[ARM] 5560/1: Avoid buffer overrun in case of an invalid IRQ

handle_bad_irq() expects the IRQ number to be valid (used for statistics),
so it cannot be called with an illegal vector. The problem was reported
by a static analysis tool.

The change makes bad_irq_desc redundant, so delete it.

Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 6 insertions, 18 deletions

diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 096f600dc8d8..b7c3490eaa24 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -98,17 +98,6 @@ unlock:
         return 0;
 }
 
-/* Handle bad interrupts */
-static struct irq_desc bad_irq_desc = {
-        .handle_irq = handle_bad_irq,
-        .lock = __SPIN_LOCK_UNLOCKED(bad_irq_desc.lock),
-};
-
-#ifdef CONFIG_CPUMASK_OFFSTACK
-/* We are not allocating bad_irq_desc.affinity or .pending_mask */
-#error "ARM architecture does not support CONFIG_CPUMASK_OFFSTACK."
-#endif
-
 /*
  * do_IRQ handles all hardware IRQ's.  Decoded IRQs should not
  * come via this function.  Instead, they should provide their
@@ -124,10 +113,13 @@ asmlinkage void __exception asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
          * Some hardware gives randomly wrong interrupts.  Rather
          * than crashing, do something sensible.
          */
-        if (irq >= NR_IRQS)
-                handle_bad_irq(irq, &bad_irq_desc);
-        else
+        if (unlikely(irq >= NR_IRQS)) {
+                if (printk_ratelimit())
+                        printk(KERN_WARNING "Bad IRQ%u\n", irq);
+                ack_bad_irq(irq);
+        } else {
                 generic_handle_irq(irq);
+        }
 
         /* AT91 specific workaround */
         irq_finish(irq);
@@ -165,10 +157,6 @@ void __init init_IRQ(void)
         for (irq = 0; irq < NR_IRQS; irq++)
                 irq_desc[irq].status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 
-#ifdef CONFIG_SMP
-        cpumask_setall(bad_irq_desc.affinity);
-        bad_irq_desc.node = smp_processor_id();
-#endif
         init_arch_irq();
 }