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From: "SZ Lin (林上智)" <>
To: unlisted-recipients:; (no To-header on input)
Cc: "SZ Lin (林上智)" <>,
	"Taiyi Wu" <>,
	"Alessandro Zummo" <>,
	"Alexandre Belloni" <>,,
Subject: [RESEND PATCH] rtc: tps65910: add bounds checking
Date: Tue, 10 Apr 2018 15:24:17 +0800	[thread overview]
Message-ID: <> (raw)

Since tm->tm_year is the offset relative to 1900, it needs to check for
positive value to avoid overflow in YEARS_REG register.

The system will hang at the following stage on the next boot when overflow
has occurred.

[    2.221192] systemd[1]: Time has been changed

This patch fixes the above hanging issue by adding bounds checking.

Signed-off-by: Taiyi Wu <>
Signed-off-by: SZ Lin (林上智) <>
 drivers/rtc/rtc-tps65910.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c
index d0244d7979fc..6be9f7bb0f1b 100644
--- a/drivers/rtc/rtc-tps65910.c
+++ b/drivers/rtc/rtc-tps65910.c
@@ -105,6 +105,12 @@ static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	struct tps65910 *tps = dev_get_drvdata(dev->parent);
 	int ret;
+	if ((tm->tm_year - 100) < 0) {
+		dev_err(dev, "the requested year %d is unsupported\n",
+			1900 + tm->tm_year);
+		return -EINVAL;
+	}
 	rtc_data[0] = bin2bcd(tm->tm_sec);
 	rtc_data[1] = bin2bcd(tm->tm_min);
 	rtc_data[2] = bin2bcd(tm->tm_hour);

             reply	other threads:[~2018-04-10  7:26 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-10  7:24 SZ Lin (林上智) [this message]
2018-04-10  7:56 ` [RESEND PATCH] rtc: tps65910: add bounds checking Alexandre Belloni

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