* [PATCH v2] hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write()
@ 2022-01-21 11:55 Dan Carpenter
2022-01-21 14:05 ` Guenter Roeck
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2022-01-21 11:55 UTC (permalink / raw)
To: Jean Delvare, Chris Packham
Cc: Guenter Roeck, Chris Packham, linux-hwmon, kernel-janitors
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.
Negatives are also invalid so return -EINVAL for those too.
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..fb6d14d213a1 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 <= 0)
+ return -EINVAL;
+
val = FAN_RPM_TO_PERIOD(val);
val = clamp_val(val, 1, 65534);
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write()
2022-01-21 11:55 [PATCH v2] hwmon: (adt7470) Prevent divide by zero in adt7470_fan_write() Dan Carpenter
@ 2022-01-21 14:05 ` Guenter Roeck
0 siblings, 0 replies; 2+ messages in thread
From: Guenter Roeck @ 2022-01-21 14:05 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Jean Delvare, Chris Packham, linux-hwmon, kernel-janitors
On Fri, Jan 21, 2022 at 02:55:43PM +0300, Dan Carpenter wrote:
> 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.
> Negatives are also invalid so return -EINVAL for those too.
>
> Fixes: fc958a61ff6d ("hwmon: (adt7470) Convert to devm_hwmon_device_register_with_info API")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Applied.
Thanks,
Guenter
> ---
> drivers/hwmon/adt7470.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
> index d519aca4a9d6..fb6d14d213a1 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 <= 0)
> + return -EINVAL;
> +
> val = FAN_RPM_TO_PERIOD(val);
> val = clamp_val(val, 1, 65534);
>
> --
> 2.20.1
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-01-21 14:05 ` Guenter Roeck
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