From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936808AbeE1KNn (ORCPT ); Mon, 28 May 2018 06:13:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:33488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936720AbeE1KNi (ORCPT ); Mon, 28 May 2018 06:13:38 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Geert Uytterhoeven , Sasha Levin Subject: [PATCH 3.18 171/185] serial: arc_uart: Fix out-of-bounds access through DT alias Date: Mon, 28 May 2018 12:03:32 +0200 Message-Id: <20180528100113.787538386@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180528100050.700971285@linuxfoundation.org> References: <20180528100050.700971285@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Geert Uytterhoeven [ Upstream commit f9f5786987e81d166c60833edcb7d1836aa16944 ] The arc_uart_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_ARC_NR_PORTS), so this can even be triggered using a legitimate DTB. Fixes: ea28fd56fcde69af ("serial/arc-uart: switch to devicetree based probing") Signed-off-by: Geert Uytterhoeven Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/arc_uart.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -597,6 +597,11 @@ static int arc_serial_probe(struct platf if (dev_id < 0) dev_id = 0; + if (dev_id >= ARRAY_SIZE(arc_uart_ports)) { + dev_err(&pdev->dev, "serial%d out of range\n", dev_id); + return -EINVAL; + } + uart = &arc_uart_ports[dev_id]; port = &uart->port;