Re: [PATCH v3 2/6] irqchip: Add interrupt controller support for Realtek DHC SoCs

[Dan Carpenter <dan.carpenter@linaro.org>]

On Wed, Nov 29, 2023 at 11:21:06AM +0300, Dan Carpenter wrote:
> > +int realtek_intc_probe(struct platform_device *pdev, const struct realtek_intc_info *info)
> > +{
> > +	struct realtek_intc_data *data;
> > +	struct device *dev = &pdev->dev;
> > +	struct device_node *node = dev->of_node;
> > +	int ret, i;
> > +
> > +	data = devm_kzalloc(dev, struct_size(data, subset_data, info->cfg_num), GFP_KERNEL);
> > +	if (!data)
> > +		return -ENOMEM;
> > +
> > +	data->base = of_iomap(node, 0);
> > +	if (!data->base) {
> > +		ret = -ENOMEM;
> > +		goto out_cleanup;
> 
> devm_ allocations are cleaned up automatically so there is no need to
> call devm_kfree() before returning.
> 
> regards,
> dan carpenter
> 
> > +	}
> > +
> > +	data->info = info;
> > +
> > +	raw_spin_lock_init(&data->lock);
> > +
> > +	data->domain = irq_domain_add_linear(node, 32, &realtek_intc_domain_ops, data);

Btw, as I was testing the other static checker warning for <= 0, my
static checker really wants this irq_domain_add_linear() to be cleaned
up on the error path.

Otherwise it probably leads to a use after free because we free data
(automatically or manually) but it's still on a list somewhere.

> > +	if (!data->domain) {
> > +		ret = -ENOMEM;
> > +		goto out_cleanup;
> > +	}
> > +
> > +	data->subset_data_num = info->cfg_num;
> > +	for (i = 0; i < info->cfg_num; i++) {
> > +		ret = realtek_intc_subset(node, data, i);
> > +		if (ret) {
> > +			WARN(ret, "failed to init subset %d: %d", i, ret);
> > +			ret = -ENOMEM;
> > +			goto out_cleanup;

This error path.

regards,
dan carpenter


> > +		}
> > +	}
> > +
> > +	platform_set_drvdata(pdev, data);
> > +
> > +	return 0;
> > +
> > +out_cleanup:
> > +
> > +	if (data->base)
> > +		iounmap(data->base);
> > +
> > +	devm_kfree(dev, data);
> > +
> > +	return ret;
> > +}