[PATCH v2] mac80211: Disallow changing chan type on monitor when CHAN_MODE_FIXED

[Pontus Fuchs <pontus.fuchs@gmail.com>]

If you add a monitor interface in paralell 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>
---
 net/mac80211/cfg.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 498c94e..a87591b 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 ||
+		    (!netdev && local->_oper_channel_type != channel_type))
 			return -EBUSY;
 		if (!sdata && local->_oper_channel_type == channel_type)
 			return 0;
-- 
1.7.5.4