[PATCH nf-next] netfilter: nf_table_offload: Fix the incorrect rcu usage in nft_indr_block_get_and_ing_cmd

[wenxu@ucloud.cn]

From: wenxu <wenxu@ucloud.cn>

The nft_indr_block_get_and_ing_cmd is called in netdevice notify
It is the incorrect rcu case, To fix it just traverse the list under
the commit mutex.

Fixes: 9a32669fecfb ("netfilter: nf_tables_offload: support indr block call")
Signed-off-by: wenxu <wenxu@ucloud.cn>
---
 net/netfilter/nf_tables_offload.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c
index b95e27b..bcaafc8 100644
--- a/net/netfilter/nf_tables_offload.c
+++ b/net/netfilter/nf_tables_offload.c
@@ -359,15 +359,18 @@ void nft_indr_block_get_and_ing_cmd(struct net_device *dev,
 				    void *cb_priv,
 				    enum flow_block_command command)
 {
-	struct net *net = dev_net(dev);
+	const struct nft_chain *chain, *nr;
 	const struct nft_table *table;
-	const struct nft_chain *chain;
+	struct nft_ctx ctx = {
+		.net	= dev_net(dev),
+	};
 
-	list_for_each_entry_rcu(table, &net->nft.tables, list) {
+	mutex_lock(&ctx.net->nft.commit_mutex);
+	list_for_each_entry(table, &ctx.net->nft.tables, list) {
 		if (table->family != NFPROTO_NETDEV)
 			continue;
 
-		list_for_each_entry_rcu(chain, &table->chains, list) {
+		list_for_each_entry_safe(chain, nr, &table->chains, list) {
 			if (nft_is_base_chain(chain)) {
 				struct nft_base_chain *basechain;
 
@@ -382,4 +385,5 @@ void nft_indr_block_get_and_ing_cmd(struct net_device *dev,
 			}
 		}
 	}
+	mutex_unlock(&ctx.net->nft.commit_mutex);
 }
-- 
1.8.3.1