================================================================== BUG: KCSAN: data-race in __neigh_event_send / neigh_resolve_output write to 0xffff8880804f0085 of 1 bytes by interrupt on cpu 1: __neigh_event_send+0x185/0x9f0 net/core/neighbour.c:1128 neigh_event_send include/net/neighbour.h:445 [inline] neigh_resolve_output+0x385/0x4c0 net/core/neighbour.c:1474 neigh_output include/net/neighbour.h:511 [inline] ip_finish_output2+0x408/0xea0 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:296 [inline] ip_output+0xfe/0x230 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:436 [inline] ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532 sctp_v4_xmit+0xf4/0x110 net/sctp/protocol.c:976 sctp_packet_transmit+0x111e/0x1800 net/sctp/output.c:629 sctp_packet_singleton net/sctp/outqueue.c:772 [inline] sctp_outq_flush_ctrl.constprop.0+0x5d4/0x760 net/sctp/outqueue.c:903 sctp_outq_flush+0xb9/0x14c0 net/sctp/outqueue.c:1185 sctp_outq_uncork+0x64/0x80 net/sctp/outqueue.c:757 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1786 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1189 [inline] sctp_do_sm+0x37f/0x2f10 net/sctp/sm_sideeffect.c:1160 sctp_generate_timeout_event+0x11c/0x1b0 net/sctp/sm_sideeffect.c:295 sctp_generate_t1_init_event+0x27/0x30 net/sctp/sm_sideeffect.c:321 call_timer_fn+0x5f/0x2f0 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0xc0c/0xcd0 kernel/time/timer.c:1786 __do_softirq+0x115/0x33f kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0xbb/0xe0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:690 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x1c2/0x290 kernel/sched/idle.c:269 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361 start_secondary+0x168/0x1b0 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 read to 0xffff8880804f0085 of 1 bytes by interrupt on cpu 0: neigh_event_send include/net/neighbour.h:444 [inline] neigh_resolve_output+0xb5/0x4c0 net/core/neighbour.c:1474 neigh_output include/net/neighbour.h:511 [inline] ip_finish_output2+0x408/0xea0 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:296 [inline] ip_output+0xfe/0x230 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:436 [inline] ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532 sctp_v4_xmit+0xf4/0x110 net/sctp/protocol.c:976 sctp_packet_transmit+0x111e/0x1800 net/sctp/output.c:629 sctp_packet_singleton net/sctp/outqueue.c:772 [inline] sctp_outq_flush_ctrl.constprop.0+0x5d4/0x760 net/sctp/outqueue.c:903 sctp_outq_flush+0xb9/0x14c0 net/sctp/outqueue.c:1185 sctp_outq_uncork+0x64/0x80 net/sctp/outqueue.c:757 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1786 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1189 [inline] sctp_do_sm+0x37f/0x2f10 net/sctp/sm_sideeffect.c:1160 sctp_generate_timeout_event+0x11c/0x1b0 net/sctp/sm_sideeffect.c:295 sctp_generate_t1_init_event+0x27/0x30 net/sctp/sm_sideeffect.c:321 call_timer_fn+0x5f/0x2f0 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0xc0c/0xcd0 kernel/time/timer.c:1786 __do_softirq+0x115/0x33f kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0xbb/0xe0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:690 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x1c2/0x290 kernel/sched/idle.c:269 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361 rest_init+0xec/0xf6 init/main.c:452 arch_call_rest_init+0x17/0x37 start_kernel+0x838/0x85e init/main.c:786 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x72/0x76 arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================