diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f02d04540c0c..b591073c5f83 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -130,13 +130,14 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
 	bpf_map_init_from_attr(&dtab->map, attr);
 
 	if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+		/* hash table size must be power of 2; roundup_pow_of_two() can
+		 * overflow into UB on 32-bit arches, so check that first
+		 */
+		if (dtab->map.max_entries > 1UL << 31)
+			return -EINVAL;
+
 		dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
 
-		if (!dtab->n_buckets) /* Overflow check */
-			return -EINVAL;
-	}
-
-	if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
 		dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets,
 							   dtab->map.numa_node);
 		if (!dtab->dev_index_head)