netfilter: nf_tables: validate NFTA_SET_ELEM_OBJREF based on NFT_SET_OBJECT flag

If the NFTA_SET_ELEM_OBJREF netlink attribute is present and
NFT_SET_OBJECT flag is set on, report EINVAL.

Move existing sanity check earlier to validate that NFT_SET_OBJECT
requires NFTA_SET_ELEM_OBJREF.

Fixes: 8aeff920dcc9 ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 1b9459a..bcfe812 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5894,6 +5894,15 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
                        return -EINVAL;
        }
 
+       if (set->flags & NFT_SET_OBJECT) {
+               if (!nla[NFTA_SET_ELEM_OBJREF] &&
+                   !(flags & NFT_SET_ELEM_INTERVAL_END))
+                       return -EINVAL;
+       } else {
+               if (nla[NFTA_SET_ELEM_OBJREF])
+                       return -EINVAL;
+       }
+
        if ((flags & NFT_SET_ELEM_INTERVAL_END) &&
             (nla[NFTA_SET_ELEM_DATA] ||
              nla[NFTA_SET_ELEM_OBJREF] ||
@@ -6032,10 +6041,6 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
        }
 
        if (nla[NFTA_SET_ELEM_OBJREF] != NULL) {
-               if (!(set->flags & NFT_SET_OBJECT)) {
-                       err = -EINVAL;
-                       goto err_parse_key_end;
-               }
                obj = nft_obj_lookup(ctx->net, ctx->table,
                                     nla[NFTA_SET_ELEM_OBJREF],
                                     set->objtype, genmask);