================================================================== BUG: KCSAN: data-race in do_epoll_wait / ep_poll_callback write to 0xffff88811fe8cc50 of 8 bytes by interrupt on cpu 0: 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:4796 [inline] tcp_data_queue+0x1b71/0x3160 net/ipv4/tcp_input.c:4861 tcp_rcv_established+0x667/0x1520 net/ipv4/tcp_input.c:5754 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 do_softirq+0x86/0xb0 kernel/softirq.c:337 __local_bh_enable_ip+0x63/0x70 kernel/softirq.c:189 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x33/0x40 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:398 [inline] release_sock+0x104/0x110 net/core/sock.c:3077 tcp_recvmsg+0x16ba/0x1c10 net/ipv4/tcp.c:2252 inet_recvmsg+0xa9/0x210 net/ipv4/af_inet.c:845 sock_recvmsg_nosec net/socket.c:886 [inline] sock_recvmsg net/socket.c:904 [inline] sock_read_iter+0x19c/0x1e0 net/socket.c:977 call_read_iter include/linux/fs.h:1902 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x523/0x590 fs/read_write.c:481 ksys_read+0xce/0x180 fs/read_write.c:607 __do_sys_read fs/read_write.c:617 [inline] __se_sys_read fs/read_write.c:615 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:615 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88811fe8cc50 of 8 bytes by task 8641 on cpu 1: 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: 1 PID: 8641 Comm: syz-fuzzer Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================