[PATCH 5.9 190/757] ath6kl: prevent potential array overflow in ath6kl_add_new_sta()

[Greg Kroah-Hartman]

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit 54f9ab7b870934b70e5a21786d951fbcf663970f ]

The value for "aid" comes from skb->data so Smatch marks it as
untrusted.  If it's invalid then it can result in an out of bounds array
access in ath6kl_add_new_sta().

Fixes: 572e27c00c9d ("ath6kl: Fix AP mode connect event parsing and TIM updates")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200813141315.GB457408@mwanda
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/wireless/ath/ath6kl/main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/ath/ath6kl/main.c b/drivers/net/wireless/ath/ath6kl/main.c
index 5e7ea838a9218..814131a0680a4 100644
--- a/drivers/net/wireless/ath/ath6kl/main.c
+++ b/drivers/net/wireless/ath/ath6kl/main.c
@@ -430,6 +430,9 @@ void ath6kl_connect_ap_mode_sta(struct ath6kl_vif *vif, u16 aid, u8 *mac_addr,
 
 	ath6kl_dbg(ATH6KL_DBG_TRC, "new station %pM aid=%d\n", mac_addr, aid);
 
+	if (aid < 1 || aid > AP_MAX_NUM_STA)
+		return;
+
 	if (assoc_req_len > sizeof(struct ieee80211_hdr_3addr)) {
 		struct ieee80211_mgmt *mgmt =
 			(struct ieee80211_mgmt *) assoc_info;
-- 
2.25.1