diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index 27668f4e44ea..217ab3644c25 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -218,11 +218,11 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 			       struct nft_rbtree_elem *new,
 			       struct nft_set_ext **ext)
 {
+	bool overlap = false, dup_end_left = false, dup_end_right = false;
 	struct nft_rbtree *priv = nft_set_priv(set);
 	u8 genmask = nft_genmask_next(net);
 	struct nft_rbtree_elem *rbe;
 	struct rb_node *parent, **p;
-	bool overlap = false;
 	int d;
 
 	/* Detect overlaps as we descend the tree. Set the flag in these cases:
@@ -262,6 +262,20 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 	 *
 	 * which always happen as last step and imply that no further
 	 * overlapping is possible.
+	 *
+	 * Another special case comes from the fact that start elements matching
+	 * an already existing start element are allowed: insertion is not
+	 * performed but we return -EEXIST in that case, and the error will be
+	 * cleared by the caller if NLM_F_EXCL is not present in the request.
+	 * This way, request for insertion of an exact overlap isn't reported as
+	 * error to userspace if not desired.
+	 *
+	 * However, if the existing start matches a pre-existing start, but the
+	 * end element doesn't match the corresponding pre-existing end element,
+	 * we need to report a partial overlap. This is a local condition that
+	 * can be noticed without need for a tracking flag, by checking for a
+	 * local duplicated end for a corresponding start, from left and right,
+	 * separately.
 	 */
 
 	parent = NULL;
@@ -281,19 +295,35 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 				    !nft_set_elem_expired(&rbe->ext) && !*p)
 					overlap = false;
 			} else {
+				if (dup_end_left && !*p)
+					return -ENOTEMPTY;
+
 				overlap = nft_rbtree_interval_end(rbe) &&
 					  nft_set_elem_active(&rbe->ext,
 							      genmask) &&
 					  !nft_set_elem_expired(&rbe->ext);
+
+				if (overlap) {
+					dup_end_right = true;
+					continue;
+				}
 			}
 		} else if (d > 0) {
 			p = &parent->rb_right;
 
 			if (nft_rbtree_interval_end(new)) {
+				if (dup_end_right && !*p)
+					return -ENOTEMPTY;
+
 				overlap = nft_rbtree_interval_end(rbe) &&
 					  nft_set_elem_active(&rbe->ext,
 							      genmask) &&
 					  !nft_set_elem_expired(&rbe->ext);
+
+				if (overlap) {
+					dup_end_left = true;
+					continue;
+				}
 			} else if (nft_set_elem_active(&rbe->ext, genmask) &&
 				   !nft_set_elem_expired(&rbe->ext)) {
 				overlap = nft_rbtree_interval_end(rbe);
@@ -321,6 +351,8 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 				p = &parent->rb_left;
 			}
 		}
+
+		dup_end_left = dup_end_right = false;
 	}
 
 	if (overlap)