================================================================== BUG: KCSAN: data-race in __mod_timer / timer_clear_idle write to 0xffff88812c01cb24 of 1 bytes by task 0 on cpu 0: timer_clear_idle+0x2e/0x40 kernel/time/timer.c:1675 tick_nohz_idle_retain_tick+0x3e/0x40 kernel/time/tick-sched.c:1004 cpuidle_idle_call kernel/sched/idle.c:210 [inline] do_idle+0x287/0x310 kernel/sched/idle.c:276 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:372 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 read to 0xffff88812c01cb24 of 1 bytes by interrupt on cpu 1: forward_timer_base kernel/time/timer.c:891 [inline] __mod_timer+0xb87/0xf00 kernel/time/timer.c:983 mod_timer+0x1b/0x20 kernel/time/timer.c:1100 sk_reset_timer+0x1f/0xa0 net/core/sock.c:2953 tcp_send_delayed_ack+0x191/0x250 net/ipv4/tcp_output.c:3748 __tcp_ack_snd_check+0x326/0x500 net/ipv4/tcp_input.c:5293 tcp_ack_snd_check net/ipv4/tcp_input.c:5333 [inline] tcp_rcv_established+0xb3e/0x1520 net/ipv4/tcp_input.c:5754 tcp_v4_do_rcv+0x25e/0x480 net/ipv4/tcp_ipv4.c:1629 tcp_v4_rcv+0x219b/0x2420 net/ipv4/tcp_ipv4.c:2011 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:441 [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 run_ksoftirqd+0x2f/0x60 kernel/softirq.c:630 smpboot_thread_fn+0x347/0x530 kernel/smpboot.c:165 kthread+0x20d/0x230 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.8.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================