diff mbox series

[4.19] dmaengine: at_hdmac: Fix memory leak

Message ID 20200920082838.GA813@amd (mailing list archive)
State New, archived
Headers show
Series [4.19] dmaengine: at_hdmac: Fix memory leak | expand

Commit Message

Pavel Machek Sept. 20, 2020, 8:28 a.m. UTC
This fixes memory leak in at_hdmac. Mainline does not have the same
problem.

Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>

Comments

Ludovic Desroches Sept. 23, 2020, 6:39 a.m. UTC | #1
On Sun, Sep 20, 2020 at 10:28:38AM +0200, Pavel Machek wrote:
> Date: Sun, 20 Sep 2020 10:28:38 +0200
> From: Pavel Machek <pavel@ucw.cz>
> To: linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
>  linux-arm-kernel@lists.infradead.org, dan.j.williams@intel.com,
>  vkoul@kernel.org, ludovic.desroches@microchip.com, stable@vger.kernel.org,
>  Greg KH <greg@kroah.com>
> Subject: [PATCH 4.19] dmaengine: at_hdmac: Fix memory leak
> 
> 
> This fixes memory leak in at_hdmac. Mainline does not have the same
> problem.
> 
> Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>

Thanks.

> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 86427f6ba78c..0847b2055857 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -1714,8 +1714,10 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
>  	atslave->dma_dev = &dmac_pdev->dev;
>  
>  	chan = dma_request_channel(mask, at_dma_filter, atslave);
> -	if (!chan)
> +	if (!chan) {
> +		kfree(atslave);
>  		return NULL;
> +	}
>  
>  	atchan = to_at_dma_chan(chan);
>  	atchan->per_if = dma_spec->args[0] & 0xff;
> 
> -- 
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
Tudor Ambarus Sept. 23, 2020, 8:13 a.m. UTC | #2
Hi, Pavel,

On 9/20/20 11:28 AM, Pavel Machek wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> This fixes memory leak in at_hdmac. Mainline does not have the same
> problem.
> 
> Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 86427f6ba78c..0847b2055857 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -1714,8 +1714,10 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
>         atslave->dma_dev = &dmac_pdev->dev;
> 
>         chan = dma_request_channel(mask, at_dma_filter, atslave);
> -       if (!chan)
> +       if (!chan) {
> +               kfree(atslave);
>                 return NULL;
> +       }

Thanks for submitting this to stable. While the fix is good, you can instead
cherry-pick the commit that hit upstream. In order to do that cleanly on top
of v4.19.145, you have to pick two other fixes:

commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
commit 3832b78b3ec2 ("dmaengine: at_hdmac: add missing put_device() call in at_dma_xlate()")
commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")

There are also some locking/deadlock fixes in mainline for this driver,
depending on the time you can allocate for this, the list of patches can increase.
I should have Cc'ed stable@vger.kernel.org in the first place, my bad.

Also it may worth to read the rules for submitting to stable at:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html

Cheers,
ta
Tudor Ambarus Sept. 23, 2020, 8:19 a.m. UTC | #3
On 9/23/20 11:13 AM, Tudor.Ambarus@microchip.com wrote:
> Hi, Pavel,
> 
> On 9/20/20 11:28 AM, Pavel Machek wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> This fixes memory leak in at_hdmac. Mainline does not have the same
>> problem.
>>
>> Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
>>
>> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
>> index 86427f6ba78c..0847b2055857 100644
>> --- a/drivers/dma/at_hdmac.c
>> +++ b/drivers/dma/at_hdmac.c
>> @@ -1714,8 +1714,10 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
>>         atslave->dma_dev = &dmac_pdev->dev;
>>
>>         chan = dma_request_channel(mask, at_dma_filter, atslave);
>> -       if (!chan)
>> +       if (!chan) {
>> +               kfree(atslave);
>>                 return NULL;
>> +       }
> 
> Thanks for submitting this to stable. While the fix is good, you can instead
> cherry-pick the commit that hit upstream. In order to do that cleanly on top
> of v4.19.145, you have to pick two other fixes:
> 
> commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
> commit 3832b78b3ec2 ("dmaengine: at_hdmac: add missing put_device() call in at_dma_xlate()")
> commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")

this last commit should have been
commit e097eb7473d9 ("dmaengine: at_hdmac: add missing kfree() call in at_dma_xlate()")

bad copy and paste :)

