* [PATCH] misc: rp1: do not put borrowed OF node
@ 2026-06-16 15:08 Pengpeng Hou
2026-06-23 16:01 ` Andrea della Porta
0 siblings, 1 reply; 2+ messages in thread
From: Pengpeng Hou @ 2026-06-16 15:08 UTC (permalink / raw)
To: Andrea della Porta
Cc: Arnd Bergmann, Greg Kroah-Hartman, linux-kernel, Pengpeng Hou
dev_of_node() returns the device's OF node without taking a new
reference. rp1_probe() stores that borrowed pointer in rp1_node, but
drops it with of_node_put() on both success and failure paths.
Dropping a reference that was never acquired can underflow the node's
refcount and leave later users with a stale OF node. Remove the
of_node_put() calls and keep rp1_node as a borrowed pointer.
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
---
drivers/misc/rp1/rp1_pci.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)
diff --git a/drivers/misc/rp1/rp1_pci.c b/drivers/misc/rp1/rp1_pci.c
index 81685e3f3296..ddee00045fd3 100644
--- a/drivers/misc/rp1/rp1_pci.c
+++ b/drivers/misc/rp1/rp1_pci.c
@@ -191,13 +191,13 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
if (!rp1_node) {
dev_err(dev, "Missing of_node for device\n");
err = -EINVAL;
- goto err_put_node;
+ goto err_out;
}
rp1 = devm_kzalloc(&pdev->dev, sizeof(*rp1), GFP_KERNEL);
if (!rp1) {
err = -ENOMEM;
- goto err_put_node;
+ goto err_out;
}
rp1->pdev = pdev;
@@ -206,21 +206,21 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
dev_err(&pdev->dev,
"Not initialized - is the firmware running?\n");
err = -EINVAL;
- goto err_put_node;
+ goto err_out;
}
err = pcim_enable_device(pdev);
if (err < 0) {
err = dev_err_probe(&pdev->dev, err,
"Enabling PCI device has failed");
- goto err_put_node;
+ goto err_out;
}
rp1->bar1 = pcim_iomap(pdev, 1, 0);
if (!rp1->bar1) {
dev_err(&pdev->dev, "Cannot map PCI BAR\n");
err = -EIO;
- goto err_put_node;
+ goto err_out;
}
pci_set_master(pdev);
@@ -230,11 +230,11 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
if (err < 0) {
err = dev_err_probe(&pdev->dev, err,
"Failed to allocate MSI-X vectors\n");
- goto err_put_node;
+ goto err_out;
} else if (err != RP1_INT_END) {
dev_err(&pdev->dev, "Cannot allocate enough interrupts\n");
err = -EINVAL;
- goto err_put_node;
+ goto err_out;
}
pci_set_drvdata(pdev, rp1);
@@ -267,15 +267,11 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
goto err_unregister_interrupts;
}
- of_node_put(rp1_node);
-
return 0;
err_unregister_interrupts:
rp1_unregister_interrupts(pdev);
-err_put_node:
- of_node_put(rp1_node);
-
+err_out:
return err;
}
--
2.43.0
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] misc: rp1: do not put borrowed OF node
2026-06-16 15:08 [PATCH] misc: rp1: do not put borrowed OF node Pengpeng Hou
@ 2026-06-23 16:01 ` Andrea della Porta
0 siblings, 0 replies; 2+ messages in thread
From: Andrea della Porta @ 2026-06-23 16:01 UTC (permalink / raw)
To: Pengpeng Hou
Cc: Andrea della Porta, Arnd Bergmann, Greg Kroah-Hartman,
linux-kernel
Hi,
On 23:08 Tue 16 Jun , Pengpeng Hou wrote:
> dev_of_node() returns the device's OF node without taking a new
> reference. rp1_probe() stores that borrowed pointer in rp1_node, but
> drops it with of_node_put() on both success and failure paths.
>
> Dropping a reference that was never acquired can underflow the node's
> refcount and leave later users with a stale OF node. Remove the
> of_node_put() calls and keep rp1_node as a borrowed pointer.
>
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
> ---
> drivers/misc/rp1/rp1_pci.c | 20 ++++++++------------
> 1 file changed, 8 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/misc/rp1/rp1_pci.c b/drivers/misc/rp1/rp1_pci.c
> index 81685e3f3296..ddee00045fd3 100644
> --- a/drivers/misc/rp1/rp1_pci.c
> +++ b/drivers/misc/rp1/rp1_pci.c
> @@ -191,13 +191,13 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> if (!rp1_node) {
> dev_err(dev, "Missing of_node for device\n");
> err = -EINVAL;
> - goto err_put_node;
> + goto err_out;
> }
>
> rp1 = devm_kzalloc(&pdev->dev, sizeof(*rp1), GFP_KERNEL);
> if (!rp1) {
> err = -ENOMEM;
> - goto err_put_node;
> + goto err_out;
> }
>
> rp1->pdev = pdev;
> @@ -206,21 +206,21 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> dev_err(&pdev->dev,
> "Not initialized - is the firmware running?\n");
> err = -EINVAL;
> - goto err_put_node;
> + goto err_out;
> }
>
> err = pcim_enable_device(pdev);
> if (err < 0) {
> err = dev_err_probe(&pdev->dev, err,
> "Enabling PCI device has failed");
> - goto err_put_node;
> + goto err_out;
> }
>
> rp1->bar1 = pcim_iomap(pdev, 1, 0);
> if (!rp1->bar1) {
> dev_err(&pdev->dev, "Cannot map PCI BAR\n");
> err = -EIO;
> - goto err_put_node;
> + goto err_out;
> }
>
> pci_set_master(pdev);
> @@ -230,11 +230,11 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> if (err < 0) {
> err = dev_err_probe(&pdev->dev, err,
> "Failed to allocate MSI-X vectors\n");
> - goto err_put_node;
> + goto err_out;
> } else if (err != RP1_INT_END) {
> dev_err(&pdev->dev, "Cannot allocate enough interrupts\n");
> err = -EINVAL;
> - goto err_put_node;
> + goto err_out;
> }
>
> pci_set_drvdata(pdev, rp1);
> @@ -267,15 +267,11 @@ static int rp1_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> goto err_unregister_interrupts;
> }
>
> - of_node_put(rp1_node);
> -
> return 0;
>
> err_unregister_interrupts:
> rp1_unregister_interrupts(pdev);
> -err_put_node:
> - of_node_put(rp1_node);
> -
> +err_out:
> return err;
> }
>
> --
> 2.43.0
>
Thanks for your patch!
Reviewed-by: Andrea della Porta <andrea.porta@suse.com>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2026-06-16 15:08 [PATCH] misc: rp1: do not put borrowed OF node Pengpeng Hou
2026-06-23 16:01 ` Andrea della Porta
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