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 2CCB8C433EF for ; Fri, 22 Jul 2022 18:24:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236320AbiGVSYn (ORCPT ); Fri, 22 Jul 2022 14:24:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235664AbiGVSYm (ORCPT ); Fri, 22 Jul 2022 14:24:42 -0400 Received: from smtp-fw-9103.amazon.com (smtp-fw-9103.amazon.com [207.171.188.200]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 476B29E7A7 for ; Fri, 22 Jul 2022 11:24:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1658514281; x=1690050281; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=In4Wd+SYQwY74S1FEFiUwR1FHom6iUohzZSuXmsIcBg=; b=BK1eFgsXrCNfWA6rp2KtPWtvmYhYQsKkgzI8uz6wNS6n+2KO2jm0xwBI trH+GudRFxRclxOJhwc/+kUxEUZTzuav1X+M1uOzvd1tEfqv1ASsF/NsI UFRxHrQ9zq3tpx8Py8fwLccDYjDrVObI7FO1fi3KmsIJZCAzQd06RK9lh o=; X-IronPort-AV: E=Sophos;i="5.93,186,1654560000"; d="scan'208";a="1037018079" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-pdx-2b-c275e159.us-west-2.amazon.com) ([10.25.36.214]) by smtp-border-fw-9103.sea19.amazon.com with ESMTP; 22 Jul 2022 18:24:22 +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-2b-c275e159.us-west-2.amazon.com (Postfix) with ESMTPS id C7F9E92CC3; Fri, 22 Jul 2022 18:24:22 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Fri, 22 Jul 2022 18:24:22 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.159) 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 15.2.1118.9; Fri, 22 Jul 2022 18:24:19 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Amit Cohen Subject: [PATCH v1 net 7/7] ipv4: Fix data-races around sysctl_fib_notify_on_flag_change. Date: Fri, 22 Jul 2022 11:22:05 -0700 Message-ID: <20220722182205.96838-8-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220722182205.96838-1-kuniyu@amazon.com> References: <20220722182205.96838-1-kuniyu@amazon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.160.159] X-ClientProxiedBy: EX13D13UWB004.ant.amazon.com (10.43.161.218) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org While reading sysctl_fib_notify_on_flag_change, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 680aea08e78c ("net: ipv4: Emit notification when fib hardware flags are changed") Signed-off-by: Kuniyuki Iwashima --- CC: Amit Cohen --- net/ipv4/fib_trie.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 46e8a5125853..452ff177e4da 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -1042,6 +1042,7 @@ fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri) void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri) { + u8 fib_notify_on_flag_change; struct fib_alias *fa_match; struct sk_buff *skb; int err; @@ -1063,14 +1064,16 @@ void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri) WRITE_ONCE(fa_match->offload, fri->offload); WRITE_ONCE(fa_match->trap, fri->trap); + fib_notify_on_flag_change = READ_ONCE(net->ipv4.sysctl_fib_notify_on_flag_change); + /* 2 means send notifications only if offload_failed was changed. */ - if (net->ipv4.sysctl_fib_notify_on_flag_change == 2 && + if (fib_notify_on_flag_change == 2 && READ_ONCE(fa_match->offload_failed) == fri->offload_failed) goto out; WRITE_ONCE(fa_match->offload_failed, fri->offload_failed); - if (!net->ipv4.sysctl_fib_notify_on_flag_change) + if (!fib_notify_on_flag_change) goto out; skb = nlmsg_new(fib_nlmsg_size(fa_match->fa_info), GFP_ATOMIC); -- 2.30.2