From: Nick Crews <ncrews@chromium.org>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>,
Alessandro Zummo <a.zummo@towertech.it>
Cc: linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org,
Duncan Laurie <dlaurie@google.com>,
Enric Balletbo i Serra <enric.balletbo@collabora.com>,
Nick Crews <ncrews@chromium.org>
Subject: [PATCH] rtc: wilco-ec: Sanitize values received from RTC
Date: Tue, 10 Sep 2019 16:19:29 +0100 [thread overview]
Message-ID: <20190910151929.780-1-ncrews@chromium.org> (raw)
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 (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");
MODULE_DESCRIPTION("Wilco EC RTC driver");
--
2.11.0
next reply other threads:[~2019-09-10 15:19 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-10 15:19 Nick Crews [this message]
2019-09-12 8:09 ` [PATCH] rtc: wilco-ec: Sanitize values received from RTC Alexandre Belloni
2019-09-15 22:44 ` Nick Crews
2019-09-16 8:02 ` Alexandre Belloni
2019-09-16 17:56 ` Nick Crews
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