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:21048 pid:5833 tgid:5833 ppid:1 task_flags:0x40014c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7009 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 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+0x1d4/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6c5/0x2310 kernel/exit.c:973 do_group_exit+0x21c/0x2d0 kernel/exit.c:1114 __do_sys_exit_group kernel/exit.c:1125 [inline] __se_sys_exit_group kernel/exit.c:1123 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1123 x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1de1f8f749 RSP: 002b:00007ffd8cf39828 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f1de2013da2 RCX: 00007f1de1f8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000002 R08: 00007ffd8cf375c7 R09: 00007ffd8cf3aae0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd8cf3aae0 R13: 00007f1de2013d7d R14: 00000000000850dd R15: 00007ffd8cf3bbb0 INFO: task kworker/0:6:5969 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:19320 pid:5969 tgid:5969 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events rfkill_global_led_trigger_worker Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7009 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 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:246 INFO: task syz-executor:14675 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:19424 pid:14675 tgid:14675 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7009 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 rfkill_fop_open+0x12d/0x820 net/rfkill/core.c:1178 misc_open+0x2d5/0x350 drivers/char/misc.c:163 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x340e/0x3dd0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7bdfb8df90 RSP: 002b:00007ffdd10c5f70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f7bdfb8df90 RDX: 0000000000000002 RSI: 00007f7bdfc14a62 RDI: 00000000ffffff9c RBP: 00007f7bdfc14a62 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffdd10c6348 R15: 0000000000000000 INFO: task syz.5.2499:14930 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.2499 state:D stack:22960 pid:14930 tgid:14930 ppid:5831 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7009 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 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+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+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f784fd8f749 RSP: 002b:00007ffcfe36a758 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f784ffe7da0 RCX: 00007f784fd8f749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f784ffe7da0 R08: 000000000000125c R09: 0000001bfe36aa4f R10: 00007f784ffe7cb0 R11: 0000000000000246 R12: 00000000000842b8 R13: 00007f784ffe6360 R14: ffffffffffffffff R15: 00007ffcfe36a870 INFO: task syz.0.2519:15045 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2519 state:D stack:27672 pid:15045 tgid:15044 ppid:5825 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7009 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 misc_open+0x51/0x350 drivers/char/misc.c:125 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x340e/0x3dd0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2afff8df90 RSP: 002b:00007f2b00ed8ef0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f2afff8df90 RDX: 0000000000000002 RSI: 00007f2b00013c6c RDI: 00000000ffffff9c RBP: 00007f2b00013c6c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000036 R14: 0000200000000080 R15: 00007ffcbabe4388 INFO: task syz.1.2522:15056 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2522 state:D stack:28152 pid:15056 tgid:15055 ppid:5826 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7009 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 misc_open+0x51/0x350 drivers/char/misc.c:125 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x340e/0x3dd0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f746478df90 RSP: 002b:00007f746570cef0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f746478df90 RDX: 0000000000000002 RSI: 00007f7464813c6c RDI: 00000000ffffff9c RBP: 00007f7464813c6c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 0000000000000024 R14: 0000200000000080 R15: 00007ffd271da048 INFO: task syz.8.2523:15062 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.2523 state:D stack:28152 pid:15062 tgid:15061 ppid:12242 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7009 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 misc_open+0x51/0x350 drivers/char/misc.c:125 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x340e/0x3dd0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6980f8df90 RSP: 002b:00007f6981e0fef0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f6980f8df90 RDX: 0000000000000002 RSI: 00007f6981013c6c RDI: 00000000ffffff9c RBP: 00007f6981013c6c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 0000000000000024 R14: 0000200000000080 R15: 00007fff548b67e8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df42000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df42000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df42000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by klogd/5185: #0: ffff8880b883a698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 2 locks held by getty/5586: #0: ffff88803054c0a0 (&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 1 lock held by syz-executor/5833: #0: ffffffff8f5de4e8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 4 locks held by kworker/0:4/5934: #0: ffff88801a051948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a051948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3346 #1: ffffc900045dfb80 ((rfkill_op_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900045dfb80 ((rfkill_op_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3346 #2: ffffffff8f5de4e8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_epo+0x4c/0x180 net/rfkill/core.c:462 #3: ffff88805452a100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff88805452a100 (&dev->mutex){....}-{4:4}, at: nfc_dev_down net/nfc/core.c:143 [inline] #3: ffff88805452a100 (&dev->mutex){....}-{4:4}, at: nfc_rfkill_set_block+0x50/0x2e0 net/nfc/core.c:179 3 locks held by kworker/0:6/5969: #0: ffff88801a051948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a051948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3346 #1: ffffc90004acfb80 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004acfb80 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3346 #2: ffffffff8f5de4e8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182 2 locks held by syz-executor/14675: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 #1: ffffffff8f5de4e8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_fop_open+0x12d/0x820 net/rfkill/core.c:1178 2 locks held by syz.5.2499/14930: #0: ffff88805452a100 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #0: ffff88805452a100 (&dev->mutex){....}-{4:4}, at: nfc_unregister_device+0x63/0x2a0 net/nfc/core.c:1165 #1: ffffffff8f5de4e8 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 1 lock held by syz.0.2519/15045: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz.1.2522/15056: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz.8.2523/15062: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15078: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15129: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15131: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15133: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15135: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15142: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15144: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15146: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15148: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15150: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15152: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15159: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15161: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15163: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15165: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15167: #0: ffffffff8e78cc28 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 1 lock held by syz-executor/15169: #0: ffffffff8e78cc28 (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 10/25/2025 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:332 [inline] watchdog+0xf3c/0xf80 kernel/hung_task.c:495 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:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6027 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_is_held_type+0x103/0x190 kernel/locking/lockdep.c:5941 Code: 74 12 31 c0 f6 43 22 03 0f 95 c0 31 db 39 c5 0f 94 c3 eb 05 bb 01 00 00 00 48 c7 c7 09 db 94 8d e8 e2 19 00 00 b8 ff ff ff ff <65> 0f c1 05 25 bf 2f 07 83 f8 01 75 44 48 c7 04 24 00 00 00 00 9c RSP: 0018:ffffc90004c3f690 EFLAGS: 00000082 RAX: 00000000ffffffff RBX: 0000000000000001 RCX: cbef24d2784e7a00 RDX: 0000000000000003 RSI: ffffffff8d94db09 RDI: ffffffff8bbfc000 RBP: 00000000ffffffff R08: ffffffff8193beb8 R09: ffffffff8df42000 R10: dffffc0000000000 R11: ffffffff819728f0 R12: 0000000000000046 R13: ffff888079869e80 R14: ffff8880b883a698 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8881260c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055906377f000 CR3: 000000000dd3a000 CR4: 0000000000350ef0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] lockdep_assert_rq_held kernel/sched/sched.h:1547 [inline] rq_clock_task kernel/sched/sched.h:1703 [inline] set_next_task_idle+0x98/0x1d0 kernel/sched/idle.c:470 put_prev_set_next_task kernel/sched/sched.h:2643 [inline] pick_next_task kernel/sched/core.c:6190 [inline] __schedule+0x392d/0x5000 kernel/sched/core.c:6797 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0x165/0x360 kernel/sched/core.c:6952 toggle_allocation_gate+0x159/0x240 mm/kfence/core.c:854 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 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:246