Messages in this thread | | | Date | Thu, 12 Sep 2019 10:09:53 +0200 | From | Alexandre Belloni <> | Subject | Re: [PATCH] rtc: wilco-ec: Sanitize values received from RTC |
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Hi Nick,
On 10/09/2019 16:19:29+0100, Nick Crews wrote: > Check that the time received from the RTC HW is valid, > otherwise the computation of rtc_year_days() in the next > line could, and sometimes does, crash the kernel. > > While we're at it, fix the license to plain "GPL". > > Signed-off-by: Nick Crews <ncrews@chromium.org> > --- > drivers/rtc/rtc-wilco-ec.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/rtc/rtc-wilco-ec.c b/drivers/rtc/rtc-wilco-ec.c > index 8ad4c4e6d557..0ccbf2dce832 100644 > --- a/drivers/rtc/rtc-wilco-ec.c > +++ b/drivers/rtc/rtc-wilco-ec.c > @@ -110,8 +110,16 @@ static int wilco_ec_rtc_read(struct device *dev, struct rtc_time *tm) > tm->tm_mday = rtc.day; > tm->tm_mon = rtc.month - 1; > tm->tm_year = rtc.year + (rtc.century * 100) - 1900; > - tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
If your driver doesn't care about yday, userspace doesn't either. You can simply not set it.
> > + if (rtc_valid_tm(tm)) { > + dev_warn(dev, > + "Time computed from EC RTC is invalid: sec=%d, min=%d, hour=%d, mday=%d, mon=%d, year=%d", > + tm->tm_sec, tm->tm_min, tm->tm_hour, tm->mday, > + tm->mon, tm->year); > + return -EIO; > + } > + > + tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); > /* Don't compute day of week, we don't need it. */ > tm->tm_wday = -1; > > @@ -188,5 +196,5 @@ module_platform_driver(wilco_ec_rtc_driver); > > MODULE_ALIAS("platform:rtc-wilco-ec"); > MODULE_AUTHOR("Nick Crews <ncrews@chromium.org>"); > -MODULE_LICENSE("GPL v2"); > +MODULE_LICENSE("GPL");
This should be in a separate patch.
> MODULE_DESCRIPTION("Wilco EC RTC driver"); > -- > 2.11.0 >
-- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
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