On 7/11/2018 9:48 AM, Ray Jui wrote:
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);
I forgot to mention this in my previous reply. Given that this is a fix
for a potential NULL pointer dereference and then a kernel crash in the
case when 'platform_get_resource' returns NULL, can you please add the
Fixes tag so this fix is picked by all LTS kernels under maintenance?
Thanks,
Ray
Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
---
Reviewed-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
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.
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) {
--
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