mac80211: Disallow changing chan type on monitor when CHAN_MODE_FIXED

If you add a monitor interface in parallel to a normal interface
mac80211 will let you to change the channel type on the monitor
interface even if you are connected. Add an explicit check to
disallow this.

Signed-off-by: Pontus Fuchs <pontus.fuchs@gmail.com>
[fix typo in commit log, use sdata instead of netdev]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 9a974579ba89..cd8b1fb05d42 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -689,7 +689,8 @@ static int ieee80211_set_channel(struct wiphy *wiphy,
         case CHAN_MODE_HOPPING:
                 return -EBUSY;
         case CHAN_MODE_FIXED:
-                if (local->oper_channel != chan)
+                if (local->oper_channel != chan ||
+                    (!sdata && local->_oper_channel_type != channel_type))
                         return -EBUSY;
                 if (!sdata && local->_oper_channel_type == channel_type)
                         return 0;