[PATCH] genirq: check __free_irq()'s return value for NULL

[Alexandru Moise]

__free_irq() can return a NULL irqaction for example when trying to
free already-free IRQ. Fix this by adding a check and return NULL.

Signed-off-by: Alexandru Moise <00moses.alexande...@gmail.com>
---
 kernel/irq/manage.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 573dc52b0806..649bc34521da 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1643,6 +1643,10 @@ const void *free_irq(unsigned int irq, void *dev_id)
 #endif
 
        action = __free_irq(irq, dev_id);
+
+       if (!action)
+               return NULL;
+
        devname = action->name;
        kfree(action);
        return devname;
-- 
2.14.1