Commit f107cee9 authored Aug 11, 2020 by Guenter Roeck Committed by Thomas Gleixner Aug 13, 2020

genirq: Unlock irq descriptor after errors

In irq_set_irqchip_state(), the irq descriptor is not unlocked after an
error is encountered. While that should never happen in practice, a buggy
driver may trigger it. This would result in a lockup, so fix it.

Fixes: 1d0326f3 ("genirq: Check irq_data_get_irq_chip() return value before use")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200811180012.80269-1-linux@roeck-us.net

parent e27b1636

kernel/irq/manage.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -2731,8 +2731,10 @@ int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,

		do {
		chip = irq_data_get_irq_chip(data);
		if (WARN_ON_ONCE(!chip))
		return -ENODEV;
		if (WARN_ON_ONCE(!chip)) {
		err = -ENODEV;
		goto out_unlock;
		}
		if (chip->irq_set_irqchip_state)
		break;
		#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
		@@ -2745,6 +2747,7 @@ int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
		if (data)
		err = chip->irq_set_irqchip_state(data, which, val);

		out_unlock:
		irq_put_desc_busunlock(desc, flags);
		return err;
		}