genirq: Validate action before dereferencing it in handle_irq_event_percpu()

[deliverable/linux.git] / kernel / irq / handle.c

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index a302cf9a2126c8a911ff4da1a944c88c6d3b3f8a..57bff7857e879bf2301a92723ade0a968870e637 100644 (file)
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -138,7 +138,8 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
        unsigned int flags = 0, irq = desc->irq_data.irq;
        struct irqaction *action = desc->action;
 
-       do {
+       /* action might have become NULL since we dropped the lock */
+       while (action) {
                irqreturn_t res;
 
                trace_irq_handler_entry(irq, action);
@@ -173,7 +174,7 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
 
                retval |= res;
                action = action->next;
-       } while (action);
+       }
 
        add_interrupt_randomness(irq, flags);