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 0F00EC43334 for ; Tue, 19 Jul 2022 12:27:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239684AbiGSM1K (ORCPT ); Tue, 19 Jul 2022 08:27:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237241AbiGSMY4 (ORCPT ); Tue, 19 Jul 2022 08:24:56 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8317D5071E; Tue, 19 Jul 2022 05:09:48 -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 306EEB81B32; Tue, 19 Jul 2022 12:09:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81BB6C36AE5; Tue, 19 Jul 2022 12:09:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658232550; bh=hPEDbcvAPKZfOqkxksytzGutu2Ale869Ev1r8RuDN8o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NPmnYLYLxNabr/MVQKjUuQW0kryQhNSZgi2ScT/oFdKu18bAT+x++DBHwPTAm/fKo QXIshbO68YpUVAnBQcUiaQp9rHA5QgaTT+wHyJC/QzSPdAuC2Lg4AuD2SgSawwrKi2 RVz26R8HkOYL5+cmO25c/w6fZQza3gWzrpGgpmyQ= 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 5.10 063/112] nexthop: Fix data-races around nexthop_compat_mode. Date: Tue, 19 Jul 2022 13:53:56 +0200 Message-Id: <20220719114632.594100958@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220719114626.156073229@linuxfoundation.org> References: <20220719114626.156073229@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 bdf00bf24bef9be1ca641a6390fd5487873e0d2e ] While reading nexthop_compat_mode, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 4f80116d3df3 ("net: ipv4: add sysctl for nexthop api compatibility mode") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/fib_semantics.c | 2 +- net/ipv4/nexthop.c | 5 +++-- net/ipv6/route.c | 2 +- 3 files changed, 5 insertions(+), 4 deletions(-) --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -1831,7 +1831,7 @@ int fib_dump_info(struct sk_buff *skb, u goto nla_put_failure; if (nexthop_is_blackhole(fi->nh)) rtm->rtm_type = RTN_BLACKHOLE; - if (!fi->fib_net->ipv4.sysctl_nexthop_compat_mode) + if (!READ_ONCE(fi->fib_net->ipv4.sysctl_nexthop_compat_mode)) goto offload; } --- a/net/ipv4/nexthop.c +++ b/net/ipv4/nexthop.c @@ -882,7 +882,7 @@ static void __remove_nexthop_fib(struct /* __ip6_del_rt does a release, so do a hold here */ fib6_info_hold(f6i); ipv6_stub->ip6_del_rt(net, f6i, - !net->ipv4.sysctl_nexthop_compat_mode); + !READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode)); } } @@ -1194,7 +1194,8 @@ out: if (!rc) { nh_base_seq_inc(net); nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo); - if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode) + if (replace_notify && + READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode)) nexthop_replace_notify(net, new_nh, &cfg->nlinfo); } --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5641,7 +5641,7 @@ static int rt6_fill_node(struct net *net if (nexthop_is_blackhole(rt->nh)) rtm->rtm_type = RTN_BLACKHOLE; - if (net->ipv4.sysctl_nexthop_compat_mode && + if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) && rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0) goto nla_put_failure;