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BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit

read-write to 0xffff888022608198 of 8 bytes by task 12870 on cpu 1:
 ip_tunnel_xmit+0x213/0x11b0 net/ipv4/ip_tunnel.c:658
 __gre_xmit net/ipv4/ip_gre.c:466 [inline]
 ipgre_xmit+0x4d9/0x530 net/ipv4/ip_gre.c:648
 __netdev_start_xmit include/linux/netdevice.h:4718 [inline]
 netdev_start_xmit include/linux/netdevice.h:4732 [inline]
 xmit_one+0xf9/0x2e0 net/core/dev.c:3564
 dev_hard_start_xmit net/core/dev.c:3580 [inline]
 __dev_queue_xmit+0xeef/0x1510 net/core/dev.c:4140
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4173
 __bpf_tx_skb net/core/filter.c:2116 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2141 [inline]
 __bpf_redirect+0x544/0x750 net/core/filter.c:2164
 ____bpf_clone_redirect net/core/filter.c:2448 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2420
 0xffffffffa0052f74
 bpf_dispatcher_nop_func include/linux/bpf.h:644 [inline]
 bpf_test_run+0x266/0x450 net/bpf/test_run.c:50
 bpf_prog_test_run_skb+0x6f0/0xe70 net/bpf/test_run.c:581
 bpf_prog_test_run kernel/bpf/syscall.c:3125 [inline]
 __do_sys_bpf+0x39d6/0x9aa0 kernel/bpf/syscall.c:4417
 __se_sys_bpf kernel/bpf/syscall.c:4357 [inline]
 __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4357
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read-write to 0xffff888022608198 of 8 bytes by task 12836 on cpu 0:
 ip_tunnel_xmit+0x213/0x11b0 net/ipv4/ip_tunnel.c:658
 __gre_xmit net/ipv4/ip_gre.c:466 [inline]
 ipgre_xmit+0x4d9/0x530 net/ipv4/ip_gre.c:648
 __netdev_start_xmit include/linux/netdevice.h:4718 [inline]
 netdev_start_xmit include/linux/netdevice.h:4732 [inline]
 xmit_one+0xf9/0x2e0 net/core/dev.c:3564
 dev_hard_start_xmit net/core/dev.c:3580 [inline]
 __dev_queue_xmit+0xeef/0x1510 net/core/dev.c:4140
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4173
 __bpf_tx_skb net/core/filter.c:2116 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2141 [inline]
 __bpf_redirect+0x544/0x750 net/core/filter.c:2164
 ____bpf_clone_redirect net/core/filter.c:2448 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2420
 bpf_prog_eb4214e34d195ba1+0x58/0xb70
 bpf_dispatcher_nop_func include/linux/bpf.h:644 [inline]
 bpf_test_run+0x266/0x450 net/bpf/test_run.c:50
 bpf_prog_test_run_skb+0x6f0/0xe70 net/bpf/test_run.c:581
 bpf_prog_test_run kernel/bpf/syscall.c:3125 [inline]
 __do_sys_bpf+0x39d6/0x9aa0 kernel/bpf/syscall.c:4417
 __se_sys_bpf kernel/bpf/syscall.c:4357 [inline]
 __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4357
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12836 Comm: syz-executor.3 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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