From 6081c82c2ff8dc739dbc57c2bc2da9bd38f17ca1 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 22 Sep 2021 16:55:48 -0700
Subject: [PATCH] net: ethernet: mtk_eth_soc: avoid creating duplicate offload entries
Git-commit: e68daf61ed13832aef8892200a874139700ca754
Patch-mainline: v5.15-rc3
References: stable-5.14.9

[ Upstream commit e68daf61ed13832aef8892200a874139700ca754 ]

Sometimes multiple CLS_REPLACE calls are issued for the same connection.
rhashtable_insert_fast does not check for these duplicates, so multiple
hardware flow entries can be created.
Fix this by checking for an existing entry early

Fixes: 502e84e2382d ("net: ethernet: mtk_eth_soc: add flow offloading support")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/ethernet/mediatek/mtk_ppe_offload.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
index b5f68f66d42a..7bb1f20002b5 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
+++ b/drivers/net/ethernet/mediatek/mtk_ppe_offload.c
@@ -186,6 +186,9 @@ mtk_flow_offload_replace(struct mtk_eth *eth, struct flow_cls_offload *f)
 	int hash;
 	int i;
 
+	if (rhashtable_lookup(&eth->flow_table, &f->cookie, mtk_flow_ht_params))
+		return -EEXIST;
+
 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_META)) {
 		struct flow_match_meta match;
 
-- 
2.26.2