> 
> There are also some locking/deadlock fixes in mainline for this driver,
> depending on the time you can allocate for this, the list of patches can increase.
> I should have Cc'ed stable@vger.kernel.org in the first place, my bad.
> 
> Also it may worth to read the rules for submitting to stable at:
> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
> 
> Cheers,
> ta
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
Greg KH Jan. 4, 2021, 11:02 a.m. UTC | #4
On Wed, Sep 23, 2020 at 08:19:18AM +0000, Tudor.Ambarus@microchip.com wrote:
> On 9/23/20 11:13 AM, Tudor.Ambarus@microchip.com wrote:
> > Hi, Pavel,
> > 
> > On 9/20/20 11:28 AM, Pavel Machek wrote:
> >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> >>
> >> This fixes memory leak in at_hdmac. Mainline does not have the same
> >> problem.
> >>
> >> Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
> >>
> >> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> >> index 86427f6ba78c..0847b2055857 100644
> >> --- a/drivers/dma/at_hdmac.c
> >> +++ b/drivers/dma/at_hdmac.c
> >> @@ -1714,8 +1714,10 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
> >>         atslave->dma_dev = &dmac_pdev->dev;
> >>
> >>         chan = dma_request_channel(mask, at_dma_filter, atslave);
> >> -       if (!chan)
> >> +       if (!chan) {
> >> +               kfree(atslave);
> >>                 return NULL;
> >> +       }
> > 
> > Thanks for submitting this to stable. While the fix is good, you can instead
> > cherry-pick the commit that hit upstream. In order to do that cleanly on top
> > of v4.19.145, you have to pick two other fixes:
> > 
> > commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
> > commit 3832b78b3ec2 ("dmaengine: at_hdmac: add missing put_device() call in at_dma_xlate()")
> > commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
> 
> this last commit should have been
> commit e097eb7473d9 ("dmaengine: at_hdmac: add missing kfree() call in at_dma_xlate()")
> 
> bad copy and paste :)

So are all 3 of those needed on both 5.4.y and 4.19.y to resolve this
issue?

thanks,

greg k-h
Tudor Ambarus Jan. 5, 2021, 8:03 a.m. UTC | #5
On 1/4/21 1:02 PM, Greg KH wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On Wed, Sep 23, 2020 at 08:19:18AM +0000, Tudor.Ambarus@microchip.com wrote:
>> On 9/23/20 11:13 AM, Tudor.Ambarus@microchip.com wrote:
>>> Hi, Pavel,
>>>
>>> On 9/20/20 11:28 AM, Pavel Machek wrote:
>>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>>
>>>> This fixes memory leak in at_hdmac. Mainline does not have the same
>>>> problem.
>>>>
>>>> Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
>>>>
>>>> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
>>>> index 86427f6ba78c..0847b2055857 100644
>>>> --- a/drivers/dma/at_hdmac.c
>>>> +++ b/drivers/dma/at_hdmac.c
>>>> @@ -1714,8 +1714,10 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
>>>>         atslave->dma_dev = &dmac_pdev->dev;
>>>>
>>>>         chan = dma_request_channel(mask, at_dma_filter, atslave);
>>>> -       if (!chan)
>>>> +       if (!chan) {
>>>> +               kfree(atslave);
>>>>                 return NULL;
>>>> +       }
>>>
>>> Thanks for submitting this to stable. While the fix is good, you can instead
>>> cherry-pick the commit that hit upstream. In order to do that cleanly on top
>>> of v4.19.145, you have to pick two other fixes:
>>>
>>> commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
>>> commit 3832b78b3ec2 ("dmaengine: at_hdmac: add missing put_device() call in at_dma_xlate()")>>> commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
>>
>> this last commit should have been
>> commit e097eb7473d9 ("dmaengine: at_hdmac: add missing kfree() call in at_dma_xlate()")
>>
>> bad copy and paste :)
> 
> So are all 3 of those needed on both 5.4.y and 4.19.y to resolve this
> issue?
> 

