When i2c_smbus_read_i2c_block_data() fails, the read data in "buf" could be incorrect and should not be used. The fix checks if i2c_smbus_read_i2c_block_data fails, and if so, return its error code upstream. Signed-off-by: Kangjie Lu <kjlu@xxxxxxx> --- drivers/rtc/rtc-hym8563.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/rtc/rtc-hym8563.c b/drivers/rtc/rtc-hym8563.c index e5ad527cb75e..d03f5d212eea 100644 --- a/drivers/rtc/rtc-hym8563.c +++ b/drivers/rtc/rtc-hym8563.c @@ -109,6 +109,8 @@ static int hym8563_rtc_read_time(struct device *dev, struct rtc_time *tm) } ret = i2c_smbus_read_i2c_block_data(client, HYM8563_SEC, 7, buf); + if (ret < 0) + return ret; tm->tm_sec = bcd2bin(buf[0] & HYM8563_SEC_MASK); tm->tm_min = bcd2bin(buf[1] & HYM8563_MIN_MASK); -- 2.17.2 (Apple Git-113)