staging: rtl8723bs: prevent ->Ssid overflow in rtw_wx_set_scan()

This code has a check to prevent read overflow but it needs another
check to prevent writing beyond the end of the ->Ssid[] array.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Denis Efremov (Oracle) <efremov@linux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
index d8d44fd9a92f48cab897accad7771953bf2220e1..ea2fd3a73c3a845ae6fc74a3fc039d651ae11b4c 100644 (file)
--- a/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
+++ b/drivers/staging/rtl8723bs/os_dep/ioctl_linux.c
@@ -1351,9 +1351,11 @@ static int rtw_wx_set_scan(struct net_device *dev, struct iw_request_info *a,
 
                                        sec_len = *(pos++); len-= 1;
 
-                                       if (sec_len>0 && sec_len<=len) {
+                                       if (sec_len > 0 &&
+                                           sec_len <= len &&
+                                           sec_len <= 32) {
                                                ssid[ssid_index].SsidLength = sec_len;
-                                               memcpy(ssid[ssid_index].Ssid, pos, ssid[ssid_index].SsidLength);
+                                               memcpy(ssid[ssid_index].Ssid, pos, sec_len);
                                                /* DBG_871X("%s COMBO_SCAN with specific ssid:%s, %d\n", __func__ */
                                                /*      , ssid[ssid_index].Ssid, ssid[ssid_index].SsidLength); */
                                                ssid_index++;