[PATCH 1/2] soc: qcom: ocmem: fix device leak on lookup

[PATCH 1/2] soc: qcom: ocmem: fix device leak on lookup

[Johan Hovold]

Make sure to drop the reference taken to the ocmem platform device when
looking up its driver data.

Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.

Also note that commit 0ff027027e05 ("soc: qcom: ocmem: Fix missing
put_device() call in of_get_ocmem") fixed the leak in a lookup error
path, but the reference is still leaking on success.

Fixes: 88c1e9404f1d ("soc: qcom: add OCMEM driver")
Cc: stable@vger.kernel.org	# 5.5: 0ff027027e05
Cc: Brian Masney <bmasney@redhat.com>
Cc: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/soc/qcom/ocmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/qcom/ocmem.c b/drivers/soc/qcom/ocmem.c
index 9c3bd37b6579..71130a2f62e9 100644
--- a/drivers/soc/qcom/ocmem.c
+++ b/drivers/soc/qcom/ocmem.c
@@ -202,9 +202,9 @@ struct ocmem *of_get_ocmem(struct device *dev)
 	}
 
 	ocmem = platform_get_drvdata(pdev);
+	put_device(&pdev->dev);
 	if (!ocmem) {
 		dev_err(dev, "Cannot get ocmem\n");
-		put_device(&pdev->dev);
 		return ERR_PTR(-ENODEV);
 	}
 	return ocmem;
-- 
2.49.1

Re: [PATCH 1/2] soc: qcom: ocmem: fix device leak on lookup

[Markus Elfring]

> Make sure to drop the reference taken to the ocmem platform device when
> looking up its driver data.
…

How do you think about to increase the application of scope-based resource management?
https://elixir.bootlin.com/linux/v6.17-rc7/source/include/linux/device.h#L1180

Regards,
Markus

Re: [PATCH 1/2] soc: qcom: ocmem: fix device leak on lookup

[Brian Masney]

On Fri, Sep 26, 2025 at 04:35:10PM +0200, Johan Hovold wrote:
> Make sure to drop the reference taken to the ocmem platform device when
> looking up its driver data.
> 
> Note that holding a reference to a device does not prevent its driver
> data from going away so there is no point in keeping the reference.
> 
> Also note that commit 0ff027027e05 ("soc: qcom: ocmem: Fix missing
> put_device() call in of_get_ocmem") fixed the leak in a lookup error
> path, but the reference is still leaking on success.
> 
> Fixes: 88c1e9404f1d ("soc: qcom: add OCMEM driver")
> Cc: stable@vger.kernel.org	# 5.5: 0ff027027e05
> Cc: Brian Masney <bmasney@redhat.com>
> Cc: Miaoqian Lin <linmq006@gmail.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>

Reviewed-by: Brian Masney <bmasney@redhat.com>

[PATCH 2/2] soc: qcom: pbs: fix device leak on lookup

[Johan Hovold]

Make sure to drop the reference taken to the pbs platform device when
looking up its driver data.

Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.

Fixes: 5b2dd77be1d8 ("soc: qcom: add QCOM PBS driver")
Cc: stable@vger.kernel.org	# 6.9
Cc: Anjelique Melendez <quic_amelende@quicinc.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/soc/qcom/qcom-pbs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/soc/qcom/qcom-pbs.c b/drivers/soc/qcom/qcom-pbs.c
index 1cc5d045f9dd..06b4a596e275 100644
--- a/drivers/soc/qcom/qcom-pbs.c
+++ b/drivers/soc/qcom/qcom-pbs.c
@@ -173,6 +173,8 @@ struct pbs_dev *get_pbs_client_device(struct device *dev)
 		return ERR_PTR(-EINVAL);
 	}
 
+	platform_device_put(pdev);
+
 	return pbs;
 }
 EXPORT_SYMBOL_GPL(get_pbs_client_device);
-- 
2.49.1

Re: [PATCH 2/2] soc: qcom: pbs: fix device leak on lookup

[Markus Elfring]

> Make sure to drop the reference taken to the pbs platform device when
> looking up its driver data.
…

How do you think about to increase the application of scope-based resource management?

Is there a need to improve the API description for platform_device_put()?
https://elixir.bootlin.com/linux/v6.17-rc7/source/drivers/base/platform.c#L543-L547

Regards,
Markus