================================================================== BUG: KCSAN: data-race in do_epoll_wait / ep_poll_callback write to 0xffff888120666c50 of 8 bytes by interrupt on cpu 1: list_add_tail_lockless fs/eventpoll.c:1158 [inline] ep_poll_callback+0x29c/0x510 fs/eventpoll.c:1248 __wake_up_common+0xbc/0x130 kernel/sched/wait.c:93 __wake_up_common_lock kernel/sched/wait.c:123 [inline] __wake_up_sync_key+0x83/0xc0 kernel/sched/wait.c:190 sock_def_readable+0x61/0xe0 net/core/sock.c:2909 tcp_data_ready net/ipv4/tcp_input.c:4795 [inline] tcp_rcv_established+0x13c0/0x1520 net/ipv4/tcp_input.c:5724 tcp_v4_do_rcv+0x25e/0x480 net/ipv4/tcp_ipv4.c:1641 tcp_v4_rcv+0x219b/0x2420 net/ipv4/tcp_ipv4.c:2023 ip_protocol_deliver_rcu+0x1f9/0x400 net/ipv4/ip_input.c:204 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip_local_deliver+0x1d6/0x2a0 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:449 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:550 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:600 [inline] ip_sublist_rcv+0x4d4/0x5a0 net/ipv4/ip_input.c:608 ip_list_rcv+0x262/0x290 net/ipv4/ip_input.c:643 __netif_receive_skb_list_ptype net/core/dev.c:5324 [inline] __netif_receive_skb_list_core+0x34b/0x450 net/core/dev.c:5372 __netif_receive_skb_list+0x298/0x310 net/core/dev.c:5424 netif_receive_skb_list_internal+0xda/0x330 net/core/dev.c:5531 gro_normal_list net/core/dev.c:5642 [inline] gro_normal_one net/core/dev.c:5654 [inline] napi_skb_finish net/core/dev.c:5982 [inline] napi_gro_receive+0x329/0x5a0 net/core/dev.c:6014 receive_buf+0x7a4/0xcf0 drivers/net/virtio_net.c:1082 virtnet_receive drivers/net/virtio_net.c:1346 [inline] virtnet_poll+0x2fa/0x780 drivers/net/virtio_net.c:1451 napi_poll+0x178/0x4a0 net/core/dev.c:6684 net_rx_action+0x1ba/0x530 net/core/dev.c:6752 __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 common_interrupt+0x14e/0x1e0 arch/x86/kernel/irq.c:239 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:578 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+0x2ff/0x680 drivers/acpi/processor_idle.c:651 cpuidle_enter_state+0x245/0x5d0 drivers/cpuidle/cpuidle.c:235 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:346 call_cpuidle kernel/sched/idle.c:126 [inline] cpuidle_idle_call kernel/sched/idle.c:214 [inline] do_idle+0x229/0x310 kernel/sched/idle.c:276 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:372 start_secondary+0xe3/0x110 arch/x86/kernel/smpboot.c:268 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 read to 0xffff888120666c50 of 8 bytes by task 8627 on cpu 0: list_empty_careful include/linux/list.h:300 [inline] ep_events_available fs/eventpoll.c:379 [inline] ep_poll fs/eventpoll.c:1855 [inline] do_epoll_wait+0x2e2/0x870 fs/eventpoll.c:2333 __do_sys_epoll_pwait fs/eventpoll.c:2364 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2350 [inline] __x64_sys_epoll_pwait+0x92/0x150 fs/eventpoll.c:2350 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 8627 Comm: syz-fuzzer Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================