On Tue, Nov 05, 2024 at 08:07:35PM +0800, Zhongqiu Han wrote:
> If platform_get_resource_byname() fails and returns NULL, dereferencing
> res->start will cause a NULL pointer access. Add a check to prevent it.
>
> Fixes: 1bf5f25324f7 ("PCI: endpoint: Add PCI Endpoint function driver for MHI bus")
> Signed-off-by: Zhongqiu Han <quic_zhonhan@xxxxxxxxxxx>
> ---
> drivers/pci/endpoint/functions/pci-epf-mhi.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> index 7d070b1def11..2712026733ab 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> @@ -873,6 +873,11 @@ static int pci_epf_mhi_bind(struct pci_epf *epf)
>
> /* Get MMIO base address from Endpoint controller */
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mmio");
> + if (!res) {
> + dev_err(&pdev->dev, "Failed to get MMIO base address\n");
dev_err(&epf->dev, "Failed to get mmio resource\n");
or
dev_err(&epf->dev, "Failed to get \"mmio\" resource\n");
Note: &epf->dev instead of &pdev->dev in order to be consistent with other
EPF ->bind() functions.
With that, feel free to add:
Reviewed-by: Niklas Cassel <cassel@xxxxxxxxxx>
Kind regards,
Niklas
> + return -ENODEV;
> + }
> +
> epf_mhi->mmio_phys = res->start;
> epf_mhi->mmio_size = resource_size(res);
>
> --
> 2.25.1
>
