================================================================== BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit write to 0xffff8880ba1e3190 of 8 bytes by task 3745 on cpu 0: 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:4611 [inline] netdev_start_xmit include/linux/netdevice.h:4625 [inline] xmit_one+0xc0/0x310 net/core/dev.c:3556 dev_hard_start_xmit net/core/dev.c:3572 [inline] __dev_queue_xmit+0xecc/0x1550 net/core/dev.c:4131 dev_queue_xmit+0x13/0x20 net/core/dev.c:4164 neigh_direct_output+0x11/0x20 net/core/neighbour.c:1529 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:296 [inline] ip_output+0xf6/0x1a0 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:435 [inline] ip_local_out net/ipv4/ip_output.c:125 [inline] ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1560 udp_send_skb+0x62d/0x860 net/ipv4/udp.c:894 udp_sendmsg+0x126e/0x1510 net/ipv4/udp.c:1181 udpv6_sendmsg+0x94b/0x1770 net/ipv6/udp.c:1286 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:638 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmmsg+0x322/0x4b0 net/socket.c:2496 __do_sys_sendmmsg net/socket.c:2525 [inline] __se_sys_sendmmsg net/socket.c:2522 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2522 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880ba1e3190 of 8 bytes by task 3737 on cpu 1: 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:4611 [inline] netdev_start_xmit include/linux/netdevice.h:4625 [inline] xmit_one+0xc0/0x310 net/core/dev.c:3556 dev_hard_start_xmit net/core/dev.c:3572 [inline] __dev_queue_xmit+0xecc/0x1550 net/core/dev.c:4131 dev_queue_xmit+0x13/0x20 net/core/dev.c:4164 neigh_direct_output+0x11/0x20 net/core/neighbour.c:1529 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:296 [inline] ip_output+0xf6/0x1a0 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:435 [inline] ip_local_out net/ipv4/ip_output.c:125 [inline] ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1560 udp_send_skb+0x62d/0x860 net/ipv4/udp.c:894 udp_sendmsg+0x126e/0x1510 net/ipv4/udp.c:1181 udpv6_sendmsg+0x94b/0x1770 net/ipv6/udp.c:1286 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:638 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmmsg+0x322/0x4b0 net/socket.c:2496 __do_sys_sendmmsg net/socket.c:2525 [inline] __se_sys_sendmmsg net/socket.c:2522 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2522 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 3737 Comm: syz-executor.1 Not tainted 5.8.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================