Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 85B93607C6
Subject: Re: [PATCH v2] thunderbolt: Fix to check return value of
 ida_simple_get
To:     Mika Westerberg <mika.westerberg@linux.intel.com>,
        Aditya Pakki <pakki001@umn.edu>
Cc:     kjlu@umn.edu, Andreas Noever <andreas.noever@gmail.com>,
        Michael Jamet <michael.jamet@intel.com>,
        Yehezkel Bernat <YehezkelShB@gmail.com>,
        linux-kernel@vger.kernel.org
References: <20190320162446.30500-1-pakki001@umn.edu>
 <20190320162924.GA3622@lahna.fi.intel.com>
From:   Mukesh Ojha <mojha@codeaurora.org>
Message-ID: <78aa904a-6b98-9fb3-e2ca-b9994dc04869@codeaurora.org>
Date:   Thu, 21 Mar 2019 02:09:41 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.4.0
MIME-Version: 1.0
In-Reply-To: <20190320162924.GA3622@lahna.fi.intel.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 3/20/2019 9:59 PM, Mika Westerberg wrote:
> On Wed, Mar 20, 2019 at 11:24:45AM -0500, Aditya Pakki wrote:
>> In enumerate_services, ida_simple_get on failure can return an error and
>> leaks memory during device_register failure. The patch ensures that
>> the dev_set_name is set on non failure cases, and releases memory in
>> case of failure.
>>
>> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
>>
>> ---
>> v1: Missed cleanup of svc in case of allocation failure and
>> device_register failure.
>> ---
>>   drivers/thunderbolt/xdomain.c | 9 ++++++++-
>>   1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
>> index e27dd8beb94b..eb08275185bf 100644
>> --- a/drivers/thunderbolt/xdomain.c
>> +++ b/drivers/thunderbolt/xdomain.c
>> @@ -740,6 +740,7 @@ static void enumerate_services(struct tb_xdomain *xd)
>>   	struct tb_service *svc;
>>   	struct tb_property *p;
>>   	struct device *dev;
>> +	int id;
>>   
>>   	/*
>>   	 * First remove all services that are not available anymore in
>> @@ -768,7 +769,12 @@ static void enumerate_services(struct tb_xdomain *xd)
>>   			break;
>>   		}
>>   
>> -		svc->id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
>> +		id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
>> +		if (id < 0) {
>> +			kfree(svc);
>> +			break;
>> +		}
>> +		svc->id = id;
>>   		svc->dev.bus = &tb_bus_type;
>>   		svc->dev.type = &tb_service_type;
>>   		svc->dev.parent = &xd->dev;
>> @@ -776,6 +782,7 @@ static void enumerate_services(struct tb_xdomain *xd)
>>   
>>   		if (device_register(&svc->dev)) {
>>   			put_device(&svc->dev);
>> +			kfree(svc);
> You can't do this after device_register() is called. The put_device()
> above is sufficient.


If  device_register fails, how would svc gets freed? we need  to kfree 
svc here as well.

Thanks,
Mukesh