[PATCH 1/2] Thermal:Fix memory leak if occur goto unregister

[PATCH 1/2] Thermal:Fix memory leak if occur goto unregister

[Yao Dongdong]

Signed-off-by:yaodongdong@huawei.com

---
 drivers/thermal/thermal_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 71b0ec0..5b7d466 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1574,6 +1574,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 unregister:
    release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
    device_unregister(&tz->device);
+   kfree(tz);
    return ERR_PTR(result);
 }
 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
--
1.8.0.1

Re: [PATCH 1/2] Thermal:Fix memory leak if occur goto unregister

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 840 bytes --]

Hello,

On Mon, Oct 20, 2014 at 04:27:36PM +0800, Yao Dongdong wrote:
> Signed-off-by:yaodongdong@huawei.com

Acked-by: Eduardo Valentin <edubezval@gmail.com>

Rui, would you take care of this?

> 
> ---
>  drivers/thermal/thermal_core.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 71b0ec0..5b7d466 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -1574,6 +1574,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
>  unregister:
>     release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
>     device_unregister(&tz->device);
> +   kfree(tz);
>     return ERR_PTR(result);
>  }
>  EXPORT_SYMBOL_GPL(thermal_zone_device_register);
> --
> 1.8.0.1
> 
> 

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 473 bytes --]

RE: [PATCH 1/2] Thermal:Fix memory leak if occur goto unregister

[R, Durgadoss]

>-----Original Message-----
>From: linux-pm-owner@vger.kernel.org [mailto:linux-pm-
>owner@vger.kernel.org] On Behalf Of Eduardo Valentin
>Sent: Monday, October 20, 2014 6:04 PM
>To: Yao Dongdong
>Cc: Zhang, Rui; linux-pm@vger.kernel.org; LKML
>Subject: Re: [PATCH 1/2] Thermal:Fix memory leak if occur goto unregister
>
>Hello,
>
>On Mon, Oct 20, 2014 at 04:27:36PM +0800, Yao Dongdong wrote:
>> Signed-off-by:yaodongdong@huawei.com
>
>Acked-by: Eduardo Valentin <edubezval@gmail.com>
>
>Rui, would you take care of this?
>

If I remember it right, this 'tz' is freed in the thermal_release()
function, during device_unregister().

It is similar in all other functions in thermal_core.c

So, Yao, Did you really test this patch ?
And did not see any crashes ?

Thanks,
Durga

>>
>> ---
>>  drivers/thermal/thermal_core.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
>> index 71b0ec0..5b7d466 100644
>> --- a/drivers/thermal/thermal_core.c
>> +++ b/drivers/thermal/thermal_core.c
>> @@ -1574,6 +1574,7 @@ struct thermal_zone_device
>*thermal_zone_device_register(const char *type,
>>  unregister:
>>     release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
>>     device_unregister(&tz->device);
>> +   kfree(tz);
>>     return ERR_PTR(result);
>>  }
>>  EXPORT_SYMBOL_GPL(thermal_zone_device_register);
>> --
>> 1.8.0.1
>>
>>

Re: [PATCH 1/2] Thermal:Fix memory leak if occur goto unregister

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 2053 bytes --]

Hello,

On Mon, Nov 03, 2014 at 06:17:37PM +0000, R, Durgadoss wrote:
> >-----Original Message-----
> >From: linux-pm-owner@vger.kernel.org [mailto:linux-pm-
> >owner@vger.kernel.org] On Behalf Of Eduardo Valentin
> >Sent: Monday, October 20, 2014 6:04 PM
> >To: Yao Dongdong
> >Cc: Zhang, Rui; linux-pm@vger.kernel.org; LKML
> >Subject: Re: [PATCH 1/2] Thermal:Fix memory leak if occur goto unregister
> >
> >Hello,
> >
> >On Mon, Oct 20, 2014 at 04:27:36PM +0800, Yao Dongdong wrote:
> >> Signed-off-by:yaodongdong@huawei.com
> >
> >Acked-by: Eduardo Valentin <edubezval@gmail.com>
> >
> >Rui, would you take care of this?
> >
> 
> If I remember it right, this 'tz' is freed in the thermal_release()
> function, during device_unregister().
> 
> It is similar in all other functions in thermal_core.c
> 
> So, Yao, Did you really test this patch ?
> And did not see any crashes ?
> 

Yao, reading the patch change carefully, now I see that Durga is correct
here. 

