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authorZhangXiaoxu <zhangxiaoxu5@huawei.com>2018-12-20 17:36:56 +0800
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2019-01-10 22:02:44 +0100
commit074b01a51d058f4216b7ce541e96b778aa6af60d (patch)
treef28558c2770740be30cdc607b1b5ca21a021c2e9 /drivers/rtc/lib.c
parent7c617e0c5f37d2f681b3a568c3642115a32b7427 (diff)
downloadlinux-074b01a51d058f4216b7ce541e96b778aa6af60d.tar.gz
rtc: Fix UBSAN overflow warning
Users may call 'ioctl' and pass a very big value on 'tm->tm_year'. It can be overflowed in 'int' after add 1900. In function 'rtc_month_days' and 'mktime64', also treated it as an 'unsigned' parameter. UBSAN: Undefined behaviour in drivers/rtc/rtc-lib.c:103:59 signed integer overflow: 2147483647 + 1900 cannot be represented in type 'int' UBSAN: Undefined behaviour in drivers/rtc/rtc-lib.c:119:30 signed integer overflow: 2147483647 + 1900 cannot be represented in type 'int' So, covert it to 'unsigned' explicitly. Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc/lib.c')
-rw-r--r--drivers/rtc/lib.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/rtc/lib.c b/drivers/rtc/lib.c
index ef160da842200..9714cb3d1e298 100644
--- a/drivers/rtc/lib.c
+++ b/drivers/rtc/lib.c
@@ -100,7 +100,7 @@ int rtc_valid_tm(struct rtc_time *tm)
if (tm->tm_year < 70
|| ((unsigned)tm->tm_mon) >= 12
|| tm->tm_mday < 1
- || tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
+ || tm->tm_mday > rtc_month_days(tm->tm_mon, ((unsigned)tm->tm_year + 1900))
|| ((unsigned)tm->tm_hour) >= 24
|| ((unsigned)tm->tm_min) >= 60
|| ((unsigned)tm->tm_sec) >= 60)
@@ -116,8 +116,8 @@ EXPORT_SYMBOL(rtc_valid_tm);
*/
time64_t rtc_tm_to_time64(struct rtc_time *tm)
{
- return mktime64(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
- tm->tm_hour, tm->tm_min, tm->tm_sec);
+ return mktime64(((unsigned)tm->tm_year + 1900), tm->tm_mon + 1,
+ tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
}
EXPORT_SYMBOL(rtc_tm_to_time64);