mac80211: fix potential use-after-free

commit d2722f8b87fb172ff2f31d3a2816b31d58678d40 upstream.

The bss struct might be freed in ieee80211_rx_bss_put(),
so we shouldn't use it afterwards.

Fixes: 817cee7675237 ("mac80211: track AP's beacon rate and give it to the driver")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 245dce9..8fdbac7 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2708,8 +2708,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
        bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
                                        channel);
        if (bss) {
-               ieee80211_rx_bss_put(local, bss);
                sdata->vif.bss_conf.beacon_rate = bss->beacon_rate;
+               ieee80211_rx_bss_put(local, bss);
        }
 }