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BUG: KCSAN: data-race in vti_tunnel_xmit / vti_tunnel_xmit

write to 0xffff8880a9554130 of 8 bytes by task 26311 on cpu 0:
 vti_tunnel_xmit+0x41a/0xb20 net/ipv4/ip_vti.c:291
 __netdev_start_xmit include/linux/netdevice.h:4510 [inline]
 netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3486
 __dev_queue_xmit+0x14e9/0x1ba0 net/core/dev.c:4063
 dev_queue_xmit+0x21/0x30 net/core/dev.c:4096
 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1527
 neigh_output include/net/neighbour.h:510 [inline]
 ip_finish_output2+0x408/0xea0 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:306 [inline]
 __ip_finish_output+0x23a/0x4b0 net/ipv4/ip_output.c:288
 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0xfe/0x230 net/ipv4/ip_output.c:430
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125
 iptunnel_xmit+0x356/0x520 net/ipv4/ip_tunnel_core.c:81
 ip_tunnel_xmit+0x9b5/0x1450 net/ipv4/ip_tunnel.c:818
 __gre_xmit+0x389/0x4e0 net/ipv4/ip_gre.c:448
 ipgre_xmit+0x332/0x630 net/ipv4/ip_gre.c:632
 __netdev_start_xmit include/linux/netdevice.h:4510 [inline]
 netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3486
 __dev_queue_xmit+0x14e9/0x1ba0 net/core/dev.c:4063
 dev_queue_xmit+0x21/0x30 net/core/dev.c:4096
 __bpf_tx_skb net/core/filter.c:2061 [inline]
 __bpf_redirect_common net/core/filter.c:2100 [inline]
 __bpf_redirect+0x4c7/0x730 net/core/filter.c:2107
 ____bpf_clone_redirect net/core/filter.c:2140 [inline]
 bpf_clone_redirect+0x1a5/0x1f0 net/core/filter.c:2112
 bpf_prog_bebbfe2050753572+0x5c0/0x1000
 bpf_dispatcher_nopfunc include/linux/bpf.h:521 [inline]
 bpf_test_run+0x24a/0x560 net/bpf/test_run.c:48
 bpf_prog_test_run_skb+0x60c/0xa70 net/bpf/test_run.c:388
 bpf_prog_test_run kernel/bpf/syscall.c:2572 [inline]
 __do_sys_bpf+0xa47/0x2da0 kernel/bpf/syscall.c:3414
 __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
 __x64_sys_bpf+0x4c/0x60 kernel/bpf/syscall.c:3355
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880a9554130 of 8 bytes by task 26341 on cpu 1:
 vti_tunnel_xmit+0x407/0xb20 net/ipv4/ip_vti.c:291
 __netdev_start_xmit include/linux/netdevice.h:4510 [inline]
 netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3486
 __dev_queue_xmit+0x14e9/0x1ba0 net/core/dev.c:4063
 dev_queue_xmit+0x21/0x30 net/core/dev.c:4096
 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1527
 neigh_output include/net/neighbour.h:510 [inline]
 ip_finish_output2+0x408/0xea0 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:306 [inline]
 __ip_finish_output+0x23a/0x4b0 net/ipv4/ip_output.c:288
 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0xfe/0x230 net/ipv4/ip_output.c:430
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125
 iptunnel_xmit+0x356/0x520 net/ipv4/ip_tunnel_core.c:81
 ip_tunnel_xmit+0x9b5/0x1450 net/ipv4/ip_tunnel.c:818
 __gre_xmit+0x389/0x4e0 net/ipv4/ip_gre.c:448
 ipgre_xmit+0x332/0x630 net/ipv4/ip_gre.c:632
 __netdev_start_xmit include/linux/netdevice.h:4510 [inline]
 netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3486
 __dev_queue_xmit+0x14e9/0x1ba0 net/core/dev.c:4063
 dev_queue_xmit+0x21/0x30 net/core/dev.c:4096
 __bpf_tx_skb net/core/filter.c:2061 [inline]
 __bpf_redirect_common net/core/filter.c:2100 [inline]
 __bpf_redirect+0x4c7/0x730 net/core/filter.c:2107
 ____bpf_clone_redirect net/core/filter.c:2140 [inline]
 bpf_clone_redirect+0x1a5/0x1f0 net/core/filter.c:2112
 bpf_prog_bebbfe2050753572+0xb30/0x1000
 bpf_dispatcher_nopfunc include/linux/bpf.h:521 [inline]
 bpf_test_run+0x24a/0x560 net/bpf/test_run.c:48
 bpf_prog_test_run_skb+0x60c/0xa70 net/bpf/test_run.c:388
 bpf_prog_test_run kernel/bpf/syscall.c:2572 [inline]
 __do_sys_bpf+0xa47/0x2da0 kernel/bpf/syscall.c:3414
 __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
 __x64_sys_bpf+0x4c/0x60 kernel/bpf/syscall.c:3355
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26341 Comm: syz-executor.1 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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