================================================================== BUG: KCSAN: data-race in __neigh_event_send / ip_finish_output2 write to 0xffff88809fc9de85 of 1 bytes by interrupt on cpu 1: __neigh_event_send+0x403/0xb10 net/core/neighbour.c:1126 neigh_event_send include/net/neighbour.h:443 [inline] neigh_resolve_output+0x104/0x400 net/core/neighbour.c:1473 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_queue_xmit+0x997/0x9c0 net/ipv4/ip_output.c:530 ip_queue_xmit+0x34/0x40 include/net/ip.h:237 __tcp_transmit_skb+0x1320/0x1810 net/ipv4/tcp_output.c:1238 tcp_transmit_skb net/ipv4/tcp_output.c:1254 [inline] __tcp_retransmit_skb+0xf46/0x1590 net/ipv4/tcp_output.c:3060 tcp_retransmit_skb+0x22/0x150 net/ipv4/tcp_output.c:3083 tcp_retransmit_timer+0x751/0xdb0 net/ipv4/tcp_timer.c:528 tcp_write_timer_handler+0x15d/0x500 net/ipv4/tcp_timer.c:611 tcp_write_timer+0xb6/0x160 net/ipv4/tcp_timer.c:631 call_timer_fn+0x30/0x2a0 kernel/time/timer.c:1404 expire_timers+0x116/0x290 kernel/time/timer.c:1449 __run_timers+0x443/0x500 kernel/time/timer.c:1773 run_timer_softirq+0x2e/0x60 kernel/time/timer.c:1786 __do_softirq+0x198/0x360 kernel/softirq.c:292 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x5d/0x80 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:387 [inline] __irq_exit_rcu+0x115/0x120 kernel/softirq.c:417 sysvec_apic_timer_interrupt+0xd9/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] acpi_idle_do_entry drivers/acpi/processor_idle.c:525 [inline] acpi_idle_enter+0x319/0x650 drivers/acpi/processor_idle.c:651 cpuidle_enter_state+0x245/0x5d0 drivers/cpuidle/cpuidle.c:234 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:345 call_cpuidle kernel/sched/idle.c:117 [inline] cpuidle_idle_call kernel/sched/idle.c:207 [inline] do_idle+0x1ce/0x320 kernel/sched/idle.c:269 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:365 start_secondary+0xe3/0x110 arch/x86/kernel/smpboot.c:268 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 read to 0xffff88809fc9de85 of 1 bytes by interrupt on cpu 0: neigh_output include/net/neighbour.h:506 [inline] ip_finish_output2+0x476/0xb60 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_queue_xmit+0x997/0x9c0 net/ipv4/ip_output.c:530 ip_queue_xmit+0x34/0x40 include/net/ip.h:237 __tcp_transmit_skb+0x1320/0x1810 net/ipv4/tcp_output.c:1238 tcp_transmit_skb net/ipv4/tcp_output.c:1254 [inline] __tcp_retransmit_skb+0xf46/0x1590 net/ipv4/tcp_output.c:3060 tcp_retransmit_skb+0x22/0x150 net/ipv4/tcp_output.c:3083 tcp_retransmit_timer+0x751/0xdb0 net/ipv4/tcp_timer.c:528 tcp_write_timer_handler+0x15d/0x500 net/ipv4/tcp_timer.c:611 tcp_write_timer+0xb6/0x160 net/ipv4/tcp_timer.c:631 call_timer_fn+0x30/0x2a0 kernel/time/timer.c:1404 expire_timers+0x116/0x290 kernel/time/timer.c:1449 __run_timers+0x443/0x500 kernel/time/timer.c:1773 run_timer_softirq+0x2e/0x60 kernel/time/timer.c:1786 __do_softirq+0x198/0x360 kernel/softirq.c:292 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x5d/0x80 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:387 [inline] __irq_exit_rcu+0x115/0x120 kernel/softirq.c:417 sysvec_apic_timer_interrupt+0xd9/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] acpi_idle_do_entry drivers/acpi/processor_idle.c:525 [inline] acpi_idle_enter+0x319/0x650 drivers/acpi/processor_idle.c:651 cpuidle_enter_state+0x245/0x5d0 drivers/cpuidle/cpuidle.c:234 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:345 call_cpuidle kernel/sched/idle.c:117 [inline] cpuidle_idle_call kernel/sched/idle.c:207 [inline] do_idle+0x1ce/0x320 kernel/sched/idle.c:269 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:365 rest_init+0xd8/0xe0 init/main.c:705 arch_call_rest_init+0xa/0xb start_kernel+0x608/0x6d0 init/main.c:1043 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.8.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================