syzbot

==================================================================
BUG: KCSAN: data-race in dev_get_tstats64 / udp_tunnel6_xmit_skb

write to 0xffffe8ffffd53f90 of 8 bytes by task 3695 on cpu 1:
 iptunnel_xmit_stats include/net/ip_tunnels.h:449 [inline]
 ip6tunnel_xmit include/net/ip6_tunnel.h:165 [inline]
 udp_tunnel6_xmit_skb+0x392/0x490 net/ipv6/ip6_udp_tunnel.c:109
 send6+0x2ed/0x3b0 drivers/net/wireguard/socket.c:152
 wg_socket_send_skb_to_peer+0xbb/0x130 drivers/net/wireguard/socket.c:177
 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline]
 wg_packet_tx_worker+0x142/0x360 drivers/net/wireguard/send.c:276
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffffe8ffffd53f90 of 8 bytes by task 8418 on cpu 0:
 dev_fetch_sw_netstats net/core/dev.c:10560 [inline]
 dev_get_tstats64+0xfa/0x1d0 net/core/dev.c:10583
 dev_get_stats+0x65/0x180 net/core/dev.c:10525
 rtnl_fill_stats+0x45/0x320 net/core/rtnetlink.c:1211
 rtnl_fill_ifinfo+0xe98/0x2440 net/core/rtnetlink.c:1783
 rtmsg_ifinfo_build_skb+0xa8/0x130 net/core/rtnetlink.c:3798
 rtmsg_ifinfo_event net/core/rtnetlink.c:3830 [inline]
 rtmsg_ifinfo+0x58/0xc0 net/core/rtnetlink.c:3839
 __dev_notify_flags+0x63/0x3a0 net/core/dev.c:8691
 dev_change_flags+0xa2/0xc0 net/core/dev.c:8733
 do_setlink+0x746/0x2280 net/core/rtnetlink.c:2708
 __rtnl_newlink net/core/rtnetlink.c:3376 [inline]
 rtnl_newlink+0xe7e/0x1310 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x728/0x7c0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2502
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5571
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x5fc/0x6c0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x6f8/0x7c0 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 __sys_sendto+0x2a8/0x370 net/socket.c:1977
 __do_sys_sendto net/socket.c:1989 [inline]
 __se_sys_sendto net/socket.c:1985 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:1985
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8418 Comm: syz-executor.0 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================