================================================================== BUG: KCSAN: data-race in __dev_queue_xmit / pfifo_fast_dequeue write to 0xffff888124a76508 of 1 bytes by task 8751 on cpu 0: pfifo_fast_dequeue+0x49a/0x6e0 net/sched/sch_generic.c:660 dequeue_skb net/sched/sch_generic.c:263 [inline] qdisc_restart net/sched/sch_generic.c:366 [inline] __qdisc_run+0x14f/0xdd0 net/sched/sch_generic.c:384 __dev_xmit_skb net/core/dev.c:3401 [inline] __dev_queue_xmit+0x1acd/0x1b40 net/core/dev.c:3761 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x836/0xe40 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 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807 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 0xffff888124a76508 of 1 bytes by task 8757 on cpu 1: __dev_xmit_skb net/core/dev.c:3389 [inline] __dev_queue_xmit+0x9db/0x1b40 net/core/dev.c:3761 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x836/0xe40 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 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807 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: 1 PID: 8757 Comm: syz-executor.1 Not tainted 5.4.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================