================================================================== BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit write to 0xffff88809a790190 of 8 bytes by task 27952 on cpu 1: ip_tunnel_xmit+0x5fa/0x11c0 net/ipv4/ip_tunnel.c:754 ipip_tunnel_xmit+0x264/0x2c0 net/ipv4/ipip.c:305 __netdev_start_xmit include/linux/netdevice.h:4634 [inline] netdev_start_xmit include/linux/netdevice.h:4648 [inline] xmit_one+0xc0/0x310 net/core/dev.c:3561 dev_hard_start_xmit net/core/dev.c:3577 [inline] __dev_queue_xmit+0xf00/0x15a0 net/core/dev.c:4136 dev_queue_xmit+0x13/0x20 net/core/dev.c:4169 neigh_connected_output+0x24f/0x280 net/core/neighbour.c:1518 neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x4e2/0xb60 net/ipv4/ip_output.c:228 __ip_finish_output+0x395/0x3e0 net/ipv4/ip_output.c:306 ip_finish_output+0x39/0x160 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_output+0xf6/0x1a0 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:125 [inline] ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1566 udp_send_skb+0x62d/0x860 net/ipv4/udp.c:948 udp_sendmsg+0x1298/0x1550 net/ipv4/udp.c:1235 udpv6_sendmsg+0x94b/0x1780 net/ipv6/udp.c:1344 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:638 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2353 ___sys_sendmsg net/socket.c:2407 [inline] __sys_sendmmsg+0x322/0x4b0 net/socket.c:2497 __do_sys_sendmmsg net/socket.c:2526 [inline] __se_sys_sendmmsg net/socket.c:2523 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2523 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88809a790190 of 8 bytes by task 27957 on cpu 0: ip_tunnel_xmit+0x5e8/0x11c0 net/ipv4/ip_tunnel.c:754 ipip_tunnel_xmit+0x264/0x2c0 net/ipv4/ipip.c:305 __netdev_start_xmit include/linux/netdevice.h:4634 [inline] netdev_start_xmit include/linux/netdevice.h:4648 [inline] xmit_one+0xc0/0x310 net/core/dev.c:3561 dev_hard_start_xmit net/core/dev.c:3577 [inline] __dev_queue_xmit+0xf00/0x15a0 net/core/dev.c:4136 dev_queue_xmit+0x13/0x20 net/core/dev.c:4169 neigh_connected_output+0x24f/0x280 net/core/neighbour.c:1518 neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x4e2/0xb60 net/ipv4/ip_output.c:228 __ip_finish_output+0x395/0x3e0 net/ipv4/ip_output.c:306 ip_finish_output+0x39/0x160 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_output+0xf6/0x1a0 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:125 [inline] ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1566 udp_send_skb+0x62d/0x860 net/ipv4/udp.c:948 udp_sendmsg+0x1298/0x1550 net/ipv4/udp.c:1235 udpv6_sendmsg+0x94b/0x1780 net/ipv6/udp.c:1344 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:638 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2353 ___sys_sendmsg net/socket.c:2407 [inline] __sys_sendmmsg+0x322/0x4b0 net/socket.c:2497 __do_sys_sendmmsg net/socket.c:2526 [inline] __se_sys_sendmmsg net/socket.c:2523 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2523 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: 27957 Comm: syz-executor.1 Not tainted 5.9.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================