Re: [PATCH V1 12/15] spmi-pmic-arb: fix a possible null pointer dereference

From: Stephen Boyd
Date: Wed May 31 2017 - 13:31:37 EST


On 05/30, Kiran Gunda wrote:
> diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
> index 2afe359..412481d 100644
> --- a/drivers/spmi/spmi-pmic-arb.c
> +++ b/drivers/spmi/spmi-pmic-arb.c
> @@ -1003,6 +1003,12 @@ static int spmi_pmic_arb_probe(struct platform_device *pdev)
> pa->spmic = ctrl;
>
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "core");
> + if (!res) {
> + dev_err(&pdev->dev, "core resource not specified\n");
> + err = -EINVAL;
> + goto err_put_ctrl;
> + }
> +
> pa->core_size = resource_size(res);
> if (pa->core_size <= 0x800) {
> dev_err(&pdev->dev, "core_size is smaller than 0x800. Failing Probe\n");

I would prefer this patch instead, so that we can piggyback on
the error checking of the devm_ioremap_resource() code. Also, add
a Fixes: tag please so we can backport it as needed.


diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 5ec3a595dc7d..0cedbda60707 100644
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -878,12 +878,12 @@ static int spmi_pmic_arb_probe(struct platform_device *pdev)
pa->spmic = ctrl;

res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "core");
- pa->core_size = resource_size(res);
core = devm_ioremap_resource(&ctrl->dev, res);
if (IS_ERR(core)) {
err = PTR_ERR(core);
goto err_put_ctrl;
}
+ pa->core_size = resource_size(res);

hw_ver = readl_relaxed(core + PMIC_ARB_VERSION);
is_v1 = (hw_ver < PMIC_ARB_VERSION_V2_MIN);

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