The reference taken by 'of_find_device_by_node()' must be released when
not needed anymore.
Add the corresponding 'put_device()' in the error handling paths.

Fixes: ede1c2e7d4dc ("iommu/omap: Store iommu_dev pointer in arch_data")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 drivers/iommu/omap-iommu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 91749654fd49..cbc7ca5e890a 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1684,6 +1684,7 @@ static struct iommu_device *omap_iommu_probe_device(struct device *dev)
 		oiommu = platform_get_drvdata(pdev);
 		if (!oiommu) {
 			of_node_put(np);
+			put_device(&pdev->dev);
 			kfree(arch_data);
 			return ERR_PTR(-EINVAL);
 		}
-- 
2.17.1

Hi Miaoqian,

On 1/7/22 2:04 AM, Miaoqian Lin wrote:
> The reference taken by 'of_find_device_by_node()' must be released when
> not needed anymore.

Thanks for catching this.

> Add the corresponding 'put_device()' in the error handling paths.

Also, need it in the regular path, not just in error handling path.

> 
> Fixes: ede1c2e7d4dc ("iommu/omap: Store iommu_dev pointer in arch_data")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
>  drivers/iommu/omap-iommu.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
> index 91749654fd49..cbc7ca5e890a 100644
> --- a/drivers/iommu/omap-iommu.c
> +++ b/drivers/iommu/omap-iommu.c
> @@ -1684,6 +1684,7 @@ static struct iommu_device *omap_iommu_probe_device(struct device *dev)
>  		oiommu = platform_get_drvdata(pdev);
>  		if (!oiommu) {
>  			of_node_put(np);
> +			put_device(&pdev->dev);

nit, doesn't matter for functionality, but prefer the put_device before
of_node_put().

regards
Suman

>  			kfree(arch_data);
>  			return ERR_PTR(-EINVAL);
>  		}
> 

Hi Suman Anna,
On Fri, Jan 07, 2022 at 08:42:16AM -0600, Suman Anna wrote:
> Hi Miaoqian,
> 
> 
> > Add the corresponding 'put_device()' in the error handling paths.
> 
> Also, need it in the regular path, not just in error handling path.
I think after calling platform_get_drvdata() normally, the
reference will be released in other functions, so don't need it in the
regular path.

Hi Miaoqian,

On 1/9/22 8:43 PM, Miaoqian Lin wrote:
> Hi Suman Anna,
> On Fri, Jan 07, 2022 at 08:42:16AM -0600, Suman Anna wrote:
>> Hi Miaoqian,
>>
>>
>>> Add the corresponding 'put_device()' in the error handling paths.
>>
>> Also, need it in the regular path, not just in error handling path.
> I think after calling platform_get_drvdata() normally, the
> reference will be released in other functions, so don't need it in the
> regular path.
> 

No, it's a local reference and is acquired within omap_iommu_probe_device() and
needs to be released within this function. What other function are you referring
to here?

regards
Suman

Hi Suman,

On Mon, Jan 10, 2022 at 12:43:57PM -0600, Suman Anna wrote:
> Hi Miaoqian,
> 
> On 1/9/22 8:43 PM, Miaoqian Lin wrote:
> > Hi Suman Anna,
> > On Fri, Jan 07, 2022 at 08:42:16AM -0600, Suman Anna wrote:
> >> Hi Miaoqian,
> >>
> >>
> >>> Add the corresponding 'put_device()' in the error handling paths.
> >>
> >> Also, need it in the regular path, not just in error handling path.
> > I think after calling platform_get_drvdata() normally, the
> > reference will be released in other functions, so don't need it in the
> > regular path.
> > 
> 
> No, it's a local reference and is acquired within omap_iommu_probe_device() and
> needs to be released within this function. What other function are you referring
> to here?
> 

I am referring to the release function of this device, here is
omap_iommu_release_device(). But I find omap_iommu_release_device()
doesn't handle the reference, and calls kfree(arch_data) directly.

The reference taken by 'of_find_device_by_node()' must be released when
not needed anymore.
Add the corresponding 'put_device()' in the error handling path and
the regular path.

Fixes: ede1c2e7d4dc ("iommu/omap: Store iommu_dev pointer in arch_data")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
changes in v2:
- move put_device() before of_node_put().
- add put_device() in the regular path.
---
 drivers/iommu/omap-iommu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 91749654fd49..2222b30a0a00 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1683,6 +1683,7 @@ static struct iommu_device *omap_iommu_probe_device(struct device *dev)
 
 		oiommu = platform_get_drvdata(pdev);
 		if (!oiommu) {
+			put_device(&pdev->dev);
 			of_node_put(np);
 			kfree(arch_data);
 			return ERR_PTR(-EINVAL);
@@ -1691,6 +1692,7 @@ static struct iommu_device *omap_iommu_probe_device(struct device *dev)
 		tmp->iommu_dev = oiommu;
 		tmp->dev = &pdev->dev;
 
+		put_device(&pdev->dev);
 		of_node_put(np);
 	}
 
-- 
2.17.1