From patchwork Sat Mar 10 06:27:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 884104 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-rtc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zyw0P22Vxz9spp for ; Sat, 10 Mar 2018 17:52:05 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750820AbeCJGwE (ORCPT ); Sat, 10 Mar 2018 01:52:04 -0500 Received: from gateway24.websitewelcome.com ([192.185.50.45]:26990 "EHLO gateway24.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750735AbeCJGwE (ORCPT ); Sat, 10 Mar 2018 01:52:04 -0500 X-Greylist: delayed 1468 seconds by postgrey-1.27 at vger.kernel.org; Sat, 10 Mar 2018 01:52:04 EST Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway24.websitewelcome.com (Postfix) with ESMTP id 3CF8B11E78 for ; Sat, 10 Mar 2018 00:27:36 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id uXyieQcbJcGlpuXyieIpOH; Sat, 10 Mar 2018 00:27:36 -0600 Received: from [189.175.117.58] (port=42578 helo=embeddedgus) by gator4166.hostgator.com with esmtpa (Exim 4.89_1) (envelope-from ) id 1euXyh-001I5o-K6; Sat, 10 Mar 2018 00:27:35 -0600 Date: Sat, 10 Mar 2018 00:27:35 -0600 From: "Gustavo A. R. Silva" To: Sangbeom Kim , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Alessandro Zummo , Alexandre Belloni Cc: linux-samsung-soc@vger.kernel.org, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, Kernel Hardening , Kees Cook , "Gustavo A. R. Silva" Subject: [PATCH 2/2] rtc: s5m: Remove VLA usage Message-ID: <543a0a74122172acae549329b35964f402da8b77.1520660422.git.gustavo@embeddedor.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.175.117.58 X-Source-L: No X-Exim-ID: 1euXyh-001I5o-K6 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.175.117.58]:42578 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 29 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org In preparation to enabling -Wvla, remove VLAs and replace them with fixed-length arrays instead. From a security viewpoint, the use of Variable Length Arrays can be a vector for stack overflow attacks. Also, in general, as the code evolves it is easy to lose track of how big a VLA can get. Thus, we can end up having segfaults that are hard to debug. Also, fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Gustavo A. R. Silva Reviewed-by: Krzysztof Kozlowski --- drivers/rtc/rtc-s5m.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/rtc/rtc-s5m.c b/drivers/rtc/rtc-s5m.c index 4c363de..8428455 100644 --- a/drivers/rtc/rtc-s5m.c +++ b/drivers/rtc/rtc-s5m.c @@ -47,6 +47,8 @@ enum { RTC_MONTH, RTC_YEAR1, RTC_YEAR2, + /* Make sure this is always the last enum name. */ + RTC_MAX_NUM_TIME_REGS }; /* @@ -378,7 +380,7 @@ static void s5m8763_tm_to_data(struct rtc_time *tm, u8 *data) static int s5m_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct s5m_rtc_info *info = dev_get_drvdata(dev); - u8 data[info->regs->regs_count]; + u8 data[RTC_MAX_NUM_TIME_REGS]; int ret; if (info->regs->read_time_udr_mask) { @@ -424,7 +426,7 @@ static int s5m_rtc_read_time(struct device *dev, struct rtc_time *tm) static int s5m_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct s5m_rtc_info *info = dev_get_drvdata(dev); - u8 data[info->regs->regs_count]; + u8 data[RTC_MAX_NUM_TIME_REGS]; int ret = 0; switch (info->device_type) { @@ -461,7 +463,7 @@ static int s5m_rtc_set_time(struct device *dev, struct rtc_time *tm) static int s5m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct s5m_rtc_info *info = dev_get_drvdata(dev); - u8 data[info->regs->regs_count]; + u8 data[RTC_MAX_NUM_TIME_REGS]; unsigned int val; int ret, i; @@ -511,7 +513,7 @@ static int s5m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) static int s5m_rtc_stop_alarm(struct s5m_rtc_info *info) { - u8 data[info->regs->regs_count]; + u8 data[RTC_MAX_NUM_TIME_REGS]; int ret, i; struct rtc_time tm; @@ -556,7 +558,7 @@ static int s5m_rtc_stop_alarm(struct s5m_rtc_info *info) static int s5m_rtc_start_alarm(struct s5m_rtc_info *info) { int ret; - u8 data[info->regs->regs_count]; + u8 data[RTC_MAX_NUM_TIME_REGS]; u8 alarm0_conf; struct rtc_time tm; @@ -609,7 +611,7 @@ static int s5m_rtc_start_alarm(struct s5m_rtc_info *info) static int s5m_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct s5m_rtc_info *info = dev_get_drvdata(dev); - u8 data[info->regs->regs_count]; + u8 data[RTC_MAX_NUM_TIME_REGS]; int ret; switch (info->device_type) {