netfilter: nf_tables: NFTA_SET_ELEM_KEY_END requires concat and interval flags

If the NFT_SET_CONCAT|NFT_SET_INTERVAL flags are set on, then the
netlink attribute NFTA_SET_ELEM_KEY_END must be specified. Otherwise,
NFTA_SET_ELEM_KEY_END should not be present.

For catch-all element, NFTA_SET_ELEM_KEY_END should not be present.
The NFT_SET_ELEM_INTERVAL_END is never used with this set flags
combination.

Fixes: 7b225d0b5c6d ("netfilter: nf_tables: add NFTA_SET_ELEM_KEY_END attribute")
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 bcfe812..1d14d69 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5844,6 +5844,24 @@ static void nft_setelem_remove(const struct net *net,
                set->ops->remove(net, set, elem);
 }
 
+static bool nft_setelem_valid_key_end(const struct nft_set *set,
+                                     struct nlattr **nla, u32 flags)
+{
+       if ((set->flags & (NFT_SET_CONCAT | NFT_SET_INTERVAL)) ==
+                         (NFT_SET_CONCAT | NFT_SET_INTERVAL)) {
+               if (flags & NFT_SET_ELEM_INTERVAL_END)
+                       return false;
+               if (!nla[NFTA_SET_ELEM_KEY_END] &&
+                   !(flags & NFT_SET_ELEM_CATCHALL))
+                       return false;
+       } else {
+               if (nla[NFTA_SET_ELEM_KEY_END])
+                       return false;
+       }
+
+       return true;
+}
+
 static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
                            const struct nlattr *attr, u32 nlmsg_flags)
 {
@@ -5903,6 +5921,9 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
                        return -EINVAL;
        }
 
+       if (!nft_setelem_valid_key_end(set, nla, flags))
+               return -EINVAL;
+
        if ((flags & NFT_SET_ELEM_INTERVAL_END) &&
             (nla[NFTA_SET_ELEM_DATA] ||
              nla[NFTA_SET_ELEM_OBJREF] ||
@@ -6333,6 +6354,9 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
        if (!nla[NFTA_SET_ELEM_KEY] && !(flags & NFT_SET_ELEM_CATCHALL))
                return -EINVAL;
 
+       if (!nft_setelem_valid_key_end(set, nla, flags))
+               return -EINVAL;
+
        nft_set_ext_prepare(&tmpl);
 
        if (flags != 0) {