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From:   Amol Grover <frextrite@gmail.com>
To:     Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        "David S . Miller" <davem@davemloft.net>,
        Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        Jakub Kicinski <kuba@kernel.org>
Cc:     linux-kernel@vger.kernel.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        Joel Fernandes <joel@joelfernandes.org>,
        Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
        netdev@vger.kernel.org, Amol Grover <frextrite@gmail.com>
Subject: [PATCH] netfilter: ipt_CLUSTERIP: Pass lockdep expression to RCU lists
Date:   Wed, 19 Feb 2020 15:46:27 +0530
Message-Id: <20200219101626.31943-1-frextrite@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

cn->configs is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of cn->lock.

Hence, add corresponding lockdep expression to silence false-positive
warnings, and harden RCU lists.

Signed-off-by: Amol Grover <frextrite@gmail.com>
---
 net/ipv4/netfilter/ipt_CLUSTERIP.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
index 6bdb1ab8af61..df856ff835b7 100644
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -139,7 +139,8 @@ __clusterip_config_find(struct net *net, __be32 clusterip)
 	struct clusterip_config *c;
 	struct clusterip_net *cn = clusterip_pernet(net);
 
-	list_for_each_entry_rcu(c, &cn->configs, list) {
+	list_for_each_entry_rcu(c, &cn->configs, list,
+				lockdep_is_held(&cn->lock)) {
 		if (c->clusterip == clusterip)
 			return c;
 	}
@@ -194,7 +195,8 @@ clusterip_netdev_event(struct notifier_block *this, unsigned long event,
 	struct clusterip_config *c;
 
 	spin_lock_bh(&cn->lock);
-	list_for_each_entry_rcu(c, &cn->configs, list) {
+	list_for_each_entry_rcu(c, &cn->configs, list,
+				lockdep_is_held(&cn->lock)) {
 		switch (event) {
 		case NETDEV_REGISTER:
 			if (!strcmp(dev->name, c->ifname)) {
-- 
2.24.1