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BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit

write to 0xffff8880ae5dc130 of 8 bytes by task 5544 on cpu 1:
 ip_tunnel_xmit+0xd22/0x1450 net/ipv4/ip_tunnel.c:827
 ipip_tunnel_xmit+0x2cb/0x310 net/ipv4/ipip.c:305
 __netdev_start_xmit include/linux/netdevice.h:4447 [inline]
 netdev_start_xmit include/linux/netdevice.h:4461 [inline]
 xmit_one net/core/dev.c:3420 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3436
 __dev_queue_xmit+0x14e9/0x1ba0 net/core/dev.c:4013
 dev_queue_xmit+0x21/0x30 net/core/dev.c:4046
 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip_finish_output2+0x408/0xea0 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x23a/0x490 net/ipv4/ip_output.c:290
 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0xfe/0x230 net/ipv4/ip_output.c:432
 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:4447 [inline]
 netdev_start_xmit include/linux/netdevice.h:4461 [inline]
 xmit_one net/core/dev.c:3420 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3436
 __dev_queue_xmit+0x14e9/0x1ba0 net/core/dev.c:4013
 dev_queue_xmit+0x21/0x30 net/core/dev.c:4046
 __bpf_tx_skb net/core/filter.c:2060 [inline]
 __bpf_redirect_common net/core/filter.c:2099 [inline]
 __bpf_redirect+0x4b4/0x710 net/core/filter.c:2106
 ____bpf_clone_redirect net/core/filter.c:2139 [inline]
 bpf_clone_redirect+0x1a5/0x1f0 net/core/filter.c:2111
 0xffffffffa0006504
 bpf_test_run+0x1c3/0x490 net/bpf/test_run.c:44
 bpf_prog_test_run_skb+0x511/0x8a0 net/bpf/test_run.c:362
 bpf_prog_test_run kernel/bpf/syscall.c:2272 [inline]
 __do_sys_bpf+0xf77/0x3150 kernel/bpf/syscall.c:3048
 __se_sys_bpf kernel/bpf/syscall.c:2989 [inline]
 __x64_sys_bpf+0x4c/0x60 kernel/bpf/syscall.c:2989
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880ae5dc130 of 8 bytes by task 5562 on cpu 0:
 ip_tunnel_xmit+0xd0f/0x1450 net/ipv4/ip_tunnel.c:827
 ipip_tunnel_xmit+0x2cb/0x310 net/ipv4/ipip.c:305
 __netdev_start_xmit include/linux/netdevice.h:4447 [inline]
 netdev_start_xmit include/linux/netdevice.h:4461 [inline]
 xmit_one net/core/dev.c:3420 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3436
 __dev_queue_xmit+0x14e9/0x1ba0 net/core/dev.c:4013
 dev_queue_xmit+0x21/0x30 net/core/dev.c:4046
 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip_finish_output2+0x408/0xea0 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x23a/0x490 net/ipv4/ip_output.c:290
 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0xfe/0x230 net/ipv4/ip_output.c:432
 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:4447 [inline]
 netdev_start_xmit include/linux/netdevice.h:4461 [inline]
 xmit_one net/core/dev.c:3420 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3436
 __dev_queue_xmit+0x14e9/0x1ba0 net/core/dev.c:4013
 dev_queue_xmit+0x21/0x30 net/core/dev.c:4046
 __bpf_tx_skb net/core/filter.c:2060 [inline]
 __bpf_redirect_common net/core/filter.c:2099 [inline]
 __bpf_redirect+0x4b4/0x710 net/core/filter.c:2106
 ____bpf_clone_redirect net/core/filter.c:2139 [inline]
 bpf_clone_redirect+0x1a5/0x1f0 net/core/filter.c:2111
 bpf_prog_bebbfe2050753572+0x830/0x1000
 bpf_test_run+0x1c3/0x490 net/bpf/test_run.c:44
 bpf_prog_test_run_skb+0x511/0x8a0 net/bpf/test_run.c:362
 bpf_prog_test_run kernel/bpf/syscall.c:2272 [inline]
 __do_sys_bpf+0xf77/0x3150 kernel/bpf/syscall.c:3048
 __se_sys_bpf kernel/bpf/syscall.c:2989 [inline]
 __x64_sys_bpf+0x4c/0x60 kernel/bpf/syscall.c:2989
 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: 0 PID: 5562 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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