diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 9b0f37d4b9d4..6a99a459b80b 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2313,7 +2313,7 @@ static int cdrom_ioctl_media_changed(struct cdrom_device_info *cdi,
 		return -EINVAL;
 
 	/* Prevent arg from speculatively bypassing the length check */
-	barrier_nospec();
+	arg = array_index_nospec(arg, cdi->capacity);
 
 	info = kmalloc(sizeof(*info), GFP_KERNEL);
 	if (!info)