[PATCH -next] gpio: pxa: fix potential NULL dereference in pxa_gpio_probe()

[PATCH -next] gpio: pxa: fix potential NULL dereference in pxa_gpio_probe()

[Wei Yongjun]

platform_get_resource() may fail and return NULL, so we should
better check it's return value to avoid a NULL pointer dereference
a bit later in the code.

This is detected by Coccinelle semantic patch.

@@
expression pdev, res, n, t, e, e1, e2;
@@

res = platform_get_resource(pdev, t, n);
+ if (!res)
+   return -EINVAL;
... when != res = NULL
e = devm_ioremap(e1, res->start, e2);

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
---
 drivers/gpio/gpio-pxa.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
index 3c1f65b..c3899ed 100644
--- a/drivers/gpio/gpio-pxa.c
+++ b/drivers/gpio/gpio-pxa.c
@@ -646,6 +646,8 @@ static int pxa_gpio_probe(struct platform_device *pdev)
 	pchip->irq0 = irq0;
 	pchip->irq1 = irq1;
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
 	gpio_reg_base = devm_ioremap(&pdev->dev, res->start,
 				     resource_size(res));
 	if (!gpio_reg_base)

Re: [PATCH -next] gpio: pxa: fix potential NULL dereference in pxa_gpio_probe()

[Robert Jarzmik]

Wei Yongjun <weiyongjun1@huawei.com> writes:

> platform_get_resource() may fail and return NULL, so we should
> better check it's return value to avoid a NULL pointer dereference
> a bit later in the code.
>
> This is detected by Coccinelle semantic patch.
>
> @@
> expression pdev, res, n, t, e, e1, e2;
> @@
>
> res = platform_get_resource(pdev, t, n);
> + if (!res)
> +   return -EINVAL;
> ... when != res = NULL
> e = devm_ioremap(e1, res->start, e2);
>
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>

Cheers.

--
Robert

Re: [PATCH -next] gpio: pxa: fix potential NULL dereference in pxa_gpio_probe()

[Linus Walleij]

On Wed, Jul 11, 2018 at 3:10 PM Wei Yongjun <weiyongjun1@huawei.com> wrote:

> platform_get_resource() may fail and return NULL, so we should
> better check it's return value to avoid a NULL pointer dereference
> a bit later in the code.
>
> This is detected by Coccinelle semantic patch.
>
> @@
> expression pdev, res, n, t, e, e1, e2;
> @@
>
> res = platform_get_resource(pdev, t, n);
> + if (!res)
> +   return -EINVAL;
> ... when != res = NULL
> e = devm_ioremap(e1, res->start, e2);
>
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>

Patch applied with Robert's ACK.

Yours,
Linus Walleij