netfilter: nf_tables: destroy basechain and rules on netdevice removal

If the netdevice is destroyed, the resources that are attached should
be released too as they belong to the device that is now gone.

Suggested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 18 insertions, 27 deletions

diff --git a/net/netfilter/nf_tables_netdev.c b/net/netfilter/nf_tables_netdev.c
index 2bfd1fbccec8..3e9c87b961ba 100644
--- a/net/netfilter/nf_tables_netdev.c
+++ b/net/netfilter/nf_tables_netdev.c
@@ -156,35 +156,17 @@ static const struct nf_chain_type nft_filter_chain_netdev = {
 	.hook_mask	= (1 << NF_NETDEV_INGRESS),
 };
 
-static void nft_netdev_event(unsigned long event, struct nft_af_info *afi,
-			     struct net_device *dev, struct nft_table *table,
-			     struct nft_base_chain *basechain)
+static void nft_netdev_event(unsigned long event, struct net_device *dev,
+			     struct nft_ctx *ctx)
 {
-	switch (event) {
-	case NETDEV_REGISTER:
-		if (strcmp(basechain->dev_name, dev->name) != 0)
-			return;
+	struct nft_base_chain *basechain = nft_base_chain(ctx->chain);
 
-		BUG_ON(!(basechain->flags & NFT_BASECHAIN_DISABLED));
-
-		dev_hold(dev);
-		basechain->ops[0].dev = dev;
-		basechain->flags &= ~NFT_BASECHAIN_DISABLED;
-		if (!(table->flags & NFT_TABLE_F_DORMANT))
-			nft_register_basechain(basechain, afi->nops);
-		break;
+	switch (event) {
 	case NETDEV_UNREGISTER:
 		if (strcmp(basechain->dev_name, dev->name) != 0)
 			return;
 
-		BUG_ON(basechain->flags & NFT_BASECHAIN_DISABLED);
-
-		if (!(table->flags & NFT_TABLE_F_DORMANT))
-			nft_unregister_basechain(basechain, afi->nops);
-
-		dev_put(basechain->ops[0].dev);
-		basechain->ops[0].dev = NULL;
-		basechain->flags |= NFT_BASECHAIN_DISABLED;
+		__nft_release_basechain(ctx);
 		break;
 	case NETDEV_CHANGENAME:
 		if (dev->ifindex != basechain->ops[0].dev->ifindex)
@@ -201,20 +183,29 @@ static int nf_tables_netdev_event(struct notifier_block *this,
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct nft_af_info *afi;
 	struct nft_table *table;
-	struct nft_chain *chain;
+	struct nft_chain *chain, *nr;
+	struct nft_ctx ctx = {
+		.net	= dev_net(dev),
+	};
+
+	if (event != NETDEV_UNREGISTER &&
+	    event != NETDEV_CHANGENAME)
+		return NOTIFY_DONE;
 
 	nfnl_lock(NFNL_SUBSYS_NFTABLES);
 	list_for_each_entry(afi, &dev_net(dev)->nft.af_info, list) {
+		ctx.afi = afi;
 		if (afi->family != NFPROTO_NETDEV)
 			continue;
 
 		list_for_each_entry(table, &afi->tables, list) {
-			list_for_each_entry(chain, &table->chains, list) {
+			ctx.table = table;
+			list_for_each_entry_safe(chain, nr, &table->chains, list) {
 				if (!(chain->flags & NFT_BASE_CHAIN))
 					continue;
 
-				nft_netdev_event(event, afi, dev, table,
-						 nft_base_chain(chain));
+				ctx.chain = chain;
+				nft_netdev_event(event, dev, &ctx);
 			}
 		}
 	}