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authorEmmanuel Grumbach2017-06-12 15:10:09 +0300
committerLuca Coelho2017-07-21 12:26:37 +0300
commit61dd8a8a6a0c3cbfb6b02ab652c4f4efb93f3d79 (patch)
tree8c7d54f6a8661d448dbb9e6983a633f58b14afe7 /drivers/net
parentf6eac740a9b6f3737a969bad82931633519a1cc5 (diff)
iwlwifi: mvm: fix a NULL pointer dereference of error in recovery
Sometimes, we can have an firmware crash while trying to recover from a previous firmware problem. When that happens, lots of things can go wrong. For example the stations don't get added properly to mvm->fw_id_to_mac_id. Mac80211 tries to stop A-MPDU upon reconfig but in case of a firmware crash we will bail out fairly early and in the end, we won't delete the A-MPDU Rx timeout. When that timer expired after a double firmware crash, we end up dereferencing mvm->fw_id_to_mac_id[sta_id] which is NULL. Fixes: 10b2b2019d81 ("iwlwifi: mvm: add infrastructure for tracking BA session in driver") Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/wireless/intel/iwlwifi/mvm/sta.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 4df5f13fcdae..4a6df45b73df 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -277,6 +277,18 @@ static void iwl_mvm_rx_agg_session_expired(unsigned long data)
/* Timer expired */
sta = rcu_dereference(ba_data->mvm->fw_id_to_mac_id[ba_data->sta_id]);
+
+ /*
+ * sta should be valid unless the following happens:
+ * The firmware asserts which triggers a reconfig flow, but
+ * the reconfig fails before we set the pointer to sta into
+ * the fw_id_to_mac_id pointer table. Mac80211 can't stop
+ * A-MDPU and hence the timer continues to run. Then, the
+ * timer expires and sta is NULL.
+ */
+ if (!sta)
+ goto unlock;
+
mvm_sta = iwl_mvm_sta_from_mac80211(sta);
ieee80211_stop_rx_ba_session_offl(mvm_sta->vif,
sta->addr, ba_data->tid);