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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ECE1DC32774 for ; Tue, 23 Aug 2022 19:15:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232031AbiHWTPr (ORCPT ); Tue, 23 Aug 2022 15:15:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231426AbiHWTPS (ORCPT ); Tue, 23 Aug 2022 15:15:18 -0400 Received: from smtp-fw-33001.amazon.com (smtp-fw-33001.amazon.com [207.171.190.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A925F7EFCD for ; Tue, 23 Aug 2022 10:52:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1661277158; x=1692813158; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=+2FVkKObQOh3GrpXfvEKdKt9rboCcdoyqGLpNHC76lg=; b=Ltcbg+AtsXw5NcQ2JsgOZdP2x4QhHA2vodSF3/foSV1naCF7hKKHv5/5 6S9ELXpGMEADRocZ0xZuLXNY25TmFE2OyCiDO4Vv9J0GQLdMrma8bj1Bp VVN17qJxreGUAgh+o17PdGud8a2IGaUirhYBuL5BSU7a08vNTINwFz61i 8=; X-IronPort-AV: E=Sophos;i="5.93,258,1654560000"; d="scan'208";a="220380891" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-pdx-2c-a264e6fe.us-west-2.amazon.com) ([10.43.8.6]) by smtp-border-fw-33001.sea14.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Aug 2022 17:51:49 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-pdx-2c-a264e6fe.us-west-2.amazon.com (Postfix) with ESMTPS id 0B56645133; Tue, 23 Aug 2022 17:51:47 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Tue, 23 Aug 2022 17:51:46 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.160) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.12; Tue, 23 Aug 2022 17:51:44 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Cong Wang Subject: [PATCH v4 net 14/17] net: Fix data-races around sysctl_devconf_inherit_init_net. Date: Tue, 23 Aug 2022 10:46:57 -0700 Message-ID: <20220823174700.88411-15-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220823174700.88411-1-kuniyu@amazon.com> References: <20220823174700.88411-1-kuniyu@amazon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.160.160] X-ClientProxiedBy: EX13D07UWA003.ant.amazon.com (10.43.160.35) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org While reading sysctl_devconf_inherit_init_net, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 856c395cfa63 ("net: introduce a knob to control whether to inherit devconf config") Signed-off-by: Kuniyuki Iwashima --- CC: Cong Wang --- include/linux/netdevice.h | 9 +++++++++ net/ipv4/devinet.c | 16 ++++++++++------ net/ipv6/addrconf.c | 5 ++--- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 6d3a33fd0cdb..05d6f3facd5a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -650,6 +650,15 @@ static inline bool net_has_fallback_tunnels(const struct net *net) #endif } +static inline int net_inherit_devconf(void) +{ +#if IS_ENABLED(CONFIG_SYSCTL) + return READ_ONCE(sysctl_devconf_inherit_init_net); +#else + return 0; +#endif +} + static inline int netdev_queue_numa_node_read(const struct netdev_queue *q) { #if defined(CONFIG_XPS) && defined(CONFIG_NUMA) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 92b778e423df..e8b9a9202fec 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -2682,23 +2682,27 @@ static __net_init int devinet_init_net(struct net *net) #endif if (!net_eq(net, &init_net)) { - if (IS_ENABLED(CONFIG_SYSCTL) && - sysctl_devconf_inherit_init_net == 3) { + switch (net_inherit_devconf()) { + case 3: /* copy from the current netns */ memcpy(all, current->nsproxy->net_ns->ipv4.devconf_all, sizeof(ipv4_devconf)); memcpy(dflt, current->nsproxy->net_ns->ipv4.devconf_dflt, sizeof(ipv4_devconf_dflt)); - } else if (!IS_ENABLED(CONFIG_SYSCTL) || - sysctl_devconf_inherit_init_net != 2) { - /* inherit == 0 or 1: copy from init_net */ + break; + case 0: + case 1: + /* copy from init_net */ memcpy(all, init_net.ipv4.devconf_all, sizeof(ipv4_devconf)); memcpy(dflt, init_net.ipv4.devconf_dflt, sizeof(ipv4_devconf_dflt)); + break; + case 2: + /* use compiled values */ + break; } - /* else inherit == 2: use compiled values */ } #ifdef CONFIG_SYSCTL diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index b624e3d8c5f0..e15f64f22fa8 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -7162,9 +7162,8 @@ static int __net_init addrconf_init_net(struct net *net) if (!dflt) goto err_alloc_dflt; - if (IS_ENABLED(CONFIG_SYSCTL) && - !net_eq(net, &init_net)) { - switch (sysctl_devconf_inherit_init_net) { + if (!net_eq(net, &init_net)) { + switch (net_inherit_devconf()) { case 1: /* copy from init_net */ memcpy(all, init_net.ipv6.devconf_all, sizeof(ipv6_devconf)); -- 2.30.2