[PATCH 3.16.y-ckt 031/183] iwlwifi: mvm: validate tid and sta_id in ba_notif

[Luis Henriques]

3.16.7-ckt8 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eyal Shapira <eyal at wizery.com>

commit 2cee4762c528a9bd2cdff793197bf591a2196c11 upstream.

These are coming from the FW and are used to access arrays.
Bad values can cause an out of bounds access so discard
such ba_notifs and warn.

Signed-off-by: Eyal Shapira <eyalx.shapira at intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/wireless/iwlwifi/mvm/tx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/wireless/iwlwifi/mvm/tx.c b/drivers/net/wireless/iwlwifi/mvm/tx.c
index 3846a6c41eb1..ccc5eaf2e77c 100644
--- a/drivers/net/wireless/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/iwlwifi/mvm/tx.c
@@ -859,6 +859,11 @@ int iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 	sta_id = ba_notif->sta_id;
 	tid = ba_notif->tid;
 
+	if (WARN_ONCE(sta_id >= IWL_MVM_STATION_COUNT ||
+		      tid >= IWL_MAX_TID_COUNT,
+		      "sta_id %d tid %d", sta_id, tid))
+		return 0;
+
 	rcu_read_lock();
 
 	sta = rcu_dereference(mvm->fw_id_to_mac_id[sta_id]);