diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2010-03-23 22:40:53 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2010-03-24 14:38:23 +0100 |
| commit | cc8c3b78433222e5dbc1fdfcfdde29e1743f181a (patch) | |
| tree | 7efe13d87d7d92b1ff409455e65c85129bc30121 | |
| parent | 0b1adaa031a55e44f5dd942f234bf09d28e8a0d6 (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.c | 4 |
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; } |