diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index 6d8ee3b1587276494274617d65029534df1d1af6..8abd80dbcbed7974b4ace4265dd9dad1bca89edd 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -151,13 +151,19 @@ static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
 		goto exit;
 	}
 
+	if (u_cmd.outsize != s_cmd->outsize ||
+	    u_cmd.insize != s_cmd->insize) {
+		ret = -EINVAL;
+		goto exit;
+	}
+
 	s_cmd->command += ec->cmd_offset;
 	ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd);
 	/* Only copy data to userland if data was received. */
 	if (ret < 0)
 		goto exit;
 
-	if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + u_cmd.insize))
+	if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize))
 		ret = -EFAULT;
 exit:
 	kfree(s_cmd);