================================================================== BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit read to 0xffff8881387c5150 of 8 bytes by task 4266 on cpu 1: ip_tunnel_xmit+0x9ec/0x1210 net/ipv4/ip_tunnel.c:819 __gre_xmit net/ipv4/ip_gre.c:471 [inline] ipgre_xmit+0x553/0x5a0 net/ipv4/ip_gre.c:658 __netdev_start_xmit include/linux/netdevice.h:4987 [inline] netdev_start_xmit include/linux/netdevice.h:5001 [inline] xmit_one+0x105/0x2f0 net/core/dev.c:3590 dev_hard_start_xmit net/core/dev.c:3606 [inline] __dev_queue_xmit+0x869/0xf70 net/core/dev.c:4226 dev_queue_xmit+0x13/0x20 net/core/dev.c:4259 neigh_connected_output+0x264/0x290 net/core/neighbour.c:1552 neigh_output include/net/neighbour.h:527 [inline] ip_finish_output2+0x72e/0xb40 net/ipv4/ip_output.c:221 ip_finish_output+0xfb/0x240 net/ipv4/ip_output.c:309 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_mc_output+0x2a7/0x360 net/ipv4/ip_output.c:408 dst_output include/net/dst.h:450 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1555 udp_send_skb+0x62d/0x860 net/ipv4/udp.c:966 udp_sendmsg+0x12e4/0x14c0 net/ipv4/udp.c:1253 udpv6_sendmsg+0x6a3/0x16e0 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:644 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae write to 0xffff8881387c5150 of 8 bytes by task 4278 on cpu 0: ip_tunnel_xmit+0x9fe/0x1210 net/ipv4/ip_tunnel.c:819 __gre_xmit net/ipv4/ip_gre.c:471 [inline] ipgre_xmit+0x553/0x5a0 net/ipv4/ip_gre.c:658 __netdev_start_xmit include/linux/netdevice.h:4987 [inline] netdev_start_xmit include/linux/netdevice.h:5001 [inline] xmit_one+0x105/0x2f0 net/core/dev.c:3590 dev_hard_start_xmit net/core/dev.c:3606 [inline] __dev_queue_xmit+0x869/0xf70 net/core/dev.c:4226 dev_queue_xmit+0x13/0x20 net/core/dev.c:4259 neigh_connected_output+0x264/0x290 net/core/neighbour.c:1552 neigh_output include/net/neighbour.h:527 [inline] ip_finish_output2+0x72e/0xb40 net/ipv4/ip_output.c:221 ip_finish_output+0xfb/0x240 net/ipv4/ip_output.c:309 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_mc_output+0x2a7/0x360 net/ipv4/ip_output.c:408 dst_output include/net/dst.h:450 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1555 udp_send_skb+0x62d/0x860 net/ipv4/udp.c:966 udp_sendmsg+0x12e4/0x14c0 net/ipv4/udp.c:1253 udpv6_sendmsg+0x6a3/0x16e0 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:644 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x000000000000150f -> 0x0000000000001510 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 4278 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== syz-executor.3 (4278) used greatest stack depth: 10080 bytes left