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BUG: KCSAN: data-race in vti_tunnel_xmit / vti_tunnel_xmit

read to 0xffff8880b6252138 of 8 bytes by task 14347 on cpu 1:
 vti_tunnel_xmit+0x293/0xa50 net/ipv4/ip_vti.c:282
 __netdev_start_xmit include/linux/netdevice.h:4413 [inline]
 netdev_start_xmit include/linux/netdevice.h:4427 [inline]
 dev_direct_xmit+0x283/0x390 net/core/dev.c:3858
 packet_direct_xmit+0xe3/0x140 net/packet/af_packet.c:240
 packet_snd net/packet/af_packet.c:2959 [inline]
 packet_sendmsg+0x1e91/0x3af0 net/packet/af_packet.c:2984
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311
 __sys_sendmmsg+0x123/0x350 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880b6252138 of 8 bytes by task 14357 on cpu 0:
 vti_tunnel_xmit+0x2a6/0xa50 net/ipv4/ip_vti.c:282
 __netdev_start_xmit include/linux/netdevice.h:4413 [inline]
 netdev_start_xmit include/linux/netdevice.h:4427 [inline]
 dev_direct_xmit+0x283/0x390 net/core/dev.c:3858
 packet_direct_xmit+0xe3/0x140 net/packet/af_packet.c:240
 packet_snd net/packet/af_packet.c:2959 [inline]
 packet_sendmsg+0x1e91/0x3af0 net/packet/af_packet.c:2984
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311
 __sys_sendmmsg+0x123/0x350 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14357 Comm: syz-executor.0 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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