From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arvind Yadav Subject: Re: [PATCH 01/20] coresight: Fix memory leak in coresight_register Date: Wed, 6 Jun 2018 12:14:33 +0530 Message-ID: References: <1528235011-30691-1-git-send-email-suzuki.poulose@arm.com> <1528235011-30691-2-git-send-email-suzuki.poulose@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1528235011-30691-2-git-send-email-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Suzuki K Poulose , linux-arm-kernel@lists.infradead.org Cc: mathieu.poirier@linaro.org, robh@kernel.org, frowand.list@gmail.com, mark.rutland@arm.com, sudeep.holla@arm.com, arm@kernel.org, linux-kernel@vger.kernel.org, matt.sealey@arm.com, john.horley@arm.com, charles.garcia-tobin@arm.com, coresight@lists.linaro.org, devicetree@vger.kernel.org, mike.leach@linaro.org List-Id: devicetree@vger.kernel.org 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. ~arvind > > Fixes: commit 6403587a930c ("coresight: use put_device() instead of kfree()") > Cc: Mathieu Poirier > Cc: Arvind Yadav > Signed-off-by: Suzuki K Poulose > --- > drivers/hwtracing/coresight/coresight.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c > index 4969b32..2893cfe 100644 > --- a/drivers/hwtracing/coresight/coresight.c > +++ b/drivers/hwtracing/coresight/coresight.c > @@ -1020,7 +1020,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) > ret = device_register(&csdev->dev); > if (ret) { > put_device(&csdev->dev); > - goto err_kzalloc_csdev; > + goto err_kzalloc_refcnts; > } > > mutex_lock(&coresight_mutex);