3 files changed, 36 insertions, 13 deletions

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 221d27f09623..bd9715e5ff26 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3483,12 +3483,12 @@ static int nft_setelem_parse_flags(const struct nft_set *set,
 }
 
 static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
-			    const struct nlattr *attr)
+			    const struct nlattr *attr, u32 nlmsg_flags)
 {
 	struct nlattr *nla[NFTA_SET_ELEM_MAX + 1];
 	struct nft_data_desc d1, d2;
 	struct nft_set_ext_tmpl tmpl;
-	struct nft_set_ext *ext;
+	struct nft_set_ext *ext, *ext2;
 	struct nft_set_elem elem;
 	struct nft_set_binding *binding;
 	struct nft_userdata *udata;
@@ -3615,9 +3615,19 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 		goto err4;
 
 	ext->genmask = nft_genmask_cur(ctx->net) | NFT_SET_ELEM_BUSY_MASK;
-	err = set->ops->insert(ctx->net, set, &elem);
-	if (err < 0)
+	err = set->ops->insert(ctx->net, set, &elem, &ext2);
+	if (err) {
+		if (err == -EEXIST) {
+			if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA) &&
+			    nft_set_ext_exists(ext2, NFT_SET_EXT_DATA) &&
+			    memcmp(nft_set_ext_data(ext),
+				   nft_set_ext_data(ext2), set->dlen) != 0)
+				err = -EBUSY;
+			else if (!(nlmsg_flags & NLM_F_EXCL))
+				err = 0;
+		}
 		goto err5;
+	}
 
 	nft_trans_elem(trans) = elem;
 	list_add_tail(&trans->list, &ctx->net->nft.commit_list);
@@ -3673,7 +3683,7 @@ static int nf_tables_newsetelem(struct net *net, struct sock *nlsk,
 		    !atomic_add_unless(&set->nelems, 1, set->size + set->ndeact))
 			return -ENFILE;
 
-		err = nft_add_set_elem(&ctx, set, attr);
+		err = nft_add_set_elem(&ctx, set, attr, nlh->nlmsg_flags);
 		if (err < 0) {
 			atomic_dec(&set->nelems);
 			break;
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 564fa7929ed5..3794cb2fc788 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -126,7 +126,8 @@ err1:
 }
 
 static int nft_hash_insert(const struct net *net, const struct nft_set *set,
-			   const struct nft_set_elem *elem)
+			   const struct nft_set_elem *elem,
+			   struct nft_set_ext **ext)
 {
 	struct nft_hash *priv = nft_set_priv(set);
 	struct nft_hash_elem *he = elem->priv;
@@ -135,9 +136,17 @@ static int nft_hash_insert(const struct net *net, const struct nft_set *set,
 		.set	 = set,
 		.key	 = elem->key.val.data,
 	};
-
-	return rhashtable_lookup_insert_key(&priv->ht, &arg, &he->node,
-					    nft_hash_params);
+	struct nft_hash_elem *prev;
+
+	prev = rhashtable_lookup_get_insert_key(&priv->ht, &arg, &he->node,
+					       nft_hash_params);
+	if (IS_ERR(prev))
+		return PTR_ERR(prev);
+	if (prev) {
+		*ext = &prev->ext;
+		return -EEXIST;
+	}
+	return 0;
 }
 
 static void nft_hash_activate(const struct net *net, const struct nft_set *set,
diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index 6473936d05c6..038682d48261 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -94,7 +94,8 @@ out:
 }
 
 static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
-			       struct nft_rbtree_elem *new)
+			       struct nft_rbtree_elem *new,
+			       struct nft_set_ext **ext)
 {
 	struct nft_rbtree *priv = nft_set_priv(set);
 	u8 genmask = nft_genmask_next(net);
@@ -122,8 +123,10 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 				else if (!nft_rbtree_interval_end(rbe) &&
 					 nft_rbtree_interval_end(new))
 					p = &parent->rb_right;
-				else
+				else {
+					*ext = &rbe->ext;
 					return -EEXIST;
+				}
 			}
 		}
 	}
@@ -133,13 +136,14 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 }
 
 static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
-			     const struct nft_set_elem *elem)
+			     const struct nft_set_elem *elem,
+			     struct nft_set_ext **ext)
 {
 	struct nft_rbtree_elem *rbe = elem->priv;
 	int err;
 
 	spin_lock_bh(&nft_rbtree_lock);
-	err = __nft_rbtree_insert(net, set, rbe);
+	err = __nft_rbtree_insert(net, set, rbe, ext);
 	spin_unlock_bh(&nft_rbtree_lock);
 
 	return err;