mac80211: fix NULL pointer dereference in ieee80211_compatible_rates

Fix a possible NULL pointer dereference in ieee80211_compatible_rates
introduced in the patch "mac80211: fix association with some APs". If no bss
is available just use all supported rates in the association request.

Signed-off-by: Helmut Schaa <hschaa@suse.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index e470bf12b765df36713d86cdf3af6367c05d963a..7cfd12e0d1e24971735848f3e427dfcfcb1735e1 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -730,7 +730,17 @@ static void ieee80211_send_assoc(struct net_device *dev,
                if (bss->wmm_ie) {
                        wmm = 1;
                }
+
+               /* get all rates supported by the device and the AP as
+                * some APs don't like getting a superset of their rates
+                * in the association request (e.g. D-Link DAP 1353 in
+                * b-only mode) */
+               rates_len = ieee80211_compatible_rates(bss, sband, &rates);
+
                ieee80211_rx_bss_put(dev, bss);
+       } else {
+               rates = ~0;
+               rates_len = sband->n_bitrates;
        }
 
        mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
@@ -761,10 +771,7 @@ static void ieee80211_send_assoc(struct net_device *dev,
        *pos++ = ifsta->ssid_len;
        memcpy(pos, ifsta->ssid, ifsta->ssid_len);
 
-       /* all supported rates should be added here but some APs
-        * (e.g. D-Link DAP 1353 in b-only mode) don't like that
-        * Therefore only add rates the AP supports */
-       rates_len = ieee80211_compatible_rates(bss, sband, &rates);
+       /* add all rates which were marked to be used above */
        supp_rates_len = rates_len;
        if (supp_rates_len > 8)
                supp_rates_len = 8;