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BUG: KCSAN: data-race in do_sys_poll / pollwake

write to 0xffffc9001541bc40 of 4 bytes by interrupt on cpu 0:
 __pollwake fs/select.c:197 [inline]
 pollwake+0xa7/0xf0 fs/select.c:217
 __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+0x61/0xd0 net/core/sock.c:2907
 __udp_enqueue_schedule_skb+0x4bf/0x510 net/ipv4/udp.c:1509
 __udpv6_queue_rcv_skb net/ipv6/udp.c:577 [inline]
 udpv6_queue_rcv_one_skb+0x625/0x9e0 net/ipv6/udp.c:672
 udpv6_queue_rcv_skb+0xd2/0x460 net/ipv6/udp.c:689
 udp6_unicast_rcv_skb net/ipv6/udp.c:831 [inline]
 __udp6_lib_rcv+0xc3a/0x1640 net/ipv6/udp.c:915
 udpv6_rcv+0x1d/0x20 net/ipv6/udp.c:1017
 ip6_protocol_deliver_rcu+0x71b/0xc60 net/ipv6/ip6_input.c:433
 ip6_input_finish net/ipv6/ip6_input.c:474 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip6_input+0x76/0x120 net/ipv6/ip6_input.c:483
 dst_input include/net/dst.h:441 [inline]
 ip6_rcv_finish+0x1d5/0x260 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ipv6_rcv+0x88/0x140 net/ipv6/ip6_input.c:307
 __netif_receive_skb_one_core net/core/dev.c:5279 [inline]
 __netif_receive_skb+0x8b/0x1b0 net/core/dev.c:5393
 process_backlog+0x29f/0x4a0 net/core/dev.c:6237
 napi_poll+0x154/0x480 net/core/dev.c:6682
 net_rx_action+0x1ba/0x530 net/core/dev.c:6750
 __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
 local_bh_enable+0x1b/0x20 include/linux/bottom_half.h:32
 rcu_read_unlock_bh include/linux/rcupdate.h:723 [inline]
 ip6_finish_output2+0x986/0xb20 net/ipv6/ip6_output.c:118
 __ip6_finish_output+0x302/0x330 net/ipv6/ip6_output.c:143
 ip6_finish_output+0x39/0x160 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x10e/0x210 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:435 [inline]
 ip6_local_out+0x60/0x80 net/ipv6/output_core.c:179
 ip6_send_skb+0x43/0xf0 net/ipv6/ip6_output.c:1865
 udp_v6_send_skb+0x7a3/0xa00 net/ipv6/udp.c:1175
 udpv6_sendmsg+0x151a/0x1770 net/ipv6/udp.c:1473
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:638
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmmsg+0x322/0x4b0 net/socket.c:2496
 __do_sys_sendmmsg net/socket.c:2525 [inline]
 __se_sys_sendmmsg net/socket.c:2522 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2522
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffc9001541bc40 of 4 bytes by task 10897 on cpu 1:
 poll_schedule_timeout fs/select.c:242 [inline]
 do_poll fs/select.c:961 [inline]
 do_sys_poll+0x9b6/0xbd0 fs/select.c:1011
 __do_sys_ppoll fs/select.c:1111 [inline]
 __se_sys_ppoll+0x169/0x1b0 fs/select.c:1091
 __x64_sys_ppoll+0x63/0x70 fs/select.c:1091
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10897 Comm: syz-executor.0 Not tainted 5.8.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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