[PATCH -next] pinctrl: nsp: fix potential NULL dereference in nsp_pinmux_probe()
From: Ray Jui <hidden>
Date: 2018-07-11 16:48:51
Also in:
kernel-janitors, linux-gpio
On 7/11/2018 5:34 AM, Wei Yongjun 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_nocache(e1, res->start, e2); Signed-off-by: Wei Yongjun <redacted> ---
Reviewed-by: Ray Jui <redacted> Change looks good to me, although the check could have been avoided if 'devm_ioremap_resource' is used on the next line instead of 'devm_ioremap_nocache', where validation of resource pointer is done. But there's probably a reason why 'devm_ioremap_nocache' was used in this code here.
quoted hunk ↗ jump to hunk
drivers/pinctrl/bcm/pinctrl-nsp-mux.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/drivers/pinctrl/bcm/pinctrl-nsp-mux.c b/drivers/pinctrl/bcm/pinctrl-nsp-mux.c index 5cd8166..87618a4 100644 --- a/drivers/pinctrl/bcm/pinctrl-nsp-mux.c +++ b/drivers/pinctrl/bcm/pinctrl-nsp-mux.c@@ -577,6 +577,8 @@ static int nsp_pinmux_probe(struct platform_device *pdev) return PTR_ERR(pinctrl->base0); res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + if (!res) + return -EINVAL; pinctrl->base1 = devm_ioremap_nocache(&pdev->dev, res->start, resource_size(res)); if (!pinctrl->base1) {