Re: [PATCH 5.10 48/76] platform/x86: intel_pmc_core: fix memleak on registration failure

On Fri, Dec 31, 2021 at 11:04:05AM +0100, Pavel Machek wrote:

Hi!

On Mon 2021-12-27 16:31:03, Greg Kroah-Hartman wrote:

quoted

From: Johan Hovold <johan@kernel.org>

commit 26a8b09437804fabfb1db080d676b96c0de68e7c upstream.

In case device registration fails during module initialisation, the
platform device structure needs to be freed using platform_device_put()
to properly free all resources (e.g. the device name).

Does it? What exactly was leaking here?

quoted

+++ b/drivers/platform/x86/intel_pmc_core_pltdrv.c

@@ -65,7 +65,7 @@ static int __init pmc_core_platform_init
 
 	retval = platform_device_register(pmc_core_device);
 	if (retval)
-		kfree(pmc_core_device);
+		platform_device_put(pmc_core_device);
 

This is strange. Failing registration should have no effects that need
to be undone.

Sadly, that is not how the driver model has ever worked for various
reasons.

greg k-h