[PATCH nf,v2 2/2] netfilter: nf_tables: NFTA_SET_ELEM_KEY_END requires concat and interval flags

[PATCH nf,v2 2/2] netfilter: nf_tables: NFTA_SET_ELEM_KEY_END requires concat and interval flags

[Pablo Neira Ayuso]

If the NFT_SET_CONCAT flag is set on, then the netlink attribute
NFTA_SET_ELEM_KEY_END must be specified. Otherwise, NFTA_SET_ELEM_KEY_END
should not be present.

There are two special cases where NFTA_SET_ELEM_KEY_END is optional,
either if this is a closing interval element or this is a catch-all
element.

Fixes: 7b225d0b5c6d ("netfilter: nf_tables: add NFTA_SET_ELEM_KEY_END attribute")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v2: restrict to (NFT_SET_CONCAT | NFT_SET_INTERVAL)

 net/netfilter/nf_tables_api.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index bcfe8120e014..29fe6fd41799 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5903,6 +5903,16 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 			return -EINVAL;
 	}
 
+	if ((set->flags & (NFT_SET_CONCAT | NFT_SET_INTERVAL)) ==
+			  (NFT_SET_CONCAT | NFT_SET_INTERVAL)) {
+		if (!nla[NFTA_SET_ELEM_KEY_END] &&
+		    !(flags & (NFT_SET_ELEM_INTERVAL_END | NFT_SET_ELEM_CATCHALL)))
+			return -EINVAL;
+	} else {
+		if (nla[NFTA_SET_ELEM_KEY_END])
+			return -EINVAL;
+	}
+
 	if ((flags & NFT_SET_ELEM_INTERVAL_END) &&
 	     (nla[NFTA_SET_ELEM_DATA] ||
 	      nla[NFTA_SET_ELEM_OBJREF] ||
-- 
2.30.2