INFO: task kworker/1:3:5896 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:3 state:D stack:20120 pid:5896 tgid:5896 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: events rfkill_global_led_trigger_worker Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872 __schedule_loop kernel/sched/core.c:6954 [inline] schedule+0x165/0x360 kernel/sched/core.c:6969 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026 __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+0x94a/0x15d0 kernel/workqueue.c:3267 process_scheduled_works kernel/workqueue.c:3350 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task kworker/1:6:5917 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:6 state:D stack:20504 pid:5917 tgid:5917 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events rfkill_sync_work Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872 __schedule_loop kernel/sched/core.c:6954 [inline] schedule+0x165/0x360 kernel/sched/core.c:6969 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026 __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+0x3b/0x290 net/nfc/core.c:143 nfc_rfkill_set_block+0x2d/0x100 net/nfc/core.c:179 rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346 rfkill_sync net/rfkill/core.c:379 [inline] rfkill_sync_work+0x114/0x200 net/rfkill/core.c:1056 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267 process_scheduled_works kernel/workqueue.c:3350 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.0.1693:11998 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1693 state:D stack:27808 pid:11998 tgid:11998 ppid:5824 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872 __schedule_loop kernel/sched/core.c:6954 [inline] schedule+0x165/0x360 kernel/sched/core.c:6969 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4277 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4397 rfkill_unregister+0x92/0x220 net/rfkill/core.c:1139 nfc_unregister_device+0x96/0x300 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+0x1d4/0x260 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+0xff/0x4f0 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+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe50f78f6c9 RSP: 002b:00007ffe841da318 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000065535 RCX: 00007fe50f78f6c9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fe50f9e7da0 R08: 0000000000000001 R09: 00000011841da60f R10: 0000001b2fa20000 R11: 0000000000000246 R12: 00007fe50f9e5fac R13: 00007fe50f9e5fa0 R14: ffffffffffffffff R15: 00007ffe841da430 INFO: task syz-executor:12007 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:27400 pid:12007 tgid:12007 ppid:1 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5264 [inline] __schedule+0x1848/0x4ec0 kernel/sched/core.c:6872 __schedule_loop kernel/sched/core.c:6954 [inline] schedule+0x165/0x360 kernel/sched/core.c:6969 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7026 __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+0x3f2/0x8b0 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+0x5c9/0xb30 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/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efcf798e140 RSP: 002b:00007ffdf5ae5088 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007efcf798e140 RDX: 0000000000000002 RSI: 00007ffdf5ae509a RDI: 00000000000000ca RBP: 00007efcf7be67b8 R08: 0000000000000000 R09: 00007efcf871d6c0 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffdf5ae53e8 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33b720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33b720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33b720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by klogd/5185: #0: ffff8880b863a3d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638 2 locks held by getty/5584: #0: ffff88814d8bd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:3/5896: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242 #1: ffffc900044bfb80 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243 #2: ffffffff8f9d0f48 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182 4 locks held by kworker/1:6/5917: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15d0 kernel/workqueue.c:3242 #1: ffffc900045dfb80 ((work_completion)(&rfkill->sync_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15d0 kernel/workqueue.c:3243 #2: ffffffff8f9d0f48 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_sync_work+0x2e/0x200 net/rfkill/core.c:1055 #3: ffff88805e2c6100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff88805e2c6100 (&dev->mutex){....}-{4:4}, at: nfc_dev_down+0x3b/0x290 net/nfc/core.c:143 1 lock held by syz.2.353/7204: #0: ffffffff8f9d0f48 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 1 lock held by syz.0.1693/11998: #0: ffff88805e2c6100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff88805e2c6100 (&dev->mutex){....}-{4:4}, at: nfc_unregister_device+0x63/0x300 net/nfc/core.c:1165 2 locks held by syz-executor/12007: #0: ffff888031d1b118 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device+0x34/0x650 drivers/bluetooth/hci_vhci.c:478 #1: ffffffff8f9d0f48 (rfkill_global_mutex){+.+.}-{4:4} , at: rfkill_register+0x37/0x8e0 net/rfkill/core.c:1071 2 locks held by syz-executor/12170: #0: ffff88807d7f8918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device+0x34/0x650 drivers/bluetooth/hci_vhci.c:478 #1: ffffffff8f9d0f48 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x37/0x8e0 net/rfkill/core.c:1071 2 locks held by syz.1.1790/12299: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 #1: ffffffff8f9d0f48 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_open+0x12d/0x820 net/rfkill/core.c:1178 1 lock held by syz.3.1791/12302: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz.3.1791/12303: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/12308: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/12309: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/12311: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/12313: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/12319: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/12320: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/12322: #0: ffffffff8eb94a08 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/12324: #0: ffffffff8eb94a08 ( misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 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 10/02/2025 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:336 [inline] watchdog+0xfa9/0xff0 kernel/hung_task.c:499 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 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: 1224 Comm: kworker/0:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 9e cf 9b fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 5f 3a 02 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 5a 9d 42 06 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc9000425f2d0 EFLAGS: 00000002 RAX: 1ffffffff33f5e00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff99faf750 R08: ffff888022f70237 R09: 1ffff110045ee046 R10: dffffc0000000000 R11: ffffffff85260040 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99faf4c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125a79000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc5b642478 CR3: 000000004213c000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:1961 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3108 [inline] console_flush_one_record kernel/printk/printk.c:3194 [inline] console_flush_all+0x6f6/0xb10 kernel/printk/printk.c:3268 __console_flush_and_unlock kernel/printk/printk.c:3298 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3338 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423 _printk+0xcf/0x120 kernel/printk/printk.c:2448 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_query+0x2f6/0x830 drivers/media/usb/dvb-usb/m920x.c:-1 legacy_dvb_usb_read_remote_control+0x100/0x470 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123 process_one_work+0x94a/0x15d0 kernel/workqueue.c:3267 process_scheduled_works kernel/workqueue.c:3350 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3431 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245