[PATCH] rtc: nct3018y: fix possible NULL dereference

From: alexandre . belloni
Date: Thu Feb 29 2024 - 17:22:16 EST


From: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>

alarm_enable and alarm_flag are allowed to be NULL but will be dereferenced
later by the dev_dbg call.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Closes: https://lore.kernel.org/r/202305180042.DEzW1pSd-lkp@xxxxxxxxx/
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
---
drivers/rtc/rtc-nct3018y.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-nct3018y.c b/drivers/rtc/rtc-nct3018y.c
index f488a189a465..076d8b99f913 100644
--- a/drivers/rtc/rtc-nct3018y.c
+++ b/drivers/rtc/rtc-nct3018y.c
@@ -102,6 +102,8 @@ static int nct3018y_get_alarm_mode(struct i2c_client *client, unsigned char *ala
if (flags < 0)
return flags;
*alarm_enable = flags & NCT3018Y_BIT_AIE;
+ dev_dbg(&client->dev, "%s:alarm_enable:%x\n", __func__, *alarm_enable);
+
}

if (alarm_flag) {
@@ -110,11 +112,9 @@ static int nct3018y_get_alarm_mode(struct i2c_client *client, unsigned char *ala
if (flags < 0)
return flags;
*alarm_flag = flags & NCT3018Y_BIT_AF;
+ dev_dbg(&client->dev, "%s:alarm_flag:%x\n", __func__, *alarm_flag);
}

- dev_dbg(&client->dev, "%s:alarm_enable:%x alarm_flag:%x\n",
- __func__, *alarm_enable, *alarm_flag);
-
return 0;
}

--
2.43.0