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authorThomas Gleixner <tglx@linutronix.de>2010-03-23 22:40:53 +0100
committerThomas Gleixner <tglx@linutronix.de>2010-03-24 14:38:23 +0100
commitcc8c3b78433222e5dbc1fdfcfdde29e1743f181a (patch)
tree7efe13d87d7d92b1ff409455e65c85129bc30121
parent0b1adaa031a55e44f5dd942f234bf09d28e8a0d6 (diff)
genirq: Protect access to irq_desc->action in can_request_irq()
can_request_irq() accesses and dereferences irq_desc->action w/o holding irq_desc->lock. So action can be freed on another CPU before it's dereferenced. Unlikely, but ... Protect it with desc->lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--kernel/irq/manage.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 69a3d7b9414c..398fda155f6e 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -382,6 +382,7 @@ int can_request_irq(unsigned int irq, unsigned long irqflags)
{
struct irq_desc *desc = irq_to_desc(irq);
struct irqaction *action;
+ unsigned long flags;
if (!desc)
return 0;
@@ -389,11 +390,14 @@ int can_request_irq(unsigned int irq, unsigned long irqflags)
if (desc->status & IRQ_NOREQUEST)
return 0;
+ raw_spin_lock_irqsave(&desc->lock, flags);
action = desc->action;
if (action)
if (irqflags & action->flags & IRQF_SHARED)
action = NULL;
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+
return !action;
}