From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28672C71122 for ; Sun, 14 Oct 2018 15:30:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE1A120835 for ; Sun, 14 Oct 2018 15:30:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BE1A120835 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726868AbeJNXLj (ORCPT ); Sun, 14 Oct 2018 19:11:39 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35564 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726401AbeJNXLj (ORCPT ); Sun, 14 Oct 2018 19:11:39 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1gBiLS-0004cp-PR; Sun, 14 Oct 2018 16:30:19 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLN-00009r-Ji; Sun, 14 Oct 2018 16:30:13 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Geert Uytterhoeven" , "Greg Kroah-Hartman" Date: Sun, 14 Oct 2018 16:25:40 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 018/366] serial: arc_uart: Fix out-of-bounds access through DT alias In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Geert Uytterhoeven commit f9f5786987e81d166c60833edcb7d1836aa16944 upstream. 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: Greg Kroah-Hartman [bwh: Backported to 3.16: Put the check in arc_uart_init_one() and move initialisation of the uart variable below it] Signed-off-by: Ben Hutchings --- --- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -531,8 +531,14 @@ arc_uart_init_one(struct platform_device { struct resource *res, *res2; unsigned long *plat_data; - struct arc_uart_port *uart = &arc_uart_ports[dev_id]; + struct arc_uart_port *uart; + 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]; plat_data = dev_get_platdata(&pdev->dev); if (!plat_data) return -ENODEV;