From mboxrd@z Thu Jan 1 00:00:00 1970 From: suzuki.poulose@arm.com (Suzuki K Poulose) Date: Wed, 6 Jun 2018 11:16:26 +0100 Subject: [PATCH 01/20] coresight: Fix memory leak in coresight_register In-Reply-To: References: <1528235011-30691-1-git-send-email-suzuki.poulose@arm.com> <1528235011-30691-2-git-send-email-suzuki.poulose@arm.com> Message-ID: <16154816-2760-8582-23f1-da607b344db6@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/06/2018 07:44 AM, Arvind Yadav wrote: > Hi Suzuki, > > > On Wednesday 06 June 2018 03:13 AM, Suzuki K Poulose wrote: >> commit 6403587a930c ("coresight: use put_device() instead of kfree()") >> introduced a memory leak where, if we fail to register the device >> for coresight_device, we don't free the "coresight_device" object, >> which was allocated via kzalloc(). Fix this by jumping to the >> appropriate error path. > put_device() will decrement the last reference and then > free the memory by calling dev->release.? Internally > put_device() -> kobject_put() -> kobject_cleanup() which is > responsible to call 'dev -> release' and also free other kobject > resources. If you will see the coresight_device_release. There > we are releasing all allocated memory. Still if you call kfree() again > then it'll be redundancy. You're right. I think it would be good to have a comment explaining this to prevent this fix popping up in the future :-). I will add it Thanks Suzuki