netfilter: nf_tables: discard table flag update with pending basechain deletion

commit 1bc83a019bbe268be3526406245ec28c2458a518 upstream.

Hook unregistration is deferred to the commit phase, same occurs with
hook updates triggered by the table dormant flag. When both commands are
combined, this results in deleting a basechain while leaving its hook
still registered in the core.

Fixes: 179d9ba5559a ("netfilter: nf_tables: fix table flag updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ef271628975a9c75e1b43dc53cc45de74c14ac7d..ab7f7e45b9846d5971d3a05c6f3fb38b7c0779a3 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1084,6 +1084,24 @@ static void nf_tables_table_disable(struct net *net, struct nft_table *table)
 #define __NFT_TABLE_F_UPDATE           (__NFT_TABLE_F_WAS_DORMANT | \
                                         __NFT_TABLE_F_WAS_AWAKEN)
 
+static bool nft_table_pending_update(const struct nft_ctx *ctx)
+{
+       struct nftables_pernet *nft_net = net_generic(ctx->net, nf_tables_net_id);
+       struct nft_trans *trans;
+
+       if (ctx->table->flags & __NFT_TABLE_F_UPDATE)
+               return true;
+
+       list_for_each_entry(trans, &nft_net->commit_list, list) {
+               if (trans->ctx.table == ctx->table &&
+                   trans->msg_type == NFT_MSG_DELCHAIN &&
+                   nft_is_base_chain(trans->ctx.chain))
+                       return true;
+       }
+
+       return false;
+}
+
 static int nf_tables_updtable(struct nft_ctx *ctx)
 {
        struct nft_trans *trans;
@@ -1101,7 +1119,7 @@ static int nf_tables_updtable(struct nft_ctx *ctx)
                return 0;
 
        /* No dormant off/on/off/on games in single transaction */
-       if (ctx->table->flags & __NFT_TABLE_F_UPDATE)
+       if (nft_table_pending_update(ctx))
                return -EINVAL;
 
        trans = nft_trans_alloc(ctx, NFT_MSG_NEWTABLE,