[PATCH v4] irqchip/renesas-irqc: fix generic interrupt chip leak on remove

[Qingshuang Fu]

From: Qingshuang Fu <fuqingshuang@xxxxxxxxxx>

The driver allocates domain generic chips using
irq_alloc_domain_generic_chips() during probe. However, on driver
remove, the generic chips are not automatically freed when the interrupt
domain is removed because the domain flags do not include
IRQ_DOMAIN_FLAG_DESTROY_GC.

This causes both the domain generic chips structure and the associated
generic chips to be leaked. Additionally, the generic chips remain on
the global gc_list and may later be visited by generic interrupt chip
suspend, resume, or shutdown callbacks after the driver has been removed,
potentially resulting in a use-after-free and kernel crash.

Fix the resource leak by setting IRQ_DOMAIN_FLAG_DESTROY_GC on the
interrupt domain; this lets the interrupt domain core automatically
release all generic chips when irq_domain_remove() is called, removing
the need for manual cleanup calls in error paths and remove callback.

Fixes: 99c221df33fbfa1b ("irqchip/renesas-irqc: Move over to nested generic chip")
Signed-off-by: Qingshuang Fu <fuqingshuang@xxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
 drivers/irqchip/irq-renesas-irqc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/irqchip/irq-renesas-irqc.c b/drivers/irqchip/irq-renesas-irqc.c
index a20a6471b0e4..4b8b86c89b6a 100644
--- a/drivers/irqchip/irq-renesas-irqc.c
+++ b/drivers/irqchip/irq-renesas-irqc.c
@@ -194,6 +194,9 @@ static int irqc_probe(struct platform_device *pdev)
 	p->gc->chip_types[0].chip.irq_set_wake	= irqc_irq_set_wake;
 	p->gc->chip_types[0].chip.flags	= IRQCHIP_MASK_ON_SUSPEND;
 
+	/* Automatically free generic chips when interrupt domain is destroyed */
+	p->irq_domain->flags |= IRQ_DOMAIN_FLAG_DESTROY_GC;
+
 	irq_domain_set_pm_device(p->irq_domain, dev);
 
 	/* request interrupts one by one */

base-commit: 0e35b9b6ec0ffcc5e23cbdec09f5c622ad532b53
-- 
2.25.1