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From: Eric Dumazet <edumazet@google.com>
Date: Sat, 9 Mar 2024 14:50:59 +0100
Message-ID: <CANn89iJRXjYTojFyHN6s1Qu9Vkkk6RwxPF=bAKPjOg9zT-GupA@mail.gmail.com>
Subject: Re: [PATCH] net: mark racy access on sk->sk_rcvbuf
To: linke li <lilinke99@qq.com>
Cc: "David S. Miller" <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>, 
	Paolo Abeni <pabeni@redhat.com>, Kuniyuki Iwashima <kuniyu@amazon.com>, 
	Willem de Bruijn <willemb@google.com>, Abel Wu <wuyun.abel@bytedance.com>, 
	Breno Leitao <leitao@debian.org>, Alexander Mikhalitsyn <alexander@mihalicyn.com>, 
	David Howells <dhowells@redhat.com>, netdev@vger.kernel.org, linux-kernel@vger.kernel.org
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On Sat, Mar 9, 2024 at 2:35=E2=80=AFPM linke li <lilinke99@qq.com> wrote:
>
> sk->sk_rcvbuf can be changed by other threads. Mark this as benign using
> READ_ONCE.
>
> This patch is aimed at reducing the number of benign races reported by
> KCSAN in order to focus future debugging effort on harmful races.
>
> Signed-off-by: linke li <lilinke99@qq.com>
> ---
>  net/core/sock.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 5e78798456fd..4c5524e70534 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -551,7 +551,7 @@ int __sk_receive_skb(struct sock *sk, struct sk_buff =
*skb,
>
>         skb->dev =3D NULL;
>
> -       if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
> +       if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
>                 atomic_inc(&sk->sk_drops);
>                 goto discard_and_relse;

OK, but what about __sock_queue_rcv_skb() in the same file ?