debugfs: Directory 'hsr0' with parent 'hsr' already present!
Cannot create hsr debugfs directory
BUG: MAX_LOCKDEP_CHAINS too low!
turning off the locking correctness validator.
CPU: 1 PID: 9345 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call trace:
 dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 add_chain_cache kernel/locking/lockdep.c:-1 [inline]
 lookup_chain_cache_add kernel/locking/lockdep.c:3772 [inline]
 validate_chain kernel/locking/lockdep.c:3793 [inline]
 __lock_acquire+0x1864/0x6800 kernel/locking/lockdep.c:5049
 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662
 __timer_delete_sync+0xa0/0x21c kernel/time/timer.c:1556
 timer_delete_sync+0x24/0x34 kernel/time/timer.c:1629
 del_timer_sync include/linux/timer.h:200 [inline]
 lapb_unregister+0x21c/0x4d8 net/lapb/lapb_iface.c:198
 lapbeth_close+0x4c/0xac drivers/net/wan/lapbether.c:349
 __dev_close_many+0x2b0/0x3a0 net/core/dev.c:1585
 dev_close_many+0x1e4/0x440 net/core/dev.c:1610
 dev_close+0x14c/0x204 net/core/dev.c:1636
 lapbeth_device_event+0x264/0x3a8 drivers/net/wan/lapbether.c:466
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455
 call_netdevice_notifiers_info net/core/dev.c:2014 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline]
 call_netdevice_notifiers net/core/dev.c:2066 [inline]
 __dev_close_many+0x194/0x3a0 net/core/dev.c:1559
 dev_close_many+0x1e4/0x440 net/core/dev.c:1610
 unregister_netdevice_many_notify+0x3dc/0x1834 net/core/dev.c:10997
 unregister_netdevice_many net/core/dev.c:11077 [inline]
 unregister_netdevice_queue+0x2b8/0x30c net/core/dev.c:10960
 unregister_netdevice include/linux/netdevice.h:3075 [inline]
 nsim_destroy+0x58/0x164 drivers/net/netdevsim/netdev.c:382
 __nsim_dev_port_del+0x144/0x1a4 drivers/net/netdevsim/dev.c:1433
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1445 [inline]
 nsim_dev_reload_destroy+0x240/0x43c drivers/net/netdevsim/dev.c:1663
 nsim_drv_remove+0x64/0x158 drivers/net/netdevsim/dev.c:1679
 nsim_bus_remove+0x20/0x30 drivers/net/netdevsim/bus.c:246
 device_remove drivers/base/dd.c:548 [inline]
 __device_release_driver drivers/base/dd.c:1280 [inline]
 device_release_driver_internal+0x3d4/0x6d0 drivers/base/dd.c:1306
 device_release_driver+0x28/0x38 drivers/base/dd.c:1329
 bus_remove_device+0x294/0x384 drivers/base/bus.c:531
 device_del+0x580/0x984 drivers/base/core.c:3900
 device_unregister+0x2c/0xc8 drivers/base/core.c:3943
 nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline]
 del_device_store+0x284/0x32c drivers/net/netdevsim/bus.c:219
 bus_attr_store+0x80/0xa4 drivers/base/bus.c:124
 sysfs_kf_write+0x1f8/0x278 fs/sysfs/file.c:136
 kernfs_fop_write_iter+0x348/0x4c0 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x3ec/0x7f0 fs/read_write.c:584
 ksys_write+0x12c/0x224 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585