Merge r429273 for AST-2014-019

git-svn-id: https://origsvn.digium.com/svn/asterisk/tags/13.1.0-rc2@429317 65c4cc65-6c06-0410-ace0-fbb531ad65f3

ChangeLog

@@ -1,3 +1,25 @@
+2014-12-10  Asterisk Development Team <asteriskteam@digium.com>
+
+	* Asterisk 13.1.0-rc2 Released.
+
+	* AST-2014-019: Fix crash when receiving a WebSocket packet with a
+	  payload length of zero.
+
+	  Frames with a payload length of 0 were incorrectly handled in
+	  res_http_websocket. Provided a frame with a payload had been
+	  received prior it was possible for a double free to occur. The
+	  realloc operation would succeed (thus freeing the payload) but be
+	  treated as an error. When the session was then torn down the payload
+	  would be freed again causing a crash. The read function now takes
+	  this into account.
+
+	  This change also fixes assumptions made by users of
+	  res_http_websocket. There is no guarantee that a frame received from
+	  it will be NULL terminated.
+
+	  ASTERISK-24472 #close
+	  Reported by: Badalian Vyacheslav
+
 2014-12-08  Asterisk Development Team <asteriskteam@digium.com>
 
 	* Asterisk 13.1.0-rc1 Released.

channels/chan_sip.c

@@ -2644,12 +2644,16 @@ static void sip_websocket_callback(struct ast_websocket *session, struct ast_var
 
 		if (opcode == AST_WEBSOCKET_OPCODE_TEXT || opcode == AST_WEBSOCKET_OPCODE_BINARY) {
 			struct sip_request req = { 0, };
+			char data[payload_len + 1];
 
 			if (!(req.data = ast_str_create(payload_len + 1))) {
 				goto end;
 			}
 
-			if (ast_str_set(&req.data, -1, "%s", payload) == AST_DYNSTR_BUILD_FAILED) {
+			strncpy(data, payload, payload_len);
+			data[payload_len] = '\0';
+
+			if (ast_str_set(&req.data, -1, "%s", data) == AST_DYNSTR_BUILD_FAILED) {
 				deinit_req(&req);
 				goto end;
 			}

res/res_http_websocket.c

@@ -513,14 +513,6 @@ int AST_OPTIONAL_API_NAME(ast_websocket_read)(struct ast_websocket *session, cha
 			}
 		}
 
-		if (!(new_payload = ast_realloc(session->payload, (session->payload_len + *payload_len)))) {
-			ast_log(LOG_WARNING, "Failed allocation: %p, %zu, %"PRIu64"\n",
-				session->payload, session->payload_len, *payload_len);
-			*payload_len = 0;
-			ast_websocket_close(session, 1009);
-			return 0;
-		}
-
 		/* Per the RFC for PING we need to send back an opcode with the application data as received */
 		if ((*opcode == AST_WEBSOCKET_OPCODE_PING) && (ast_websocket_write(session, AST_WEBSOCKET_OPCODE_PONG, *payload, *payload_len))) {
 			*payload_len = 0;
@@ -528,9 +520,22 @@ int AST_OPTIONAL_API_NAME(ast_websocket_read)(struct ast_websocket *session, cha
 			return 0;
 		}
 
-		session->payload = new_payload;
+		if (*payload_len) {
-		memcpy((session->payload + session->payload_len), (*payload), (*payload_len));
+			if (!(new_payload = ast_realloc(session->payload, (session->payload_len + *payload_len)))) {
-		session->payload_len += *payload_len;
+				ast_log(LOG_WARNING, "Failed allocation: %p, %zu, %"PRIu64"\n",
+					session->payload, session->payload_len, *payload_len);
+				*payload_len = 0;
+				ast_websocket_close(session, 1009);
+				return 0;
+			}
+
+			session->payload = new_payload;
+			memcpy((session->payload + session->payload_len), (*payload), (*payload_len));
+			session->payload_len += *payload_len;
+		} else if (!session->payload_len && session->payload) {
+			ast_free(session->payload);
+			session->payload = NULL;
+		}
 
 		if (!fin && session->reconstruct && (session->payload_len < session->reconstruct)) {
 			/* If this is not a final message we need to defer returning it until later */

res/res_pjsip_transport_websocket.c

@@ -200,7 +200,8 @@ static int transport_read(void *data)
 
 	pj_gettimeofday(&rdata->pkt_info.timestamp);
 
-	pj_memcpy(rdata->pkt_info.packet, read_data->payload, sizeof(rdata->pkt_info.packet));
+	pj_memcpy(rdata->pkt_info.packet, read_data->payload,
+		PJSIP_MAX_PKT_LEN < read_data->payload_len ? PJSIP_MAX_PKT_LEN : read_data->payload_len);
 	rdata->pkt_info.len = read_data->payload_len;
 	rdata->pkt_info.zero = 0;