Clear control interface command explicitly from stack

The control interface commands may include passwords or other private
key material, so clear it explicitly from memory as soon as the
temporary buffer is not needed anymore.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/ctrl_iface_unix.c

@@ -197,6 +197,13 @@ static void wpa_supplicant_ctrl_iface_receive(int sock, void *eloop_ctx,
 		reply_buf = wpa_supplicant_ctrl_iface_process(wpa_s, buf,
 							      &reply_len);
 		reply = reply_buf;
+
+		/*
+		 * There could be some password/key material in the command, so
+		 * clear the buffer explicitly now that it is not needed
+		 * anymore.
+		 */
+		os_memset(buf, 0, res);
 	}
 
 	if (!reply && reply_len == 1) {
@@ -846,6 +853,13 @@ static void wpa_supplicant_global_ctrl_iface_receive(int sock, void *eloop_ctx,
 		reply_buf = wpa_supplicant_global_ctrl_iface_process(
 			global, buf, &reply_len);
 		reply = reply_buf;
+
+		/*
+		 * There could be some password/key material in the command, so
+		 * clear the buffer explicitly now that it is not needed
+		 * anymore.
+		 */
+		os_memset(buf, 0, res);
 	}
 
 	if (!reply && reply_len == 1) {