nl80211: allow CAC only if no operation is going on

A CAC should fail if it is triggered while the interface is already
running.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index ae617112b8f5..2838206ddad3 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5591,6 +5591,9 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
         if (err)
                 return err;
 
+        if (netif_carrier_ok(dev))
+                return -EBUSY;
+
         if (wdev->cac_started)
                 return -EBUSY;