INFO: task kworker/0:8:4408 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:20944 pid:4408 ppid:2 flags:0x00004000 Workqueue: events rfkill_global_led_trigger_worker Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 rfkill_global_led_trigger_worker+0x23/0xc0 net/rfkill/core.c:181 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task syz.4.186:5258 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.186 state:D stack:26240 pid:5258 ppid:4264 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 rfkill_unregister+0xc4/0x220 net/rfkill/core.c:1130 nfc_unregister_device+0x92/0x290 net/nfc/core.c:1167 virtual_ncidev_close+0x55/0x90 drivers/nfc/virtual_ncidev.c:170 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f887358f749 RSP: 002b:00007ffced527838 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000002362f RCX: 00007f887358f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f88737e7da0 R08: 0000000000000001 R09: 0000001eed527b2f R10: 0000001b2e520000 R11: 0000000000000246 R12: 00007f88737e5fac R13: 00007f88737e5fa0 R14: ffffffffffffffff R15: 00007ffced527950 INFO: task syz.3.188:5269 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.188 state:D stack:25728 pid:5269 ppid:4263 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 device_lock include/linux/device.h:840 [inline] nfc_dev_down net/nfc/core.c:143 [inline] nfc_rfkill_set_block+0x4c/0x2d0 net/nfc/core.c:179 rfkill_set_block+0x1c6/0x420 net/rfkill/core.c:345 rfkill_fop_write+0x458/0x560 net/rfkill/core.c:1286 vfs_write+0x2c4/0x960 fs/read_write.c:582 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f516a58f749 RSP: 002b:00007f516b369038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f516a7e5fa0 RCX: 00007f516a58f749 RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007f516a613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f516a7e6038 R14: 00007f516a7e5fa0 R15: 00007ffcb6917598 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4022: #0: ffff88802f7cb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 5 locks held by kworker/1:9/4388: #0: ffff888143e8e938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000490fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888027b0f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #2: ffff888027b0f190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x54e0 drivers/usb/core/hub.c:5845 #3: ffff888054c2e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #3: ffff888054c2e190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990 #4: ffff8880567fd118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #4: ffff8880567fd118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990 3 locks held by kworker/0:8/4408: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900049cfd00 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_global_led_trigger_worker+0x23/0xc0 net/rfkill/core.c:181 2 locks held by syz.4.186/5258: #0: ffff88802d55c100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #0: ffff88802d55c100 (&dev->mutex){....}-{3:3}, at: nfc_unregister_device+0x5f/0x290 net/nfc/core.c:1165 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_unregister+0xc4/0x220 net/rfkill/core.c:1130 2 locks held by syz.3.188/5269: #0: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x19e/0x560 net/rfkill/core.c:1278 #1: ffff88802d55c100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #1: ffff88802d55c100 (&dev->mutex){....}-{3:3}, at: nfc_dev_down net/nfc/core.c:143 [inline] #1: ffff88802d55c100 (&dev->mutex){....}-{3:3}, at: nfc_rfkill_set_block+0x4c/0x2d0 net/nfc/core.c:179 2 locks held by syz-executor/5574: #0: ffff888072c77118 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5575: #0: ffff888056768918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz.2.243/5603: #0: ffffffff8db9b3f0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffffffff8db9b208 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8db9b208 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x103/0x780 net/netlink/genetlink.c:848 3 locks held by syz.1.248/5595: #0: ffffffff8db9b3f0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffffffff8db9b208 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8db9b208 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x103/0x780 net/netlink/genetlink.c:848 #2: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz.0.253/5611: #0: ffffffff8db9b3f0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffffffff8db9b208 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8db9b208 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x103/0x780 net/netlink/genetlink.c:848 2 locks held by syz.0.253/5612: #0: ffffffff8db9b3f0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffffffff8db9b208 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8db9b208 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x103/0x780 net/netlink/genetlink.c:848 2 locks held by syz-executor/5620: #0: ffff88807c884118 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5623: #0: ffff888079b66918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5624: #0: ffff888079b61918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5627: #0: ffff888055c80118 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5628: #0: ffff8880580d5918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5631: #0: ffff888072da4918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5634: #0: ffff888054a68918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5635: #0: ffff88801fb6a918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5641: #0: ffff888055e27118 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 2 locks held by syz-executor/5642: #0: ffff888055e25918 (&data->open_mutex){+.+.}-{3:3}, at: vhci_create_device+0x34/0x740 drivers/bluetooth/hci_vhci.c:378 #1: ffffffff8ddf7488 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_register+0x33/0x8a0 net/rfkill/core.c:1057 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3625 Comm: klogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_switch+0x3f/0xe0 kernel/kcov.c:-1 Code: 00 b8 8b 00 00 00 0f a3 c8 0f 83 b3 00 00 00 48 8b 06 48 85 c0 0f 84 a7 00 00 00 41 57 41 56 41 54 53 48 8b 0c cd 78 1a 70 8a <48> 8b 54 24 20 65 4c 8b 05 c4 8a 81 7e 45 31 c9 eb 08 49 ff c1 4c RSP: 0018:ffffc90003297930 EFLAGS: 00000202 RAX: 0000000000000002 RBX: 00000000ffffef89 RCX: 0000000000000005 RDX: 0000000000000000 RSI: ffffffff8c922950 RDI: 0000000000000002 RBP: ffffffff8c81e558 R08: dffffc0000000000 R09: fffffbfff1903cac R10: fffffbfff1903cac R11: 1ffffffff1903cab R12: 00000000ffffef89 R13: 0000000000000002 R14: 00000000ffffe000 R15: 80000000ffffef89 FS: 00007f712482bc80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055faeb2de000 CR3: 000000002e144000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: desc_read+0x174/0x3f0 kernel/printk/printk_ringbuffer.c:445 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1763 [inline] prb_read kernel/printk/printk_ringbuffer.c:1811 [inline] _prb_read_valid+0x26e/0xa10 kernel/printk/printk_ringbuffer.c:1891 prb_read_valid+0x39/0x60 kernel/printk/printk_ringbuffer.c:1940 syslog_print+0x244/0x590 kernel/printk/printk.c:1526 do_syslog+0x7bd/0x8b0 kernel/printk/printk.c:1679 __do_sys_syslog kernel/printk/printk.c:1771 [inline] __se_sys_syslog kernel/printk/printk.c:1769 [inline] __x64_sys_syslog+0x78/0x90 kernel/printk/printk.c:1769 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f71249f5a37 Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc6496c788 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f7124b95490 RCX: 00007f71249f5a37 RDX: 00000000000003ff RSI: 00007f7124b95490 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f7124b95490 R13: 00007f7124b72dfe R14: 00007f7124b954c2 R15: 00007f7124b954c2