2019-03-19 00:27:38

by Aditya Pakki

Subject: [PATCH] PCI: Fix to avoid potential NULL pointer dereference

In gen_pci_probe, of_match_node can return a NULL pointer in case of
failure. The patch avoids a NULL pointer dereference in such a scenario.

Signed-off-by: Aditya Pakki <[email protected]>
---
drivers/pci/controller/pci-host-generic.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/pci-host-generic.c b/drivers/pci/controller/pci-host-generic.c
index dea3ec7592a2..85f473f50e96 100644
--- a/drivers/pci/controller/pci-host-generic.c
+++ b/drivers/pci/controller/pci-host-generic.c
@@ -83,6 +83,8 @@ static int gen_pci_probe(struct platform_device *pdev)
struct pci_ecam_ops *ops;

of_id = of_match_node(gen_pci_of_match, pdev->dev.of_node);
+ if (!of_id)
+ return -ENXIO;
ops = (struct pci_ecam_ops *)of_id->data;

return pci_host_common_probe(pdev, ops);
--
2.17.1

2019-03-19 05:38:23

by Jisheng Zhang

Subject: Re: [PATCH] PCI: Fix to avoid potential NULL pointer dereference

On Mon, 18 Mar 2019 19:26:30 -0500 Aditya Pakki wrote:

>
> In gen_pci_probe, of_match_node can return a NULL pointer in case of

This could not happen. If the probe is called, it means OF registered a
device with a valid compatible string, so of_match_node cannot be NULL.

> failure. The patch avoids a NULL pointer dereference in such a scenario.
>
> Signed-off-by: Aditya Pakki <[email protected]>
> ---
> drivers/pci/controller/pci-host-generic.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/pci/controller/pci-host-generic.c b/drivers/pci/controller/pci-host-generic.c
> index dea3ec7592a2..85f473f50e96 100644
> --- a/drivers/pci/controller/pci-host-generic.c
> +++ b/drivers/pci/controller/pci-host-generic.c
> @@ -83,6 +83,8 @@ static int gen_pci_probe(struct platform_device *pdev)
> struct pci_ecam_ops *ops;
>
> of_id = of_match_node(gen_pci_of_match, pdev->dev.of_node);
> + if (!of_id)
> + return -ENXIO;
> ops = (struct pci_ecam_ops *)of_id->data;
>
> return pci_host_common_probe(pdev, ops);
> --
> 2.17.1
>
>
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