BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low! turning off the locking correctness validator. CPU: 0 PID: 5435 Comm: syz-executor.5 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 add_chain_cache kernel/locking/lockdep.c:2840 [inline] lookup_chain_cache_add kernel/locking/lockdep.c:2914 [inline] validate_chain kernel/locking/lockdep.c:2935 [inline] __lock_acquire.cold+0x263/0x288 kernel/locking/lockdep.c:3954 lock_acquire+0x197/0x420 kernel/locking/lockdep.c:4484 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] kfree_call_rcu+0x2a9/0x400 kernel/rcu/tree.c:2855 __hw_addr_del_entry net/core/dev_addr_lists.c:107 [inline] __hw_addr_del_entry+0x2dd/0x3b0 net/core/dev_addr_lists.c:88 __hw_addr_del_ex+0x129/0x150 net/core/dev_addr_lists.c:121 __dev_mc_del+0x74/0xd0 net/core/dev_addr_lists.c:806 igmp6_group_dropped+0x2f5/0x9b0 net/ipv6/mcast.c:708 ipv6_mc_down+0x5c/0x120 net/ipv6/mcast.c:2541 ipv6_mc_destroy_dev+0x1a/0x160 net/ipv6/mcast.c:2603 addrconf_ifdown+0xd8a/0x12f0 net/ipv6/addrconf.c:3848 addrconf_notify+0x5a6/0x2270 net/ipv6/addrconf.c:3639 notifier_call_chain+0xc0/0x230 kernel/notifier.c:83 call_netdevice_notifiers_info net/core/dev.c:1948 [inline] call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1933 call_netdevice_notifiers_extack net/core/dev.c:1960 [inline] call_netdevice_notifiers net/core/dev.c:1974 [inline] rollback_registered_many+0x75c/0xe70 net/core/dev.c:8826 unregister_netdevice_many.part.0+0x16/0x1e0 net/core/dev.c:9986 unregister_netdevice_many+0x36/0x50 net/core/dev.c:9985 __rtnl_newlink+0x1265/0x1590 net/core/rtnetlink.c:3374 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3391 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5454 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6b9/0x7d0 net/socket.c:2345 ___sys_sendmsg+0x100/0x170 net/socket.c:2399 __sys_sendmsg+0xec/0x1b0 net/socket.c:2432 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fef74684c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fef746856d4 RCX: 000000000045c849 RDX: 0000000006000000 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009fc R14: 00000000004ccb3c R15: 000000000076bf0c