From 9513c5e18a0dc55a1fc9c890715098ba2315830b Mon Sep 17 00:00:00 2001 From: Avri Altman Date: Mon, 19 Oct 2015 16:29:11 +0200 Subject: [PATCH] iwlwifi: mvm: Avoid dereferencing sta if it was already flushed Be a little bit more careful when dereferencing sta on key removal, As it might already get flushed on other thread. Signed-off-by: Avri Altman Signed-off-by: Emmanuel Grumbach --- drivers/net/wireless/iwlwifi/mvm/sta.c | 44 ++++++++++++-------------- 1 file changed, 20 insertions(+), 24 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/mvm/sta.c b/drivers/net/wireless/iwlwifi/mvm/sta.c index 4e260083b6a0..354acbde088e 100644 --- a/drivers/net/wireless/iwlwifi/mvm/sta.c +++ b/drivers/net/wireless/iwlwifi/mvm/sta.c @@ -1201,7 +1201,8 @@ static int iwl_mvm_set_fw_key_idx(struct iwl_mvm *mvm) return max_offs; } -static u8 iwl_mvm_get_key_sta_id(struct ieee80211_vif *vif, +static u8 iwl_mvm_get_key_sta_id(struct iwl_mvm *mvm, + struct ieee80211_vif *vif, struct ieee80211_sta *sta) { struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif); @@ -1218,8 +1219,21 @@ static u8 iwl_mvm_get_key_sta_id(struct ieee80211_vif *vif, * station ID, then use AP's station ID. */ if (vif->type == NL80211_IFTYPE_STATION && - mvmvif->ap_sta_id != IWL_MVM_STATION_COUNT) - return mvmvif->ap_sta_id; + mvmvif->ap_sta_id != IWL_MVM_STATION_COUNT) { + u8 sta_id = mvmvif->ap_sta_id; + + sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id], + lockdep_is_held(&mvm->mutex)); + /* + * It is possible that the 'sta' parameter is NULL, + * for example when a GTK is removed - the sta_id will then + * be the AP ID, and no station was passed by mac80211. + */ + if (IS_ERR_OR_NULL(sta)) + return IWL_MVM_STATION_COUNT; + + return sta_id; + } return IWL_MVM_STATION_COUNT; } @@ -1445,7 +1459,7 @@ int iwl_mvm_set_sta_key(struct iwl_mvm *mvm, lockdep_assert_held(&mvm->mutex); /* Get the station id from the mvm local station table */ - sta_id = iwl_mvm_get_key_sta_id(vif, sta); + sta_id = iwl_mvm_get_key_sta_id(mvm, vif, sta); if (sta_id == IWL_MVM_STATION_COUNT) { IWL_ERR(mvm, "Failed to find station id\n"); return -EINVAL; @@ -1531,7 +1545,7 @@ int iwl_mvm_remove_sta_key(struct iwl_mvm *mvm, lockdep_assert_held(&mvm->mutex); /* Get the station id from the mvm local station table */ - sta_id = iwl_mvm_get_key_sta_id(vif, sta); + sta_id = iwl_mvm_get_key_sta_id(mvm, vif, sta); IWL_DEBUG_WEP(mvm, "mvm remove dynamic key: idx=%d sta=%d\n", keyconf->keyidx, sta_id); @@ -1557,24 +1571,6 @@ int iwl_mvm_remove_sta_key(struct iwl_mvm *mvm, return 0; } - /* - * It is possible that the 'sta' parameter is NULL, and thus - * there is a need to retrieve the sta from the local station table, - * for example when a GTK is removed (where the sta_id will then be - * the AP ID, and no station was passed by mac80211.) - */ - if (!sta) { - sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[sta_id], - lockdep_is_held(&mvm->mutex)); - if (!sta) { - IWL_ERR(mvm, "Invalid station id\n"); - return -EINVAL; - } - } - - if (WARN_ON_ONCE(iwl_mvm_sta_from_mac80211(sta)->vif != vif)) - return -EINVAL; - ret = __iwl_mvm_remove_sta_key(mvm, sta_id, keyconf, mcast); if (ret) return ret; @@ -1594,7 +1590,7 @@ void iwl_mvm_update_tkip_key(struct iwl_mvm *mvm, u16 *phase1key) { struct iwl_mvm_sta *mvm_sta; - u8 sta_id = iwl_mvm_get_key_sta_id(vif, sta); + u8 sta_id = iwl_mvm_get_key_sta_id(mvm, vif, sta); bool mcast = !(keyconf->flags & IEEE80211_KEY_FLAG_PAIRWISE); if (WARN_ON_ONCE(sta_id == IWL_MVM_STATION_COUNT)) -- 2.20.1