mac80211: disable beacons before removing the associated interface

When downing interfaces, it's a good idea to tell the driver to
stop sending beacons; that way the driver doesn't need special
code in ops->remove_interface() when it should already handle the
case in bss_info_changed().

This fixes a potential crash with at least ath5k since the vif
pointer will be nullified while beacon interrupts are still active.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 6c655b6547fb..6614d4ff273d 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -522,6 +522,16 @@ static int ieee80211_stop(struct net_device *dev)
                                 ieee80211_scan_completed(&local->hw, true);
                 }
 
+                /*
+                 * Disable beaconing for AP and mesh, IBSS can't
+                 * still be joined to a network at this point.
+                 */
+                if (sdata->vif.type == NL80211_IFTYPE_AP ||
+                    sdata->vif.type == NL80211_IFTYPE_MESH_POINT) {
+                        ieee80211_bss_info_change_notify(sdata,
+                                BSS_CHANGED_BEACON_ENABLED);
+                }
+
                 conf.vif = &sdata->vif;
                 conf.type = sdata->vif.type;
                 conf.mac_addr = dev->dev_addr;