[PATCH] irqchip: fix an OF node reference leak in platform_irqchip_probe()

From: Joe Hattori
Date: Sat Dec 14 2024 - 22:40:03 EST


platform_irqchip_probe() leaks an OF node when irq_init_cb fails. Fix it
by declaring par_np with the __free(device_node) cleanup construct.

This bug was found by an experimental static analysis tool that I am
developing.

Fixes: f8410e626569 ("irqchip: Add IRQCHIP_PLATFORM_DRIVER_BEGIN/END and IRQCHIP_MATCH helper macros")
Signed-off-by: Joe Hattori <joe@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/irqchip/irqchip.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/irqchip/irqchip.c b/drivers/irqchip/irqchip.c
index 1eeb0d0156ce..0ee7b6b71f5f 100644
--- a/drivers/irqchip/irqchip.c
+++ b/drivers/irqchip/irqchip.c
@@ -35,11 +35,10 @@ void __init irqchip_init(void)
int platform_irqchip_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
- struct device_node *par_np = of_irq_find_parent(np);
+ struct device_node *par_np __free(device_node) = of_irq_find_parent(np);
of_irq_init_cb_t irq_init_cb = of_device_get_match_data(&pdev->dev);

if (!irq_init_cb) {
- of_node_put(par_np);
return -EINVAL;
}

@@ -55,7 +54,6 @@ int platform_irqchip_probe(struct platform_device *pdev)
* interrupt controller can check for specific domains as necessary.
*/
if (par_np && !irq_find_matching_host(par_np, DOMAIN_BUS_ANY)) {
- of_node_put(par_np);
return -EPROBE_DEFER;
}

--
2.34.1