[PATCH] perf/dwc_pcie: Fix PCI device reference leak in probe

[PATCH] perf/dwc_pcie: Fix PCI device reference leak in probe

[Ruoyu Wang]

pci_get_domain_bus_and_slot() returns a referenced PCI device. When the
subsequent RAS DES capability lookup fails, dwc_pcie_pmu_probe() returns
-ENODEV without releasing that reference. Repeated failed probes can
therefore keep the PCI device allocated after removal.

Move the existing pci_dev_put() immediately after capability discovery
so the temporary lookup reference is released on both success and
failure paths.

This issue was found by a static analysis checker and confirmed by
manual source review.

Fixes: 7f35b429802a ("perf/dwc_pcie: fix duplicate pci_dev devices")
Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
---
 drivers/perf/dwc_pcie_pmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
index 5385401fa9cf6..baa736fd9a6ef 100644
--- a/drivers/perf/dwc_pcie_pmu.c
+++ b/drivers/perf/dwc_pcie_pmu.c
@@ -710,10 +710,10 @@ static int dwc_pcie_pmu_probe(struct platform_device *plat_dev)
 	}
 
 	vsec = dwc_pcie_des_cap(pdev);
+	pci_dev_put(pdev);
 	if (!vsec)
 		return -ENODEV;
 
-	pci_dev_put(pdev);
 	name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%x", sbdf);
 	if (!name)
 		return -ENOMEM;
-- 
2.51.0

Re: [PATCH] perf/dwc_pcie: Fix PCI device reference leak in probe

[Shuai Xue]

On 8/14/26 9:39 PM, Ruoyu Wang wrote:
> pci_get_domain_bus_and_slot() returns a referenced PCI device. When the
> subsequent RAS DES capability lookup fails, dwc_pcie_pmu_probe() returns
> -ENODEV without releasing that reference. Repeated failed probes can
> therefore keep the PCI device allocated after removal.
> 
> Move the existing pci_dev_put() immediately after capability discovery
> so the temporary lookup reference is released on both success and
> failure paths.
> 
> This issue was found by a static analysis checker and confirmed by
> manual source review.
> 
> Fixes: 7f35b429802a ("perf/dwc_pcie: fix duplicate pci_dev devices")
> Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
> ---
>   drivers/perf/dwc_pcie_pmu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
> index 5385401fa9cf6..baa736fd9a6ef 100644
> --- a/drivers/perf/dwc_pcie_pmu.c
> +++ b/drivers/perf/dwc_pcie_pmu.c
> @@ -710,10 +710,10 @@ static int dwc_pcie_pmu_probe(struct platform_device *plat_dev)
>   	}
>   
>   	vsec = dwc_pcie_des_cap(pdev);
> +	pci_dev_put(pdev);
>   	if (!vsec)
>   		return -ENODEV;
>   
> -	pci_dev_put(pdev);
>   	name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%x", sbdf);
>   	if (!name)
>   		return -ENOMEM;


Good catch.

Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>

Thanks.
Shuai

Re: [PATCH] perf/dwc_pcie: Fix PCI device reference leak in probe

[Markus Elfring]

…
> Move the existing pci_dev_put() immediately after capability discovery
> so the temporary lookup reference is released on both success and
> failure paths.
…

How do you think about to apply the attribute “__free(pci_dev_put)”?
https://elixir.bootlin.com/linux/v7.2-rc7/source/include/linux/pci.h#L1269

Regards,
Markus