[Devel] [PATCH RH7 1/2] ms/netfilter: nf_tables: fix update chain error

[Vasily Averin]

From: JingPiao Chen <chenjingpiao at gmail.com>

 # nft add table filter
 # nft add chain filter c1
 # nft rename chain filter c1 c2

Error: Could not process rule: No such file or directory
rename chain filter c1 c2
^^^^^^^^^^^^^^^^^^^^^^^^^^

 # nft add chain filter c2
 # nft rename chain filter c1 c2
 # nft list table filter

table ip filter {
	chain c2 {
	}

	chain c2 {
	}
}

Fixes: 664b0f8cd8 ("netfilter: nf_tables: add generation mask to chains")
Signed-off-by: JingPiao Chen <chenjingpiao at gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
(cherry picked from commit 0d18779be13766b33c69cbc26df38383598da373)
https://bugs.openvz.org/browse/OVZ-7223
Signed-off-by: Vasily Averin <vvs at virtuozzo.com>
---
 net/netfilter/nf_tables_api.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 1cea127..d6dff4a 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1369,8 +1369,8 @@ static int nf_tables_newchain(struct net *net, struct sock *nlsk,
 			chain2 = nf_tables_chain_lookup(table,
 							nla[NFTA_CHAIN_NAME],
 							genmask);
-			if (IS_ERR(chain2))
-				return PTR_ERR(chain2);
+			if (!IS_ERR(chain2))
+				return -EEXIST;
 		}
 
 		if (nla[NFTA_CHAIN_COUNTERS]) {
-- 
1.8.3.1