[PATCH] gpio: brcmstb: fix UAF after IRQ domain setup failure

[Guangshuo Li <lgs201920130244@gmail.com>]

When devm_request_irq() fails in brcmstb_gpio_irq_setup(), the error
path removes the IRQ domain but leaves priv->irq_domain non-NULL.

The probe error path subsequently calls brcmstb_gpio_remove(), which
checks priv->irq_domain and attempts to access the already-freed
domain through irq_find_mapping(). It also attempts to remove the
domain again, resulting in a use-after-free and potentially further
memory corruption.

Set priv->irq_domain to NULL after removing it so that the common
cleanup path skips the already-freed IRQ domain.

This issue was found by our static analysis tool under development.

Fixes: 0ba31dc201de ("gpio: brcmstb: consolidate interrupt domains")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/gpio/gpio-brcmstb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c
index 44ca798cf832..3b1aaea63951 100644
--- a/drivers/gpio/gpio-brcmstb.c
+++ b/drivers/gpio/gpio-brcmstb.c
@@ -513,6 +513,7 @@ static int brcmstb_gpio_irq_setup(struct platform_device *pdev,
 
 out_free_domain:
 	irq_domain_remove(priv->irq_domain);
+	priv->irq_domain = NULL;
 
 	return err;
 }
-- 
2.43.0