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 ECF97C00144 for ; Mon, 1 Aug 2022 12:07:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233439AbiHAMFj (ORCPT ); Mon, 1 Aug 2022 08:05:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233326AbiHAMFE (ORCPT ); Mon, 1 Aug 2022 08:05:04 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 797933DBC9; Mon, 1 Aug 2022 04:54:40 -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 04441B81177; Mon, 1 Aug 2022 11:54:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 607D3C433D6; Mon, 1 Aug 2022 11:54:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354877; bh=QCM+pkoBB3k0TyrYAg7KgYY8WjHYnJqZJO075BhLf2o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UHc9dFVxKxx6Th2YhTD3/u44JeuKGHjLIEwsKJaKACQgWKqQOg6WBhHLIP1ukPqMU 9YnRrCxkFPePC930LUDYE91f/Vcpgh9BCPV74IKjZRtUOKR0V4CgC525oJZUaDoLkf HQtvoD4zrplJgYsFSabW9p/H+PpuohLbY5GC9Z6k= 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 5.15 53/69] ipv4: Fix data-races around sysctl_fib_notify_on_flag_change. Date: Mon, 1 Aug 2022 13:47:17 +0200 Message-Id: <20220801114136.635281463@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220801114134.468284027@linuxfoundation.org> References: <20220801114134.468284027@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 96b9bd8c6d125490f9adfb57d387ef81a55a103e ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 a9cd9c2bd84e..19c6e7b93d3d 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -1037,6 +1037,7 @@ 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; @@ -1058,14 +1059,16 @@ 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); -- 2.35.1