Yes. I've just cherry-picked all three commits on both v5.4.86 and v4.19.164,
everything looks ok. I also compiled using sama5_defconfig, all good.

The order in which they should be taken is 1/ a6e7f19c9100, then 2/ 3832b78b3ec2,
and 3/ e097eb7473d9.

Cheers,
ta
Greg KH Jan. 6, 2021, 4:53 p.m. UTC | #6
On Tue, Jan 05, 2021 at 08:03:20AM +0000, Tudor.Ambarus@microchip.com wrote:
> On 1/4/21 1:02 PM, Greg KH wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> > 
> > On Wed, Sep 23, 2020 at 08:19:18AM +0000, Tudor.Ambarus@microchip.com wrote:
> >> On 9/23/20 11:13 AM, Tudor.Ambarus@microchip.com wrote:
> >>> Hi, Pavel,
> >>>
> >>> On 9/20/20 11:28 AM, Pavel Machek wrote:
> >>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> >>>>
> >>>> This fixes memory leak in at_hdmac. Mainline does not have the same
> >>>> problem.
> >>>>
> >>>> Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
> >>>>
> >>>> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> >>>> index 86427f6ba78c..0847b2055857 100644
> >>>> --- a/drivers/dma/at_hdmac.c
> >>>> +++ b/drivers/dma/at_hdmac.c
> >>>> @@ -1714,8 +1714,10 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
> >>>>         atslave->dma_dev = &dmac_pdev->dev;
> >>>>
> >>>>         chan = dma_request_channel(mask, at_dma_filter, atslave);
> >>>> -       if (!chan)
> >>>> +       if (!chan) {
> >>>> +               kfree(atslave);
> >>>>                 return NULL;
> >>>> +       }
> >>>
> >>> Thanks for submitting this to stable. While the fix is good, you can instead
> >>> cherry-pick the commit that hit upstream. In order to do that cleanly on top
> >>> of v4.19.145, you have to pick two other fixes:
> >>>
> >>> commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
> >>> commit 3832b78b3ec2 ("dmaengine: at_hdmac: add missing put_device() call in at_dma_xlate()")>>> commit a6e7f19c9100 ("dmaengine: at_hdmac: Substitute kzalloc with kmalloc")
> >>
> >> this last commit should have been
> >> commit e097eb7473d9 ("dmaengine: at_hdmac: add missing kfree() call in at_dma_xlate()")
> >>
> >> bad copy and paste :)
> > 
> > So are all 3 of those needed on both 5.4.y and 4.19.y to resolve this
> > issue?
> > 
> 
> Yes. I've just cherry-picked all three commits on both v5.4.86 and v4.19.164,
> everything looks ok. I also compiled using sama5_defconfig, all good.
> 
> The order in which they should be taken is 1/ a6e7f19c9100, then 2/ 3832b78b3ec2,
> and 3/ e097eb7473d9.

Thanks, will go queue those up now.

greg k-h
diff mbox series

Patch

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 86427f6ba78c..0847b2055857 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1714,8 +1714,10 @@  static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
 	atslave->dma_dev = &dmac_pdev->dev;
 
 	chan = dma_request_channel(mask, at_dma_filter, atslave);
-	if (!chan)
+	if (!chan) {
+		kfree(atslave);
 		return NULL;
+	}
 
 	atchan = to_at_dma_chan(chan);
 	atchan->per_if = dma_spec->args[0] & 0xff;