The following commit has been merged into the irq/urgent branch of tip:

Commit-ID:     f107cee94ba4d2c7357fde59a1d84346c73d4958
Gitweb:        
https://git.kernel.org/tip/f107cee94ba4d2c7357fde59a1d84346c73d4958
Author:        Guenter Roeck <[email protected]>
AuthorDate:    Tue, 11 Aug 2020 11:00:12 -07:00
Committer:     Thomas Gleixner <[email protected]>
CommitterDate: Thu, 13 Aug 2020 09:35:59 +02:00

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: 1d0326f352bb ("genirq: Check irq_data_get_irq_chip() return value before 
use")
Signed-off-by: Guenter Roeck <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]

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

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d55ba62..52ac539 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -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;
 }

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