BUG: MAX_LOCKDEP_CHAINS too low! turning off the locking correctness validator. CPU: 1 PID: 8400 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026 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 __mutex_lock_common+0x190/0x1f60 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 nsim_dev_hwstats_event_unregister drivers/net/netdevsim/hwstats.c:174 [inline] nsim_dev_hwstats_event drivers/net/netdevsim/hwstats.c:192 [inline] nsim_dev_netdevice_event+0x198/0x654 drivers/net/netdevsim/hwstats.c:207 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:2011 [inline] call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] unregister_netdevice_many+0xe40/0x177c net/core/dev.c:11016 unregister_netdevice_queue+0x2b0/0x304 net/core/dev.c:10947 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:1260 [inline] device_release_driver_internal+0x3d4/0x6d0 drivers/base/dd.c:1286 device_release_driver+0x28/0x38 drivers/base/dd.c:1309 bus_remove_device+0x294/0x384 drivers/base/bus.c:531 device_del+0x580/0x984 drivers/base/core.c:3885 device_unregister+0x2c/0xc8 drivers/base/core.c:3928 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+0x98/0x2b4 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 netdevsim netdevsim1 netdevsim0: renamed from eth0 netdevsim netdevsim1 netdevsim1: renamed from eth1 netdevsim netdevsim1 netdevsim2: renamed from eth2 netdevsim netdevsim1 netdevsim3: renamed from eth3 8021q: adding VLAN 0 to HW filter on device bond0 8021q: adding VLAN 0 to HW filter on device team0 IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready 8021q: adding VLAN 0 to HW filter on device batadv0 device veth0_vlan entered promiscuous mode device veth1_vlan entered promiscuous mode device veth0_macvtap entered promiscuous mode device veth1_macvtap entered promiscuous mode batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: batadv0: Interface activated: batadv_slave_0 batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3f) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3f) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3f) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3f) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3f) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: batadv0: Interface activated: batadv_slave_1 netdevsim netdevsim1 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0 ieee80211 phy25: Selected rate control algorithm 'minstrel_ht' ieee80211 phy26: Selected rate control algorithm 'minstrel_ht'