[PATCH 4.19 046/273] netfilter: nft_flow_offload: fix underflow in flowtable reference counter

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: wenxu <wenxu@ucloud.cn>

commit 8ca79606cdfde2e37ee4f0707b9d1874a6f0eb38 upstream.

The .deactivate and .activate interfaces already deal with the reference
counter. Otherwise, this results in spurious "Device is busy" errors.

Fixes: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/netfilter/nft_flow_offload.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -197,9 +197,6 @@ static void nft_flow_offload_activate(co
 static void nft_flow_offload_destroy(const struct nft_ctx *ctx,
 				     const struct nft_expr *expr)
 {
-	struct nft_flow_offload *priv = nft_expr_priv(expr);
-
-	priv->flowtable->use--;
 	nf_ct_netns_put(ctx->net, ctx->family);
 }