mwifiex: fix potential buffer overflow in dt configuration

If cfgdata length exceeds the command buffer size we will end up
getting buffer overflow problem. Fix it by checking the buffer
size less the command header length.

Reviewed-by: Paul Stewart <pstew@chromium.org>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/mwifiex/sta_cmd.c b/drivers/net/wireless/mwifiex/sta_cmd.c
index 9c2404cd755f34dcfd85922c4b7c9bf8a816dbb8..9208a8816b800f619426eb41403d4177ad2d0ad3 100644 (file)
--- a/drivers/net/wireless/mwifiex/sta_cmd.c
+++ b/drivers/net/wireless/mwifiex/sta_cmd.c
@@ -1170,8 +1170,9 @@ int mwifiex_dnld_dt_cfgdata(struct mwifiex_private *priv,
                    strncmp(prop->name, prefix, len))
                        continue;
 
-               /* property header is 6 bytes */
-               if (prop && prop->value && prop->length > 6) {
+               /* property header is 6 bytes, data must fit in cmd buffer */
+               if (prop && prop->value && prop->length > 6 &&
+                   prop->length <= MWIFIEX_SIZE_OF_CMD_BUFFER - S_DS_GEN) {
                        ret = mwifiex_send_cmd_sync(priv, HostCmd_CMD_CFG_DATA,
                                                    HostCmd_ACT_GEN_SET, 0,
                                                    prop);