diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
index 3ad5d19e4d04..23c794813e6a 100644
--- a/drivers/usb/misc/chaoskey.c
+++ b/drivers/usb/misc/chaoskey.c
@@ -472,7 +472,7 @@ static int chaoskey_rng_read(struct hwrng *rng, void *data,
 	if (this_time > max)
 		this_time = max;
 
-	memcpy(data, dev->buf, this_time);
+	memcpy(data, dev->buf + dev->used, this_time);
 
 	dev->used += this_time;