From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jean Delvare <jdelvare@suse.com>,
Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: Guenter Roeck <linux@roeck-us.net>,
linux-hwmon@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH] hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write()
Date: Fri, 21 Jan 2022 08:39:17 +0300 [thread overview]
Message-ID: <20220121053917.GB27293@kili> (raw)
The "val" variable is controlled by the user and comes from
hwmon_attr_store(). The FAN_RPM_TO_PERIOD() macro divides by "val"
so a zero will crash the system. Check for that and return -EINVAL.
Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/hwmon/adt7470.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
index d519aca4a9d6..cd474584dc0b 100644
--- a/drivers/hwmon/adt7470.c
+++ b/drivers/hwmon/adt7470.c
@@ -662,6 +662,9 @@ static int adt7470_fan_write(struct device *dev, u32 attr, int channel, long val
struct adt7470_data *data = dev_get_drvdata(dev);
int err;
+ if (!val)
+ return -EINVAL;
+
val = FAN_RPM_TO_PERIOD(val);
val = clamp_val(val, 1, 65534);
--
2.20.1
next reply other threads:[~2022-01-21 5:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-21 5:39 Dan Carpenter [this message]
2022-01-21 6:10 ` [PATCH] hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write() Guenter Roeck
2022-01-21 7:37 ` Dan Carpenter
2022-01-21 14:03 ` Guenter Roeck
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