1cde220 INFO: task syz-executor:14932 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:28680 pid:14932 tgid:14932 ppid:1 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 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+0x818/0x1060 kernel/locking/mutex.c:760 rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 hci_register_dev+0x3cc/0xc60 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/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08c298e140 RSP: 002b:00007ffd0f5bc1f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f08c298e140 RDX: 0000000000000002 RSI: 00007ffd0f5bc20a RDI: 00000000000000ca RBP: 00007f08c2be67b8 R08: 0000000000000000 R09: 00007f08c371d6c0 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffd0f5bc558 R15: 0000000000000000 Showing all locks held in the system: 4 locks held by kworker/1:0/24: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900001e7d00 ((rfkill_op_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff905920c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_epo+0x55/0x1d0 net/rfkill/core.c:462 #3: ffff88802c056100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff88802c056100 (&dev->mutex){....}-{4:4}, at: nfc_dev_down+0x2d/0x2e0 net/nfc/core.c:143 1 lock held by khungtaskd/31: #0: ffffffff8e3c4760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c4760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c4760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:7/3560: 2 locks held by getty/5572: #0: ffff8880314450a0 (&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 3 locks held by kworker/1:4/5884: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000444fd00 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff905920c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x1b/0x160 net/rfkill/core.c:182 2 locks held by syz.4.3531/14412: #0: ffff88802c056100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff88802c056100 (&dev->mutex){....}-{4:4}, at: nfc_unregister_device+0x60/0x330 net/nfc/core.c:1165 #1: ffffffff905920c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xec/0x2c0 net/rfkill/core.c:1145 2 locks held by syz-executor/14932: #0: ffff888056d86118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:478 [inline] #0: ffff888056d86118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline] #0: ffff888056d86118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:616 #1: ffffffff905920c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 5 locks held by kworker/u8:8/15207: 2 locks held by syz.5.3885/15254: #0: ffff88802815a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffffff905920c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 3 locks held by syz.1.3887/15260: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 #1: ffff88802f558100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #1: ffff88802f558100 (&dev->mutex){....}-{4:4}, at: nfc_register_device+0x9a/0x3c0 net/nfc/core.c:1128 #2: ffffffff905920c8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 1 lock held by syz.0.3895/15284: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz.6.3911/15322: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15332: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15333: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15335: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15337: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15339: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15346: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15347: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15349: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15351: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15353: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15360: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15361: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15363: #0: ffffffff8f0743e8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15365: #0: ffffffff8f0743e8 (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] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 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 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: c7 6c 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 e3 74 29 00 fb f4 3c 0a 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: 00000000002ec355 RBX: 0000000000000000 RCX: ffffffff8b60b2a9 RDX: 0000000000000000 RSI: ffffffff8da2bfb6 RDI: ffffffff8bf070c0 RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e097a00 R14: ffffffff908212d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124a05000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560e52f2bad0 CR3: 000000000e182000 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:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4e0 init/main.c:1111 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