Re: [PATCH v1 01/10] ACPI: fan: Fix memory leak due to leftover devm_kcalloc() argument

From: Andy Shevchenko

Date: Fri Sep 11 2026 - 12:54:05 EST


On Fri, Sep 11, 2026 at 03:00:51PM +0200, Rafael J. Wysocki wrote:

> An ACPI device object's dev field in passed as the first argument to
> devm_kcalloc() in acpi_fan_get_fps() which is incorrect and leads to
> a memory leak on driver probe errors and removal because the driver
> is not bound to that ACPI device.
>
> Address this by replacing that pointer with a pointer to the device the
> driver is actually bound to.
>
> While at it, drop a redundant error message after a memory allocation
> failure (that also gets printed relative to the ACPI device).

...

> fan->fps_count = obj->package.count - 1; /* minus revision field */
> - fan->fps = devm_kcalloc(&device->dev,
> - fan->fps_count, sizeof(struct acpi_fan_fps),
> - GFP_KERNEL);
> + fan->fps = devm_kcalloc(dev, fan->fps_count, sizeof(*fan->fps), GFP_KERNEL);
> if (!fan->fps) {
> - dev_err(&device->dev, "Not enough memory\n");
> status = -ENOMEM;
> goto err;

I was about ranting on goto after devm_*(), but looking at the context,
I understand why it's not a problem. While at it, a side note: perhaps it makes
sense to use ACPI_FREE(obj) instead of kfree()? Or even better to have __free()
version of it, so we can declare the object with autoclean.

--
With Best Regards,
Andy Shevchenko