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BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg

write to 0xffff8881242e12f8 of 8 bytes by interrupt on cpu 1:
 __sk_add_backlog include/net/sock.h:907 [inline]
 sk_add_backlog include/net/sock.h:938 [inline]
 tcp_add_backlog+0x476/0xce0 net/ipv4/tcp_ipv4.c:1759
 tcp_v4_rcv+0x1a70/0x1bd0 net/ipv4/tcp_ipv4.c:1947
 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:4929
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5043
 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5133
 napi_skb_finish net/core/dev.c:5596 [inline]
 napi_gro_receive+0x28f/0x330 net/core/dev.c:5629
 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:6311 [inline]
 net_rx_action+0x3ae/0xa90 net/core/dev.c:6379
 __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]
 do_IRQ+0xa6/0x180 arch/x86/kernel/irq.c:263
 ret_from_intr+0x0/0x19
 tomoyo_check_path_acl+0x1/0xa0 security/tomoyo/file.c:254
 tomoyo_path_permission security/tomoyo/file.c:586 [inline]
 tomoyo_path_permission+0xe3/0x160 security/tomoyo/file.c:573
 tomoyo_check_open_permission+0x2fd/0x320 security/tomoyo/file.c:777
 tomoyo_file_open security/tomoyo/tomoyo.c:319 [inline]
 tomoyo_file_open+0x75/0x90 security/tomoyo/tomoyo.c:314
 security_file_open+0x69/0x210 security/security.c:1497
 do_dentry_open+0x20a/0x8f0 fs/open.c:784
 vfs_open+0x62/0x80 fs/open.c:914
 do_last fs/namei.c:3408 [inline]
 path_openat+0xf73/0x36e0 fs/namei.c:3525
 do_filp_open+0x11e/0x1b0 fs/namei.c:3555
 do_sys_open+0x3b3/0x4f0 fs/open.c:1097
 __do_sys_open fs/open.c:1115 [inline]
 __se_sys_open fs/open.c:1110 [inline]
 __x64_sys_open+0x55/0x70 fs/open.c:1110
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881242e12f8 of 8 bytes by task 8054 on cpu 0:
 tcp_recvmsg+0x46e/0x1b40 net/ipv4/tcp.c:2050
 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
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8054 Comm: syz-fuzzer Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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