From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELubxusHGo6un3ZdmXV0ajnz2APGo/lDaeG4HEyJkXV+oOECcTqI4QqXkFM3w+dxs5AO2Ga+ ARC-Seal: i=1; a=rsa-sha256; t=1520529655; cv=none; d=google.com; s=arc-20160816; b=0xihoiD4V9kQlq9BtZxn8RJcPTkV9UafeGlHNxFhe9HJ9M5vxXLdQbOWx/vtAFxA3c 2gFVbksqzzPOS51jSc+G92fwQSS57gKO8t3JdM4qCFSMyAIz6ipIF9CBfNrk3sPilqHB IqixfwucNTBnSF4Stpq9hlhh/2HJxQQKlotZ67nMCLEzfa3Hi9/E6AC+vxQTDRXzK8IT c0JuP5qgkOMHW78jqD/b/5HfjKfmj0Vv6nfq5si57CVKp2mVJyrsTJiSimCeQqu+kAS0 k2aU+MJJlIP7h3oePMV8VUvANYB972Z0tPjPOHmrehya9N2MC7VdnqTzFOv+w504cMBz stkw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:content-disposition:mime-version:message-id:subject:cc :to:from:date:delivered-to:list-id:list-subscribe:list-unsubscribe :list-help:list-post:precedence:mailing-list :arc-authentication-results; bh=nSAAsSuKIHxTU5aSprXRug7VF+e392PFASfqZFeUc1o=; b=xBAnKwxivFyq4wu/N0iCZyXxx1Zy+BpeS5ZaWte8CZDu8PZBa0A1yegN4rKhzLlPd6 OcZKeBEk1wDIR7Y2YdmLtcphmLboh9CKe8L7twLHlYalmjCk5xOr0ZCBSCJGWt4wrjI1 DrJ8HyTGa8JyeaYcTaYzZgE+Gkrndg/lWMhvJzTSqGGYw1rwrIrqFcDQU1FMGl8kS5kr yJEOOjdpipPAqRjqdb+uc7CIJdHu9d2tR8CSFcH+sJomjzdf5HmFAgXcyMo6FCGxIWsT b3Ji+v1kLfZq9iSkPOBXkovRZr0zryOTcw/iG9qaZefG6uKEH/Aat7BKuNywd/uZ/oo2 GdOQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12241-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12241-gregkh=linuxfoundation.org@lists.openwall.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12241-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12241-gregkh=linuxfoundation.org@lists.openwall.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: Date: Thu, 8 Mar 2018 11:20:31 -0600 From: "Gustavo A. R. Silva" To: Sangbeom Kim , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Alessandro Zummo , Alexandre Belloni Cc: linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-rtc@vger.kernel.org, kernel-hardening@lists.openwall.com, Kees Cook , "Gustavo A. R. Silva" Subject: [PATCH] rtc: s5m: Remove VLA usage Message-ID: <20180308172031.GA14541@embeddedgus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 - lists.openwall.com 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: 1etzDU-001sYn-4f X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.175.117.58]:58486 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 16 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594390903982064564?= X-GMAIL-MSGID: =?utf-8?q?1594390903982064564?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 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 --- drivers/rtc/rtc-s5m.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/rtc/rtc-s5m.c b/drivers/rtc/rtc-s5m.c index 6deae10..2b5f4f7 100644 --- a/drivers/rtc/rtc-s5m.c +++ b/drivers/rtc/rtc-s5m.c @@ -38,6 +38,9 @@ */ #define UDR_READ_RETRY_CNT 5 +/* Maximum number of registers for setting time/alarm0/alarm1 */ +#define MAX_NUM_TIME_REGS 8 + /* * Registers used by the driver which are different between chipsets. * @@ -367,7 +370,7 @@ 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[MAX_NUM_TIME_REGS]; int ret; if (info->regs->read_time_udr_mask) { @@ -413,7 +416,7 @@ 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[MAX_NUM_TIME_REGS]; int ret = 0; switch (info->device_type) { @@ -450,7 +453,7 @@ 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[MAX_NUM_TIME_REGS]; unsigned int val; int ret, i; @@ -500,7 +503,7 @@ 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[MAX_NUM_TIME_REGS]; int ret, i; struct rtc_time tm; @@ -545,7 +548,7 @@ 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[MAX_NUM_TIME_REGS]; u8 alarm0_conf; struct rtc_time tm; @@ -598,7 +601,7 @@ 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[MAX_NUM_TIME_REGS]; int ret; switch (info->device_type) { -- 2.7.4