sparc: fix array overrun check in of_device_64.c

Do the array length check and fixup before copying the array.

Signed-off-by: Robert Reif <reif@earthlink.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 9 deletions

diff --git a/arch/sparc/kernel/of_device_64.c b/arch/sparc/kernel/of_device_64.c
index 0f616ae3246c..46e231f7c5ce 100644
--- a/arch/sparc/kernel/of_device_64.c
+++ b/arch/sparc/kernel/of_device_64.c
@@ -811,20 +811,20 @@ static struct of_device * __init scan_one_device(struct device_node *dp,
 
         irq = of_get_property(dp, "interrupts", &len);
         if (irq) {
-                memcpy(op->irqs, irq, len);
                 op->num_irqs = len / 4;
+
+                /* Prevent overrunning the op->irqs[] array.  */
+                if (op->num_irqs > PROMINTR_MAX) {
+                        printk(KERN_WARNING "%s: Too many irqs (%d), "
+                               "limiting to %d.\n",
+                               dp->full_name, op->num_irqs, PROMINTR_MAX);
+                        op->num_irqs = PROMINTR_MAX;
+                }
+                memcpy(op->irqs, irq, op->num_irqs * 4);
         } else {
                 op->num_irqs = 0;
         }
 
-        /* Prevent overrunning the op->irqs[] array.  */
-        if (op->num_irqs > PROMINTR_MAX) {
-                printk(KERN_WARNING "%s: Too many irqs (%d), "
-                       "limiting to %d.\n",
-                       dp->full_name, op->num_irqs, PROMINTR_MAX);
-                op->num_irqs = PROMINTR_MAX;
-        }
-
         build_device_resources(op, parent);
         for (i = 0; i < op->num_irqs; i++)
                 op->irqs[i] = build_one_device_irq(op, parent, op->irqs[i]);