[PATCH] wifi: rsi: Skip TX aggregation setup for non-QoS frames

[Alex Kazinsky <a.kazinsky@ideco.ru>]

When transmitting a non-QoS unicast frame to a station in AP mode,
rsi_core_xmit() assigns IEEE80211_NONQOS_TID (16) to tid. The station
lookup succeeds, allowing tid to index start_tx_aggr[], which has only
IEEE80211_NUM_TIDS (16) elements. This causes an out-of-bounds read and,
if the value read is zero, an out-of-bounds write.

Only access the aggregation state for tids below IEEE80211_NUM_TIDS,
excluding the non-QoS sentinel from TX aggregation setup.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 19844c0a9a19 ("rsi: data and managemet path changes for AP mode")
Cc: stable@vger.kernel.org
Signed-off-by: Alex Kazinsky <a.kazinsky@ideco.ru>
---
 drivers/net/wireless/rsi/rsi_91x_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_core.c b/drivers/net/wireless/rsi/rsi_91x_core.c
index ead4d4e04328..3281fc94e107 100644
--- a/drivers/net/wireless/rsi/rsi_91x_core.c
+++ b/drivers/net/wireless/rsi/rsi_91x_core.c
@@ -458,7 +458,7 @@ void rsi_core_xmit(struct rsi_common *common, struct sk_buff *skb)
 			tx_params->sta_id = 0;
 		}
 
-		if (rsta) {
+		if (rsta && tid < IEEE80211_NUM_TIDS) {
 			/* Start aggregation if not done for this tid */
 			if (!rsta->start_tx_aggr[tid]) {
 				rsta->start_tx_aggr[tid] = true;
-- 
2.56.0