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 <avri.altman@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
This commit is contained in:
Avri Altman 2015-10-19 16:29:11 +02:00 committed by Emmanuel Grumbach
parent d6ee54a9d7
commit 9513c5e18a

View File

@ -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))