mac80211: check csa wiphy flag in ibss before switching

When external CSA IEs are received (beacons or action messages), a
channel switch is triggered as well. This should only be allowed on
devices which actually support channel switches, otherwise disconnect.
(For the corresponding userspace invocation, the wiphy flag is checked
in nl80211).

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 531be040b9ae85972d61bf7df248ae28308d811b..27a39de89679b7d3710fea18a65b6d5df6d003d0 100644 (file)
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -823,6 +823,10 @@ ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
        if (err)
                return false;
 
+       /* channel switch is not supported, disconnect */
+       if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
+               goto disconnect;
+
        params.count = csa_ie.count;
        params.chandef = csa_ie.chandef;