==================================================================
BUG: KCSAN: data-race in iptunnel_xmit / iptunnel_xmit

read to 0xffff888108e63168 of 8 bytes by task 28921 on cpu 1:
 iptunnel_xmit_stats include/net/ip_tunnels.h:463 [inline]
 iptunnel_xmit+0x45f/0x4f0 net/ipv4/ip_tunnel_core.c:87
 ip_tunnel_xmit+0xf89/0x1220 net/ipv4/ip_tunnel.c:810
 __gre_xmit net/ipv4/ip_gre.c:471 [inline]
 ipgre_xmit+0x558/0x5a0 net/ipv4/ip_gre.c:659
 __netdev_start_xmit include/linux/netdevice.h:4778 [inline]
 netdev_start_xmit include/linux/netdevice.h:4792 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3532
 dev_hard_start_xmit net/core/dev.c:3548 [inline]
 __dev_queue_xmit+0x8f9/0x10c0 net/core/dev.c:4176
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4209
 __bpf_tx_skb net/core/filter.c:2113 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2138 [inline]
 __bpf_redirect+0x55f/0x8a0 net/core/filter.c:2161
 ____bpf_clone_redirect net/core/filter.c:2428 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2400
 ___bpf_prog_run+0xc87/0x30c0 kernel/bpf/core.c:1835
 __bpf_prog_run512+0x70/0xa0 kernel/bpf/core.c:2064
 bpf_dispatcher_nop_func include/linux/bpf.h:804 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 bpf_test_run+0x1ac/0x410 net/bpf/test_run.c:401
 bpf_prog_test_run_skb+0x778/0xf20 net/bpf/test_run.c:1110
 bpf_prog_test_run kernel/bpf/syscall.c:3369 [inline]
 __sys_bpf+0x3cf3/0xa1f0 kernel/bpf/syscall.c:4681
 __do_sys_bpf kernel/bpf/syscall.c:4767 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4765 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:4765
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

write to 0xffff888108e63168 of 8 bytes by task 28930 on cpu 0:
 iptunnel_xmit_stats include/net/ip_tunnels.h:463 [inline]
 iptunnel_xmit+0x471/0x4f0 net/ipv4/ip_tunnel_core.c:87
 ip_tunnel_xmit+0xf89/0x1220 net/ipv4/ip_tunnel.c:810
 __gre_xmit net/ipv4/ip_gre.c:471 [inline]
 ipgre_xmit+0x558/0x5a0 net/ipv4/ip_gre.c:659
 __netdev_start_xmit include/linux/netdevice.h:4778 [inline]
 netdev_start_xmit include/linux/netdevice.h:4792 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3532
 dev_hard_start_xmit net/core/dev.c:3548 [inline]
 __dev_queue_xmit+0x8f9/0x10c0 net/core/dev.c:4176
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4209
 __bpf_tx_skb net/core/filter.c:2113 [inline]
 __bpf_redirect_no_mac net/core/filter.c:2138 [inline]
 __bpf_redirect+0x55f/0x8a0 net/core/filter.c:2161
 ____bpf_clone_redirect net/core/filter.c:2428 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2400
 ___bpf_prog_run+0xc87/0x30c0 kernel/bpf/core.c:1835
 __bpf_prog_run512+0x70/0xa0 kernel/bpf/core.c:2064
 bpf_dispatcher_nop_func include/linux/bpf.h:804 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 bpf_test_run+0x1ac/0x410 net/bpf/test_run.c:401
 bpf_prog_test_run_skb+0x778/0xf20 net/bpf/test_run.c:1110
 bpf_prog_test_run kernel/bpf/syscall.c:3369 [inline]
 __sys_bpf+0x3cf3/0xa1f0 kernel/bpf/syscall.c:4681
 __do_sys_bpf kernel/bpf/syscall.c:4767 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4765 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:4765
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000aba -> 0x0000000000000abb

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 28930 Comm: syz-executor.4 Not tainted 5.17.0-syzkaller-12882-g1930a6e739c4-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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syz-executor.4 (28930) used greatest stack depth: 10288 bytes left