From fab57a6cc227468ca9e6a4c7ff8d3b10727785ee Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Wed, 29 Jan 2014 13:28:02 +0100
Subject: [PATCH] mac80211: fix virtual monitor interface iteration
During channel context assignment, the interface should
be found by interface iteration, so we need to assign the
pointer before the channel context.
Reported-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Tested-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
net/mac80211/iface.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index ae2eb148a028..d6d1f1df9119 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -418,20 +418,24 @@ int ieee80211_add_virtual_monitor(struct ieee80211_local *local)
return ret;
}
+ mutex_lock(&local->iflist_mtx);
+ rcu_assign_pointer(local->monitor_sdata, sdata);
+ mutex_unlock(&local->iflist_mtx);
+
mutex_lock(&local->mtx);
ret = ieee80211_vif_use_channel(sdata, &local->monitor_chandef,
IEEE80211_CHANCTX_EXCLUSIVE);
mutex_unlock(&local->mtx);
if (ret) {
+ mutex_lock(&local->iflist_mtx);
+ rcu_assign_pointer(local->monitor_sdata, NULL);
+ mutex_unlock(&local->iflist_mtx);
+ synchronize_net();
drv_remove_interface(local, sdata);
kfree(sdata);
return ret;
}
- mutex_lock(&local->iflist_mtx);
- rcu_assign_pointer(local->monitor_sdata, sdata);
- mutex_unlock(&local->iflist_mtx);
-
return 0;
}