2020-09-20 08:31:37

by Pavel Machek

[permalink] [raw]
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) <[email protected]>

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


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2020-09-23 06:43:15

by Ludovic Desroches

[permalink] [raw]
Subject: Re: [PATCH 4.19] dmaengine: at_hdmac: Fix memory leak

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 <[email protected]>
> To: [email protected], [email protected],
> [email protected], [email protected],
> [email protected], [email protected], [email protected],
> Greg KH <[email protected]>
> 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) <[email protected]>
Acked-by: Ludovic Desroches <[email protected]>

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



2020-09-23 08:15:14

by Tudor Ambarus

[permalink] [raw]
Subject: Re: [PATCH 4.19] dmaengine: at_hdmac: Fix memory leak

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) <[email protected]>
>
> 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 [email protected] 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

2020-09-23 08:21:22

by Tudor Ambarus

[permalink] [raw]
Subject: Re: [PATCH 4.19] dmaengine: at_hdmac: Fix memory leak

On 9/23/20 11:13 AM, [email protected] 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) <[email protected]>
>>
>> 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 [email protected] 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
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

2021-01-04 11:03:31

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH 4.19] dmaengine: at_hdmac: Fix memory leak

On Wed, Sep 23, 2020 at 08:19:18AM +0000, [email protected] wrote:
> On 9/23/20 11:13 AM, [email protected] 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) <[email protected]>
> >>
> >> 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

2021-01-05 08:06:31

by Tudor Ambarus

[permalink] [raw]
Subject: Re: [PATCH 4.19] dmaengine: at_hdmac: Fix memory leak

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, [email protected] wrote:
>> On 9/23/20 11:13 AM, [email protected] 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) <[email protected]>
>>>>
>>>> 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

2021-01-06 16:53:44

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH 4.19] dmaengine: at_hdmac: Fix memory leak

On Tue, Jan 05, 2021 at 08:03:20AM +0000, [email protected] 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, [email protected] wrote:
> >> On 9/23/20 11:13 AM, [email protected] 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) <[email protected]>
> >>>>
> >>>> 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