From: Navaneeth K <knavaneeth786@gmail.com>
Date: Thu, 20 Nov 2025 16:33:08 +0000 (+0000)
Subject: staging: rtl8723bs: fix stack buffer overflow in OnAssocReq IE parsing
X-Git-Tag: v6.19-rc1~62^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6ef0e1c10455927867cac8f0ed6b49f328f8cf95;p=thirdparty%2Flinux.git

staging: rtl8723bs: fix stack buffer overflow in OnAssocReq IE parsing

The Supported Rates IE length from an incoming Association Request frame
was used directly as the memcpy() length when copying into a fixed-size
16-byte stack buffer (supportRate). A malicious station can advertise an
IE length larger than 16 bytes, causing a stack buffer overflow.

Clamp ie_len to the buffer size before copying the Supported Rates IE,
and correct the bounds check when merging Extended Supported Rates to
prevent a second potential overflow.

This prevents kernel stack corruption triggered by malformed association
requests.

Signed-off-by: Navaneeth K <knavaneeth786@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
index fb170a144d28f..f6c5eb30f9f6a 100644
--- a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
+++ b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
@@ -1028,6 +1028,9 @@ unsigned int OnAssocReq(struct adapter *padapter, union recv_frame *precv_frame)
 		status = WLAN_STATUS_CHALLENGE_FAIL;
 		goto OnAssocReqFail;
 	} else {
+		if (ie_len > sizeof(supportRate))
+			ie_len = sizeof(supportRate);
+
 		memcpy(supportRate, p+2, ie_len);
 		supportRateNum = ie_len;
 
@@ -1035,7 +1038,7 @@ unsigned int OnAssocReq(struct adapter *padapter, union recv_frame *precv_frame)
 				pkt_len - WLAN_HDR_A3_LEN - ie_offset);
 		if (p) {
 
-			if (supportRateNum <= sizeof(supportRate)) {
+			if (supportRateNum + ie_len <= sizeof(supportRate)) {
 				memcpy(supportRate+supportRateNum, p+2, ie_len);
 				supportRateNum += ie_len;
 			}