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BUG: KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit

read-write to 0xffff888138a50158 of 8 bytes by task 24447 on cpu 0:
 ip6_tnl_start_xmit+0x866/0xa90 net/ipv6/ip6_tunnel.c:1441
 __netdev_start_xmit include/linux/netdevice.h:4840 [inline]
 netdev_start_xmit include/linux/netdevice.h:4854 [inline]
 xmit_one+0xc0/0x2a0 net/core/dev.c:3590
 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3606
 __dev_queue_xmit+0x84c/0xfe0 net/core/dev.c:4256
 dev_queue_xmit include/linux/netdevice.h:3008 [inline]
 neigh_connected_output+0x266/0x2a0 net/core/neighbour.c:1581
 neigh_output include/net/neighbour.h:546 [inline]
 ip_finish_output2+0x74d/0x850 net/ipv4/ip_output.c:228
 ip_finish_output+0xf3/0x250 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:430
 dst_output include/net/dst.h:445 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1586
 udp_send_skb+0x626/0x860 net/ipv4/udp.c:971
 udp_sendmsg+0x114b/0x1200 net/ipv4/udp.c:1258
 udpv6_sendmsg+0x64e/0x14a0
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:665
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2482
 ___sys_sendmsg net/socket.c:2536 [inline]
 __sys_sendmmsg+0x27c/0x4a0 net/socket.c:2622
 __do_sys_sendmmsg net/socket.c:2651 [inline]
 __se_sys_sendmmsg net/socket.c:2648 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2648
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read-write to 0xffff888138a50158 of 8 bytes by task 24455 on cpu 1:
 ip6_tnl_start_xmit+0x866/0xa90 net/ipv6/ip6_tunnel.c:1441
 __netdev_start_xmit include/linux/netdevice.h:4840 [inline]
 netdev_start_xmit include/linux/netdevice.h:4854 [inline]
 xmit_one+0xc0/0x2a0 net/core/dev.c:3590
 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3606
 __dev_queue_xmit+0x84c/0xfe0 net/core/dev.c:4256
 dev_queue_xmit include/linux/netdevice.h:3008 [inline]
 neigh_connected_output+0x266/0x2a0 net/core/neighbour.c:1581
 neigh_output include/net/neighbour.h:546 [inline]
 ip_finish_output2+0x74d/0x850 net/ipv4/ip_output.c:228
 ip_finish_output+0xf3/0x250 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:291 [inline]
 ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:430
 dst_output include/net/dst.h:445 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1586
 udp_send_skb+0x626/0x860 net/ipv4/udp.c:971
 udp_sendmsg+0x114b/0x1200 net/ipv4/udp.c:1258
 udpv6_sendmsg+0x64e/0x14a0
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:665
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2482
 ___sys_sendmsg net/socket.c:2536 [inline]
 __sys_sendmmsg+0x27c/0x4a0 net/socket.c:2622
 __do_sys_sendmmsg net/socket.c:2651 [inline]
 __se_sys_sendmmsg net/socket.c:2648 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2648
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000000005a9 -> 0x00000000000005aa

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24455 Comm: syz-executor.1 Not tainted 6.1.0-rc4-syzkaller-00362-gfef7fd48922d-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
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syz-executor.1 (24455) used greatest stack depth: 9872 bytes left