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authorJohannes Berg <johannes.berg@intel.com>2013-12-04 20:11:06 +0100
committerJohannes Berg <johannes.berg@intel.com>2013-12-16 11:29:45 +0100
commita710c8160dd93e981163759aad754f758850273a (patch)
tree1b125791f1a332af6a219bca9072bd7085d28f92
parent1ddbbb0c83de82599b1baf14bf6bb69a774d4fc7 (diff)
downloadop-kernel-dev-a710c8160dd93e981163759aad754f758850273a.zip
op-kernel-dev-a710c8160dd93e981163759aad754f758850273a.tar.gz
mac80211: move 4-addr sta pointer clearing before synchronize_rcu()
The pointer should be cleared before synchronize_rcu() so that the consequently dead station won't be found by any lookups in the TX or RX paths. Also check that the station is actually the one being removed, the check is not needed because each 4-addr VLAN can only have a single station and non-4-addr VLANs always have a NULL pointer there, but the code is clearer this way (and we avoid the memory write.) Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r--net/mac80211/sta_info.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 1e14774..557ac25 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -875,6 +875,10 @@ int __must_check __sta_info_destroy(struct sta_info *sta)
drv_sta_pre_rcu_remove(local, sta->sdata, sta);
+ if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+ rcu_access_pointer(sdata->u.vlan.sta) == sta)
+ RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
+
/* this always calls synchronize_net() */
ieee80211_free_sta_keys(local, sta);
@@ -883,9 +887,6 @@ int __must_check __sta_info_destroy(struct sta_info *sta)
local->num_sta--;
local->sta_generation++;
- if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
- RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
-
while (sta->sta_state > IEEE80211_STA_NONE) {
ret = sta_info_move_state(sta, sta->sta_state - 1);
if (ret) {
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