cfg80211: check iface combinations only when iface is running

commit f8cdddb8d61d16a156229f0910f7ecfc7a82c003 upstream.

Don't validate interface combinations on a stopped
interface. Otherwise we might end up being able to
create a new interface with a certain type, but
won't be able to change an existing interface
into that type.

This also skips some other functions when
interface is stopped and changing interface type.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/wireless/util.c b/net/wireless/util.c
index d38815d167b239257891adaed29e34e84873e170..74d529236a6562983850be5a03997447d645b76b 100644 (file)
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -813,7 +813,7 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
             ntype == NL80211_IFTYPE_P2P_CLIENT))
                return -EBUSY;
 
-       if (ntype != otype) {
+       if (ntype != otype && netif_running(dev)) {
                err = cfg80211_can_change_interface(rdev, dev->ieee80211_ptr,
                                                    ntype);
                if (err)