[PATCH v5 3/9] irqchip/imx-irqsteer: Validate IRQ count before creating domain

[Zhipeng Wang (OSS)]

> On Fri, Aug 21, 2026 at 07:10:33PM +0900, Zhipeng.wang_1 at oss.nxp.com
> wrote:
> > From: Fabio Estevam <festevam at nabladev.com>
> >
> > The IRQ count is validated after creating the IRQ domain. If it is
> > invalid, probe returns without removing the domain, leaving its host
> > data pointing at devm-managed memory that is freed on probe failure.
> >
> > Validate the count before allocating resources to avoid the leak and
> > dangling pointer.
> >
> > Fixes: 28528fca4908 ("irqchip/imx-irqsteer: Add multi output
> > interrupts support")
> > Signed-off-by: Fabio Estevam <festevam at nabladev.com>
> > Signed-off-by: Zhipeng Wang <zhipeng.wang_1 at nxp.com>
> > ---
> 
> This patch should be second patch.  After move to second patch, some error
> handle will be nice to have.
> 
> your 3 patch needn't because no error after it. change to devm_ version will be
> improvement patch and put after new API added.
> 
> Frank
> 
Hi Frank,

Makes sense, I'll restructure it that way for the next version:

 - Move Fabio's IRQ-count validation up so the count is validated before
   the domain is created, and add proper error handling there.
 - Since the invalid count is then rejected before the domain exists,
   the domain leak can no longer happen, so managing the domain with
   devm is no longer a fix. I'll drop its Fixes tag and reframe it as an
   improvement.
 - Move that devm conversion after the new devm_irq_domain_create_linear()
   helper, together with the other cleanup.

Thanks for the review.

Zhipeng
> 
> >  drivers/irqchip/irq-imx-irqsteer.c | 7 ++-----
> >  1 file changed, 2 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/irqchip/irq-imx-irqsteer.c
> > b/drivers/irqchip/irq-imx-irqsteer.c
> > index c1df84551efa..571324de8bd1 100644
> > --- a/drivers/irqchip/irq-imx-irqsteer.c
> > +++ b/drivers/irqchip/irq-imx-irqsteer.c
> > @@ -218,6 +218,8 @@ static int imx_irqsteer_probe(struct platform_device
> *pdev)
> >  	 */
> >  	data->irq_count = DIV_ROUND_UP(irqs_num, 64);
> >  	data->reg_num = irqs_num / 32;
> > +	if (!data->irq_count || data->irq_count > CHAN_MAX_OUTPUT_INT)
> > +		return -EINVAL;
> >
> >  	if (IS_ENABLED(CONFIG_PM)) {
> >  		data->saved_reg = devm_kzalloc(&pdev->dev, @@ -253,11 +255,6
> @@
> > static int imx_irqsteer_probe(struct platform_device *pdev)
> >  	}
> >  	irq_domain_set_pm_device(data->domain, &pdev->dev);
> >
> > -	if (!data->irq_count || data->irq_count > CHAN_MAX_OUTPUT_INT) {
> > -		ret = -EINVAL;
> > -		goto out;
> > -	}
> > -
> >  	for (i = 0; i < data->irq_count; i++) {
> >  		data->irq[i] = irq_of_parse_and_map(np, i);
> >  		if (!data->irq[i])
> > --
> > 2.34.1
> >
> >