From 5e0c1f0503cf79a04896875f59f82b73f9d754d4 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 29 Dec 2017 16:31:03 +0800
Subject: [PATCH] rtlwifi: check for array overflow
Git-commit: 5e0c1f0503cf79a04896875f59f82b73f9d754d4
Patch-mainline: v4.16-rc1
References: FATE#326906

This is merged by Ping-Ke Shih from commit dc33bd4309d2 ("staging:
Rtlwifi: check for array overflow"), and the original commit log is
reserved below.

Smatch is distrustful of the "capab" value and marks it as user
controlled.  I think it actually comes from the firmware?  Anyway, I
looked at other drivers and they added a bounds check and it seems like
a harmless thing to have so I have added it here as well.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/realtek/rtlwifi/base.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtlwifi/base.c b/drivers/net/wireless/realtek/rtlwifi/base.c
index 704741d6f495..2052e0e5e083 100644
--- a/drivers/net/wireless/realtek/rtlwifi/base.c
+++ b/drivers/net/wireless/realtek/rtlwifi/base.c
@@ -1321,6 +1321,10 @@ bool rtl_action_proc(struct ieee80211_hw *hw, struct sk_buff *skb, u8 is_tx)
 				  le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 				tid = (capab &
 				       IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
+				if (tid >= MAX_TID_COUNT) {
+					rcu_read_unlock();
+					return true;
+				}
 				tid_data = &sta_entry->tids[tid];
 				if (tid_data->agg.rx_agg_state ==
 				    RTL_RX_AGG_START)
-- 
2.19.2