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BUG: KCSAN: data-race in vti_tunnel_xmit / vti_tunnel_xmit

read to 0xffff8880b5749138 of 8 bytes by task 9126 on cpu 1:
 vti_tunnel_xmit+0x293/0xa50 net/ipv4/ip_vti.c:282
 __netdev_start_xmit include/linux/netdevice.h:4420 [inline]
 netdev_start_xmit include/linux/netdevice.h:4434 [inline]
 xmit_one net/core/dev.c:3280 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3296
 __dev_queue_xmit+0x14c9/0x1b60 net/core/dev.c:3873
 dev_queue_xmit+0x21/0x30 net/core/dev.c:3906
 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a6/0xec0 net/ipv6/ip6_output.c:116
 ip6_fragment+0xcac/0x1220 net/ipv6/ip6_output.c:916
 __ip6_finish_output net/ipv6/ip6_output.c:140 [inline]
 __ip6_finish_output+0x2f9/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1792
 ip6_push_pending_frames+0x9d/0xc0 net/ipv6/ip6_output.c:1812
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x1d22/0x21e0 net/ipv6/raw.c:956

write to 0xffff8880b5749138 of 8 bytes by task 9131 on cpu 0:
 vti_tunnel_xmit+0x2a6/0xa50 net/ipv4/ip_vti.c:282
 __netdev_start_xmit include/linux/netdevice.h:4420 [inline]
 netdev_start_xmit include/linux/netdevice.h:4434 [inline]
 xmit_one net/core/dev.c:3280 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3296
 __dev_queue_xmit+0x14c9/0x1b60 net/core/dev.c:3873
 dev_queue_xmit+0x21/0x30 net/core/dev.c:3906
 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a6/0xec0 net/ipv6/ip6_output.c:116
 ip6_fragment+0xcac/0x1220 net/ipv6/ip6_output.c:916
 __ip6_finish_output net/ipv6/ip6_output.c:140 [inline]
 __ip6_finish_output+0x2f9/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1792
 ip6_push_pending_frames+0x9d/0xc0 net/ipv6/ip6_output.c:1812

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9131 Comm: syz-executor.0 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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