ath5k: fix potential NULL pointer dereference in ath5k_beacon_update()

The dereference should be moved below the NULL test.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index 9fd6d9a9942e..9f31cfa56cc0 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -1804,7 +1804,7 @@ ath5k_beacon_update(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 {
         int ret;
         struct ath5k_hw *ah = hw->priv;
-        struct ath5k_vif *avf = (void *)vif->drv_priv;
+        struct ath5k_vif *avf;
         struct sk_buff *skb;
 
         if (WARN_ON(!vif)) {
@@ -1819,6 +1819,7 @@ ath5k_beacon_update(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
                 goto out;
         }
 
+        avf = (void *)vif->drv_priv;
         ath5k_txbuf_free_skb(ah, avf->bbuf);
         avf->bbuf->skb = skb;
         ret = ath5k_beacon_setup(ah, avf->bbuf);