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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2020-10-07 10:51:48 +0300 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2020-12-02 17:42:22 -0800 |
| commit | 96eca8c97fccd3c02f61a87b0341a079b4096730 (patch) | |
| tree | c4138ffcfa285661924f9613b3ea81c51ec5cc06 /drivers/hwmon/acpi_power_meter.c | |
| parent | bce776f10069c806290eaac712ba73432ae8ecd7 (diff) | |
| download | lwn-96eca8c97fccd3c02f61a87b0341a079b4096730.tar.gz lwn-96eca8c97fccd3c02f61a87b0341a079b4096730.zip | |
hwmon: (acpi_power_meter) clean up freeing code
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@oracle.com>
Link: https://lore.kernel.org/r/20201007075148.GB2529578@mwanda
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/acpi_power_meter.c')
| -rw-r--r-- | drivers/hwmon/acpi_power_meter.c | 9 |
1 files 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; |