rtlwifi: Fix oops on rate-control failure

When the rate-control indexing is incorrectly set up, mac80211 issues
a warning and returns NULL from the call to ieee80211_get_tx_rate().
When this happens, avoid a NULL pointer dereference.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/net/wireless/rtlwifi/base.c b/drivers/net/wireless/rtlwifi/base.c
index 510023554e5..e54488db0e1 100644
--- a/drivers/net/wireless/rtlwifi/base.c
+++ b/drivers/net/wireless/rtlwifi/base.c
@@ -838,7 +838,10 @@ void rtl_get_tcb_desc(struct ieee80211_hw *hw,
         __le16 fc = hdr->frame_control;
 
         txrate = ieee80211_get_tx_rate(hw, info);
-        tcb_desc->hw_rate = txrate->hw_value;
+        if (txrate)
+                tcb_desc->hw_rate = txrate->hw_value;
+        else
+                tcb_desc->hw_rate = 0;
 
         if (ieee80211_is_data(fc)) {
                 /*