From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42BEEC282DA for ; Thu, 18 Apr 2019 01:46:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10C92217FA for ; Thu, 18 Apr 2019 01:46:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387868AbfDRBqT (ORCPT ); Wed, 17 Apr 2019 21:46:19 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:6639 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1733067AbfDRBqS (ORCPT ); Wed, 17 Apr 2019 21:46:18 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id ACA47F1AEAD17067CAD0; Thu, 18 Apr 2019 09:46:14 +0800 (CST) Received: from [127.0.0.1] (10.184.189.20) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.408.0; Thu, 18 Apr 2019 09:46:05 +0800 Subject: Re: [PATCH] ipvs:set sock send/receive buffer correctly To: Eric Dumazet , , , , , , , , , , , , CC: Mingfangsen , References: <501e5522-1d69-7c67-a1bc-fd8502d3b5d1@huawei.com> <60c11e72-99eb-fcde-e130-a35ecdc1d2d1@gmail.com> From: linmiaohe Message-ID: Date: Thu, 18 Apr 2019 09:45:59 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <60c11e72-99eb-fcde-e130-a35ecdc1d2d1@gmail.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.184.189.20] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/4/17 21:18, Eric Dumazet wrote: > > > On 04/17/2019 02:18 AM, linmiaohe wrote: >> From: Jie Liu >> >> If we set sysctl_wmem_max or sysctl_rmem_max larger than INT_MAX, >> the send/receive buffer of sock will be an negative value. Same as >> when the val is larger than INT_MAX/2. >> >> Fixes: 1c003b1580e2 ("ipvs: wakeup master thread") >> Reported-by: Qiang Ning >> Reviewed-by: Miaohe Lin >> Signed-off-by: Jie Liu >> --- >> net/netfilter/ipvs/ip_vs_sync.c | 10 ++++------ >> 1 file changed, 4 insertions(+), 6 deletions(-) >> >> diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c >> index 2526be6b3d90..c0e4cbed6e74 100644 >> --- a/net/netfilter/ipvs/ip_vs_sync.c >> +++ b/net/netfilter/ipvs/ip_vs_sync.c >> @@ -1278,14 +1278,12 @@ static void set_sock_size(struct sock *sk, int mode, int val) >> /* setsockopt(sock, SOL_SOCKET, SO_RCVBUF, &val, sizeof(val)); */ >> lock_sock(sk); >> if (mode) { >> - val = clamp_t(int, val, (SOCK_MIN_SNDBUF + 1) / 2, >> - sysctl_wmem_max); >> - sk->sk_sndbuf = val * 2; >> + val = min_t(u32, val, sysctl_wmem_max); >> + sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF); > > What prevents val * 2 to overflow ? > > Code in sock_setsockopt() looks quite different. > . > In fact, I just implemented this function with reference to sock_setsockopt(). When val * 2 overflow, we will set the buffer as SOCK_MIN_SNDBUF, just as sock_setsockopt() do.