ath9k: Fix NULL pointer dereference on early irq

The ah struct might not have been initialized when
interrupt comes so check for it.

Signed-off-by: Wojciech Dubowik <Wojciech.Dubowik@neratec.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index e6ac8d2e610c..4b148bbb2bf6 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -513,7 +513,7 @@ irqreturn_t ath_isr(int irq, void *dev)
          * touch anything. Note this can happen early
          * on if the IRQ is shared.
          */
-        if (test_bit(ATH_OP_INVALID, &common->op_flags))
+        if (!ah || test_bit(ATH_OP_INVALID, &common->op_flags))
                 return IRQ_NONE;
 
         /* shared irq, not for us */