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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Shijie Luo <luoshijie1@huawei.com>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.2 052/162] netfilter: ipset: Fix rename concurrency with listing
Date:   Tue, 27 Aug 2019 09:49:40 +0200
Message-Id: <20190827072740.023277554@linuxfoundation.org>
In-Reply-To: <20190827072738.093683223@linuxfoundation.org>
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[ Upstream commit 6c1f7e2c1b96ab9b09ac97c4df2bd9dc327206f6 ]

Shijie Luo reported that when stress-testing ipset with multiple concurrent
create, rename, flush, list, destroy commands, it can result

ipset <version>: Broken LIST kernel message: missing DATA part!

error messages and broken list results. The problem was the rename operation
was not properly handled with respect of listing. The patch fixes the issue.

Reported-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/ipset/ip_set_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 16afa0df4004d..e103c875383a5 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1161,7 +1161,7 @@ static int ip_set_rename(struct net *net, struct sock *ctnl,
 		return -ENOENT;
 
 	write_lock_bh(&ip_set_ref_lock);
-	if (set->ref != 0) {
+	if (set->ref != 0 || set->ref_netlink != 0) {
 		ret = -IPSET_ERR_REFERENCED;
 		goto out;
 	}
-- 
2.20.1