[PATCH] staging: rtl8192e: Fix possible buffer overflow in _rtl92e_wx_set_scan

[Lee Gibson]

Function _rtl92e_wx_set_scan calls memcpy without checking the length.
A user could control that length and trigger a buffer overflow.
Fix by checking the length is within the maximum allowed size.

Signed-off-by: Lee Gibson <leegib@xxxxxxxxx>
---
 drivers/staging/rtl8192e/rtl8192e/rtl_wx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/rtl8192e/rtl8192e/rtl_wx.c b/drivers/staging/rtl8192e/rtl8192e/rtl_wx.c
index 16bcee13f64b..2acc4f314732 100644
--- a/drivers/staging/rtl8192e/rtl8192e/rtl_wx.c
+++ b/drivers/staging/rtl8192e/rtl8192e/rtl_wx.c
@@ -406,6 +406,9 @@ static int _rtl92e_wx_set_scan(struct net_device *dev,
 		struct iw_scan_req *req = (struct iw_scan_req *)b;
 
 		if (req->essid_len) {
+			if (req->essid_len > IW_ESSID_MAX_SIZE)
+				req->essid_len = IW_ESSID_MAX_SIZE;
+
 			ieee->current_network.ssid_len = req->essid_len;
 			memcpy(ieee->current_network.ssid, req->essid,
 			       req->essid_len);
-- 
2.25.1