From: Alexandru Moise <00moses.alexander00@gmail.com>
Date: Tue, 19 Sep 2017 20:04:12 +0000 (+0200)
Subject: genirq: Check __free_irq() return value for NULL
X-Git-Tag: v4.14-rc3~7^2~4
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2827a418ca1b23e432e62c9b3d0e7cf3255dfe88;p=platform%2Fkernel%2Flinux-rpi3.git

genirq: Check __free_irq() return value for NULL

__free_irq() can return a NULL irqaction for example when trying to free
already-free IRQ, but the callsite unconditionally dereferences the
returned pointer.

Fix this by adding a check and return NULL.

Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20170919200412.GA29985@gmail.com
---

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 573dc52..d00132b 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;