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BUG: KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit

read-write to 0xffff888136b95168 of 8 bytes by task 12663 on cpu 0:
 ip6_tnl_start_xmit+0x883/0xa90 net/ipv6/ip6_tunnel.c:1444
 __netdev_start_xmit include/linux/netdevice.h:4805 [inline]
 netdev_start_xmit include/linux/netdevice.h:4819 [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:4255
 dev_queue_xmit include/linux/netdevice.h:2994 [inline]
 neigh_connected_output+0x266/0x2a0 net/core/neighbour.c:1557
 neigh_output include/net/neighbour.h:549 [inline]
 ip6_finish_output2+0xa12/0xc30 net/ipv6/ip6_output.c:134
 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
 ip6_finish_output+0x395/0x4f0 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x10e/0x210 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:451 [inline]
 ip6_local_out+0x60/0x80 net/ipv6/output_core.c:161
 ip6_send_skb net/ipv6/ip6_output.c:1947 [inline]
 ip6_push_pending_frames+0xb6/0x170 net/ipv6/ip6_output.c:1967
 rawv6_push_pending_frames+0x3a2/0x3f0 net/ipv6/raw.c:613
 rawv6_sendmsg+0xd56/0xe40 net/ipv6/raw.c:956
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2488
 ___sys_sendmsg net/socket.c:2542 [inline]
 __sys_sendmmsg+0x5c3/0x6a0 net/socket.c:2628
 __do_sys_sendmmsg net/socket.c:2657 [inline]
 __se_sys_sendmmsg net/socket.c:2654 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2654
 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 0xffff888136b95168 of 8 bytes by task 12624 on cpu 1:
 ip6_tnl_start_xmit+0x883/0xa90 net/ipv6/ip6_tunnel.c:1444
 __netdev_start_xmit include/linux/netdevice.h:4805 [inline]
 netdev_start_xmit include/linux/netdevice.h:4819 [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:4255
 dev_queue_xmit include/linux/netdevice.h:2994 [inline]
 neigh_connected_output+0x266/0x2a0 net/core/neighbour.c:1557
 neigh_output include/net/neighbour.h:549 [inline]
 ip6_finish_output2+0xa12/0xc30 net/ipv6/ip6_output.c:134
 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
 ip6_finish_output+0x395/0x4f0 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x10e/0x210 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:451 [inline]
 ip6_local_out+0x60/0x80 net/ipv6/output_core.c:161
 ip6_send_skb net/ipv6/ip6_output.c:1947 [inline]
 ip6_push_pending_frames+0xb6/0x170 net/ipv6/ip6_output.c:1967
 rawv6_push_pending_frames+0x3a2/0x3f0 net/ipv6/raw.c:613
 rawv6_sendmsg+0xd56/0xe40 net/ipv6/raw.c:956
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2488
 ___sys_sendmsg net/socket.c:2542 [inline]
 __sys_sendmmsg+0x5c3/0x6a0 net/socket.c:2628
 __do_sys_sendmmsg net/socket.c:2657 [inline]
 __se_sys_sendmmsg net/socket.c:2654 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2654
 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: 0x00000000000014c1 -> 0x00000000000014c3

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12624 Comm: syz-executor.1 Not tainted 5.19.0-rc7-syzkaller-00007-g353f7988dd84-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
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