Mp4: added and updated sanity checks for "end" handling. When handling incorrect data in ngx_http_mp4_crop_stsc_data(), trak->end_chunk_samples might end up being arbitrary large, leading to reading before the buffer in ngx_http_mp4_update_stsz_atom(). Fix is to check that trak->end_chunk_samples corresponds to a memory within the stsz atom data. For consistency, trak->start_chunk_samples is checked similarly. Similarly, trak->end_chunk might end up being smaller than trak->start_chunk, leading to reading memory after the buffer in ngx_http_mp4_update_stco_atom() and ngx_http_mp4_update_co64_atom(). Corresponding checks are updated to explicitly test (trak->end_chunk - trak->start_chunk) instead of just checking trak->end_chunk and assuming it is larger than trak->start_chunk. This is generally in line with existing checks of (trak->end_sample - trak->start_sample) in ngx_http_mp4_update_stsz_atom(), where trak->end_sample might also become smaller than trak->start_sample when handling incorrect data in ngx_http_mp4_crop_stts_data().

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_PARSE_H_INCLUDED_
#define _NGX_PARSE_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


ssize_t ngx_parse_size(ngx_str_t *line);
off_t ngx_parse_offset(ngx_str_t *line);
ngx_int_t ngx_parse_time(ngx_str_t *line, ngx_uint_t is_sec);


#endif /* _NGX_PARSE_H_INCLUDED_ */