================================================================== BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog write to 0xffff8881268012ec of 4 bytes by interrupt on cpu 1: sk_add_backlog include/net/sock.h:934 [inline] tcp_add_backlog+0x4a0/0xcc0 net/ipv4/tcp_ipv4.c:1756 tcp_v4_rcv+0x1a60/0x1bb0 net/ipv4/tcp_ipv4.c:1944 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:442 [inline] ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5214 napi_skb_finish net/core/dev.c:5677 [inline] napi_gro_receive+0x28f/0x330 net/core/dev.c:5710 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061 virtnet_receive drivers/net/virtio_net.c:1323 [inline] virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428 napi_poll net/core/dev.c:6392 [inline] net_rx_action+0x3ae/0xa90 net/core/dev.c:6460 read to 0xffff8881268012ec of 4 bytes by task 7195 on cpu 0: tcp_space include/net/tcp.h:1383 [inline] __tcp_select_window+0x6b/0x4d0 net/ipv4/tcp_output.c:2696 tcp_select_window net/ipv4/tcp_output.c:260 [inline] __tcp_transmit_skb+0x700/0x1d60 net/ipv4/tcp_output.c:1124 __tcp_send_ack+0x246/0x300 net/ipv4/tcp_output.c:3696 tcp_send_ack+0x34/0x40 net/ipv4/tcp_output.c:3702 tcp_cleanup_rbuf+0x130/0x360 net/ipv4/tcp.c:1576 tcp_recvmsg+0x633/0x1a30 net/ipv4/tcp.c:2180 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 sock_read_iter+0x15f/0x1e0 net/socket.c:967 call_read_iter include/linux/fs.h:1889 [inline] new_sync_read+0x389/0x4f0 fs/read_write.c:414 __vfs_read+0xb1/0xc0 fs/read_write.c:427 vfs_read fs/read_write.c:461 [inline] vfs_read+0x143/0x2c0 fs/read_write.c:446 ksys_read+0xd5/0x1b0 fs/read_write.c:587 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 7195 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================