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 D35F3ECAAD4 for ; Mon, 29 Aug 2022 11:25:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231949AbiH2LZH (ORCPT ); Mon, 29 Aug 2022 07:25:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232216AbiH2LYc (ORCPT ); Mon, 29 Aug 2022 07:24:32 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E65130F68; Mon, 29 Aug 2022 04:15:43 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 44A1FB80F01; Mon, 29 Aug 2022 11:13:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A951EC43142; Mon, 29 Aug 2022 11:13:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661771591; bh=bszJK+xsM2ct+CjjbxZn664cxsjOOWBnSDfF/kCyq6A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VbnObiIJw3fpxMZCrtZKmmUVPKHrmx+ekciFVu/d6xuv5SAHar0ldrGsvdJkxVk2E TQRdi/Tleu9KCVNZsKazEkU8oExbRNtYiZQV8TPNbtEy+aiWNxInSjMtGD/BNC3263 sTIOTfcUvnQ3vwz9RKnU5S/gAXkH6d31tPi6mx5E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 5.10 59/86] net: Fix data-races around sysctl_devconf_inherit_init_net. Date: Mon, 29 Aug 2022 12:59:25 +0200 Message-Id: <20220829105758.970231758@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220829105756.500128871@linuxfoundation.org> References: <20220829105756.500128871@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit a5612ca10d1aa05624ebe72633e0c8c792970833 ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 c05701f89d6dd..6564fb4ac49e1 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -643,6 +643,15 @@ 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 148ef484a66ce..8f17538755507 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -2668,23 +2668,27 @@ 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 05317e6f48f8a..ed1e5bfc97b31 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -7042,9 +7042,8 @@ 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)); -- 2.35.1