From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752469AbeDJH4Y (ORCPT ); Tue, 10 Apr 2018 03:56:24 -0400 Received: from mail.bootlin.com ([62.4.15.54]:38338 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752417AbeDJH4W (ORCPT ); Tue, 10 Apr 2018 03:56:22 -0400 Date: Tue, 10 Apr 2018 09:56:11 +0200 From: Alexandre Belloni To: SZ Lin =?utf-8?B?KOael+S4iuaZuik=?= Cc: Taiyi Wu , Alessandro Zummo , linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RESEND PATCH] rtc: tps65910: add bounds checking Message-ID: <20180410075610.GA24625@piout.net> References: <20180410072417.7078-1-sz.lin@moxa.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180410072417.7078-1-sz.lin@moxa.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 10/04/2018 15:24:17+0800, SZ Lin (林上智) wrote: > Since tm->tm_year is the offset relative to 1900, it needs to check for > positive value to avoid overflow in YEARS_REG register. > > The system will hang at the following stage on the next boot when overflow > has occurred. > > [ 2.221192] systemd[1]: Time has been changed > > This patch fixes the above hanging issue by adding bounds checking. > Did you test linux-next, this should not happen anymore after https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git/commit/?h=rtc-next&id=b3a5ac42ab18b7d1a8f2f072ca0ee76a3b754a43 > Signed-off-by: Taiyi Wu > Signed-off-by: SZ Lin (林上智) > --- > drivers/rtc/rtc-tps65910.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c > index d0244d7979fc..6be9f7bb0f1b 100644 > --- a/drivers/rtc/rtc-tps65910.c > +++ b/drivers/rtc/rtc-tps65910.c > @@ -105,6 +105,12 @@ static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm) > struct tps65910 *tps = dev_get_drvdata(dev->parent); > int ret; > > + if ((tm->tm_year - 100) < 0) { > + dev_err(dev, "the requested year %d is unsupported\n", > + 1900 + tm->tm_year); > + return -EINVAL; > + } > + > rtc_data[0] = bin2bcd(tm->tm_sec); > rtc_data[1] = bin2bcd(tm->tm_min); > rtc_data[2] = bin2bcd(tm->tm_hour); > -- > 2.17.0 > -- Alexandre Belloni, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com