================================================================== BUG: KCSAN: data-race in __dev_queue_xmit / __dev_queue_xmit write to 0xffff8880afa6a284 of 4 bytes by task 9737 on cpu 0: __netif_tx_unlock include/linux/netdevice.h:4019 [inline] __dev_queue_xmit+0x153d/0x1b80 net/core/dev.c:4066 dev_queue_xmit+0x1e/0x30 net/core/dev.c:4096 neigh_direct_output+0x1c/0x30 net/core/neighbour.c:1527 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x3f2/0xed0 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x22f/0x460 net/ipv4/ip_output.c:288 ip_finish_output+0x3e/0x160 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0xf2/0x240 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:436 [inline] ip_local_out+0x70/0x90 net/ipv4/ip_output.c:125 ip_send_skb+0x32/0xb0 net/ipv4/ip_output.c:1560 udp_send_skb.isra.0+0x3b8/0x8d0 net/ipv4/udp.c:891 udp_sendmsg+0x1589/0x1930 net/ipv4/udp.c:1178 udpv6_sendmsg+0xe75/0x1d40 net/ipv6/udp.c:1283 inet6_sendmsg+0x69/0x90 net/ipv6/af_inet6.c:576 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0x98/0xc0 net/socket.c:672 ____sys_sendmsg+0x207/0x4c0 net/socket.c:2343 ___sys_sendmsg+0xb5/0x100 net/socket.c:2397 __sys_sendmmsg+0x10e/0x310 net/socket.c:2487 __do_sys_sendmmsg net/socket.c:2516 [inline] __se_sys_sendmmsg net/socket.c:2513 [inline] __x64_sys_sendmmsg+0x60/0x80 net/socket.c:2513 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880afa6a284 of 4 bytes by task 9733 on cpu 1: __dev_queue_xmit+0xb45/0x1b80 net/core/dev.c:4051 dev_queue_xmit+0x1e/0x30 net/core/dev.c:4096 neigh_direct_output+0x1c/0x30 net/core/neighbour.c:1527 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x3f2/0xed0 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x22f/0x460 net/ipv4/ip_output.c:288 ip_finish_output+0x3e/0x160 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0xf2/0x240 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:436 [inline] ip_local_out+0x70/0x90 net/ipv4/ip_output.c:125 ip_send_skb+0x32/0xb0 net/ipv4/ip_output.c:1560 udp_send_skb.isra.0+0x3b8/0x8d0 net/ipv4/udp.c:891 udp_sendmsg+0x1589/0x1930 net/ipv4/udp.c:1178 udpv6_sendmsg+0xe75/0x1d40 net/ipv6/udp.c:1283 inet6_sendmsg+0x69/0x90 net/ipv6/af_inet6.c:576 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0x98/0xc0 net/socket.c:672 ____sys_sendmsg+0x207/0x4c0 net/socket.c:2343 ___sys_sendmsg+0xb5/0x100 net/socket.c:2397 __sys_sendmmsg+0x10e/0x310 net/socket.c:2487 __do_sys_sendmmsg net/socket.c:2516 [inline] __se_sys_sendmmsg net/socket.c:2513 [inline] __x64_sys_sendmmsg+0x60/0x80 net/socket.c:2513 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 9733 Comm: syz-executor.1 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================