From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4DAFB17F6 for ; Wed, 19 Jul 2023 17:18:55 +0000 (UTC) Received: from mail-ed1-f47.google.com (mail-ed1-f47.google.com [209.85.208.47]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7EFBD189; Wed, 19 Jul 2023 10:18:53 -0700 (PDT) Received: by mail-ed1-f47.google.com with SMTP id 4fb4d7f45d1cf-52166c7f77cso8685885a12.2; Wed, 19 Jul 2023 10:18:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689787132; x=1692379132; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=HJ8zyPA28H2PBLz8lr4+2NlPFh5DMTLYGFS9mgafKcY=; b=EdmHU8N936Tg5yFldrBTh0UBsL6U1yjpXDu+8EdaGEJtcAulimdbkyDbmHUIzsL5/T Z8NQrLkOu6HA+qdYGGriwFa5KOuZzBxRx+JpK664QqO+9AnKHUPlSas7Hya1fsqtPGTD N9xVypkjYvVFsupXiUKKjENvPYFSBRMO6vy8SA3jjC+7jeRBxJHxZbvQzBu935/mfnNR l75p3QHodqDfMZyLZIHtPDtXb7qWsH6Ka3PBGswUgWZ0O7MtZWDG8j0HkYKkyZC3xQhF 8IFpt5f7raGa4CB5j+sE6tTLhy44Rw9lthkKrWju+8Wr0Py/qlfbBffBUvHgRRHP7GPK UsPQ== X-Gm-Message-State: ABy/qLaQFG54qtG1V1rD6l97CZPsAKtY2vngbjFaeqWmvPAfoOFBBUnM sPPjDgtmbHAf1KdqMKRFkik= X-Google-Smtp-Source: APBJJlEOJvQn9kSsZWsRdnFrSThCTxwiUITIx9D1MPZqWcvz6lb1LwjVA9hbY8O/MmLpzg1hUSocNw== X-Received: by 2002:a05:6402:1a31:b0:51d:96d2:6578 with SMTP id be17-20020a0564021a3100b0051d96d26578mr3359383edb.28.1689787131622; Wed, 19 Jul 2023 10:18:51 -0700 (PDT) Received: from gmail.com (fwdproxy-cln-017.fbsv.net. [2a03:2880:31ff:11::face:b00c]) by smtp.gmail.com with ESMTPSA id k19-20020a05640212d300b00521d1c34b23sm371987edx.83.2023.07.19.10.18.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Jul 2023 10:18:51 -0700 (PDT) Date: Wed, 19 Jul 2023 10:18:49 -0700 From: Breno Leitao To: Kuniyuki Iwashima Cc: alexander@mihalicyn.com, ast@kernel.org, davem@davemloft.net, dhowells@redhat.com, edumazet@google.com, kernelxing@tencent.com, kuba@kernel.org, leit@meta.com, linux-kernel@vger.kernel.org, lucien.xin@gmail.com, martin.lau@kernel.org, netdev@vger.kernel.org, pabeni@redhat.com Subject: Re: [PATCH net-next] net: Use _K_SS_MAXSIZE instead of absolute value Message-ID: References: <20230719084415.1378696-1-leitao@debian.org> <20230719170445.30993-1-kuniyu@amazon.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230719170445.30993-1-kuniyu@amazon.com> X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,FSL_HELO_FAKE, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Wed, Jul 19, 2023 at 10:04:45AM -0700, Kuniyuki Iwashima wrote: > From: Breno Leitao > Date: Wed, 19 Jul 2023 01:44:12 -0700 > > Looking at sk_getsockopt function, it is unclear why 128 is a magical > > number. > > > > Use the proper macro, so it becomes clear to understand what the value > > mean, and get a reference where it is coming from (user-exported API). > > > > Signed-off-by: Breno Leitao > > --- > > 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 9370fd50aa2c..58b6f00197d6 100644 > > --- a/net/core/sock.c > > +++ b/net/core/sock.c > > @@ -1815,7 +1815,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname, > > > > case SO_PEERNAME: > > { > > - char address[128]; > > + char address[_K_SS_MAXSIZE]; > > I guess you saw a bug caught by the fortified memcpy(), but this > doesn't fix it properly. Not really, in fact. I was reading this code, and I found this discussion a while ago, where I got the idea: https://lore.kernel.org/lkml/20140930.005925.995989898229686123.davem@davemloft.net/