IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready 8021q: adding VLAN 0 to HW filter on device team0 ====================================================== WARNING: possible circular locking dependency detected 4.20.0-rc6-next-20181213+ #170 Not tainted ------------------------------------------------------ syz-executor594/6043 is trying to acquire lock: 00000000ba24bb99 (&tbl->lock){+.-.}, at: neigh_change_state+0x1dc/0x7a0 net/core/neighbour.c:141 but task is already holding lock: 00000000ee97b6c2 (&n->lock){++--}, at: __neigh_update+0xe6/0x1eb0 net/core/neighbour.c:1203 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&n->lock){++--}: __raw_write_lock include/linux/rwlock_api_smp.h:210 [inline] _raw_write_lock+0x2d/0x40 kernel/locking/spinlock.c:288 neigh_flush_dev+0x34f/0x960 net/core/neighbour.c:294 neigh_changeaddr+0x31/0x40 net/core/neighbour.c:325 ndisc_netdev_event+0xe6/0x5b0 net/ipv6/ndisc.c:1770 notifier_call_chain+0x17e/0x380 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1737 call_netdevice_notifiers_extack net/core/dev.c:1749 [inline] call_netdevice_notifiers net/core/dev.c:1763 [inline] dev_set_mac_address+0x293/0x3b0 net/core/dev.c:7780 do_setlink+0x7c7/0x3f30 net/core/rtnetlink.c:2447 __rtnl_newlink+0xcde/0x19e0 net/core/rtnetlink.c:3115 rtnl_newlink+0x6b/0xa0 net/core/rtnetlink.c:3240 rtnetlink_rcv_msg+0x46a/0xc20 net/core/rtnetlink.c:4969 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4987 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2117 __sys_sendmsg+0x11d/0x280 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&tbl->lock){+.-.}: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline] _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312 neigh_change_state+0x1dc/0x7a0 net/core/neighbour.c:141 __neigh_update+0x478/0x1eb0 net/core/neighbour.c:1302 neigh_update+0x37/0x50 net/core/neighbour.c:1372 arp_req_set+0x54c/0xaa0 net/ipv4/arp.c:1072 arp_ioctl+0x48b/0xae0 net/ipv4/arp.c:1230 inet_ioctl+0x237/0x360 net/ipv4/af_inet.c:932 sock_do_ioctl+0xeb/0x420 net/socket.c:951 sock_ioctl+0x313/0x690 net/socket.c:1075 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&n->lock); lock(&tbl->lock); lock(&n->lock); lock(&tbl->lock); *** DEADLOCK *** 2 locks held by syz-executor594/6043: #0: 000000004e44c6b9 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 #1: 00000000ee97b6c2 (&n->lock){++--}, at: __neigh_update+0xe6/0x1eb0 net/core/neighbour.c:1203 stack backtrace: CPU: 0 PID: 6043 Comm: syz-executor594 Not tainted 4.20.0-rc6-next-20181213+ #170 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+0x244/0x39d lib/dump_stack.c:113 print_circular_bug.isra.35.cold.56+0x1bd/0x27d kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2347 [inline] __lock_acquire+0x3399/0x4c20 kernel/locking/lockdep.c:3341 lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline] _raw_write_lock_bh+0x31/0x40 kernel/locking/spinlock.c:312 neigh_change_state+0x1dc/0x7a0 net/core/neighbour.c:141 __neigh_update+0x478/0x1eb0 net/core/neighbour.c:1302 neigh_update+0x37/0x50 net/core/neighbour.c:1372 arp_req_set+0x54c/0xaa0 net/ipv4/arp.c:1072 arp_ioctl+0x48b/0xae0 net/ipv4/arp.c:1230 inet_ioctl+0x237/0x360 net/ipv4/af_inet.c:932 sock_do_ioctl+0xeb/0x420 net/socket.c:951 sock_ioctl+0x313/0x690 net/socket.c:1075 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441299 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 db 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff9d27e828 EFLAGS: 00000203 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000020000040 RCX: 0000000000441299 RDX: 0000000020000040 RSI: 0000000000008955 RDI: 0000000000000003 RBP: 00000000006cc018 R08: 0000000000000100 R09: 0000000000000100 R10: 0000000000000100 R11: 0000000000000203 R12: 0000000000402200 R13: 0000000000402290 R14: 0000000000000000 R15: 0000000000000000 kobject: 'regulatory.0' (0000000003ff8dec): kobject_uevent_env kobject: 'regulatory.0' (0000000003ff8dec): fill_kobj_path: path = '/devices/platform/regulatory.0'