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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 A8F38C46471 for ; Mon, 6 Aug 2018 16:44:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6931D21A67 for ; Mon, 6 Aug 2018 16:44:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6931D21A67 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ispras.ru 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 S1732257AbeHFSx4 (ORCPT ); Mon, 6 Aug 2018 14:53:56 -0400 Received: from bran.ispras.ru ([83.149.199.196]:31803 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727561AbeHFSxz (ORCPT ); Mon, 6 Aug 2018 14:53:55 -0400 Received: from myklebust.intra.ispras.ru (unknown [10.10.2.207]) by smtp.ispras.ru (Postfix) with ESMTP id 29092203C7; Mon, 6 Aug 2018 19:43:58 +0300 (MSK) From: Anton Vasilyev To: Greg Kroah-Hartman Cc: Anton Vasilyev , Jiri Slaby , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: [PATCH] serial: mxs-auart: Fix potential infinite loop Date: Mon, 6 Aug 2018 19:43:46 +0300 Message-Id: <20180806164346.9986-1-vasilyev@ispras.ru> X-Mailer: git-send-email 2.18.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On the error path of mxs_auart_request_gpio_irq() is performed backward iterating with index i of enum type. Underline enum type may be unsigned char. In this case check (--i >= 0) will be always true and error handling goes into infinite loop. The patch changes type of index variable to int. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Anton Vasilyev --- drivers/tty/serial/mxs-auart.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 76aa289652f7..89b34bb09cde 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -1617,7 +1617,7 @@ static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s) static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s) { int *irq = s->gpio_irq; - enum mctrl_gpio_idx i; + int i; int err = 0; for (i = 0; (i < UART_GPIO_MAX) && !err; i++) { @@ -1634,8 +1634,9 @@ static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s) /* * If something went wrong, rollback. + * Be careful: i may be unsigned. */ - while (err && (--i >= 0)) + while (err && (i-- > 0)) if (irq[i] >= 0) free_irq(irq[i], s); -- 2.18.0