INFO: task kworker/1:4:5872 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:23000 pid:5872 tgid:5872 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events rfkill_sync_work 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_sync_work+0x1b/0x40 net/rfkill/core.c:1055 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/1:2:10795 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:22840 pid:10795 tgid:10795 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+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.7.2257:15228 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.2257 state:D stack:28088 pid:15228 tgid:15228 ppid:12235 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_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:4273 __cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4393 rfkill_unregister+0x95/0x2c0 net/rfkill/core.c:1139 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: 0033:0x7fadac98eec9 RSP: 002b:00007ffcc6917808 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fadacbe7da0 RCX: 00007fadac98eec9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fadacbe7da0 R08: 00000000000000b4 R09: 0000000ac6917aff R10: 00007fadacbe7cb0 R11: 0000000000000246 R12: 00000000000bb198 R13: 00007ffcc6917900 R14: ffffffffffffffff R15: 00007ffcc6917920 INFO: task syz.7.2257:15229 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.2257 state:D stack:25496 pid:15229 tgid:15228 ppid:12235 task_flags:0x400140 flags:0x00080003 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_fop_write+0x2c0/0x580 net/rfkill/core.c:1301 vfs_write+0x2a0/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 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: 0033:0x7fadac98eec9 RSP: 002b:00007fadad7fa038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fadacbe5fa0 RCX: 00007fadac98eec9 RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000003 RBP: 00007fadaca11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fadacbe6038 R14: 00007fadacbe5fa0 R15: 00007ffcc69176a8 INFO: task syz.1.2261:15255 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2261 state:D stack:25656 pid:15255 tgid:15249 ppid:5805 task_flags:0x400140 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_register+0x3a/0xb40 net/rfkill/core.c:1071 hci_register_dev+0x3cc/0xc60 net/bluetooth/hci_core.c:2631 hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:691 [inline] hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:717 [inline] hci_uart_tty_ioctl+0x7e2/0xc30 drivers/bluetooth/hci_ldisc.c:771 tty_ioctl+0x700/0x1680 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 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: 0033:0x7f84a5f8eec9 RSP: 002b:00007f84a6d4a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f84a61e6180 RCX: 00007f84a5f8eec9 RDX: 0000000000000004 RSI: 00000000400455c8 RDI: 0000000000000007 RBP: 00007f84a6011f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f84a61e6218 R14: 00007f84a61e6180 R15: 00007ffe56926868 INFO: task syz.8.2270:15308 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.2270 state:D stack:26664 pid:15308 tgid:15297 ppid:12280 task_flags:0x400140 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_register+0x3a/0xb40 net/rfkill/core.c:1071 hci_register_dev+0x3cc/0xc60 net/bluetooth/hci_core.c:2631 hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:691 [inline] hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:717 [inline] hci_uart_tty_ioctl+0x7e2/0xc30 drivers/bluetooth/hci_ldisc.c:771 tty_ioctl+0x700/0x1680 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 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: 0033:0x7f12cfb8eec9 RSP: 002b:00007f12cddd5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f12cfde6180 RCX: 00007f12cfb8eec9 RDX: 0000000000000004 RSI: 00000000400455c8 RDI: 0000000000000008 RBP: 00007f12cfc11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f12cfde6218 R14: 00007f12cfde6180 R15: 00007fffe0b79028 INFO: task syz.4.2294:15430 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2294 state:D stack:26376 pid:15430 tgid:15426 ppid:5808 task_flags:0x400140 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_register+0x3a/0xb40 net/rfkill/core.c:1071 hci_register_dev+0x3cc/0xc60 net/bluetooth/hci_core.c:2631 hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:691 [inline] hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:717 [inline] hci_uart_tty_ioctl+0x7e2/0xc30 drivers/bluetooth/hci_ldisc.c:771 tty_ioctl+0x700/0x1680 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 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: 0033:0x7f3c1fd8eec9 RSP: 002b:00007f3c20b90038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f3c1ffe6180 RCX: 00007f3c1fd8eec9 RDX: 0000000000000004 RSI: 00000000400455c8 RDI: 0000000000000008 RBP: 00007f3c1fe11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3c1ffe6218 R14: 00007f3c1ffe6180 R15: 00007ffda571f328 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 1 lock held by klogd/5171: #0: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline] #0: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631 2 locks held by getty/5567: #0: ffff88814d3520a0 (&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/1:4/5872: #0: ffff88813ff51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900038cfd00 ((work_completion)(&rfkill->sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_sync_work+0x1b/0x40 net/rfkill/core.c:1055 3 locks held by kworker/1:2/10795: #0: ffff88813ff51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000fec7d00 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x1b/0x160 net/rfkill/core.c:182 1 lock held by syz.7.2257/15228: #0: ffff8880515b4100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff8880515b4100 (&dev->mutex){....}-{4:4}, at: nfc_unregister_device+0x60/0x330 net/nfc/core.c:1165 2 locks held by syz.7.2257/15229: #0: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_write+0x166/0x580 net/rfkill/core.c:1293 #1: ffff8880515b4100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #1: ffff8880515b4100 (&dev->mutex){....}-{4:4}, at: nfc_dev_down+0x2d/0x2e0 net/nfc/core.c:143 2 locks held by syz.1.2261/15255: #0: ffff8880279220a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz.8.2270/15308: #0: ffff88805b26a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz.4.2294/15430: #0: ffff88805940b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz-executor/15458: #0: ffff88805adb6918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:478 [inline] #0: ffff88805adb6918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline] #0: ffff88805adb6918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:616 #1: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz-executor/15459: #0: ffff88802ec6a918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_create_device drivers/bluetooth/hci_vhci.c:478 [inline] #0: ffff88802ec6a918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline] #0: ffff88802ec6a918 (&data->open_mutex){+.+.}-{4:4}, at: vhci_write+0x2b4/0x480 drivers/bluetooth/hci_vhci.c:616 #1: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 2 locks held by syz.6.2308/15467: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 #1: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_open+0x136/0x750 net/rfkill/core.c:1178 3 locks held by syz.6.2308/15472: #0: ffffffff9019ecd0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff9019ed88 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline] #1: ffffffff9019ed88 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline] #1: ffffffff9019ed88 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:57 [inline] #1: ffffffff9019ed88 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x577/0x800 net/netlink/genetlink.c:1209 #2: ffffffff905a3e28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_register+0x3a/0xb40 net/rfkill/core.c:1071 1 lock held by syz-executor/15469: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15475: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15477: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15484: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15485: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15487: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15489: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15491: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15498: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15499: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15501: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15503: #0: ffffffff8f089c68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 1 lock held by syz-executor/15505: #0: ffffffff8f089c68 (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 10/02/2025 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 10/02/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: f7 74 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 43 05 24 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: 0000000004686795 RBX: 0000000000000000 RCX: ffffffff8b6622a9 RDX: 0000000000000000 RSI: ffffffff8db0330f RDI: ffffffff8bf1e2c0 RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e097a00 R14: ffffffff90832dd0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881249d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d2c1db8ad8 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