> Thanks,
> Durga
> 
> >>
> >> ---
> >>  drivers/thermal/thermal_core.c | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> >> index 71b0ec0..5b7d466 100644
> >> --- a/drivers/thermal/thermal_core.c
> >> +++ b/drivers/thermal/thermal_core.c
> >> @@ -1574,6 +1574,7 @@ struct thermal_zone_device
> >*thermal_zone_device_register(const char *type,
> >>  unregister:
> >>     release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
> >>     device_unregister(&tz->device);
> >> +   kfree(tz);

The device unregister is called above your kfree call, which will cause
the thermal_release to be called. Did you test the code for double kfree
calls? Your patch probably inserts a memory corruption.

I will revert your patch from my tree until you provide an answer about
your testing.

Thanks,


Eduardo Valentin

> >>     return ERR_PTR(result);
> >>  }
> >>  EXPORT_SYMBOL_GPL(thermal_zone_device_register);
> >> --
> >> 1.8.0.1
> >>
> >>

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 473 bytes --]

Re: [PATCH 1/2] Thermal:Fix memory leak if occur goto unregister

[Yao Dongdong]

On 2014/11/4 2:35, Eduardo Valentin wrote:
> Hello,
>
> On Mon, Nov 03, 2014 at 06:17:37PM +0000, R, Durgadoss wrote:
>>> -----Original Message-----
>>> From: linux-pm-owner@vger.kernel.org [mailto:linux-pm-
>>> owner@vger.kernel.org] On Behalf Of Eduardo Valentin
>>> Sent: Monday, October 20, 2014 6:04 PM
>>> To: Yao Dongdong
>>> Cc: Zhang, Rui; linux-pm@vger.kernel.org; LKML
>>> Subject: Re: [PATCH 1/2] Thermal:Fix memory leak if occur goto unregister
>>>
>>> Hello,
>>>
>>> On Mon, Oct 20, 2014 at 04:27:36PM +0800, Yao Dongdong wrote:
>>>> Signed-off-by:yaodongdong@huawei.com
>>> Acked-by: Eduardo Valentin <edubezval@gmail.com>
>>>
>>> Rui, would you take care of this?
>>>
>> If I remember it right, this 'tz' is freed in the thermal_release()
>> function, during device_unregister().
>>
>> It is similar in all other functions in thermal_core.c
>>
>> So, Yao, Did you really test this patch ?
>> And did not see any crashes ?
>>
> Yao, reading the patch change carefully, now I see that Durga is correct
> here. 
>
>> Thanks,
>> Durga
>>
>>>> ---
>>>>  drivers/thermal/thermal_core.c | 1 +
>>>>  1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
>>>> index 71b0ec0..5b7d466 100644
>>>> --- a/drivers/thermal/thermal_core.c
>>>> +++ b/drivers/thermal/thermal_core.c
>>>> @@ -1574,6 +1574,7 @@ struct thermal_zone_device
>>> *thermal_zone_device_register(const char *type,
>>>>  unregister:
>>>>     release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
>>>>     device_unregister(&tz->device);
>>>> +   kfree(tz);
> The device unregister is called above your kfree call, which will cause
> the thermal_release to be called. Did you test the code for double kfree
> calls? Your patch probably inserts a memory corruption.
>
> I will revert your patch from my tree until you provide an answer about
> your testing.

Yes, i have checked it and you are right, the patch will double kfree tz.

Thansks Durga for correcting me.

> Thanks,
>
>
> Eduardo Valentin
>
>>>>     return ERR_PTR(result);
>>>>  }
>>>>  EXPORT_SYMBOL_GPL(thermal_zone_device_register);
>>>> --
>>>> 1.8.0.1
>>>>
>>>>