On Sun, Nov 25, 2018 at 10:22:25AM +0100, Michael Straube wrote:
> Add a test for successful call to cdev_alloc() to avoid
> potential null dereference. Issue reported by smatch.
>
Fixes: 874bcba65f9a ("staging: pi433: New driver")
> Signed-off-by: Michael Straube <straube.linux@xxxxxxxxx>
> ---
> drivers/staging/pi433/pi433_if.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c
> index 786478671190..d72de2105053 100644
> --- a/drivers/staging/pi433/pi433_if.c
> +++ b/drivers/staging/pi433/pi433_if.c
> @@ -1245,6 +1245,10 @@ static int pi433_probe(struct spi_device *spi)
>
> /* create cdev */
> device->cdev = cdev_alloc();
> + if (!device->cdev) {
> + dev_dbg(device->dev, "allocation of cdev failed");
> + goto cdev_failed;
> + }
> device->cdev->owner = THIS_MODULE;
> cdev_init(device->cdev, &pi433_fops);
> retval = cdev_add(device->cdev, device->devt, 1);
There is a second related bug here if we cdev_add() fails then we should
call cdev_del(device->cdev). (cdev_del() does not take a NULL cdev
pointer).
regards,
dan carpenter
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