From: Sasha Levin <sasha.levin@oracle.com>
To: a.zummo@towertech.it, alexandre.belloni@free-electrons.com
Cc: rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org,
Sasha Levin <sasha.levin@oracle.com>
Subject: [PATCH] rtc: fix overflow and incorrect calculation in rtc_time64_to_tm
Date: Thu, 3 Dec 2015 19:12:24 -0500 [thread overview]
Message-ID: <1449187944-11730-1-git-send-email-sasha.levin@oracle.com> (raw)
At some point after humans go extinct and robots cotrol the world, dividing
he time64_t by 86400 to extract the days will overflow a 32bit integer,
leading to incorrect conversion into rtc_time in rtc_time64_to_tm().
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
drivers/rtc/rtc-lib.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c
index e6bfb9c..459cd4d 100644
--- a/drivers/rtc/rtc-lib.c
+++ b/drivers/rtc/rtc-lib.c
@@ -54,11 +54,11 @@ void rtc_time64_to_tm(time64_t time, struct rtc_time *tm)
{
unsigned int month, year;
unsigned long secs;
- int days;
+ time64_t days;
/* time must be positive */
days = div_s64(time, 86400);
- secs = time - (unsigned int) days * 86400;
+ secs = time - days * 86400;
/* day of the week, 1970-01-01 was a Thursday */
tm->tm_wday = (days + 4) % 7;
--
1.7.10.4
next reply other threads:[~2015-12-04 0:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-04 0:12 Sasha Levin [this message]
2015-12-04 0:21 ` kbuild test robot
2015-12-04 1:39 ` kbuild test robot
2015-12-04 1:41 ` kbuild test robot
2015-12-04 1:55 ` Alexandre Belloni
2015-12-04 2:06 ` Sasha Levin
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