[PATCH 5.8 005/232] genirq: Unlock irq descriptor after errors

[Greg Kroah-Hartman]

From: Guenter Roeck <linux@xxxxxxxxxxxx>

commit f107cee94ba4d2c7357fde59a1d84346c73d4958 upstream.

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: 1d0326f352bb ("genirq: Check irq_data_get_irq_chip() return value before use")
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20200811180012.80269-1-linux@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 kernel/irq/manage.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2735,8 +2735,10 @@ int irq_set_irqchip_state(unsigned int i
 
 	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
@@ -2749,6 +2751,7 @@ int irq_set_irqchip_state(unsigned int i
 	if (data)
 		err = chip->irq_set_irqchip_state(data, which, val);
 
+out_unlock:
 	irq_put_desc_busunlock(desc, flags);
 	return err;
 }