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rtc-lib: Check tm_wday for validity in rtc_valid_tm() 

RTC drivers rely on rtc_valid_tm() in order to make sure that no bogus
values from uninitialized HW registers get passed to the uppper layers.

A somewhat contrived way to reproduce this problem with DS1307 RTC
would be to do the following:

> i2c_write -b <bus> -a <addr> -r 3 0x00
> hwclock

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Andrey Smirnov 2016-01-06 22:17:32 -08:00 committed by Sascha Hauer
parent 304cdde167
commit 645320b94a
1 changed files with 2 additions and 0 deletions
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2
drivers/rtc/rtc-lib.c
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@ -90,6 +90,8 @@ int rtc_valid_tm(struct rtc_time *tm)
{
if (tm->tm_year < 70
|| ((unsigned)tm->tm_mon) >= 12
|| tm->tm_wday < 0
|| tm->tm_wday > 6
|| tm->tm_mday < 1
|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
|| ((unsigned)tm->tm_hour) >= 24