Re: [PATCH][next] PCI: mediatek-gen3: Add missing null pointer check

Jianjun Wang
2021-04-30T07:34:03Z

Hi Colin,

On Thu, 2021-04-29 at 12:00 +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> The call to platform_get_resource_byname can potentially return null, so
> add a null pointer check to avoid a null pointer dereference issue.
>
> Addresses-Coverity: ("Dereference null return")
> Fixes: 441903d9e8f0 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver for MT8192")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> drivers/pci/controller/pcie-mediatek-gen3.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
> index 20165e4a75b2..3c5b97716d40 100644
> --- a/drivers/pci/controller/pcie-mediatek-gen3.c
> +++ b/drivers/pci/controller/pcie-mediatek-gen3.c
> @@ -721,6 +721,8 @@ static int mtk_pcie_parse_port(struct mtk_pcie_port *port)
> int ret;
>
> regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
> + if (!regs)
> + return -EINVAL;

Thanks for your patch.

devm_ioremap_resource() will check and decode this null pointer
dereference error, so I don't think we need to check here.

Thanks.