1 files changed, 14 insertions, 0 deletions
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index dc5d9af3dc80..a1917025e155 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -775,6 +775,20 @@ struct dsa_switch *dsa_switch_alloc(struct device *dev, size_t n)
 	if (!ds)
 		return NULL;
 
+	/* We avoid allocating memory outside dsa_switch
+	 * if it is not needed.
+	 */
+	if (n <= sizeof(ds->_bitmap) * 8) {
+		ds->bitmap = &ds->_bitmap;
+	} else {
+		ds->bitmap = devm_kcalloc(dev,
+					  BITS_TO_LONGS(n),
+					  sizeof(unsigned long),
+					  GFP_KERNEL);
+		if (unlikely(!ds->bitmap))
+			return NULL;
+	}
+
 	ds->dev = dev;
 	ds->num_ports = n;