ath9k: fix a tx rate duration calculation bug

commit 76591bea9714a58d8924154068c78d702eb2cb17 upstream.

The rate pointer variable for a rate series is used in a loop before it is
initialized. This went unnoticed because it was used earlier for the RTS/CTS
rate. This bug can lead to the wrong PHY type being passed to the
duration calculation function.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 76fd277..c59c592 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -936,13 +936,13 @@ static void ath_buf_set_rate(struct ath_softc *sc, struct ath_buf *bf,
                }
 
                /* legacy rates */
+               rate = &sc->sbands[tx_info->band].bitrates[rates[i].idx];
                if ((tx_info->band == IEEE80211_BAND_2GHZ) &&
                    !(rate->flags & IEEE80211_RATE_ERP_G))
                        phy = WLAN_RC_PHY_CCK;
                else
                        phy = WLAN_RC_PHY_OFDM;
 
-               rate = &sc->sbands[tx_info->band].bitrates[rates[i].idx];
                info->rates[i].Rate = rate->hw_value;
                if (rate->hw_value_short) {
                        if (rates[i].flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)