[PATCH] ti-st: handle null allocation return correctly.

[PATCH] ti-st: handle null allocation return correctly.

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

static analysis with smatch picked up the following error:

get_platform_data() error: potential null dereference 'dt_pdata'.
  (kzalloc returns null)

ironically, the code already checks for a null kzalloc return and
emits an error message.  Fix by adding an error return of NULL rather
than continuing and tripping the null dereference.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/misc/ti-st/st_kim.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c
index 18e7a03..5a5265a 100644
--- a/drivers/misc/ti-st/st_kim.c
+++ b/drivers/misc/ti-st/st_kim.c
@@ -753,8 +753,10 @@ static struct ti_st_plat_data *get_platform_data(struct device *dev)
 
 	dt_pdata = kzalloc(sizeof(*dt_pdata), GFP_KERNEL);
 
-	if (!dt_pdata)
+	if (!dt_pdata) {
 		pr_err("Can't allocate device_tree platform data\n");
+		return NULL;
+	}
 
 	dt_property = of_get_property(np, "dev_name", &len);
 	if (dt_property)
-- 
2.1.4

Re: [PATCH] ti-st: handle null allocation return correctly.

[Greg Kroah-Hartman]

On Tue, May 12, 2015 at 07:23:03PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> static analysis with smatch picked up the following error:
> 
> get_platform_data() error: potential null dereference 'dt_pdata'.
>   (kzalloc returns null)
> 
> ironically, the code already checks for a null kzalloc return and
> emits an error message.  Fix by adding an error return of NULL rather
> than continuing and tripping the null dereference.
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/misc/ti-st/st_kim.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c
> index 18e7a03..5a5265a 100644
> --- a/drivers/misc/ti-st/st_kim.c
> +++ b/drivers/misc/ti-st/st_kim.c
> @@ -753,8 +753,10 @@ static struct ti_st_plat_data *get_platform_data(struct device *dev)
>  
>  	dt_pdata = kzalloc(sizeof(*dt_pdata), GFP_KERNEL);
>  
> -	if (!dt_pdata)
> +	if (!dt_pdata) {
>  		pr_err("Can't allocate device_tree platform data\n");

Care to remove this as well?  It's not needed.

thanks,

greg k-h