diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index 59d74d1b47a8..be77b7914fad 100644
--- a/drivers/w1/masters/ds2490.c
+++ b/drivers/w1/masters/ds2490.c
@@ -909,11 +909,10 @@ static void ds9490r_write_block(void *data, const u8 *buf, int len)
 	if (len <= 0)
 		return;
 
-	tbuf = kmalloc(len, GFP_KERNEL);
+	tbuf = kmemdup(buf, len, GFP_KERNEL);
 	if (!tbuf)
 		return;
 
-	memcpy(tbuf, buf, len);
 	ds_write_block(dev, tbuf, len);
 
 	kfree(tbuf);