This code works okay but Smatch flagged it as a double free. I've
changed three things to make it more clear. 1) Remove the call to
free_capabilities() in acpi_power_meter_add(). This call is a no-op
because the capabilities have not been allocated yet. 2) Set "*str" to
NULL in free_capabilities() so that way the function can be called twice
in a row without leading to a double free. 3) Call free_capabilities()
in read_capabilities() instead of open coding the free.
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/hwmon/acpi_power_meter.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
index a270b975e90b..848718ab7312 100644
--- a/drivers/hwmon/acpi_power_meter.c
+++ b/drivers/hwmon/acpi_power_meter.c
@@ -725,8 +725,10 @@ static void free_capabilities(struct acpi_power_meter_resource *resource)
int i;
str = &resource->model_number;
- for (i = 0; i < 3; i++, str++)
+ for (i = 0; i < 3; i++, str++) {
kfree(*str);
+ *str = NULL;
+ }
}
static int read_capabilities(struct acpi_power_meter_resource *resource)
@@ -801,9 +803,7 @@ static int read_capabilities(struct acpi_power_meter_resource *resource)
dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
goto end;
error:
- str = &resource->model_number;
- for (i = 0; i < 3; i++, str++)
- kfree(*str);
+ free_capabilities(resource);
end:
kfree(buffer.pointer);
return res;
@@ -874,7 +874,6 @@ static int acpi_power_meter_add(struct acpi_device *device)
strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
device->driver_data = resource;
- free_capabilities(resource);
res = read_capabilities(resource);
if (res)
goto exit_free;
--
2.28.0
