================================================================== BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit write to 0xffff8880a19fa138 of 8 bytes by task 9366 on cpu 1: ip_tunnel_xmit+0xcb3/0x1400 net/ipv4/ip_tunnel.c:827 __gre_xmit+0x389/0x4e0 net/ipv4/ip_gre.c:444 ipgre_xmit+0x332/0x630 net/ipv4/ip_gre.c:628 __netdev_start_xmit include/linux/netdevice.h:4413 [inline] netdev_start_xmit include/linux/netdevice.h:4427 [inline] xmit_one net/core/dev.c:3199 [inline] dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3215 __dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825 neigh_connected_output+0x28a/0x2e0 net/core/neighbour.c:1519 neigh_output include/net/neighbour.h:511 [inline] ip_finish_output2+0x4af/0xe40 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:294 [inline] ip_mc_output+0x143/0x620 net/ipv4/ip_output.c:417 dst_output include/net/dst.h:436 [inline] ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125 ip_send_skb+0x35/0xb0 net/ipv4/ip_output.c:1559 udp_send_skb.isra.0+0x3ce/0x8c0 net/ipv4/udp.c:891 udp_sendmsg+0x1568/0x1900 net/ipv4/udp.c:1178 udpv6_sendmsg+0xd97/0x1c20 net/ipv6/udp.c:1284 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576 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 read to 0xffff8880a19fa138 of 8 bytes by task 9357 on cpu 0: ip_tunnel_xmit+0xca0/0x1400 net/ipv4/ip_tunnel.c:827 __gre_xmit+0x389/0x4e0 net/ipv4/ip_gre.c:444 ipgre_xmit+0x332/0x630 net/ipv4/ip_gre.c:628 __netdev_start_xmit include/linux/netdevice.h:4413 [inline] netdev_start_xmit include/linux/netdevice.h:4427 [inline] xmit_one net/core/dev.c:3199 [inline] dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3215 __dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825 neigh_connected_output+0x28a/0x2e0 net/core/neighbour.c:1519 neigh_output include/net/neighbour.h:511 [inline] ip_finish_output2+0x4af/0xe40 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:294 [inline] ip_mc_output+0x143/0x620 net/ipv4/ip_output.c:417 dst_output include/net/dst.h:436 [inline] ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125 ip_send_skb+0x35/0xb0 net/ipv4/ip_output.c:1559 udp_send_skb.isra.0+0x3ce/0x8c0 net/ipv4/udp.c:891 udp_sendmsg+0x1568/0x1900 net/ipv4/udp.c:1178 udpv6_sendmsg+0xd97/0x1c20 net/ipv6/udp.c:1284 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576 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: 9357 Comm: syz-executor.4 Not tainted 5.4.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================