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

Christophe JAILLET
2021-04-30T07:55:07Z

Le 29/04/2021 à 13:00, Colin King a écrit :
> 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;
> port->base = devm_ioremap_resource(dev, regs);
> if (IS_ERR(port->base)) {
> dev_err(dev, "failed to map register base\n");
>

Nitpick:
Using 'devm_platform_ioremap_resource_byname' is slightly less
verbose and should please Coverity.

Also, which git repo are you using? On linux-next ([1)], your proposed
patch is already part of "PCI: mediatek-gen3: Add MediaTek Gen3 driver
for MT8192".

[1]:
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/drivers/pci/controller/pcie-mediatek-gen3.c

CJ