demux: ogg: add lookup limit for chained streams

modules/demux/oggseek.c

@@ -383,6 +383,10 @@ static int64_t find_first_page_granule( demux_t *p_demux,
     seek_byte( p_demux, p_sys->i_input_position );
     ogg_stream_reset( &p_stream->os );
 
+    /* prevent reading the whole file if stream is gone */
+    if( i_pos2 > p_sys->i_input_position + OGGSEEK_SERIALNO_MAX_LOOKUP_BYTES )
+        i_pos2 = p_sys->i_input_position + OGGSEEK_SERIALNO_MAX_LOOKUP_BYTES;
+
     while( 1 )
     {
 

modules/demux/oggseek.h

@@ -38,6 +38,7 @@
 #define PAGE_HEADER_BYTES 27
 
 #define OGGSEEK_BYTES_TO_READ 8500
+#define OGGSEEK_SERIALNO_MAX_LOOKUP_BYTES (OGGSEEK_BYTES_TO_READ * 25)
 
 /* index entries are structured as follows:
  *   - for theora, highest granulepos -> pagepos (bytes) where keyframe begins